the ferruginous pygmy owl ( glaucidium brasilianum ) is a small owl that breeds in south-central arizona in the united states , south through mexico and central america , to south america into bolivia , paraguay and argentina .

in central america and south america , it is the most widely distributed pygmy owl and is probably one of the most numerous owl species in those areas .

it is found in a wide range of semi-open wooded habitats in these areas

ferruginous pygmy owl

glaucidium brasilianum ( j . f . gmelin , 1788 ) – ferruginous pygmy - owl , tecolote bajeño , ferruginous pygmy owl
proudfoot , g . , r . johnson . 2000 . ferruginous pygmy - owl .
figure 1 . distribution of the ferruginous pygmy - owl in north and middle america .
3 . cactus ferruginous pygmy - owl . 9 / 24 / 99 website : urltoken
a new species of ferruginous pygmy - owl from argentina : glaucidium brasilianum stranecki n . ssp
) , elevational preferences , and habitat . due to its wide geographic range , the ferruginous pygmy - owl overlaps with many other species of pygmy - owl .
ferruginous pygmy - owl feeds mainly on grasshoppers and also eats scorpions , cicadas , reptiles , and birds .
the ferruginous pygmy owl is a very small owl with no ear - tufts . grey , brown and red morphs are known to exist , as well as intermediates .
there is little information to be found on the lifespan of ferruginous pygmy - owls .
photo of pygmy owl in saguaro courtesy of the arizona game and fish department .
cactus ferruginous pygmy - owls ( glaucidium brasilianum cactorum ) are one of three subspecies of the ferruginous pygmy - owl . they have longer tails than most owls , are reddish - brown with a cream colored belly and have a crown that is lightly streaked . cactus ferruginous pygmy - owls have yellow eyes and no ear tufts .
2003 .
urltoken
( on - line ) . ferruginous pygmy - owl biology . accessed 03 / 19 / 03 at urltoken .
ferruginous pygmy - owls and bighorn sheep are two of the roving species that could be affected .
ferruginous pygmy - owls are monogamous , and usually form pairs in their first fall after hatching .
rainforest conservation fund . 2003 .
ferruginous pygmy - owl
( on - line ) . accessed 04 / 07 / 03 at urltoken .
) , elevational preferences , and habitat . fortunately the distribution of peruvian pygmy - owl has little or no overlap with other species of pygmy - owl . in the andes , peruvian
breeding interval ferruginous pygmy - owls breed once a year . eggs are layed in april or may .
2003 .
sonoran desert conservation plan
( on - line ) . cactus ferruginous pygmy - owl . accessed 03 / 19 / 03 at urltoken .
the cactus ferruginous pygmy owl in pima county : at one time , the pygmy owl was described as
of common occurrence ,
not uncommon ,
and
fairly numerous
in southern arizona . 1 today , the owl numbers are very low and , until recently , very little was known about the owl . some of the pygmy owls ' habitat is found in the fastest growing areas of tucson .
to fool its prey , ferruginous pygmy - owl evolved so - called false eyes : patches of dark feathers on the back of its head that look like eyes .
cactus ferruginous pygmy - owls mainly eat small birds , lizards , insects , small mammals , frogs and earthworms .
the ridgway ' s pygmy - owl is also much more rufous in color than the mountain pygmy although this is not necessarily obvious in the field ( without a mountain pygmy to compare to ) . the most obvious visual difference between the mountain and ridgway ' s pygmy - owls are the white markings on their heads . the mountain pygmy - owl has white spots and the ridgway ' s pygmy - owl has white streaking . last and most noticeable of the visual differences is the tail barring . the ridgway ' s pygmy - owl has light brown ( to orangey brown ) tail bars where the mountain pygmy has white tail bars .
center for biological diversity .
cactus ferruginous pygmy - owl ( glaucidium brasilianum cactorum )
( on - line ) . accessed 04 / 07 / 03 at urltoken .
ferruginous pygmy owls are non - migratory and are found in the southwestern united states , central america , and south america .
proudfoot , g . , s . beasom . 1997 . food habits of nesting ferruginous pygmy - owls in southern texas .
proudfoot , g . a . 1996 . natural history of the cactus ferruginous pygmy - owl . master ' s thesis , texas a & m ; univ . , kingsville . close
status : the cactus ferruginous pygmy - owl was listed as federally endangered in 1997 . the species was listed because current and historical evidence suggests a significant population decline has occured in arizona , and that the the owl has been nearly extirpated .
other small owls in the same habitat and range of the ridgway ' s pygmy - owl include elf owl and the screech - owls . these other small owls that could be possibly confused are all strictly nocturnal . the elf owl is much smaller in size and lacks the clear chest and crown streaks of the ridgway ' s pygmy - owl . the screech - owls all have ear tufts and also lack the pygmy - owl ' s clear chest streaks .
ferruginous pygmy - owls were heard very frequently in both thick forests and shrubby woodlands , often calling from within the thickest foliage .
just when i was enjoying the sudden freedom from ferruginous pygmy owls ( hereinafter the owl ) , those professional pests at the center for biological diversity and defenders of wildlife ( hereinafter the pests ) are asking for the owl to be relisted as endangered .
us forest service department of agriculture . 1999 .
cactus ferruginous pygmy - owl ( glaucidium brasilianum cactorum )
( on - line ) . accessed 03 / 19 / 03 at urltoken .
young : the young are similar in plumage to the adults . just like the ferruginous pygmy - owl the young do not develop their white markings until they mature . as a juvenile owl the white spots on the crown are not developed . the northern pygmy juvenile is still distinguishable from the ferruginous pygmy , in the small range where they could possibly overlap , by his white tail bands ( the ferrug . having reddish - brown bands ) .
the ferruginous pygmy - owl is a diurnal and crepuscular owl feeding mostly on insects , such as grasshoppers , crickets , caterpillars , other large insects and scorpions . in addition , their diet consists of birds , small mammals , amphibians , and reptiles ( often lizards ) . like the northern pygmy - owl , the ferruginous pygmy - owl is a bold and ferocious daytime predator , sometimes attacking prey larger than itself , such as american robins or young domestic fowl . there are even records of attacks on captive guan , the owl grabbing on firmly to the guan and tearing at it , eventually wearing it out and killing it .
1 . u . s . fish and wildlife service . 1997 .
determination of endangered status for the cactus ferruginous pygmy owl in arizona .
federal register . volume 62 ( 46 ) .
cactus ferruginous pygmy - owls live in the desert habitat of southern arizona in the southwestern united states , and northwestern mexico . they live at
u . s . fish and wildlife service ( 1997 ) endangered and threatened wildlife and plants : determination of endangered status for the cactus ferruginous pygmy - owl in arizona . us fed . regist . 62 : 10730–10747
in recent decades , the subspecies known as cactus ferruginous pygmy - owl declined substantially in arizona and was listed as endangered between 1997 and 2006 . in 2012 , environmentalists filed suit calling for it to be listed again .
. these juveniles are best distinguished from ferruginous by voice , habitat , and elevation .
a federal judge removed the pygmy owl ' s critical habitat status in september 2001 . she stated that the u . s . fish and wildlife
) are very small owls , with a large rounded head , a pair of prominent black marks ( false
eye spots
) on the nape , and a relatively long tail . ferruginous pygmy - owl is the largest species of
the ferruginous pygmy - owl is endangered in arizona and facing loss of habitat in both texas and arizona . although it is endangered in north america ( arizona ) , it is still quite frequent over much of its mexican range . the owl is generally sedentary although its range expands after the fledging of the young .
there is no known migratory movements of this owl . the northern pygmy is believed to be largely sedentary . except for winter downslope movements and juvenile dispersals there are no further records of movements for this owl . further studies are needed .
an opportunistic predator , the ferruginous pygmy - owl has a diet as diverse as its distribution , including insects , reptiles , amphibians , birds , and small mammals . foraging rates peak during twilight hours , around sunrise and sunset . because of its small size , long tail , and atypical diurnal and crepuscular behavior , the ferruginous pygmy - owl may easily be mistaken for a passerine . when agitated , it perches with its tail cocked upward or jerks its tail up and down and from side to side .
reproduction : the cactus ferruginous pygmy owl nests in cavities in trees or cacti such as the organ pipe or saguaro . the pygmy owl begins nesting activity late winter to early spring . 3 three to five eggs are laid in late aprilmay . 2 the eggs are incubated for about twenty - eight days . the young are fed by both parents . the young fledge twenty - seven to thirty days after hatching . 2
abbate , d . , a . ditty , s . richardson and r . olding . 1996 . cactus ferruginous pygmy - owl survey and nest monitoring in the tucson basin area , arizona - 1996 . phoenix , az : arizona game and fish dep . close
in 2013 , readers of birdwatching voted ferruginous pygmy - owl one of the birds they want to see most . so , as the great texas birding classic winds down , we thought you’d enjoy this list of 10 things you might not know about the diminutive bird :
ferruginous pygmy - owl is the spud webb of birds . webb , all five feet seven inches and 133 pounds of him , played 12 seasons in the nba , in which the average player is a foot taller and 90 pounds heavier . the pygmy - owl is no bigger than a bluebird and weighs about 2 . 5 ounces , yet it has been known to prey on the larger and significantly heavier gambel’s quail and hispid cotton rat .
the oldest recorded northern pygmy - owl was a male , and at least 3 years , 11 months old when he was recaptured and rereleased during banding operations in oregon .
pygmy - owl calls elicit a strong mobbing response from many passerines , including many warblers and vireos . imitation of this vocalization often attracts more small passerines than pishing does .
diet : the owl is an opportunistic predator feeding on what is available . the prey ranges from insects to mourning doves which outweigh the owl by two and a half times .
the 18th annual great texas birding classic wraps up tomorrow , may 15 . one species that participants may locate is ferruginous pygmy - owl , a small bird of semi - open wooded areas . it can be found at the king ranch and a few other ranches in south texas .
ferruginous pygmy - owls nest in natural cavities of trees , stumps , or cactuses ( depending on what is available ) . the cavities that they nest in are often the made by woodpeckers (
yes , the owl could have a bright future if the pests would get behind this push to domesticate it . i can almost taste the deep fried owl now . what a treat !
cartron , jean - luc e . ; richardson , w . scott ; proudfoot , glenn a . 2000 . chapter 1 : the cactus ferruginous pygmy - owl : taxonomy , distribution , and natural history . in : cartron , jean - luc e . ; finch , deborah m . , tech . eds . ecology and conservation of the cactus ferruginous pygmy - owl in arizona . gen . tech . rep . rmrs - gtr - 43 . ogden , ut : u . s . department of agriculture , forest service , rocky mountain research station . p . 5 - 15
cactus ferruginous pygmy - owl are threatened by habitat loss , particularly the loss of at least 85 % of arizona’s riparian areas due to development , livestock grazing , water withdrawal and other factors . climate change may worsen other threats , particularly the spread of invasive species and an increase in fires .
the cactus ferruginous pygmy - owl is a small bird , averaging 6 . 5 inches in length and weighing 2 . 5 ounces . overall , the owl is reddish - brown with a cream - colored belly striped with the rufous coloring . the crown is lightly streaked and the eyes are yellow . black and white spots on the nape suggest eye spots . 1 the owl has a relatively long tail and no ear tufts . this owl is diurnal . its call , consisting of a monotonal ' put - put - put ' note , 2 can be heard during dusk and dawn .
habitat : current information allows only a broad general description of where the owl has historically and currently occurred in arizona . the cactus ferruginous pygmy - owl occurs in a variety of habitats , including river bottom woodlands , mesquite bosques , desert scrub , and plains and desert grasslands . 1 typical throughout these habitats are fairly dense woody thickets with trees and cacti large enough to provide nesting cavities . 3
defenders of wildlife is funding critical research on population trends of cactus ferruginous pygmy - owls on both sides the u . s . - mexico border . unfortunately , this science continues to confirm that the status of the western population of pygmy - owls is in dire straits . in fact , research done in 2006 by university of arizona research specialist aaron flesch showed that the pygmy - owl population in sonora , mexico – immediately south of the arizona border – has suffered a 26 percent decline since 2000 .
the center first petitioned to protect the owl in 1992 , and following three successful lawsuits secured an endangered listing in 1997 . we won the owl 732 , 000 acres of critical habitat in 1999 . but developers fought back in 2001 , with the tacit support of the bush administration , and their lawsuit seeking to remove the pygmy owl ' s endangered status overturned the bird ' s listing in 2006 . the argument was that pygmy owls exist in mexico and thus can be allowed to go extinct in the united states ( though the service ' s own biologists opposed the owl ' s delisting ) .
elevations below 4 , 000 feet ( 1 , 200 m ) . the owl prefers desertscrub thickets , trees and large cacti for nesting and roosting . in the sonoran desert the owl often lives where ironwood , mesquite , acacia , saguaro and organ pipe cacti can be found . the vegetation provides good cover for its favorite prey of birds , lizards , insects , small rodents , frogs and earthworms . cactus ferruginous pygmy - owls are fierce hunters and can kill a dove twice their size . the vegetation also shields it from larger birds of prey . the pygmy - owl is diurnal and hunts during the day .
in arizona the ferrug occurs in saguaro desert , mesquite , and cottonwood - mesquite habitats . in texas it is now mostly confined to remaining patches of mesquite , ebony , and cane along the lower rio grande ( may also be found in live oak forests of kenedy and willacy counties ) . in general , the ferruginous pygmy is a lowland bird found in more arid habitats than the northern pygmy - owl .
ferruginous pygmy - owls live in a variety of habitats throughout the americas . they are found in cold temperate lowlands , subtropical , and tropical areas . they can be found in habitats ranging from deserts to rainforests .
both pygmy - owls have two black patches ( outlined in white ) on their nape that vaguely resemble a pair of extra eyes . the ridgway ' s pygmy - owl has a greenish yellow bill and bright lemon yellow iris ( eyes ) . this owl lacks ear tufts . length is 6 3 / 4
( slightly smaller than a white - crowned sparrow ) and the sexes are alike .
richardson , w . scott ; cartron , jean - luc e . ; krueper , david j . ; turner , lauren ; skinner , thomas h . 2000 . chapter 3 : the status of the cactus ferruginous pygmy - owl in arizona : population surveys and habitat assessment . in : cartron , jean - luc e . ; finch , deborah m . , tech . eds . ecology and conservation of the cactus ferruginous pygmy - owl in arizona . gen . tech . rep . rmrs - gtr - 43 . ogden , ut : u . s . department of agriculture , forest service , rocky mountain research station . p . 27 - 46
proudfoot , g . a . and s . l . beasom . 1996 . responsiveness of cactus ferruginous pygmy - owls to broadcasted conspecific calls . wildl . soc . bull . no . 24 : 294 - 297 . close
we ' ll continue to advocate for the species throughout the steps toward new protection , and we ' re still funding pygmy owl research in mexico as we work with pima county on the sonoran desert conservation plan .
today the big bird - friendly ranches of south texas are the best places to find ferruginous pygmy - owl in the united states . since floods along the rio grande in july 2010 , the species has been absent from its traditional haunts near the mexico border , including bentsen - rio grande valley state park and santa ana national wildlife refuge .
presently , the appearance of the owl on a person’s property signals a rapid depreciation in the value of that property as it then becomes owl habitat and must be dedicated to the owl . the answer is obvious . the owl must be domesticated and raised like chickens . there is no shortage of chickens . and if a chicken crosses the road to get to your property , you are at liberty to introduce it to the wonders of the fricassee .
the ferruginous pygmy - owl ' s call is a long series of repeated hollow whistles which can be easily imitated by humans . howell and webb ( 1995 ) claim that calls may sometimes end with a series of
high , yelping twitters
while stiles & skutch ( 1989 ) suggest a
sharp bark or whinny
terminates some calls .
, but northern pygmy - owls are spotted rather than streaked , have whiter tails , and different vocalizations .
in late in the winter or early spring cactus ferruginous pygmy - owls begin nesting in the cavities of trees or cacti like the saguaro and organ pipe . these holes have often been made by woodpeckers . owlets leave their nest 28 days after hatching .
in : cartron , jean - luc e . ; finch , deborah m . , tech . eds . ecology and conservation of the cactus ferruginous pygmy - owl in arizona . gen . tech . rep . rmrs - gtr - 43 . ogden , ut : u . s . department of agriculture , forest service , rocky mountain research station . p . 5 - 15
in : cartron , jean - luc e . ; finch , deborah m . , tech . eds . ecology and conservation of the cactus ferruginous pygmy - owl in arizona . gen . tech . rep . rmrs - gtr - 43 . ogden , ut : u . s . department of agriculture , forest service , rocky mountain research station . p . 27 - 46
proudfoot , g . a . and a . a . radomski . 1997 . absence of hematozoa from ferruginous pygmy - owls ( glaucidium brasilianum ) in southern texas . j . helminthol . soc . wash . no . 64 : 154 - 156 . close
the keys to the distinction between the three us pygmy - owls is color , call , habitat , white markings , and tail barring . the ridgway ' s pygmy has a much lower elevation habitat , living in the saguaro ( cactus ) and riparian desert habitats of southern arizona and mesquite ( dry ) habitats in the rio grand areas of southern texas . the mountain pygmy - owl is generally associated with montane forest habitats . same hold true south of the us .
) are very small owls , with a large rounded head , a pair of prominent black marks ( false
eye spots
) on the nape , and a relatively long tail . peruvian pygmy - owl is a relatively larges species of
habits : the ferruginous pygmy owl is a partly diurnal bird , and may be seen in bright daylight on exposed perches , and may also sing by day . principal activity is at dusk or around dawn , and they are sometimes vocally active on clear , calm nights . roosts during the daytime within the shelter of foliage in trees or bushes , but always seems alert . when excited , this owl will cock its tail and flick it from side to side . flight is undulating with rapid wingbeats and gliding .
jehl , d . march , 17 2003 . rare arizona owl ( all 7 inches of it ) is in habitat furor .
ferruginous pygmy - owls can be heard calling more frequently around sunrise and sunset . sounds that they make include whistled hoot and took noises , and high yelping twitters . male calls are lower in tone than females . males give territorial - advertisement calls and females vocalize through chitters .
forests , which are characterized by low canopy heights and relatively low diversity of flora ( borges et al . 2004 ) . ferruginous pygmy - owls occur in undisturbed habitat as well as in or around human settlements , from small villages to large cities ( proudfoot and johnson 2000 ) .
subspecies : there are 2 races of ferruginous pygmy - owl here in the us . one to four other owls may be considered additional races in central america but further research needs to be done for these classifications to be agreed upon . g . b . cactorumis is found from s arizona south along the west coast of mexico . g . b . ridgwayi is found from southern texas e and s mexico to panama .
the owl uses a perch - and - pounce hunting method , and it raids nest cavities of golden - fronted woodpecker and other birds .
range : historically , this subspecies appears to be geographically isolated into eastern and western populations . the western population ranged from lowland , central arizona to the states of colima and michoacan , mexico . the eastern population ranged from southern texas into the states of tampulipas and nuevo leon , mexico . 1 currently , the cactus ferruginous pygmy - owl range is similar to the historic range , but the number of owls is much smaller . 1
in response to predators such as hawks , owls , snakes , and raccoons , ferruginous pygmy - owls either go into a vertical position and move their tail back and forth , or maintain an errect position with feathers close to their body . nestlings sometimes spread out their wings and puff themselves up .
a study conducted on the king ranch in texas recorded the owl preying on northern cardinal , blue grosbeak , eastern meadowlark , and other songbirds .
the tiny , fierce pygmy owl has become synonymous with wild sonoran desert : endangered species act protections for the owl initiated a new era of urban planning in southern arizona . within the bird ' s critical habitat areas , the u . s . fish and wildlife service limited development to just 20 percent of most properties , driving the large - scale sonoran desert conservation plan that became a model for endangered species urban planning nationwide .
one of the most important invasive species in the sonoran desert is buffel grass , which was widely planted as a forage grass . in sharp contrast to the patchy distribution of native vegetation , buffel grass forms a continuous cover , allowing fires to travel across large areas , killing saguaros and other native plant species that are not well adapted to fires . the extended droughts being wrought by climate change are increasing this fire risk and further threatening the cactus ferruginous pygmy - owl .
these conflicts are unnecessary . just allow the owl to be freely taken and create a market for this new , exotic , and formerly endangered food source .
ferruginous pygmy - owls are presumed monogamous , forming pairs during the fall of their first year after hatching , and nesting the following spring . incubation and nestling development each last about 28 days . females incubate 2–7 eggs , and both adults provide food for nestlings . adults attend to fledglings until dispersal , 7–8 weeks after fledging .
the list of possible prey in the northern pygmy - owl ' s diet is quite large . this may include all of the small mammals , small to medium sized birds , reptiles , larger insects , and amphibians within their range . the owl ' s preference seems to be mice , birds , and large insects with studies indicating that about 90 % of their diet is comprised of small mammals and birds . this little owl is a bold and ferocious daytime predator . it will kill birds such as gambel ' s or california quail that are more than twice its weight . to see a northern pygmy come tumbling out of a tree with its talons firmly locked into an american robin , that is half again its size , is an impressive sight and reminder of how fearless it is .
when the owl is domesticated and raised for profit , we will be chock - a - block in owls around here . they will start appearing on menus throughout the sonoran region as a low fat , high protein , exceptionally tender alternative to chicken . chick - fil - a , the colonel , and all the fast food outlets will be substituting owl meat for chicken . the sub - species will have been saved . owl farmers will prosper by selling their eggs and even feathers .
consider the economic impact when it designated 731 , 000 acres critical habitat for the cactus ferruginous pygmy - owl in 1999 . the u . s . fish and wildlife service is expected to redesignate their critical habitat by april 2003 , and it is hoped their habitat will double as a result . it is presently on the u . s . endangered species list . they are also in the cites , appendix ii which allows the owls to be traded commercially only if it doesn ' t harm their survival .
unlike screech - owls and northern saw - whet owls , northern pygmy - owls are not known to take up residence in human - made nest boxes .
are generally rufous (
ferruginous
) in color , especially east of the andes , but the plumage also may be a duller brown or gray - brown . this species shares the common
are opportunistic predators with diverse diets . they feed mostly on insects , but also on birds , reptiles , amphibians , and small mammals . they are diurnal and feed mostly during sunrise and sunset . in order to kill birds and some lizards the ferruginous pygmy - owl bites just behind their prey ' s head , while other lizards are swallowed whole . insects are usually decapitated and only the soft body parts of them are eaten . mammals are eaten piece by piece . specific examples of what these owls feed on inlude grasshoppers and crickets (
are very small and reach a size of only about 6 inches tall . they have round heads with black eyespots on the back , no ear tufts , and yellowish eyes . adults often have white eyebrows , and white streaks on their heads . the body of the owl is reddish - brown in color with white streaks . the long tail is also reddish - brown . their wings often have white streaks as well . the underparts are white . males and females look very similiar to one another , but the females are slightly larger and more reddish in coloration . juveniles look like adults , but their heads are often grayer and their eye spots lighter . ferruginous pygmy - owls are similar to northern pygmy - owls ,
northern pygmy - owls raise a pair of tufts on the sides of their head when threatened by a predator , such as a hawk or a cat . they also have a pair of spots on the back of the neck that look a little like eyes . scientists think these markings may help fool attackers or mobbers into thinking the owl is watching them .
common and widespread in the american tropics , this little owl enters our area only in southern texas and arizona , where it is now uncommon to rare . it is often active by day , and may feed on small birds at times ; songbirds in its range all recognize its whistled call , and will gather around to mob and harass the owl when they discover it .
s sometimes are active by day , although they primarily are crepuscular . they prey on large insects and small vertebrates , including small birds that may be almost as large as the owl .
when they find extra food , northern pygmy - owls often cache their prey in tree cavities , or by hanging the prey on thorns , as shrikes are famous for doing .
young : although the white streaking on the forehead and head is not developed on the juvenile ferruginous , the rust tail bars are , making identification possible . the young also have a high - pitched rattle begging call .
in the sonoran desert scrub , the owl can be found in associations of ironwood , palo verde , mesquite , acacia , bursage , and columnar cactus such as saguaro and organ pipe . 3
* small owl with dark brown and spotted upperparts and greyish white streaked underparts * small head with whitish eyebrows and yellow eyes . dark breast and pretty long tail * size : about 16 cm
. the upperparts often are rufous (
ferruginous
) but also may be duller grayish brown ; the underparts are white , marked with broad streaks that are the same color as the upperparts . the crown also has fine white streaks .
these owls are most active near dawn and dusk . they are either solitary or in pairs for mating purposes . in order to move within trees , they walk and hop from branch to branch . they also rapidly beat their wings in order to make short , direct flights . ferruginous pygmy - owls perch in trees similarly to other owls , with their tails straight downward . allopreening is done between paired adults , fledglings , and nestlings .
like most owls the key to identification seems to be their primary call . the ridgway ' s pygmy has much shorter spaced calls often referred to as a
popping
primary call where the mountain pygmy ' s
toots
are given in pairs ( toot - toot toot - toot ) and spaced much further apart . see the audio recordings tabs in each species to hear their sounds .
a natural recording of seven episodes of calls while surrounded by several species of small birds . i spotted a blue - and - yellow tanager , masked gnatcatcher , an unidentified small woodpecker , and two or three other small morning birds calling while the pygmy - owl remained at 6 to 7 meters high in a small tree . located 10 meters from a river flowing east from the nearby large dammed lake south of salta .
northern pygmy - owls are widespread in the mountains of western north america , and they’re active during the day , which gives you a good chance of finding them . but they’re also small and unobtrusive as they sit and wait for prey to approach them , so you’ll need to be observant . the two best ways to find them involve your ears : you may hear them giving high , evenly spaced tooting calls . or you may hear a commotion of chickadees and other small birds scolding and calling as they mob an owl they’ve discovered . try to find the agitated birds and you may find the owl that they’re trying to drive away .
) by its larger size , longer tail with a greater number of transverse pale buffy bars ( 5 - 7 bars on the upper surface of the tail , or 3 - 5 bars on the under surface of the tail , as opposed to 2 - 4 whitish bars on the tails of species in the least pygmy - owl group ) , and by the presence of narrow pale streaks ( not small pale spots ) on the crown .
holt , d . w . , berkley , r . , deppe , c . , enríquez rocha , p . , petersen , j . l . , rangel salazar , j . l . , segars , k . p . , wood , k . l . , christie , d . a . & kirwan , g . m . ( 2018 ) . ferruginous pygmy - owl ( glaucidium brasilianum ) . in : del hoyo , j . , elliott , a . , sargatal , j . , christie , d . a . & de juana , e . ( eds . ) . handbook of the birds of the world alive . lynx edicions , barcelona . ( retrieved from urltoken on 9 july 2018 ) .
for a tiny bird , the cactus ferruginous pygmy - owl has a very long name . it is small enough to hold in your hand . it averages 6 . 5 inches ( 17 cm ) in length and weighs only 2 . 5 ounces ( 62 g ) . females usually weigh a few tenths of an ounce more than the males . the feathers on their back are creamy - brown , and the underside is cream - colored with reddish - brown stripes . the top of their heads are slightly streaked and on the back of the head they have two black eye spots outlined in white . their eyes are yellow and round . their tails are longer than most owls , and they have no tufts on their ears .
small birds such as hummingbirds , wrens , warblers , jays , and blackbirds often mob northern pygmy - owls—in fact , you may be able to find these owls by following a noisy commotion of songbirds focused on one spot .
sometimes snap their mandibles together to make a “beak clap” sound . the behavior is likely a sign of distress , as this bill snapping usually is reported during situations such as when the owl is handling or during nest inspection ( proudfoot and johnson 2000 ) .
cactus ferruginous pygmy - owls don ' t migrate . in late in the winter or early spring they begin nesting in the cavities of trees or cacti like the saguaro and organ pipe . these holes have often been made by woodpeckers . they lay 3 to 5 white eggs in late april , which hatch about 28 days later . the young owls are fed by both parents . they fledge , or leave the nest about 27 to 30 days after hatching . they stay close to their parents until they are ready to be on their own .
the northern pygmy - owl may be tiny , but it’s a ferocious hunter with a taste for songbirds . these owls are mostly dark brown and white , with long tails , smoothly rounded heads , and piercing yellow eyes . they hunt during the day by sitting quietly and surprising their prey . as a defensive measure , songbirds often gather to mob sitting owls until they fly away . mobbing songbirds can help you find these unobtrusive owls , as can listening for their call , a high - pitched series of toots .
proudfoot , g . a . , j . l . mays , s . l . beasom and r . bingham . 1998 .
effectiveness of broadcast surveys in determining habitat use of ferruginous pygmy - owls ( glaucidium brasilianum ) in southern texas .
in biology and conservation of owls of the northern hemisphere . , edited by j . r . duncan , d . h . johnson and t . h . nicholls , 338 . st . paul , mn : u . s . for . serv . gen . tech . rep . nc - 190 . n . central res . station . close
it had been so listed between 1997 and 2006 . it was delisted because the u . s . fish & wildlife service determined that there is an abundance of the owl just over the hill south of here in mexico and they are only scarce here because this is the uppermost limit of their range .
johnson rr , haight lt , simson jm ( 1979 ) owl populations and species status in the southwestern united states . in : schaeffer p , ehlers sm ( eds ) , owls of the west : their ecology and conservation . national audubon society western education center , tiburon , california , pp . 40–59
most owls have asymmetrically placed ears as well as flattened facial discs around the eyes . both of these features are adaptations that give them better hearing . interestingly , northern pygmy - owls lack these features , and this may be an outcome of their diurnal habits and greater reliance on vision .
subspecies : there are four races of northern pygmy - owl in north america . g . c . swarthi is restricted to vancouver island . g . c . grinnelli stretches along the west coast of north america from s . e . alaska all the way to s . california . g . c . californicum is the most widespread race in north america . it ranges from the northern interior of british columbia and east to alberta then south into nevada and s . california . g . c . pinicola is found from idaho and montana south to california and nevada . this race is sometimes combined with g . c . californicum .
this small owl ' future is in grave danger from the loss of its habitat . it used to be very common and could be found in arizona from the new river north of phoenix to the mexican border . now they can only be found between tucson and the mexican border , and less than 50 remain in the state . most of the owls live in the ironwood forests northwest of tucson and marana . they live in the fastest growing areas of tucson . people are moving into the desert , changing the environment to suit their needs , and destroying the forest ' s fragile ecosystem . logging , woodcutting and livestock overgrazing are other threats the pygmy owls face .
since 1996 , authorities in arizona have found anywhere from 12 - 41 adult pygmy owls a year , and in 2006 , surveyors spotted only 28 owls . the population in northern mexico is also imperiled , with a documented 4 . 4 percent decline per year for the past seven years , or a 26 percent decline overall since 2000 .
hunting & food : feeds on insects , small birds and other small vertebrates such as mice . birds up to the size of a dove have been recorded as prey . this owl has powerful talons and is able to catch prey larger then itself . hunting is normally from a perch , but birds and insects may be caught among foliage with sudden dashing flights .
a biologist for one of the pests asserts it is difficult to determine the number of owls here because they keep flying around and won’t hold still for an owl census . this despite the fact that owls are easily contained because they are not high - flying birds and unlike many of their human brothers , can be intimidated by the appearance of a border fence .
surely there would be no need to relist the owl if it were domesticated . that would save the fish & wildlife people a ton of money since they would not have to deal with the then - plentiful birds . the pests could turn their attentions to wildlife that is actually in short supply and which the world cannot live without , like the gray wolf .
habitat : tropical and subtropical , mostly humid , primary or secondary forest with clearings , forest edges , riverine forest , pastureland with groups of trees and bushy areas , parks and large gardens with mature trees and thick bushes . this owl is normally found below below 1500m elevation . prefers evergreen or semi - deciduous forest with undergrowth in the lowlands , and is common in the subtropical and tropical rainforest of eastern brazil , eastern paraguay and northeast argentina where they mostly inhabit secondary forest with dense undergrowth .
this got me to thinking . why is there an alarming dearth of the owl around here ? there is no alarming shortage of sheep , goats , cattle , or even chickens . chickens ! yes , that’s the answer . these animals are not endangered for the simple reason that they are domesticated . unlike wild animals , they have to stay where they are put . they are raised so that we have plenty of them . they are owned by people who have an incentive to have them thrive .
in march 2007 , the center filed a new petition to list the owl — in southern arizona , throughout the sonoran desert , or throughout its range . we filed a notice of intent to sue in may 2008 , and were rewarded a week later when the agency said protection might be warranted and began a status review . in early 2009 , the ninth circuit court of appeals issued an appeal upholding the bird ' s delisting , but in 2011 , we reached a landmark agreement with the fish and wildlife service compelling the agency to re - propose it for protection that same year , if warranted . when no progress was made according to the agreement ' s timeline , we sued in 2012 .
like other pygmy - owls , the ferrug are cavity nesters . they nest in a natural cavity in a tree , stump or snag , in old woodpecker holes , tree forks or depressions , occasionally in a sand bank or termite mound . the breeding season for this species may begin as soon as early april and last as late as mid - june . clutch size is usually 3 or 4 eggs but 2 to 5 are not uncommon . incubation and brooding is done by the female and the eggs hatch at approximately 28 days . the male brings food to the female during incubation and brooding . both adults will bring food to the young at 3 weeks after the young hatch . intense brood competition over prey may result in fatalities of the young . fledging occurs at about 28 days after eggs hatch . adults will care for the young for an additional 3 weeks following fledging .
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thank you for taking the time to provide feedback on the iucn red list of threatened species website , we are grateful for your input .
del hoyo , j . , collar , n . j . , christie , d . a . , elliott , a . and fishpool , l . d . c . 2014 . hbw and birdlife international illustrated checklist of the birds of the world . volume 1 : non - passerines . lynx edicions birdlife international , barcelona , spain and cambridge , uk .
glaucidium brasilianum and g . tucumanum ( del hoyo and collar 2014 ) were previously lumped as g . brasilianum following sibley and monroe ( 1990 , 1993 ) .
justification : this species has an extremely large range , and hence does not approach the thresholds for vulnerable under the range size criterion ( extent of occurrence < 20 , 000 km2 combined with a declining or fluctuating range size , habitat extent / quality , or population size and a small number of locations or severe fragmentation ) . despite the fact that the population trend appears to be decreasing , the decline is not believed to be sufficiently rapid to approach the thresholds for vulnerable under the population trend criterion ( > 30 % decline over ten years or three generations ) . the population size is extremely large , and hence does not approach the thresholds for vulnerable under the population size criterion ( < 10 , 000 mature individuals with a continuing decline estimated to be > 10 % in ten years or three generations , or with a specified population structure ) . for these reasons the species is evaluated as least concern .
to make use of this information , please check the < terms of use > .
now considered endangered or threatened in limited range in united states . still widespread in tropics , although undoubtedly has declined in some areas .
mesquite thickets , desert riverine woods , saguaros . in united states , currently most numerous in low stands of live oak and mesquite in southern texas . was formerly common in mesquite forest along rivers and in desert dominated by saguaro cactus . in tropics , found in wide range of lowland habitats , mostly in semi - open country .
apparently hunts most actively near dawn and dusk . hunts by watching from raised perch , then darting out in very rapid flight to capture prey in talons . notably bold and aggressive for its small size .
3 - 4 , sometimes 5 . white . apparently incubation is mostly or entirely by female , about 28 days ; male brings food to female during incubation . young : both parents take part in providing food for young ; male may do most of hunting at first . age of young at first flight about 27 - 30 days .
both parents take part in providing food for young ; male may do most of hunting at first . age of young at first flight about 27 - 30 days .
includes insects , birds , rodents , lizards . diet is not well known , and probably varies by region . among known foods are large insects ( including crickets , caterpillars , and beetles ) , scorpions , small birds , rodents and other small mammals , and lizards .
breeding behavior is not well known . male defends nesting territory with song of monotonous repeated whistles , mostly at dusk and dawn , also at night , sometimes by day . nest site is in cavity in tree or in giant cactus , usually old woodpecker hole , but sometimes natural hollow in tree . typically low , 10 - 30 ' above ground .
audio © lang elliott , bob mcguire , kevin colver , martyn stewart and others .
officials confirm the bird - rich santa ana national wildlife refuge is the ' probable ' starting point for construction .
tell congress to oppose a harmful rider that threatens sage - grouse and other wildlife .
tell congress and the department of the interior to uphold the country ' s most important bird protection law .
is one of the most widespread birds of the lowlands of the neotropics ; the distribution of the species extends from the southern united states south to central argentina . this species occurs in a wide variety of habitats . it does not occur in closed - canopy forest , although it is found at forest edge , but otherwise is found in almost any wooded habitat including arid scrub , dry forest , evergreen forests , coffee plantations , and towns . most
plumage pattern , with two large black marks (
false eyes
) on the back of the neck , and white underparts with coarse streaks . it can be difficult to distinguish from other species of
has short white streaks on the crown , however , but most of other species have spotted crowns . the song , a long series of short whistles , is a familiar sound ;
often respond aggressively to imitations of this song , approaching the source in a rapid , direct flight .
) , version 1 . 0 . in neotropical birds online ( t . s . schulenberg , editor ) . cornell lab of ornithology , ithaca , ny , usa .
there are no sound files at this time . please check back with us .
third and final cut of the individual as xc389254 . it is part of a longer cut that was edited due to noise at background by wind .
another cut of the individual as xc389254 . and it is part of a longer cut that was edited due to noise at background by wind .
probably same individual as xc389192 , but the recording was done at 300 meters from this recording . also on forest edge of dry forest . recording distance was 20 meters . cut was amplified ( 4 db ) .
between dry forest and semideciduous forest , with erika cristina valadão and márcia pâmela carvalho .
female calls from about 0 : 01 - 0 : 11 s and male in calling in background throughout recording , both birds about 30 - 40ft away .
singing bird responding to whistled imitation , then a second bird starts calling and the two carry on calling / singing together . natural intervals . habitat is tropical deciduous forest in a somewhat disturbed cattle ranching area .
song in response to whistled imitation from a bird ( same as in xc368467 ) perched about 2 - 4m up in prosopis - dominated woodland .
song from a bird attracted by whistled imitation . about 2 - 4m up in prosopis - dominated woodland .
sonogram images © xeno - canto foundation . sonogram images share the same license terms as the recording they depict .
van rossem , 1937 – s usa ( s arizona ) and w mexico ( s to n nayarit ) .
a . r . phillips , 1966 – w mexico from s nayarit to s oaxaca .
– s usa ( s texas ) through e & s mexico to panama .
phelps , sr & phelps , jr . , 1951 – margarita i ( n venezuela ) .
( daudin , 1800 ) – n & e venezuela , trinidad and the guianas .
chapman , 1929 – amazonian colombia , s venezuela and brazil s to s peru and n bolivia .
) ; wingspan c . 38 cm . long , narrow tail and distinctive whistled “popping” call . very . . .
advertising call a prolonged series of 10–60 whistled notes , c . 3 per second , sounding like . . .
tropical lowlands and foothills in primary and secondary forest , coastal and thorn scrub , bushes . . .
mostly insects ; also reptiles , birds , mammals and amphibians ; diet varies among seasons and habitat types . examples of prey items include . . .
lays generally c . mar–jun , during dry to early wet season ; eggs found in s mexico ( oaxaca ) in apr–may ; breeding late jan and . . .


the asterozoa are a subphylum in the phylum echinodermata .

characteristics include a star-shaped body and radially divergent axes of symmetry .

the subphylum includes the two classes asteroidea , the starfish , and ophiuroidea , the brittle stars and basket stars , and the extinct order somasteroidea .

asterozoa

asterozoa .
a dictionary of zoology . . retrieved july 09 , 2018 from urltoken urltoken
asterozoa .
a dictionary of earth sciences . . retrieved july 09 , 2018 from urltoken urltoken
asterozoa .
a dictionary of zoology . . encyclopedia . com . ( july 9 , 2018 ) . urltoken
asterozoa .
a dictionary of earth sciences . . encyclopedia . com . ( july 9 , 2018 ) . urltoken
what made you want to look up asterozoa ? please tell us where you read or heard it ( including the quote , if possible ) .
taxonomy in the current linnean system ophiuroidea is regarded as a class . following a more phylogenetic view its parent would be asterozoa according to a popular hypothesis . however , according to another equally parsimonious view , ophiuroidea and asteroidea are not sister taxa , which invalidates asterozoa as their parent . [ details ]
mcknight , d . g . 1975 . classification of somasteroids and asteroids ( asterozoa : echinodermata ) . journal of the royal society of new zealand . 5 : 13 - 19 .
mcknight , d . g . 1975 . classification of somasteroids and asteroids ( asterozoa : echinodermata ) . j . roy . soc . n . z . 5 : 13 - 19 .
reich a , dunn c , akasaka k , wessel g . data from : phylogenomic analyses of echinodermata support the sister groups of asterozoa and echinozoa . database : dryad data repository [ internet ] .
citation : reich a , dunn c , akasaka k , wessel g ( 2015 ) phylogenomic analyses of echinodermata support the sister groups of asterozoa and echinozoa . plos one 10 ( 3 ) : e0119627 . urltoken
telford mj , lowe cj , cameron cb , ortega - martinez o , aronowicz j , oliveri p , et al . phylogenomic analysis of echinoderm class relationships supports asterozoa . proc biol sci . 2014 ; 281 .
the class of sea stars form the subphylum asterozoa , together with the brittle stars ( ophiuroidea ) . the seven orders of sea stars include more than 2000 species worldwide , 43 of them are registered in norway .
asterozoa in which the alimentary organs are essentially confined to a central disc from which the arms are distinctly demarcated and capable of performing the locomotor movements , the tube - feet serving as non - suctorial , sensory tentacles .
blake , daniel b . guensburg , thomas e . and lefebvre , bertrand 2016 . new early paleozoic asterozoa ( echinodermata ) from the armorican massif , france , and the western united states . annales de paléontologie , vol . 102 , issue . 3 , p . 161 .
, is basal within the subphylum asterozoa . members are most readily recognized by presence of series of rod - like so - called virgal ossicles extending laterally from each ambulacral ossicle . five somasteroid genera are recognized and assigned to two families . four genera are gondwanan , three of these (
in all existing genera the ambulacral plates fuse in pairs early in life to form median articulating joints , termed vertebrae , and the ambulacral groove is converted into an internal epineural canal . these characters sharply distinguish extant ophiuroids from other asterozoa , but they are lacking from the more generalized palaeozoic ophiuroids .
subphylum asterozoa fossil and living forms ( lower ordovician about 500 , 000 , 000 years ago to recent ) ; radially symmetrical with more or less star - shaped body resulting from growth of arms in 1 plane along 5 divergent axes ; central mouth ; 5 arms ; dorsal tube feet and mouth . class stelleroidea features…
the representatives of asterozoa ( asteroidea , echinoidea , and ophiuroidea ) have a similar structural plan of the axial complex with minor differences within each class ; this structural scheme substantially differs from that in crinozoa and holothurozoa . the axial complex consists of the coelomic organs and the haemocoel ( blood ) structures , which are morphologically and functionally integral . the coelomic organs are the stone canal , axial coelom , perihaemal coeloms ( axocoel perihaemal ring and somatocoel perihaemal ring ) , water ring , and pericardial and genital coeloms . these organs are closely associated with the epigastric and hypogastric coeloms and with the perioral coelomic ring . the haemocoel structures of the axial complex include the oral haemal ring , heart , axial organ , genital haemal ring , and gastric haemal ring . the epineural canals of echinoids and ophiuroids are of a noncoelomic nature . they are formed by the invagination of the ectoneural cord and closing of the epidermis above it . the possible functions of the axial complex in asterozoa are blood circulation and excretion .
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the root of the current tree connects the organisms featured in this tree to their containing group and the rest of the tree of life . the basal branching point in the tree represents the ancestor of the other groups in the tree . this ancestor diversified over time into several descendent subgroups , which are represented as internal nodes and terminal taxa to the right .
you can click on the root to travel down the tree of life all the way to the root of all life , and you can click on the names of descendent subgroups to travel up the tree of life all the way to individual species .
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cladogram based on arguments from spencer and wright ( 1966 ) , mcknight ( 1975 ) , and blake ( 1982 ) .
somasteroids are flattened , fivefold radially symmetrical echinoderms that range in shape from that of a pentagon to that of a star with protruding arms . it appears that somasteroids were benthic marine animals that were filter - and / or detritus - feeders . despite their relatively rigid arm structure , somasteroids are thought to have been somewhat mobile and able to scavenge along the ocean floor ( spencer , 1951 ) .
figure modified from fell ( 1963b ) . drawing by h . b . fell . copyright © 1963 royal society of london .
figure 2 . reconstructed cross - section of one arm of chininanaster sp . ( chinianasteridae ) . figure modified from fell ( 1963b ) . drawing by h . b . fell . copyright © 1963 royal society of london .
radial water vessels extend the length of each arm within a radial channel formed by the recumbent ambulacral plates and give rise to numerous tube feet ( figure 2 ) . in somasteroids , the radial water vessel is often positioned at the oral - marginal junction of ambulacrals , as in asteroids , but can also be enclosed within the ambulacral plates , as in ophiuroids . tube feet branching from the radial water vessels are seated in broad basins that , in some species , also give rise to ampulae that extend into the body cavity through ambulacral pores . the jaw ossicles of somasteroids are differentiated with small mouth angle plates , in contrast to those of asteroids that lack odontophores ( mcknight , 1975 ) . buccal slits , which function primarily as respiratory structures in ophiuroids , may or may not have been present adjacent to the mouth frame in somasteroids .
discussions addressing somasteroid origins have certainly been a major point of contention through the years primarily because the intermediate forms that gave rise to the somasteroids are lacking from the fossil record ( blake and guensburg 1993 ; blake , 1994 ) . it seems most likely , however , that the somasteroids emerged from either a crinoid lineage ( fell , 1963 ; mooi and david , 2000 ) , or an edrioasteroid lineage ( paul and smith , 1984 ; smith 1988b ) .
informative evolutionary and phylogenetic analyses within somasteroidea have been quite difficult because the examination and characterization of the group has been somewhat limited . what is known about the diversification of somasteroids , however , is primarily derived from work on three lower ordovician families : chinianasteridae ( tremadoc - early arenig ) , villebrunasteridae ( tremadoc - early arenig ) , and archegonasteridae ( late arenig ) , as discussed by nichols ( 1962 ) , fell ( 1963 ) , and blake ( 1982 ) .
the first organized classification of somasteroidea was carried out by w . k . spencer ( 1951 ) . in his report , spencer describes some of the earliest asteroid and ophiuroid specimens ever found . in addition , he describes fossils of a third asterozoan group , the somasteroids , which occur not only contemporaneously with , but also prior to all recognizable asteroid and ophiuroid fossil forms . these findings are suggestive of a scenario in which all asterozoans arose from ancient somasteroid forms .
blake , d . b . 1982 . somasteroidea , asteroidea , and the affinities of luidia ( plasterias ) latiradiata . paleontology , 25 : 167 - 191 .
blake , d . b . 1994 . re - evaluation of the palasteriscidae gregory , 1900 , and the early phylogeny of the asteroidea ( echinodermata ) . j . paleont . 68 : 123 - 134 .
blake , d . b . 1998 . morphological characters of early asteroids and ophiuroids . echinoderms : san francisco , mooi and telford ( eds . ) , balkema , rotterdam .
blake , d . b . , guensburg , t . e . , 1993 . new lower and middle ordovician stelleroids ( echinodermata ) and their bearing on the origins and early history of the stelleroid echinoderms .
fell , h . b . 1962 . a surviving somasteroid from the eastern pacific ocean . science , n . y . 136 : 633 - 636 .
fell , h . b . 1963a . a new family and genus of somasteroidea . trans . r . soc . n . z . 3 : 143 - 146 .
fell , h . b . 1963b . the phylogeny of sea - stars . phil . trans . r . soc . lond . , ser . b 246 : 381 - 435 .
mooi , r . , david , b . 2000 . what a new model of skeletal homologies tells us about asteroid evolution . amer . zool . 40 : 326 - 339 .
nichols , d . 1962 . echinoderms . huchinson and co . , london .
paul , c . r . c . , smith , a . b . 1984 . the early radiation and phylogeny of echinoderms . biological reviews , 46 : 157 - 200 .
smith , a . b . 1988 . patterns of diversification and extinction in early paleozoic echinoderms . paleontology , 31 : 799 - 828 .
smith , a . b . , jell , p . a . 1990 . cambrian ederoasteroids from australia and the origins of starfishes . mem . queen . mus . 28 : 715 - 778 .
spencer , w . k . 1951 . early paleozoic starfish . phil . trans . r . soc . lond . , ser . b 235 : 87 - 129 .
spencer , w . k . , wright , c . w . 1966 . asterozoans , pp . s4 - s107 . in r . c . moore ( ed . ) , treatise in invertebrate paleontology , part u , echinodermata 3 . geological society of america and the university of kansas press , new york and lawerance .
after spencer , w . k . 1951 . early paleozoic starfish . phil . trans . r . soc . lond . , ser . b 235 : 87 - 129 .
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each tol branch page provides a synopsis of the characteristics of a group of organisms representing a branch of the tree of life . the major distinction between a branch and a leaf of the tree of life is that each branch can be further subdivided into descendent branches , that is , subgroups representing distinct genetic lineages .
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phylogenetic hypothesis of the asteroidea based on blake ( 1987 ) . these relationships , as well as intra - order relationships , are contentious and re - evaluation of asteroid phylogeny continues ( see discussion of phylogenetic relationships , below ) .
the asteroidea is one of the largest and most familiar classes within the phylum echinodermata . these animals , commonly known as sea stars or starfishes , form a diverse and speciose group . there are approximately 1600 extant species ( hyman 1955 ; clark 1977 ; clark and downey 1992 ) which are found throughout the world ' s oceans . following the classification of blake ( 1987 ) , these species are grouped into seven orders : brisingida , forcipulatida , notomyotida , paxillosida , spinulosida , valvatida and velatida .
like other echinoderms , asteroids are important members of many marine benthic communities . they can be voracious predators , having significant impacts on community structure . for example , paine ( 1966 ) used pisaster ochraceus to illustrate his concept of the role keystone species play in community ecology . the crown - of - thorns starfish , acanthaster planci , is particularly well - known because it can cause extreme detrimental effects to coral reefs , particularly during population outbreaks ( moran 1988 ) .
figure 1 : pisaster ochraceus and acanthaster planci , two asteroids of great ecological significance . pisaster image by sherry ballard , courtesy calphotos , copyright © 1999 california academy of sciences . acanthaster image copyright © borut furlan .
the controversial concentricycloidea ( a proposed sixth class of the echinodermata ; baker et al . 1986 , rowe et al . 1988 , pearse and pearse 1994 ) have been diagnosed as unusual asteroids ( smith 1988 , belyaev 1990 , janies and mooi 1999 ) . their relationship to other asteroid taxa is not well resolved , but alliances with species from the velatida and the forcipulatida have been proposed . the unique morphology of the concentricycloids makes it difficult to assign this group to the recognized asteroid orders and is cited as sufficient distinction for class recognition .
figure 2 : a typical starfish , asterias rubens , with tubefeet visible on the edge of the arm in the foreground . image copyright © 2004 kåre telnes . cushion stars , like this culcita novaeguineae , may have arms so short that they look more like a ball than a star . image copyright © 2003 massimo boyer .
taxonomy of asteroids usually is based on externally observable characteristics of the skeleton , particularly the primary ossicular series which define the body wall ( ambulacrals , adambulacrals , marginals , terminals , actinals , abactinals ) , as well as secondary ossicles such as spines , spinelets and pedicellariae . works by perrier ( 1884 ) and sladen ( 1889 ) laid the taxonomic foundation of most asteroid groups . many other authors have contributed to and / or refined the asteroid classification scheme , notably fisher ( 1911 , 1928 ) , verrill ( 1914 ) , fell ( 1963 ) , spencer and wright ( 1966 ) and mcknight ( 1975 ) . blake and elliot ( 2003 ) provide clear definition of ossicle terminology . blake ( 1987 ) provides classification and diagnoses of asteroid groups .
figure 3 : morphology of asteroids . a , aboral and oral surfaces of a generalized asteroid . image © biodidac . b , transverse section and perspective view of a generalized arm ( soft tissues and spines removed ) ; note the arched ambulacral ossicles forming the ambulacral groove and the dorsal podial pores between ambulacral ossicles . one podium ( tubefoot ) on the left is drawn in outline only to illustrate how the podia descend through the podial pores . image © 2004 emily knott .
application of the extraxial - axial theory ( eat ) to asteroid morphology significantly aids our understanding of ossicle homologies within the asteroidea and between asteroids and other echinoderms ( mooi and david 2000 , blake and elliot 2003 , blake and hagdorn 2003 ) . according to the eat , the ambulacral and terminal ossicles of asteroids are axial elements . these ossicles are formed according to the ocular plate rule ( opr ) and are associated with the developing water vascular system during ontogeny as are the axial ossicles of other echinoderms . the remaining asteroid ossicle series are extraxial elements , which can be added during ontogeny without any particular ordering system ( although secondarily ordered serial homologous elements are common in the asteroids , e . g . adambulacrals and marginals ) . in comparison to axial elements , extraxial ossicles are prone to much more evolutionary lability ( mooi and david 1997 ) .
summarized from blake ( 1998 ; 2000 ) , mooi and david ( 2000 ) and blake and hagdorn ( 2003 ) .
deep ambulacral groove—the paired ambulacral ossicles are erect and arch across the arm axis forming a clearly defined furrow . the extent of the arch and definition of the furrow are expected to be weaker in the earliest asteroids , but these characters are difficult to observe in most fossil specimens .
dorsal podial pores—the dorsal podia pores are passageways between ambulacral ossicles through which the tubefeet descend . these pores allow for internal protection of the ampullae , dorsal outpockets of the podia , which contract and expand with extension and retraction of the podia . the ampullae of earlier asteroids were external , in closed , cup - like podial basins formed by the ossicles of the ambulacral column .
offset positioning of the ambulacral and adambulacral ossicles and differentiation of articulation structures in ossicles of the ambulacrum—these features describe a variety of related apomorphic characteristics of ambuloasteroids . offset positioning of the ambulacral and adambulacral ossicles allows for soft tissue connections between the ambulacral and both adjacent adambulacrals which is further enhanced with differentiation of articulation structures on the ossicles . this arrangement allows more complex movement in the ambuloasteroids . in non - ambuloasteroids a single ambulacral ossicle abuts a single adambulacral .
presence of an odontophore—the odontophore is a small interradial ossicle associated with the mouth angle ossicle . the odontophore is expected to the homologue of the axillary in paleozoic asteroids .
the earliest asteroids appeared in the ordovician ( figure 4 ) . however , at least two major faunal transitions have occurred within the asteroidea concomitantly with large extinction events : in the late devonian ( blake and glass in webster et . al . 1999 ) and in the late permian ( blake 1987 , gale 1987 , blake et al . 2000 , blake and elliot 2003 , blake and hagdorn 2003 ) . the asteroid orders as described here contain all extant and some extinct species which have a morphology distinct from paleozoic forms ( i . e . ambuloasteroidea ; see characteristics , blake 1982 , 1987 , 1988 ; gale 1987 , blake and elliott 2003 , blake and hagdorn 2003 ) . the asteroid orders are thought to have appeared and diversified very rapidly ( within approximately 60 million years ) during the lower and early middle jurassic , frustrating our understanding of ordinal relationships ( see discussion below ) .
figure 4 : hudsonaster sp . ( usnm 40882 ) , an early asteroid from the ordovician . image copyright © daniel b . blake
relationships among paleozoic asteroids , as well as between paleozoic asteroids and extant asteroids , are difficult if not impossible to determine because of the limitations of the asteroid fossil record . asteroid fossils are rare because 1 ) the skeletal elements rapidly dissociate after death of the animals 2 ) asteroids typically have a large body cavity that collapses with deterioration of the organs , resulting in misshapen forms and 3 ) asteroids often live on hard substrates which are not conducive to fossil formation . from the limited fossil evidence that is available we know that the basic body plan of the asteroids has remained the same since the ordovician . several papers by blake ( e . g 1989 , 2000 ) describe limitations of the fossil record in detail .
figure 5 : early neoasteroids from the triassic . images copyright © daniel b . blake
left : trichasteropsis weissmanni ( mhi 843 / 1 ) , trichasteropsida . center : trichasteropsis weissmanni ( smns 3173 / 5 ) , trichasteropsida . right : noriaster barberoi ( mpum 8420 ) , valvatida : poraniidae
a survey of asteroid nomenclature arranged by order has been compiled . clark ( 1989 , 1993 , 1996 ) and clark and mah ( 2001 ) list accepted names as well as synonyms , otherwise invalid names , references and ranges of type localities .
brisingida— brisingids are deep - sea dwelling asteroids . they usually have many ( 6 - 16 ) long , attenuated arms which are used in suspension feeding . the brisingida contains about 100 species in 17 genera and 6 families . a preliminary phylogeny for this order has been produced by mah ( 1998 ) .
forcipulatida— these asteroids are distinguished by their forcipulate pedicellariae , which are generally quite conspicuous on the body surface . the forcipulatida contains about 300 species in 68 genera and 6 families . a preliminary phylogeny for this order has been produced by mah ( 2000 ) .
notomyotida— these are deep - sea dwelling asteroids having flexible arms with characteristic longitudinal muscle bands along the inner dorsolateral surface . the notomyotida contains about 75 species in 12 genera and 1 family .
paxillosida— these asteroids are considered to be somewhat infaunal in that they can bury themselves partially under sandy sediments . they are characterized by some morphological features ( e . g . pointed , unsuckered tubefeet ) which have been considered primitive by some ( see discussion of phylogenetic relationships , below ) . the paxillosida contains about 255 species in 46 genera and 5 families .
spinulosida— these asteroids have a relatively delicate skeletal arrangement and completely lack pedicellariae . no fossil spinulosids have been found . the spinulosida contains about 120 species in 9 genera and 1 family .
valvatida— these asteroids are quite diverse , but are often characterized by their conspicuous marginal ossicles . definition of this group has been the most variable and the ordinal definition of many families included here has been controversial ( see discussion of phylogenetic relationships , below ) . the valvatida contains about 695 species in 165 genera and 14 families .
velatida— these asteroids typically have thick bodies with large discs and interradial depressions . contrary to blake ' s ( 1987 ) classification , molecular evidence suggests a relationship between some velatid and valvatid families ( see discussion of phylogenetic relationships , below ) . the velatida contains about 200 species in 25 genera and 5 families .
specific use of phylogenetic methods in studies of asteroid evolutionary relationships began in the late 1980s . these analyses ( using both morphological and molecular data ) have resulted in conflicting hypotheses of asteroid phylogeny . phylogenetic analyses are continuing to be re - evaluated with additional data . since their results are still somewhat contentious , they have yet to initiate changes in our classification system .
in 1987 , two differing hypotheses of order level relationships were proposed based on analyses of morphological characteristics ( blake 1987 , gale 1987 , figure 6 , 7 ) . these two phylogenies differ due to differences in opinion about character polarity ( assigning ancestral or derived status to a particular state of a character ) and the different morphological characters used in the analyses ( note that gale does not specifically use phylogenetic methods ) . both authors emphasized the importance of ambulacral characters to asteroid classification and recognized the distinction between paleozoic and post - paleozoic forms ( i . e . ambuloasteroidea , blake and hagdorn 2003 ) .
however , gale ( following mcknight 1975 ) focuses on the lack of suckered tubefeet in the paxillosida , considering them primitive . as a result , his phylogeny reflects two major groups : a basal paxillosida and the remaining asteroids , all having suckered tubefeet , which he termed superorder surculifera . blake considers suckered tubefeet to be the ancestral condition . his phylogeny reflects two major asteroid groups : superorder forcipulatacea ( forcipulatida + brisingida ) and a clade of the superorders valvatacea + spinulosacea ( valvatida , notomyotida , paxillosida , spinulosida and velatida ) . outgroup comparison with calliasterella and inclusion of the trichasteropsida results in a basal forcipulatacea .
the differences in these proposed phylogenies highlight questions about asteroid relationships that are still unresolved . the identification of the basal ( neo ) asteroid group has been the driving question of additional studies ( see evidence from molecular characters , below ) . additionally , ordinal definition , particularly for blake ' s valvatida , velatida and spinulosida , is problematic . such problems were not new to blake and gale . although many asteroid groups can be clearly defined morphologically ( forcipulatida , brisingida , notomyotida ) , asteroid morphology is complex and diverse . other groups are less clearly defined .
additional phylogenetic analyses incorporating molecular data with morphological data ( lafay et al . 1995 ) and using molecular data alone ( wada et al . 1996 ; knott and wray 2000 ) were presented in an effort to resolve phylogenetic arguments . unexpectedly , these studies have done little to elucidate asteroid relationships and may have only added to the confusion .
lafay et al . ( 1995 ) present an unrooted phylogeny deduced from analysis of a combined morphological data set taken from blake ( 1987 ) and gale ( 1987 ) with unordered character states ( figure 8 ) . although very few taxa were studied , their phylogeny supports the definition of asteroid orders proposed by blake but separates the paxillosida from the valvatida . their analysis with molecular data alone ( sequence data from 28s rrna ) results in several conflicting topologies due to weak phylogenetic signal . most of this signal is masked by that from the morphological data set when the two data sets are combined . however , after evaluating several rooting positions using molecular data from other echinoderms in outgroup comparison , lafay et al . ( 1995 ) conclude that the paxillosida may not be monophyletic and that the paxillosid genus astropecten may be the sister group to the remaining asteroids , reminiscent of gale ' s phylogeny .
wada et al . ( 1996 ) include more taxa for additional investigation of ordinal monophyly ( figure 9 ) . in multiple analyses of their molecular data set ( sequence data from 12s and 16s rdna ) , they find that paxillosids are paraphyletic with the paxillosid genus luidia as the basal asteroid taxon . in addition , the valvatida is not monophyletic and a forcipulatid clade falls within a group of valvatids , a velatid and spinulosids , a relationship in stark contrast to that proposed by blake ( 1987 ) . further , the spinulosida are never grouped with the velatida , which blake ( 1987 ) proposed as their sister group and which previously were considered a group within the spinulosida ( spencer and wright 1966 , mcknight 1975 , blake 1981a ) .
knott and wray ( 2000 ) expand taxon sampling even more , but their molecular data set ( sequence data from mitochondrial trna and coi genes ) fails to resolve questions of asteroid phylogeny ( figure 10 ) . significantly , the paxillosida is not basal in their results ( although astropecten is not included ) . the results of different tree reconstruction methods are not in agreement , and basal groupings are only supported by bootstrapping in the neighbor - joining analysis . the proposed phylogeny is similar to blake ( 1987 ) in that two lineages ( one largely of forcipulatids and the other largely of valvatids ) are recovered , but valvatida and velatida are not monophyletic and some velatids plus the spinulosida fall in the forcipulatid clade .
figure 8 . lafay et al . ' s ( 1995 ) hypothesis of asteroidea relationships .
figure 9 . wada et al . ' s ( 1996 ) hypothesis of asteroidea relationships .
figure 10 . knott & wray ' s ( 2000 ) hypothesis of asteroidea relationships .
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horse , ( equus caballus ) , a hoofed , herbivorous mammal of the family equidae . it comprises a single species , …
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of projecting rays and a star - shaped body . it contains the one class stelleroidea .
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telford mj 1 , lowe cj 2 , cameron cb 3 , ortega - martinez o 4 , aronowicz j 5 , oliveri p 6 , copley rr 7 .
department of genetics , evolution and environment , university college london , darwin building , gower street , london wc1e 6bt , uk m . telford @ ucl . ac . uk .
hopkins marine station , department of biology , stanford university , 120 oceanview boulevard , pacific grove , ca 93950 , usa .
départment de sciences biologiques , université de montréal , pavillion marie - victorin , c . p . 6128 , succ . centre - ville , montréal , québec , canada h3c 3j7 .
department of biological and environmental sciences , sven lovén centre for marine sciences , university of gothenburg , kristineberg 566 , fiskebäckskil 451 78 , sweden .
department of organismal biology and anatomy , university of chicago , chicago , il 60650 , usa .
department of genetics , evolution and environment , university college london , darwin building , gower street , london wc1e 6bt , uk .
cnrs , laboratoire de biologie du développement de villefranche - sur - mer ( lbdv ) , observatoire océanographique , villefranche - sur - mer 06230 , france sorbonne universites , upmc univ paris 06 , laboratoire de biologie du developpement de villefranche - sur - mer , observatoire oceanographique , villefranche - sur - mer 06230 , france copley @ obs - vlfr . fr .
pmid : 24850925 pmcid : pmc4046411 doi : 10 . 1098 / rspb . 2014 . 0479
the two hypotheses of echinoderm evolution discussed in this work . the asterozoan hypothesis unites ophiuroids and asteroids on the basis of a five - rayed body plan . the cryptosyringid hypothesis places ophiuroids as sister group to the holothurians and echinoids on the basis of , for example , closed ambulacral grooves ( see introduction ) .
results from our data stratified by overall length of gene trees ( gene rate ranking ) , from ( a ) , the slowest evolving quartile , to ( d ) the fastest evolving quartile .
research support , u . s . gov ' t , non - p . h . s .
a subphylum of echinoderms characterized by a star - shaped body and radially divergent axes of symmetry .
subphylum expresses the vtg protein , vtg1 ( prowse and byrne , 2012 ) .
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data availability : the raw reads and assembled trasncriptomes reported in this paper have been deposited in the genbank database ( ncbi bioproject no . prjna236087 ) . assembly statistics and agalma resource reports can be found at : urltoken . see also urltoken .
funding : this work was funded by the national science foundation ios - 1120972 ( gw ) ; national institutes health 2r01hd028152 ( gw ) ; national institutes health 5t32 gm007601 ( ar ) . the funders had no role in study design , data collection and analysis , decision to publish , or preparation of the manuscript .
most phylogenetic studies place echinoidea and holothuroidea as sister groups . the difficulty lies in the placement of ophiuroidea ; different methods favor different positions for brittle stars . a ) the predominant hypotheses of how extant echinoderms are related are the asterozoan and cryptosyringid hypotheses . b ) two other alternate hypotheses based on mitochondrial gene alignments .
whole ovary was dissected from gravid females and placed in trizol ( invitrogen ) . rna was extracted and then cleaned with a qiagen rneasy micro column with on - column dna digestion . the sequencing libraries were prepared with illumina reagents , ( mrna - seq sample prep kit for gaiix samples or truseq sample prep kit for hiseq samples ) with the maximum recommended rna input . the protocol was followed exactly with the addition of a gel selection step of 400–500bp , ( agarose gel for gaiix samples or caliper labchip xt for hiseq samples ) prior to pcr amplification .
all 30 datasets ( 23 de novo assembled transcriptomes and 7 refseq datasets ; s1 table ) were compared against ncbi swissprot using blastx with a cutoff of 0 . 000001 [ 23 ] . transdecoder was used to translate sequences , and similar translated sequences were identified by a pair wise blastp followed by clustering using mcl [ 32 ] to identify orthologous genes . two supermatricies that differ in gene sampling were used in the phylogenetic analyses : ‘sparse’ and ‘dense’ . the ‘sparse’ supermatrix has all 30 taxa and 34 % matrix occupancy , ( s4a fig . ) with 4 , 645 peptide sequences and 630 , 945 amino acid sites . the ‘dense’ supermatrix is a subset of the sparse matrix . it has all 30 taxa and 70 % matrix occupancy , ( s4b fig . ) with 1 , 125 peptide sequences and 101 , 652 amino acid sites . maximum likelihood phylogenetic analyses were done with raxml ( gammawag model ) with 1 , 000 boot strap iterations on the ‘dense’ supermatrix , and using the same model , 100 boot strap iterations on the ‘sparse’ supermatrix . both supermatrices and calculated phylograms can be downloaded from the data dryad repository [ 33 ] .
baysian phylogenetic analyses were done with phylobayes 1 . 3b - mpi [ 34 ] on the ‘dense’ supermatrix using the cat - gtr model with the following command : “pb _ mpi - s - d supermatrix . dense . phylip - cat - gtr outputfile” . a total of 31 , 623 generations were run over three chains . all three chains converged within 2 , 000 generations ( s5 fig . ) and after removing these 2 , 000 from each chain and sampling every 10 trees , the maximum difference was 1 . 17×10 - 3 , ( 2 , 561 sampled trees ) , and a majority consensus tree was constructed .
the sowh test was implemented using the sowhat software package , [ 35 ] ( urltoken ) with the following command : “perl sowhat—constraint = alternate . hypo . tre—aln = supermatrix . dense . phylip—model = protgammawag—dir = outdir—name = outfile—rax = ' raxmlhpc - pthreads - sse3 - t 16 ' —seqgen = seq - gen—reps = 500—stop > output . txt” . three alternate hypothesis trees were constructed to test : a ) the cryptosyringid hypothesis , b ) ophiuroidea sister to the rest of echinoderms , and c ) asteroidea sister to echinozoa ( s3 fig . ) . all three analyses were stopped after at least 99 iterations because any additional sampling was very unlikely to change the results ( s3 fig . ) .
the raw reads and assembled trasncriptomes reported in this paper have been deposited in the genbank database ( ncbi bioproject no . prjna236087 ) . assembly statistics , agalma resource reports and scripts used in the analyses can be found in the git repository [ 25 ] and the supermatrix alignments and all trees including sowh constraint trees can be downloaded from the dryad digital repository [ 33 ] . all de novo transcriptomes can also be accessed on echinobase . org , including blast searches of the annotated transcripts .
the assembly of the de novo illumina transcriptomes yielded on average 24 , 033 high quality contigs with a match to swissprot ( s1 table ) . the number of transcripts with swissprot hits in the de novo transcriptomes was comparable to the number of sequences in the refseq datasets we included for other taxa ( s1a fig . ) . the number of swissprot sequences did not appear to be artificially inflated by fragmented assemblies ( s1b fig . ) . the comparable number of swissprot sequences and comparable size of the n50s of the de novo transcriptomes in relation to the refseq datasets both suggest that the assembled transcriptomes are of high quality ; especially compared with the s . purpuratus refseq dataset , an echinoderm with a well sequenced and annotated genome [ 8 ] .
support values for the phylogenetic trees using raxml and phylobayes on the dense and sparse supermatricies . each node is scored with three support values ; an asterisk denotes 100 / 100 / 100 support . the first support value is the dense supermatrix raxml 1 , 000 bootstraps , the second value is the sparse supermatrix raxml 100 bootstraps , and the third value is the dense supermatrix phylobayes posterior probabilities . the phylogram presented here is from the dense supermatrix raxml analysis . see s2 fig . for the tree topology predicted by the phylobayes analysis .
the size of data matricies and their occupancy has varied considerably over recent phylogenomic studies , which have differed substantially in the sequencing technologies used as well as methods for identification of orthologous genes and matrix construction . the present study uses a similar matrix construction technique as previous analyses [ 31 ] , but the occupancy of the matrix is much higher . this suggests that at least part of the reason for reduced occupancy in some previous analyses was due to data acquisition , and that future studies based entirely on the most recent sequencing technologies will have much improved gene sampling .
overall , the present study provides the greatest depth and breadth of new sequence analysis for consideration of the phylogenetic relationships of echinoderms . coupled with the recent study using 219 genes for analysis from four newly sequenced echinoderms [ 18 ] , and of a broader analysis of ambulacraria using 185 genes , including six newly sequenced echinoderms [ 24 ] , mostly non - overlapping tissues and animals from the present work , we now have a rich analysis to present . since each these studies used different animals , different methodology of analysis , and different depths of data consideration , yet they each came to the same conclusions in regards to the major echinoderm taxon relationships , we now have great confidence in the relationships of these animals and provide deep datasets for further analysis .
s1 fig . histograms of the postassembly comparisons of refseq and de novo assembled datasets .
( a ) the numbers of swissprot transcripts is comparable between refseq datasets ( green and purple ) and de novo assembled transcriptomes ( orange ) . ( b ) comparing the n50 of the swissprot transcripts , the de novo transcriptomes are on average only slightly smaller than the refseq datasets . the s . purpuratus refseq dataset is in purple , outgroup refseq datasets in green and de novo assembled transcriptomes in orange ; colours as in s1 table . the number of transcriptomes is on the ordinate axis .
support values for the phylogenetic trees using raxml and phylobayes on the dense and sparse supermatricies . each node is scored with three support values ; an asterisk denotes 100 / 100 / 100 support . the first support value is the dense supermatrix raxml 1 , 000 bootstraps , the second value is the sparse supermatrix raxml 100 bootstraps , and the third value is the dense supermatrix phylobayes posterior probabilities . the phylogram presented here is from the dense supermatrix phylobayes analysis .
the sowh tests were run for at least 99 iterations on the dense supermatrix and were stopped because any further iterations were unlikely to change . the three sowh tests used the following tree topologies to test : ( a ) the crytosynirgid hypothesis , ( ( sea urchins , sea cucumbers , brittle stars ) , ( sea stars , feather star , outgroups ) ) ; , ( b ) ophiuroidea sister to the rest of echinoderms , ( ( sea urchins , sea cucumbers , sea stars , feather star ) , ( brittle stars , outgroups ) ) ; , and ( c ) asteroidea sister to echinozoa ( ( sea urchins , sea cucumbers , sea stars ) , ( brittle stars , feather star , outgroups ) ) ; . none of the three tests found support for any alternate hypothesis with p - values all equal to 0 .
s4 fig . visual representation of the sparse and dense supermatricies including all thirty taxa .
each horizontal row is a single taxa and each vertical column is a gene alignment ; presence is marked in black and absence in white . the taxa are arranged from top to bottom from most genes present to least . ( a ) the sparse supermatrix is 34 % occupied , contains all 30 taxa , and contains alignments of 4 , 645 peptide sequences . ( b ) the dense supermatrix is 70 % occupied , contains all 30 taxa , and contains alignments of 1 , 125 peptide sequences .