the blue nuthatch ( sitta azurea ) is a bird species in the sittidae family , collectively known as nuthatches .

it is a medium-sized nuthatch , measuring 13.5 cm ( 5.3 in ) in length .

the species , which lacks sexual dimorphism , has dramatic coloration unlike any other member of its genus .

its head is black or blackish-blue dark blue upper parts close to purple with azure feathers .

the wings are edged with black .

the throat and chest are white or a washed buff color , contrasting with the upper and the belly of a very dark blue ; the feathers are generally clear , blue-gray or purplish .

the blue nuthatch is found in the malay peninsula and in indonesia , on the islands of sumatra and java , inhabiting subtropical or tropical moist lowland forests and subtropical or tropical moist montane forests above 900 m ( 3,000 ft ) in altitude .

its ecology is poorly known , but it feeds on small invertebrates found on trees ; reproduction takes place from april to june or july .

three subspecies are distinguished : s. a. expectata , s. a. nigriventer and s. a. azurea , which vary chiefly in the coloring of their mantles , chests and bellies .

the species ' apparent closest relatives are the velvet-fronted nuthatch ( s. frontalis ) , the yellow-billed nuthatch ( s. solangiae ) and the sulphur-billed nuthatch ( s. oenochlamys ) .

the population of the species has not been rigorously estimated but the species appears to be at low risk of extinction because of the extent of its distribution .

it has been classified as of least concern by the international union for conservation of nature .

blue nuthatch

select an image : 1 . blue nuthatch 2 . blue nuthatch 3 . blue nuthatch 4 . blue nuthatch 5 . blue nuthatch > > juvenile 6 . blue nuthatch > > adult with prey 7 . blue nuthatch > > adult 8 . blue nuthatch > > adult 9 . blue nuthatch > > adult 10 . blue nuthatch 11 . blue nuthatch > > adult 12 . blue nuthatch 13 . blue nuthatch 14 . blue nuthatch > > juvenile 15 . blue nuthatch > > juvenile 16 . blue nuthatch > > adult with prey 17 . blue nuthatch > > adult 18 . blue nuthatch 19 . blue nuthatch 20 . blue nuthatch 21 . blue nuthatch 22 . blue nuthatch 23 . blue nuthatch 24 . blue nuthatch 25 . blue nuthatch 26 . blue nuthatch 27 . blue nuthatch 28 . blue nuthatch 29 . blue nuthatch > > adult
also known as the azure nuthatch , the blue nuthatch ( sitta azurea ) dwells in singapore , thailand , indonesia and malaysia .
nature’s paintbrush gave the blue nuthatch a remarkable variety of blues : the shoulders and mantle are a medium - dark blue , while the tips of the primaries possess light blue streaks surrounded by dark blue feathering . the feathers on the back are a very light blue , while the uppertail coverts and feathers are a medium blue , the same as on the undertail feathers . the ventral feathers behind the breast are a very dark blue , while the undertail coverts and feathers are a lighter , medium shade of blue .
blue oak occurs mostly on private lands . blue oak woodland covers 8 % of california ' s total land area [
response of blue tit , great tit and nuthatch densities ( pairs . ha - 1 ± . . . | download scientific diagram
tiny , compact nuthatch with a chisel - like bill . note brown cap , blue - gray back , and whitish underparts .
blue nuthatch , sitta azurea nigriventer . a common bird in gunung gede national park often in pairs , leading bird waves . . .
changes in blue oak wood production ( cords / 0 . 2 acre ) in blue oak transition communities [ 174 , 235 ]
harrap & quinn ( 1996 ) pp . 130–133
brown - headed nuthatch
harrap & quinn ( 1996 ) pp . 114–117
chestnut - vented nuthatch
harrap & quinn ( 1996 ) pp . 119–123
chestnut - bellied nuthatch
harrap & quinn ( 1996 ) pp . 123–125
white - tailed nuthatch
harrap & quinn ( 1996 ) pp . 125–126
white - browed nuthatch
harrap & quinn ( 1996 ) pp . 138–140
krüper ' s nuthatch
harrap & quinn ( 1996 ) pp . 144–148
red - breasted nuthatch
harrap & quinn ( 1996 ) pp . 148–150
white - cheeked nuthatch
harrap & quinn ( 1996 ) pp . 161–164
velvet - fronted nuthatch
harrap & quinn ( 1996 ) pp . 164–165
yellow - billed nuthatch
harrap & quinn ( 1996 ) pp . 165–168
sulphur - billed nuthatch
snow & perrins ( 1998 ) p . 1398
nuthatch : family sittidae
the nuthatch is mostly sedentary though a few juveniles disperse from their hatching place .
range : eurasian nuthatch is sedentary and widespread over most temperate europe and asia .
the oldest known red - breasted nuthatch was 7 years , 6 months old .
the beautiful nuthatch was first described in 1843 by british zoologist edward blyth , from a specimen he examined in darjeeling . its kinship with other members of the genus is unclear . the bright blue color of its plumage invites a comparison to the blue nuthatch ( s . azurea ) , or other blue - tinted nuthatch species such as the velvet - fronted nuthatch ( s . frontalis ) , yellow - billed nuthatch ( s . solangiae ) and the sulphur - billed nuthatch ( s . oenochlamys ) , but its distribution centered in the eastern himalayas , and the unique patterns of the plumage , argues against the assumption . according to the international ornithological congress and ornithologist alan p . peterson , no subspecies have been identified .
species boundaries in the nuthatches are difficult to define . the red - breasted nuthatch ,
the red - breasted nuthatch is said to have a call like a tin trumpet .
listen to the loud , quick - fire and varied rhythmic sound of the nuthatch .
blue nuthatch ( sitta azurea ) fraser ' s hill , malaysia aug 1994 filmed with canon ex1 hi8 & sigma 400mm lens . birding southern queensland : tom tarrant
in 2014 , eric pasquet , et al . published a phylogeny based on examination of nuclear and mitochondrial dna of 21 nuthatch species . the position of the beautiful nuthatch within the genus was not established with certainty , having a far lower statistical association than others in the model . nevertheless , under the findings the species appears closest evolutionarily to three clades of nuthatches : two nuthatches that prefer rocky environments , the western rock nuthatch ( s . neumayer ) and the eastern rock nuthatch ( s . tephronota ) ; species in the
europaea
group , including the eurasian nuthatch ( s . europaea ) , siberian nuthatch ( s . arctica ) , chestnut - vented nuthatch ( s . nagaensis ) , kashmir nuthatch ( s . cashmirensis ) , indian nuthatch ( s . castanea ) , chestnut - bellied nuthatch ( s . cinnamoventris ) and the burmese nuthatch ( s . neglecta ) ; as well as the white - tailed nuthatch ( s . himalayensis ) , and therefore , the white - browed nuthatch ( s . victoriae ) . these close relatives are generally all species that plaster the entrance to their nest with mud .
] , the boles of mature blue oaks scar easily . wildfires in sequoia national park have scarred large blue oaks even where fire severity was low [
species : blue tit , great tit , coal tit , long tailed tit , marsh tit , great spotted woodpecker , nuthatch . also badger , fox and hedgehog .
blue oak savanna . mark w . skinner @ usda - nrcs plants database .
blue oak woodland . mark w . skinner @ usda - nrcs plants database .
not stated . blue oak was likely shedding leaves during the october fire treatments .
native peoples processed blue oak acorns into meal [ 16 ] . they used blue oak sprouts for making baskets [ 14 ] , acorn leachate for dying baskets , and blue oak wood for making bowls and other implements [ 53 , 237 ] .
the velvet - fronted nuthatch is the sole member of the family which prefers tropical lowland forests .
the nuthatch ' s bill is long and pointed ( photo : northeastwildlife . co . uk )
the nuthatch can be seen in woods and parkland ( photo : northeastwildlife . co . uk )
the corsican nuthatch is classified as vulnerable ( vu ) on the iucn red list ( 1 ) .
the beautiful nuthatch is classified as vulnerable ( vu ) on the iucn red list ( 1 ) .
the most favoured natural site for a nuthatch is the old nest hole of a great spotted woodpecker .
cover value : blue oak canopies provide important shade cover for a variety of animals during california ' s hot summer months . beef cattle gain more weight on rangelands where blue oak provides relief from summer heat compared to rangelands without blue oak cover [ 120 ] .
the aptly named beautiful nuthatch ( sitta formosa ) is a large , dazzling bird . the beautiful nuthatch is streaked with varying shades of vivid blue , including cobalt - blue streaks on the head , and azure blue on the back , as well as whitish streaks on the side of the neck ( 2 ) . the rest of the upperparts are black , apart from a brilliant broad blue stripe running from the shoulder feathers across the back and rump , and two narrow white stripes on the wings ( 3 ) . the sturdy , long , straight bill of the beautiful nuthatch is blackish and the short legs are greenish ( 2 ) ( 4 ) .
during nest building , the red - breasted nuthatch is aggressive , chasing away other hole - nesting birds such as the house wren , white - breasted nuthatch , and downy woodpecker . a particularly feisty nuthatch may go after yellow - rumped warblers , house finches , violet - green swallows , and cordilleran flycatchers .
although blue oak is now generally regarded as a desirable species , blue oak populations continue to decline . continued clearing of blue oak on rangelands and poor natural regeneration were 2 major management concerns identified by the hardwood task force of the california board of forestry [ 5 ] . road construction and residential and commercial development [ 196 ] , lowering water tables [ 246 ] , and use of blue oak for fuelwood [ 173 ] all contribute to blue oak decline . since most blue oak woodlands are on private lands , development is probably the largest threat to blue oak habitats [ 196 ] . development accounted for 46 % of blue oak loss between 1973 and 1985 , surpassing the loss from rangeland clearing before that .
the blue - gray gnatcatcher migrates to the southern united states and mexico during the winter .
cross - section of a western rock nuthatch nest cavity with a mud wall and tunnel across its entrance .
species : song thrush , blackbird , robin , wren , dunnock , chaffinch , house sparrow and nuthatch .
brown - headed nuthatch ( sitta pusilla ) southeast united states and the bahamas ( 1 . 5 million )
the nuthatch has a chestnut - orange colour on its chest ( photo : northeastwildlife . co . uk )
the nuthatch sometimes pushes nuts into gaps in trees so it can use its bill to open the shell .
description : white - breasted nuthatch is a common bird frequently seen at bird - feeders and in gardens .
blue oaks beneath their parents ' canopies may show higher establishment and growth rates than seedlings in the open . blue oak ' s deciduous habit allows nearly full - sunlight penetration to the ground in some seasons , and blue oak canopies are usually sparse and diffuse in all seasons [ 43 ] , so light does not usually limit blue oak establishment beneath blue oak canopies . surveys in north - central california suggest that blue oak seedlings may persist beneath their parents ' canopies for decades before release by death of the parent trees [ 224 , 226 ] .
palatability / nutritional value : blue oak browse and acorns are highly palatable to livestock and wildlife . ungulates generally prefer browsing blue oak ' s spineless leaves over spiny leaves of associated live oaks [ 164 ] . blue oak sprouts are palatable to all classes of browsing wildlife and livestock . sampson and jesperson [ 213 ] gave mature blue oak foliage the following browse ratings :
blue oak is a valuable landscaping ornamental . a study was conducted in mendocino and sonoma counties to assess the value of blue oak on lands undergoing subdivision . it showed that the aesthetic and amenity values of blue oaks at a density of 40 stems / acre resulted in a 21 % to 27 % increase in land value when compared to sites with no blue oaks [
pygmy nuthatch ( sitta pygmaea ) western north america from british columbia to southwest mexico ( 2 . 3 million )
krueper ' s nuthatch is classified as near threatened ( nt ) on the iucn red list ( 1 ) .
blue oak / common fiddleneck - rusty popcornflower ( amsinckia menziesii var . intermedia - plagiobothrys nothofulvus )
] concluded that blue oak seedling recruitment is adequate at the hopland field station . although blue oak seedling numbers fluctuate and their spatial distribution is irregular , seedlings are always present in the understory . blue oak seedlings are maintaining a constant mortality and replacement rate over time . with canopy closure of 50 % on the study sites , blue oak seedlings may require some canopy removal for successful release . further prescribed fire and fire surrogate studies ( for example , selection cutting of overstory blue oaks ) are needed to determine how managers can successfully transition blue oaks from the seedling to sapling stage .
fire exclusion has resulted in unprecedented , dense basal areas in some blue oak woodlands . in annadel state park , coast douglas - fir is invading blue oak - california black oak - coast live oak communities , changing what was historically a savanna to a densely canopied woodland [ 20 ] . in sequoia national park , a comparison of contemporary blue oak woodland structure with that noted in historical records from the settlement period showed a large increase in blue oak cover and density . vankat and major [ 244 ] suggest that increased density of blue oak woodlands is due to a combination of fire exclusion and past livestock grazing . for example , the blue oak - california buckeye phase of the blue oak woodland type is characterized by a partially - closed canopy , and frequent surface fires probably maintained blue oak as the canopy dominant . in the absence of fire or other top - killing disturbances , california buckeye is successionally replacing blue oak on some sites in sequoia national park , with the blue oak woodland communities succeeding to closed - canopy california buckeye - blue oak forests [ 18 ] .
we have only seen nuthatch around the gardens on a few occasions , though there are plenty in the local woods .
flight : eurasian nuthatch performs undulating flight over long distances , but usually , it flies briefly from tree to tree .
however , mcclaran found a flush of blue oak establishment did not follow every fire , and about 10 % to 30 % of blue oaks on the sierra field station established in nonfire years . many factors may combine to suppress blue oak establishment after fire [ 167 ] ( see barriers to regeneration ) .
band - tailed pigeons and acorn woodpeckers preferentially select small blue oak acorns over large acorns [ 9 , 79 ] , which may positively affect blue oak seedling establishment by leaving large acorns available for establishment .
the nuthatch is a rotund and chubby little bird with blue - grey overparts and a light orange underbelly and breast . the long , pointed beak is characteristic of the bird , as is the black band around the eyes , which is like a miniature zorro ' s mask . the nuthatch is roughly the same size as the great tit .
which includes mount victoria , and their fires and traps add to the pressure on the nuthatch . the population of the white - browed nuthatch , estimated at only a few thousand , is decreasing , and no conservation measures are in place .
blue oaks that retain some live bole tissue may show a stronger sprouting response than blue oaks that are killed back to the root crown . in an across - state harvesting experiment , the percentage of blue oaks that sprouted after cutting was significantly greater for trees cut 35 inches ( 90 cm ) above ground (
all the blue oak seedlings on the study plots were top - killed . growth of sprouting blue oak seedlings was monitored from the spring of 1987 through may 1990 ( posttreatment growing seasons 1 - 3 ) .
the oldest known white - breasted nuthatch was at least 9 years , 9 months old when it was found in colorado .
one of the reasons for the expansion seems to be the nuthatch ' s increasing use of bird feeders and bird tables .
the blue - gray gnatcatcher is the northernmost occurring species of gnatcatcher , and the only truly migratory one .
blue oak ' s ability to withstand extreme drought by dropping leaves under water stress and producing a flush of new leaves when wet weather returns probably also aids in blue oak ' s postfire recovery . in wet years , crown - scorched blue oaks may produce a flush of new leaves soon after fire [ 100 ] .
standiford [ 215 ] provides models to predict blue oak crown cover and height . tietje and others [ 232 , 236 ] provide inventories of coarse woody debris size and volume in blue oak and other hardwood woodlands .
, particularly soil water , vary greatly across blue oak ' s distribution . allen - diaz and bartolome [
blue oak provides cover for cavity - nesting birds . a breeding bird survey on the hopland field station showed that cavity - nesting species dominated the avian community within blue oak woodlands . violet - green swallows and plain titmice were the 2 most common of 72 bird species that used blue oak woodland habitats [ 257 ] .
several rare or threatened species use blue oak woodland habitat . bald eagles , golden eagles , peregrine falcons , and california condors inhabit blue oak woodlands [ 245 ] . a study on the sierra national forest found california spotted owls used live blue oaks for nesting [ 220 ] . purple martins in the tehachapi mountains , where what are probably the last remaining purple martin populations in the state occur , also use blue oaks for nesting [ 254 ] . the state - endangered foothill yellow - legged frog inhabits blue oak woodlands [ 31 ] , and the western spadefoot is restricted to blue oak woodlands [ 245 ] . blue oak woodland was prime habitat for the now - extinct california grizzly bear , the largest of the brown bear subspecies [ 164 ] .
range : white - breasted nuthatch is resident in deciduous forests from southern canada , and southward to northern florida and southern mexico .
blue oak is regenerating successfully on some sites despite competition from nonnative annuals . a 1990 resurvey of plots in san benito and monterey counties , originally inventoried in 1932 , showed net gains in blue oak basal area and small tree density ( 4 - 11 inches ( 10 - 28 cm ) dbh ) . blue oak / annual grass and blue oak - gray pine / annual grass communities had significant increases in both blue oak basal area and cover of annual grasses ( for example , ripgut brome and wild oat ( avena fatua ) , while blue oak basal area and grass cover in interior live oak - blue oak / perennial bluegrass ( poa spp . ) communities were similar to the original survey [ 122 ] . some blue oak establishment may occur in annual grassland even with drought . at the hastings natural history reservation , unirrigated blue oak seedlings in annual grassland showed 33 % survivorship 1 . 5 years after acorn plantings . the area was experiencing a severe , prolonged drought [ 184 , 185 ] .
since blue oak is the dominant—and sometimes the only— oak in the foothills surrounding the central valley , many species of birds use blue oak for cover . blue oak provides preferred nesting , foraging , and escape cover for the nuttall ' s woodpecker , plain titmouse , and white - breasted nuthatch [ 30 ] . on the sierra foothill range and field station , nuttall ' s woodpeckers foraged on blue oaks more often than associated oaks or gray pine , with this preference extending across all seasons [ 29 ] . a san luis obispo survey of red - tailed hawk nest sites revealed that red - tailed hawks used blue oaks as their nest tree 74 % of the time [ 233 ] .
species : greenfinch , blue tit , great tit , coal tit , marsh tit , goldfinch , and more .
blue oak / foxtail barley - johnny - jump - up ( hordeum murinum ssp . leporinum - viola pedunculata )
the study site is a blue oak woodland - annual grassland mosaic . seventy - six percent of the study site is blue oak woodland with mature blue oaks and an understory dominated by nonnative annual grasses . a pretreatment vegetation survey found blue oak seedlings in the woodland understory , but there were no blue oak saplings . understory cover and production of the annual grasses average 65 % and 1 , 500 kg / ha , respectively . the open annual grassland occupies 18 % of the study site ; the other 6 % is a dense stand of interior live oak (
this study shows that blue oak seedling establishment is potentially compatible with prescribed fire and / or domestic sheep grazing .
plant - water - site interactions may explain the discrepancies between studies showing that blue oak decreases forage production and those showing that blue oak enhances forage production . one study [ 23 ] suggests that forage production beneath blue oaks is relatively high on dry sites but is low on more mesic sites . another study found that blue oaks with shallow , fine roots inhibited production of understory herbs compared to production of herbs beneath deeply - rooted blue oaks [ 47 ] ( see general botanical characteristics for information on how blue oaks develop roots ) . this inhibition may be partially attributable to allelopathic blue oak root exudates as well as competition for water and nutrients . variations in root morphology may also partially explain differences in understory production in blue oak ecosystems . climate fluctuations and degree of canopy closure also influence understory forage production . annual grass production varied significantly among years ( p < 0 . 05 ) on the sierra foothill range and field station , with high rainfall years favoring growth of groundlayer vegetation under blue oak canopies , and low rainfall years depressing forage production beneath blue oak canopies [ 57 ] . in the north coast ranges and sacramento valley , blue oaks on sites receiving less than 20 inches ( 500 mm ) mean annual precipitation had no effect on or enhanced understory production , while blue oaks on sites receiving more precipitation generally suppressed understory production [ 75 ] .
effects on recruitment : although it is widely accepted that blue oak woodlands evolved under a regime of frequent surface fires [ 8 , 101 , 164 , 165 , 212 ] , there is little consensus regarding the effects of fire on contemporary blue oak populations , which encounter environmental conditions severely altered from historic times ( see fire exclusion in the postsettlement period ) . some studies found that prescribed burning benefited blue oak populations . for example , mcclaran [ 164 ] found small - diameter blue oaks grew taller after fire compared to unburned small - diameter blue oaks . based on fire modeling , anderson and pasquinelli [ 17 ] concluded that periodic prescribed fire benefited blue oak regeneration , but that wildfires tended to reduce blue oak regeneration . other studies , however , found negative effects of frequent fire on blue oak populations . bartolome and others [ 24 ] and swiecki and others [ 225 , 226 ] found frequent fire reduced blue oak seedling and sapling numbers , while infrequent fire had a neutral to positive effect on seedling and sapling density .
this is the only north american nuthatch with a broad white supercilium and contrasting broad dark eye line . the chinese nuthatch is found as close as southern ussuriland ( rus . ) but is unlikely to occur as a vagrant to north america . a vagrant chinese nuthatch would be differentiated by its ill - defined eye stripe , duller underparts , and lack of a diagonal white subterminal band on the tail .
the black stripe along the nuthatch ' s head continues along the side of its face ( photo : northeastwildlife . co . uk )
krueper ' s nuthatch is listed on annex i of the eu birds directive , which aims to provide protection for habitats of endangered as well as migratory species ( 10 ) . recommended conservation measures for krueper ' s nuthatch include developing a species action plan and a monitoring programme to assess population trends . the potential threats to krueper ' s nuthatch also need to be identified and addressed ( 5 ) .
remarkably , a red - breasted nuthatch from north america spent nearly seven months at holkham in norfolk from october 1989 to may 1990 .
a 4 - year study across blue oak ' s range found growth interference from annual grasses limited establishment of true blue oak seedlings more than herbivory . blue oak emergence increased significantly when herbaceous species were controlled with herbicides and hoeing ( 50 % increase from uncontrolled plots , p = 0 . 01 ) . herbivory exclosures significantly increased first - year blue oak seedling survivorship another 18 % over unprotected seedlings . interactive effects of protection from annual grasses and herbivory were not significant [ 4 , 5 ] . however , grazing sometimes favors young blue oaks by reducing the fuel load in blue oak ecosystems , so fires are not as severe and are less likely to kill seedlings and saplings [ 153 ] .
blue oak shows rapid postfire height gain on favorable sites . in a dendrochronology study , mcclaran [ 167 ] reported that 70 % to 85 % of blue oaks in stands on the sierra foothill range and field station probably originated as sprouts that emerged within 1 year of fire . growth rates of blue oaks establishing within 1 year of fire were significantly greater than growth rates of blue oaks establishing at other times ( p < 0 . 01 ) [ 167 ] .
basal scarring occurred most often in saplings [ 102 ] . across 4 kaweah river watershed sites , fire severity and damage to blue oak was greatest on the ridgetop , and the ridgetop site supported the greatest number of sprouting blue oaks after fire [ 100 ] . fire damage and postfire response of blue oak are shown in the table and figures below .
downed blue oak woody debris provides cover for small mammals such as dusky - footed woodrats [ 247 ] and herptiles . lizards used downed blue oak logs and branches as cover on the sierra foothill range and field station [ 32 ] .
were once placed in the nuthatch family because of similarities in appearance and lifestyle , but they are not closely related . the resemblances arose via
habitat : brown - headed nuthatch is fairly common , and found in pine woodlands , in open and mature forests where periodic fires occur .
diet : brown - headed nuthatch feeds on insects and pine seeds . they consume small insects and their eggs , beetles , and spiders .
species : depending on the quality of the mix , a very broad species selection including tit family , robin , finches , nuthatch etc .
very little is known about the specific habits of this nuthatch . it prefers invertebrates and larvae in its diet and nests in rotting trees .
= 4 . 5 - year return interval ) . since the 1860s , the blue oak woodland had been used as livestock rangeland . fires were suppressed , with only a single fire that occurred in the 1920s . the blue oak woodland had increased in density compared to presettlement times , and there was almost no blue oak regeneration with cattle grazing and fire exclusion [
blue oak ' s negative effects on annual grass productivity may be at least partially ameliorated by blue oak ' s
root pump
, which facilitates annual grass growth . blue oak ' s fine roots leak water and nutrients into surrounding soil [ 42 , 127 ] . callaway [ 42 ] suggests that blue oak roots deep in the soil extract nutrients from low soil layers , then transport and exude the nutrients into upper soil layers where they are available for groundlayer herbs [ 48 ] . holland [ 118 ] and others [ 119 ] also found these facilitative effects of blue oak on annual grasses , with soil nutrient levels remaining higher under blue oak canopies than in open grassland for 10 or more years after tree death .
nuthatches are a ubiquitous genus of birds , represented in both old and new worlds and found on every continent except for south america . africa is marginally inhabited by minor populations of nuthatches ; only algeria and morocco claim a nuthatch species—the eurasian nuthatch subspecies , s . e . hispaniensis .
head : grey - blue head with distinctive black stripe across its eye , white cheeks and a long , pointed bill .
] provides a general review of diseases and insect pests on blue oak and other california oaks . see swiecki and others [
ability to sprout decreases with blue oak age [ 130 , 235 ] . bark of mature blue oak bark is thin compared to bark of most mature , associated oaks , and it tends to flake off as trees age [ 235 ] , so blue oaks are less insulated against fire than associated oaks . longhurst [ 159 ] noted blue oaks on the hopland field station sprouted less
vigorously
as they aged , with seedlings showing the most vigorous sprouting after top - kill . in a 13 - county study , blue oak sapling recruitment was positively associated with fire ( p ≥0 . 01 ) [ 226 ] .
blue oak probably has both positive ( facilitation ) and negative effects ( allelopathy ) on understory herbs , with both influencing groundlayer plant species composition . a study on the hopland field station found ripgut brome tended to dominate under blue oak canopies , while soft chess dominated open grassland . the researchers credited better performance of ripgut brome beneath blue oak canopies to increased nutrient availability there [ 207 ] . however , blue oak can retard growth of annual grasses . reciprocal transplant experiments in the field and greenhouse indicate that some blue oak root exudates are allelopathic to ripgut brome . this effect probably also extends to other annual grass species .
evergreen forest at elevations between 350 and 2 , 400 metres is the preferred habitat of the beautiful nuthatch ( 3 ) . during the summer season , the beautiful nuthatch typically occurs between 1 , 500 and 2 , 400 metres , descending to lower elevations during the winter months ( 5 ) .
protection from browsing may promote blue oak sapling recruitment . a study on a shasta county ranch found nonnative himalayan blackberry ( rubus discolor ) presence increased the number of blue oaks recruited to the sapling stage . blue oak seedlings and saplings grew in himalayan blackberry thickets more often than expected based on area covered by the thickets ( p = 0 . 01 ) . blue oak seedlings and saplings in thickets were significantly taller and thicker in basal diameter compared to open - grown blue oaks ( p = 0 . 05 ) . the researchers attributed the differential survivorship and growth to absence of cattle browsing in himalayan blackberry thickets [ 255 ] .
embed this arkive thumbnail link (
portlet
) by copying and pasting the code below . < a href =
urltoken
title =
arkive species - corsican nuthatch ( sitta whiteheadi )
> < img src =
urltoken
alt =
arkive species - corsican nuthatch ( sitta whiteheadi )
title =
arkive species - corsican nuthatch ( sitta whiteheadi )
border =
0
/ > < / a >
embed this arkive thumbnail link (
portlet
) by copying and pasting the code below . < a href =
urltoken
title =
arkive species - beautiful nuthatch ( sitta formosa )
> < img src =
urltoken
alt =
arkive species - beautiful nuthatch ( sitta formosa )
title =
arkive species - beautiful nuthatch ( sitta formosa )
border =
0
/ > < / a >
prescribed october fires on a cattle ranch in madera county had little effect on mature blue oaks ( > 4 inches ( 10 cm ) dbh ) with an annual grass ground layer , but cover of mature blue oaks was reduced from prefire levels when a chaparral understory was present . the site was a mosaic of interior live oak / chaparral , blue oak woodland / chaparral transition ( blue oak with minor amounts of chaparral and shrubby interior live oak ) , and blue oak - interior live oak / annual grass communities . interior live oaks were selectively crushed prior to prescribed burning . this prefire site preparation reduced blue oak cover only in interior live oak / chaparral communities . the fire management objective was to reduce woody cover on sites with a chaparral understory and increase herbaceous production in all 3 plant communities . prescribed burning reduced blue oak seedling density in all 3 communities compared to prefire numbers [
cold can be a problem for small birds that do not migrate . communal roosting in tight huddles can help conserve heat and several nuthatch species employ it—up to 170 pygmy nuthatches have been seen in a single roost . the pygmy nuthatch is able to lower its body temperature when roosting , conserving energy through
the nuthatch population has increased rapidly since the mid - 1970s and their range has expanded northwards into scotland . the reason for these changes is unknown .
reproduction : white - breasted nuthatch nests in holes , using natural cavity or an old woodpecker hole , and occasionally it may use nest - boxes .
climate effects : effects of long - term climate patterns on blue oak are unclear . a state - wide study of blue oak acorn production and growth patterns found synchrony over large geographic scales , suggesting that large - scale climate patterns are important in determining rates of blue oak reproduction and growth [ 146 ] ; however , a tree - ring chronology study in the tehachapi mountains found that precipitation was not correlated to blue oak stem recruitment [ 81 ] . see climate for further details of the tehachapi mountains study .
] . although moderate - severity fire usually leaves basal scarring , blue oaks generally grow bark over small fire scars within a few postfire years . mature blue oaks often show no evidence of internal fire scars , which get covered as bark grows around them [
the objective of this study was to document the effects of prescribed fire and domestic sheep grazing on naturally regenerating blue oak seedlings .
) that was absent from this study site . results of this study may not apply to all blue oak woodland sites , as
the red - breasted nuthatch ( sitta canadensis ) is found in coniferous and mixed woods in canada and northern us in the summer , wintering in the southeast . it is a chubby bird not much larger than a man’s thumb and is found crawling down tree trunks headfirst in search of insects . its calls are similar to those of the white - breasted nuthatch with which it may be found at feeders or in mixed woods . red - breasted nuthatch voice
diagnostic combination of blue crown , and yellow belly makes it easily recognizable . no white tail - feathers . sexes similar , but male slightly brighter blue . juveniles paler than adults , with greenish crown and yellowish cheeks . one of the smallest of the tits .
breeding system : blue oak is monoecious and rarely self fertile . since blue oak is mostly outcrossing [ 34 ] and its acorns are dispersed by animals [ 96 ] , genetic diversity is probably greater among than within blue oak populations [ 151 ] . for example , studies have found more variation in water - use efficiency among than within blue oak populations [ 162 , 206 ] , and a common garden study found high genetic variation in stem growth , phenology , and mineral accumulation among blue oak populations [ 163 ] . reciprocal transplant and common garden studies show between - population differences and local adaptation in seedling emergence , survivorship , and growth traits , however [ 205 , 208 ] . for information on gene flow among blue oak populations , see riggs and others [ 209 ] .
prescribed burning is conducted after annual grasses have dried in spring—usually in may—or after the first rains of fall . such burning does not mimic the natural fire regime of frequent summer and fall surface fires under which blue oak evolved ; however , since foothill woodlands have undergone a type shift from blue oak / perennial grass to blue oak / annual grass , it is impossible to recreate historic fuel conditions [ 8 ] . because sprouting ability of blue oak may vary with ecotype or site [ 66 , 102 ] , managers may want to use small prescribed fires to test the sprouting capability of juvenile blue oaks on their site before conducting prescribed burning over large areas .
probably the least numerous nuthatch in north america . has lost ground in some areas because of habitat loss , but still common where southern pine forest exists .
tiny and compact with a short tail and a sharp bill . note brown cap , blue - gray upperparts , and whitish underparts .
protection / threats / status : white - breasted nuthatch has some predators such as hawks and owls . nestlings and eggs may be eaten by squirrels and snakes . white - breasted nuthatch is common and widespread , and populations are slowly increasing . destruction and removal of dead trees may threat the quantities of cavity nesting .
grazing does not always reduce blue oak recruitment . on the hopland field station , moderate domestic sheep grazing and low - severity prescribed fire had no significant effects on blue oak seedling recruitment ( p > 0 . 10 ) . blue oak seedlings established in similar numbers on grazed , burned , and grazed - and - burned plots [ 11 ] . see fire case studies for further details on this study .
embed this arkive thumbnail link (
portlet
) by copying and pasting the code below . < a href =
urltoken
title =
arkive species - krueper ' s nuthatch ( sitta krueperi )
> < img src =
urltoken
alt =
arkive species - krueper ' s nuthatch ( sitta krueperi )
title =
arkive species - krueper ' s nuthatch ( sitta krueperi )
border =
0
/ > < / a >
description : brown - headed nuthatch has brown crown , bordered by narrow dark eye line . we can see a pale nape spot , contrasting with brown cap and blue grey upperparts . it has white cheeks , chin and throat . underparts are buffy white . flight feathers are darker blue - grey . tail is dark blue - grey with white spots on outer feathers . bill , eyes , legs and feet are black . both sexes are similar . juvenile resemble adult but duller , with more grey and less brown , and it often lacks white spot on nape .
10 - 15 % smaller and noticeably slighter than nuthatch , with proportionately finest bill , longest - looking head ( due to linear plumage pattern ) , and shortest tail of west palearctic sitta . noticeably small , rather slight nuthatch . essentially grey and white , adult ( having sharply demarcated black crown and eye - stripe contrasting dramatically with otherwise white face ; outer tail - feathers black tipped white . ) has dusky - blue crown and eye - stripe .
postfire seedling establishment is apparently rare for blue oak . fire probably plays an important role in seedling establishment , but its role is not well understood . postfire blue oak establishment from acorns may occur only when a suite of favorable factors coincide ( see barriers to regeneration ) .
] . a fire history study on 3 blue oak woodland sites in the tehachapi mountains found that prior to european settlement around 1856 , blue oak recruitment occurred at a relatively steady rate , and the woodland had open structure . mean fire - return interval in the presettlement period was 10 years . a burst of blue oak recruitment occurred in the 1850s and 1860s , when fire frequency increased during the settlement period (
blue oaks overhanging water courses provide shade in fish habitats . water temperatures increase when riparian - zone blue oaks are removed , lowering habitat quality for salmonids . blue oak woody debris affects the physical structure of rivers and streams by creating pools and reducing the sediment load . to protect fisheries , giusti and merenlender [ 82 ] call for increased protection of and management guidelines for low - elevation hardwoods in riparian zones .
duncan and clawson [ 68 ] reported that cattle prefer forage beneath blue oak to that of open grassland , even in summer after forage in both areas has dried . holland [ 118 ] found that death or removal of blue oak resulted in a gradual decline in forage production and quality . supporting this , another study showed an increase in unpalatable tarweed ( madia gracilis ) following blue oak removal [ 136 ] .
forests , although each species has a preference for a particular tree type . the strength of the association varies from the corsican nuthatch , which is closely linked with
the eastern rock nuthatch builds a similar but less complex structure across the entrance to a cavity . its nest can be quite small but may weigh up to 32
the juvenile corsican nuthatch is similar to the adult , although its plumage is typically duller , with faint brown tips to some of the feathers ( 3 ) .
the name nuthatch is derived from nut hacker , reflecting the bird ' s method of opening up nuts by jamming them into a crevice then hammering at them .
the nuthatch is fairly easy to recognise . it is steely grey - blue above , pinky buff below and has a prominent black eyetstripe , white chin and dark , dagger - like bill . nuthatches are busy and agile birds , typically seen working their way down a tree trunk searching for food .
note 1 : used colours are : light - green ( lime ) , light - blue , grey , light - brown , black .
10 cm ( 4 in ) long , grey cap , blue - grey upper parts , whitish underparts , whitish spot on the nape .
stage lights and different shapes art gallery . series 3 + version from 1 to 26 + orange - blue - purple and white color series
the following vegetation typings describe blue - oak dominated communities . typings are listed from north to south , with general , statewide typings below .
soils : blue oak grows in soils derived from a variety of parent materials . soils are characteristically shallow , skeletal , infertile , thermic , and moderately to excessively well drained . soil textures range from gravelly loam to clay [ 80 , 173 ] . blue oak can grow over hardpans [ 126 ] . a study in sequoia national park found blue oak woodland soils were lower in nitrogen , phosphorus , and organic matter content compared to soils of an adjacent mixed - evergreen woodland [ 18 ] . in a san luis obispo county study comparing soils on sites dominated by blue oak and sites dominated by coast live oak , blue oak occupied erosional soils that were relatively more acidic and had finer textures than soils with coast live oak . subsoil ph on blue oak sites ranged from 3 . 9 to 7 . 9 [ 67 ] .
except in riparian zones , xeric conditions may make blue oak woodlands poor habitat for many amphibians in summer ; however , salamanders including 3 species of concern ( yellow - blotched , tehachapi slender , and kern county slender salamanders ) utilize blue oak cavities and downed logs for thermal , foraging , and mating cover [ 30 , 222 ] . reptiles are frequently encountered in blue oak woodlands [ 30 ] , using downed blue oak logs and branches for foraging , thermal , and mating cover [ 36 ] . several species ( for example , the western fence lizard and western skink ) prefer the drier environment of blue oak and other deciduous oak woodlands , and seldom use the more mesic evergreen oak woodlands [ 30 ] . borchert and others [ 36 ] provide an inventory of herptiles found in blue oak communities of the southern coast ranges .
the nuthatch is a plump bird about the size of a great tit that resembles a small woodpecker . it is blue - grey above and whitish below , with chestnut on its sides and under its tail . it has a black stripe on its head , a long black pointed bill and short legs .
nests . several species reduce the size of the entrance hole and seal up cracks with mud . the red - breasted nuthatch makes the nest secure by daubing sticky conifer
this resident nuthatch inhabits a vast range in these countries ; however , populations are fragmented . its natural habitats are subtropical or tropical moist , lowland and montane forests .
perhaps surprisingly , the nuthatch has received little in the way of study in britain , and most of our knowledge comes from work carried out in sweden and belgium .
historic fire regimes — blue oak woodlands historically had a regime of frequent summer and fall surface fires , fueled by groundlayer perennial bunchgrasses and forbs and downed woody debris [ 8 , 101 , 164 , 165 , 176 , 212 ] . in 1902 , leiberg [ 154 ] noted that wildfires were
extensive
in blue oak - gray pine communities in the foothills of the sierra nevada , and that blue oak sprouted from the root crown or stump after wildfire or cutting . blue oak ecosystems have experienced 3 periods with differing fire regimes : the presettlement , settlement ( approximately 1850 - 1920 ) , and postsettlement periods ( after 1920 ) . presettlement and settlement fire regimes were most favorable to blue oak populations .
blue oak woodlands are important habitat for small mammals and birds [ 62 , 152 ] . a 3 - year study in the central sierra nevada foothills showed that 92 species of birds utilized blue oak woodland , with 60 species nesting in the woodland [ 30 ] . for inventories of small mammals , birds , and herptiles using blue oak habitats , see block and others [ 31 ] and verner and boss [ 245 ] .
note 1 : used colours are : red , orange , yellow , white , dark - blue , dark - green , pink and purple .
the blue - gray gnatcatcher is known for its feisty , active mannerisms . the cocked and spread tail , scolding call notes , and thin black
karlik and mckay [ 133 ] provide leaf area index and leaf mass density measurements for a blue oak stand at california hot springs near bakersfield .
blue oak acorns germinate in fall and emerge in winter . acorns planted at the hastings natural history reservation emerged from late february to late march [
vertical growth rates of blue oak establishing on the sierra field station within 1 year after fire vs . trees establishing at other times [ 167 ]
] . trees are established from acorn plantings or from transplanting nursery stock . blue oak was successfully used to revegetate upper streambanks in almaden valley [
mccreary , douglas d . 1990 . blue oaks withstand drought . california agriculture . 44 ( 2 ) : 15 - 17 . [ 12102 ]
nonnative annuals may have irreversibly altered the seasonal availability of soil moisture to blue oak seedlings [ 27 ] . an experiment using exclosures and herbicides on 6 sites across blue oak ' s distribution showed that when confounding effects of ungulate herbivory were removed , growth interference from annual grasses reduced blue oak seedling emergence . emergence was 45 % on plots where grasses were controlled with herbicides and hoeing compared to 29 % on plots without grass control . after 3 years , blue oak seedling survivorship was significantly less on uncontrolled plots compared to plots with grass control ( p ≤0 . 01 ) [ 3 ] . on sites in santa barbara and monterey counties , callaway [ 43 ] found blue oak seedling establishment was least frequent in open annual grassland and most frequent beneath coastal sage scrub species . causes of recruitment failure differed between annual grassland sites and sites with shrubs . blue oak seedling mortality from drought was most common in annual grassland , whereas acorn predation was the most common reason for blue oak recruitment failure under shrubs [ 43 ] .
range : brown - headed nuthatch is resident from eastern texas and extreme south - western oklahoma , through the southern coastal states north to delaware . also in the bahamas .
pre - and postfire growth of 24 small blue oaks on the cattle ranch was monitored with and without cattle and mule deer browsing until postfire year 13 . at that time , there was no evidence that burning had stimulated blue oak growth : greatest growth gain occurred on unburned , unbrowsed sites . browsing reduced blue oak growth rate more than fire . on browsed sites , the browse line extended to 60 inches ( 150 cm ) above ground , with 80 % of meristems on marked trees getting browsed . some blue oaks on burned , browsed sites grew above the browse line [ 24 ] .
] . blue oak probably establishes from acorns after fire , likely from several sources including animal - dispersed acorns and acorns dropping from surviving parent trees .
13·5 cm . a medium - sized nuthatch , usually appearing strikingly black and white with conspicuous pale eyering , and with complex wing pattern . nominate race in fresh . . .
the corsican nuthatch is , as its common name alludes , endemic to the island of corsica , france . this small bird is found on inland mountain ridges from tartagine south to ospedale and montagne de cagna . the largest populations of the corsican nuthatch occur in the mountainous areas around cinto , rotondo , renoso and incudine ( 3 ) ( 6 ) .
diet : eurasian nuthatch feeds mainly on insects , seeds , nuts and acorns . it may take sometimes sap and flower buds , and frequents the bird - feeders in winter .
seed banking : given blue oak ' s lack of seed dormancy [ 34 , 196 ] , the palatability of the acorns to wildlife ( see palatability / nutritional value ) , and the many diseases that infect acorns ( see germination ) , it is unlikely that blue oak forms a persistent seed bank .


the sooty barbthroat ( threnetes niger ) is a hummingbird species in the family trochilidae .

it is found in french guiana and the northeastern part of the amazon basin .

its natural habitat is humid tropical lowland forest .

the taxonomy and systematics of the sooty/pale-tailed barbthroat complex has caused much confusion .

some authors consider the sooty barbthroat to be a melanistic variant of the pale-tailed barbthroat ( t. leucurus ) .

as t. niger was described first , this scientific name is the valid name for both when they are considered conspecific .

on the other hand , the sacc for example considers t. niger and t. leucurus distinct species , because of insufficient published evidence for their being conspecific .

this " combined " species is considered to be of least concern by the iucn .

in addition , some suggest that the bronze-tailed barbthroat ( t. n. loehkeni ) should also be considered a valid species and include the doubtful christina 's barbthroat ( t. n. christinae ) as a subspecies .

freire 's sooty barbthroat ( t. n. freirei ) is intermediate between the sooty and bronze-tailed barbthroats however , and thus its status needs to be clarified before the situation is resolved .

sooty barbthroat

sooty barbthroat - buy sooty barbthroat by surhone , lambert m . | editor ; tennoe , mariam t . | editor ; henssonow , susan f . | editor online at best prices in india - urltoken
the sooty barbthroat averages 10 - 11 cm ( 3 . 9 - 4 . 3 inches ) in length .
sooty barbthroat ( english , paperback , lambert m . surhone , mariam t . tennoe , susan f . henssonow )
the sooty barbthroat ( threnetes niger ) is a south american hermit ( hummingbird ) that is endemic to the far northeastern brazil and the adjacent french guiana ( an overseas region of france located on the northern atlantic coast ) . they are quite common within their limited range ; where they inhabit humid tropical lowland forests .
the pale - tailed barbthroat and the sooty barbthroat are the only hermits with a black throat which emphasizes the whitish stripe next to the beak down to the throat ( commonly referred to as
malar stripe
) . the upper breast is dusky bronze - green and the lower breast is buffy white . the central tail feathers are greener than the back with white tips . the outer tail feathers are pale buff and the outermost feathers have a diagonal black band and white tip . the bill is slightly curved and is black with white borders . its legs are pinkish .
other synonyms catalan : colibrí ermità de gola taronja czech : kolibřík kouřový danish : sodgrøn skægstrube german : orangekehl - schattenkolibri , rußschattenkolibri english : pale - tailed barbthroat , sooty barbthroat , sooty or bronzed - tailed barbthroat spanish : ermitaño barbudo común , ermitaño barbudo guayanés spanish ( colombia ) : ermitaño coliblanco spanish ( spain ) : ermitaño barbudo guayanés finnish : nokikaulurikolibri french : ermite d ' antonia , ermite d ' antonia ou e . de loehken , ermite d ' antonie , ermite d ' antonie ou e . de loehken italian : barbuto fuligginoso japanese : usuzumihigehachidori japanese : ウスズミヒゲハチドリ latin : threnetes [ niger or loehkeni ] , threnetes leucurus , threnetes niger , threnetes niger niger , trochilus niger lithuanian : juosvasis barzdotasis kolibris dutch : beroete baardkolibrie norwegian : skjeggstubberemitt , soteremitt polish : pustelnik czarny portuguese : balança - rabo - escuro portuguese ( brazil ) : balança - rabo - de - garganta - preta , balanca - rabo - escuro , balança - rabo - escuro portuguese ( portugal ) : balança - rabo - escuro russian : чёрный бородатый колибри slovak : čiernobrádok sadzový swedish : blekstjärtad eremit , soteremit chinese : 暗色髭喉蜂鸟 , 淡尾髭喉蜂鸟 chinese ( traditional ) : 烏髭喉蜂鳥
hinkelmann , c . , kirwan , g . m . & boesman , p . ( 2018 ) . sooty barbthroat ( threnetes niger ) . 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 ) .
the sooty barbthroat is distributed throughout the amazonian and guianan lowlands where it is fairly common . in its range , it is a distinctive , being the only hermit with a black throat which makes its white malar stripe even more obvious . it is most commonly seen actively foraging in low bushes though most often trap - lines . it has a confused taxonomic history primarily due to the original form being highly localized , melanistic and with considerable though poorly delimited geographic variation .
the sooty barbthroats primarily feed on nectar taken from a variety of brightly colored , scented small flowers of trees , herbs , shrubs and epiphytes . they favor flowers with the highest sugar content ( often red - colored and tubular - shaped ) .
the female sooty barbthroat responsible for building the remarkable cone - shaped nest which hangs by a single strong string of spiders ' silk and / or rootlets from some overhead support , which could be a branch or the underside of the broad leaves of , for example , heliconia plants , banana trees or ferns about 3 - 6 ft ( 1 - 2 m ) above ground . however , these unusual nests have been found beneath bridges , in highway culverts and even hanging from roofs inside dark buildings . the nest is often near a stream or waterfall . it is constructed out of plant fibers woven together and green moss on the outside for camouflage in a protected location . she lines the nest with soft plant fibers , animal hair and feather down , and strengthens the structure with spider webbing and other sticky material , giving it an elastic quality to allow it to stretch to double its size as the chicks grow and need more room .
html public
- / / w3c / / dtd xhtml 1 . 0 strict / / en
urltoken
thank you for taking the time to provide feedback on the iucn red list of threatened species website , we are grateful for your input .
sacc . 2005 and updates . a classification of the bird species of south america . available at : urltoken .
justification : this species has a very 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 has not been quantified , but it is not believed to 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 .
the global population size has not been quantified , but the species is described as local and uncommon ( del hoyo et al . 1999 ) . trend justification : this species is suspected to lose 13 . 4 - 14 . 8 % of suitable habitat within its distribution over three generations ( 12 years ) based on a model of amazonian deforestation ( soares - filho et al . 2006 , bird et al . 2011 ) . it is therefore suspected to decline by < 25 % over three generations .
to make use of this information , please check the < terms of use > .
there are many ways to contribute—we need species information , photographs , audio , video , translations , maps , distribution data , and bird sightings . there ' s a role for everyone !
) , in neotropical birds online ( t . s . schulenberg , editor ) . cornell lab of ornithology , ithaca , ny , usa . retrieved from neotropical birds online :
hbw lumped this taxon with t . leucurus as a “melanistic form of geographically limited distribution , based on apomorphic characters within the range of variation found in leucurus ; otherwise the two are apparently inseparable , so conspecific treatment seems appropriate , with older name niger claiming priority” , adding that the race loehkeni “appears to be intermediate between leucurus and niger ” . specimen evidence in amnh , however , suggests that loehkeni is much closer to leucurus than to present species , and that latter differs from all other taxa in the aggregate t . leucurus in having no rufous throatband ( 3 ) , no pale moustache and belly ( 3 ) , no white or buff in tail ( 2 from loehkeni ; 3 from cervinicauda , rufigastra , leucurus and medianus ) . a similar conclusion seems to have been independently reached # r , but other evidence from amapá suggests an interpretation that continues to place loehkeni with present species # r , while in n pará individuals from the same locality attributed to t . niger but with divergent tail patterns suggest either that niger is more variable than previously thought ( with a distinct morph or taxon in w of its range ) or that some intergradation with t . leucurus is occurring in the area # r ; clearly , further work is needed , and present arrangement may change as a result . monotypic .
, but with more extensive black throat and iridescent green plumage on breast , otherwise . . .
more open places in humid lowland and higher - altitude tropical forest , river edge forest , . . .
not globally threatened . cites ii . local and generally uncommon throughout comparatively small range , being known only parts of french guiana ( where present at saint georges . . .
only subscribers are able to see the bibliography . login or subscribe to get access to a lot of extra features !
only members are able to post public comments . to make the most of all of hbw ' s features , discover our subscriptions now !
if you have videos , photographs or sound recordings you can share them on the internet bird collection . it ' s free and easy to do .
it has been suggested that this genus should be subsumed within glaucis # r .
get access to the contents of the hbw including all species accounts , family texts , plates , audiovisual links , updates and related resources .
also available : 2 - year subscription package : 55 . 90 € ( instead of 59 . 90 € ) 3 - year subscription package : 82 € ( instead of 89 . 85 € )
supporting members help us to develop and update the project more quickly and to reach more people by keeping prices down .
view more information , tracking references to their source ( when available on the internet ) .
also available : 2 - year subscription package : 82 . 5 € ( instead of 89 . 9 € ) 3 - year subscription package : 122 . 5 € ( instead of 134 . 85 € )
there is a registration fee of 20€ . this is a one - time only fee when you become a subscriber of hbw alive . you won’t pay it again as long as you renew your subscription before it expires .
if you represent an organization or institution , click here for more information on institutional subscriptions .
this map displays aggregated data from ibc and my birding ( anonymously ) ; markers do not indicate precise localities .
this species has a very 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 has not been quantified , but it is not believed to 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 .
recommended citation birdlife international ( 2018 ) species factsheet : threnetes niger . downloaded from urltoken on 09 / 07 / 2018 . recommended citation for factsheets for more than one species : birdlife international ( 2018 ) iucn red list for birds . downloaded from urltoken on 09 / 07 / 2018 .
sonogram images © xeno - canto foundation . sonogram images share the same license terms as the recording they depict .
its upper plumage is mostly an iridescent coppery - green . at the sides of the head the coppery color is intensified , tying into the coppery - colored throat . the under plumage is paler with greenish - coppery spots .
hummingbirds in general are solitary and neither live nor migrate in flocks ; and there is no pair bond for this species - the male ' s only involvement in the reproductive process is the actual mating with the female .
during the breeding season , the males of many hermit species form leks ( = competitive mating displays ) and congregate on traditional display grounds . once a female enters their territory , they display for her . their display may entail wiggling of their tails and singing . willing females will enter the area for the purpose of choosing a male for mating . oftentimes she will choose the best singer .
he will separate from the female immediately after copulation . one male may mate with several females . in all likelihood , the female will also mate with several males . the males do not participate in choosing the nest location , building the nest or raising the chicks .
the average clutch consists of 1 - 3 white eggs ( average 2 ) , which she incubates alone for about 17 days , while the male defends his territory and the flowers he feeds on . the young are born blind , immobile and without any down .
the female alone protects and feeds the chicks with regurgitated food ( mostly partially - digested insects since nectar is an insufficient source of protein for the growing chicks ) . the female pushes the food down the chicks ' throats with her long bill directly into their stomachs .
as is the case with other hummingbird species , the chicks are brooded only the first week or two , and left alone even on cooler nights after about 12 days - probably due to the small nest size . the chicks leave the nest when they are about 23 - 24 days old . the female raises one brood a season .
hermits are
trap - line feeders
. this feeding technique entails visiting flowers along a long route ( in this case of up to 0 . 6 miles or 1 km ) - as opposed to most other hummingbird species which generally maintain feeding territories in areas that contain their favorite plants ( those that contain flowers with high energy nectar ) , and they will aggressively protect those areas .
hermits use their long , extendible , straw - like tongues to retrieve the nectar while hovering with their tails cocked upward as they are licking at the nectar up to 13 times per second . sometimes they may be seen hanging on the flower while feeding .
many native and cultivated plants on whose flowers these birds feed heavily rely on them for pollination . the mostly tubular - shaped flowers actually exclude most bees and butterflies from feeding on them and , subsequently , from pollinating the plants .
they may also visit local hummingbird feeders for some sugar water , or drink out of bird baths or water fountains where they will either hover and sip water as it runs over the edge ; or they will perch on the edge and drink - like all the other birds ; however , they only remain still for a short moment .
they also take some small spiders and insects - important sources of protein particularly needed during the breeding season to ensure the proper development of their young . insects are often caught in flight ( hawking ) ; snatched off leaves or branches , or are taken from spider webs . a nesting female can capture up to 2 , 000 insects a day .
males establish feeding territories , where they aggressively chase away other males as well as large insects - such as bumblebees and hawk moths - that want to feed in their territory . they use aerial flights and intimidating displays to defend their territories .
for updates please follow beautyofbirds on google + ( google . com / + avianweb )
the articles or images on this page are the sole property of the authors or photographers .
; however , mistakes do happen . if you would like to correct or update any of the information , please
throughout history , crows , ravens and other black birds were feared as symbols of evil or death . …
please note : any content published on this site is commentary or opinion , and is protected under free speech . it is only provided for educational and entertainment purposes , and is in no way intended as a substitute for professional advice . avianweb / beautyofbirds or any of their authors / publishers assume no responsibility for the use or misuse of any of the published material . your use of this website indicates your agreement to these terms .
html public
- / / w3c / / dtd xhtml 1 . 0 transitional / / en
urltoken
myavibase allows you to create and manage your own lifelists , and produce useful reports to help you plan your next birding excursion .
there are more than 12 , 000 regional checklists in avibase , offered in 9 different taxonomies , including synonyms more than 175 languages . each checklist can be viewed with photos shared by the birding community , and also printed as pdf checklists for field use .
there are a few ways by which you can help the development of this page , such as joining the flickr group for photos or providing translations of the site in addition languages .
howard and moore 4th edition ( incl . corrigenda vol . 1 - 2 ) :
you must be logged in to view your sighting details . to register to myavibase click here .
avibase has been visited 263 , 296 , 520 times since 24 june 2003 . © denis lepage | privacy policy
html public
- / / w3c / / dtd html 4 . 01 transitional / / en
most searched in books : adobe pagemaker 7 . 0 advanced engineering mathematics sakeela sex autobiography of a book basic electrical engineering english to telugu dictionary online design of machine elements design of steel structures discrete mathematics electronic devices and circuits engineering mathematics 1 english to tamil dictionary glass painting kit wren and martin english grammar c programming questions agriculture supervisor learn hindi in 30 days learn python the hard way machine drawing who moved my cheese english to marathi english to oriya dictionary english marathi dictionary xxx hb security analysis social problems in india soil mechanics strength of materials the theory of everything vedic mathematics