bluuebunny/crossref_metadata_2025 huggingface dataset:
Ingesta particle size, food handling and ingestion in the tammar wallaby (Macropus eugenii Desmarest)
Authors: Lentle R. G. , Stafford K. J. , Potter M. A. , Springett B. P. , Haslett S.
Published: January 2006

The particle size distribution of stomach contents from 25 tammar wallabies
(Macropus eugenii Desmarest) shot in the Okataina State
Forest and adjoining farmland near Rotorua, New Zealand, were determined.
There was a greater percentage of finer, and a smaller percentage of larger,
particles than reported in the stomach contents of larger macropods. The
chewing and biting activities of four free-ranging tammars fitted with
radio-microphone collars were monitored. Chewing rates (chews per minute) were
similar to those of other small herbivorous vertebrates. There were
significantly lower rates of chewing and higher chew-to- bite ratios when
browsing than when grazing. Observations of browsing by three captive tammars
showed inefficient handling by mutually opposed palms and digitopalmar grip,
resulting in low rates of ingestion. We suggest that tammars lower the time
necessary for fermentation of food by reducing the size of food particles, and
that their choice between graze and browse is influenced by food handling and
chewing investment.
Affinities between southern Tasmanian plants in native bee visitor profiles
Authors: Hingston Andrew B.
Published: January 2006

Overlap between plants in the bee species visiting their flowers was
investigated in three vegetation types near Hobart in southern Tasmania.
Visitor profiles of plants were influenced by flowering phenology, the
vegetation type in which they occurred, blossom shape and colour, and
botanical family. Most Colletidae, especially in the subfamilies Euryglossinae
and Hylaeinae, predominantly visited brush-like inflorescences and/or
members of Myrtaceae. However, some Colletidae, particularly in the subfamily
Colletinae, were oligolectic on non-myrtaceous petaloid flowers. Many
Halictidae were polylectic, others foraged predominantly on the yellow
zygomorphic flowers of Fabaceae, while others were largely restricted to non-
yellow actinomorphic flowers. Both species of Anthophoridae were polylectic,
whereas both species of Megachilidae were narrowly polylectic on non-white
flowers. It is argued that pollination of nectarless flowers is likely to be
enhanced by the presence of petaloid nectariferous flowers, particularly
Fabaceae and Leucopogon spp., which provide
carbohydrates for their bee pollinators. Mutualism between sequentially, and
also possibly concomitantly, flowering nectariferous flowers is also likely
via support of shared bee pollinators.
Nocturnal behaviour of the parma wallaby, Macropus parma (Marsupialia : Macropodoidea)
Authors: Cooper Desmond W. , Ord Terry J. , Evans Christopher S.
Published: January 2006

Commercial night-vision devices permit the study of nocturnal behaviour
without visible light sources, obviating concerns about the effects of
supplemental lighting on natural behaviour. We used an inexpensive image
intensifier to document the previously unstudied nocturnal behaviour of the
parma wallaby, Macropus parma Waterhouse, 1846, based on
a captive population of 6 male and 6 female sexually mature wallabies. A total
of 150 h of observation was conducted over 34 nights and 6 days. The circadian
rhythm of this species was grossly similar to that of many other
Macropodoidea, although there was a pronounced peak in activity at dawn. The
behavioural time budgets of males and females were reliably different, with
males spending more time actively foraging than females. Social interactions
were rare in both sexes, but we were able to characterise sexual behaviour in
detail. Courtship typically began with sexual checking of the female by the
male, after which the male pawed the female’s rump repeatedly. This was
occasionally followed by mounting and copulation, but typically the male
presented his chest, drawing the female’s head toward it with his
forepaws. While this ‘head rubbing’ is clearly homologous with
components of social behaviour in other wallabies, it seems uniquely elaborate
in parmas. Interactions between males and females were accompanied by
characteristic vocalisations. Males produced repeated broad-band
‘clucking’ sounds while grooming females, who often responded by
hissing. The structure and context of these signals suggest that clucks
function to stimulate the female, while hisses probably encode threat. It is
likely that males produce both olfactory and acoustic signals during
courtship; such cues could play a role in mate choice decisions by females.
Our results demonstrate that nocturnal observations on small macropodids are
feasible and suggest that more reliable information about social behaviour is
obtained at night.
Ecomorphological implications of the microstructures on the tongue of the fawn roundleaf bat, Hipposideros cervinus (Chiroptera : Hipposideridae)
Authors: Sharma R. S. K. , Vidyadaran M. K. , Zulkifli I. , Azlan J. Mohd , Sumita S. , Azilah A. J. , Ho O. K.
Published: January 2006

The morphology of the lingual papillae on the tongue of the fawn round-leaf
bat (Hipposideros cervinus) was studied by scanning
electron microscopy to determine its functional role in feeding ecology. Both
mechanical and gustatory papillae were detected on the lingual surface. Large
pronged papillae at the lingual apex provide a rake-like surface that
facilitates quick retrieval of insect prey that may be trapped by the wing and
tail membranes. These papillae also provide additional traction and act as a
barrier, preventing the insects from escaping. Additional securing and
gripping structures include the crowned filiform papillae situated on the
anterior half of the tongue. Conical papillae on the lateral and medial
aspects of the lingual root serve as a protective barrier to the lingual
mucosa, and aid in directing insect fragments towards the oesophagus. The pair
of small vallate papillae at the lingual root may reflect a compromise in
gustatory potential. Taste perception may be a secondary feature in food
selection of this bat and fungiform papillae may resume a more important
mechanical function. Collectively, the lingual papillae of
H. cervinus portray an adaptation to mechanical
manipulation of food, instead of taste perception, which may not be of primary
importance to insect feeders.
Evolution and biogeography of the Australian grasswrens, Amytornis (Aves : Maluridae): biochemical perspectives
Authors: Christidis Leslie
Published: January 2006

Allozymes at 35 presumptive loci were screened across 43 specimens
representing seven of the eight currently recognised species of Australian
grasswrens (Maluridae). The results identified an early divergence between the
grey grasswren, Amytornis barbatus, and the remaining
species examined. The patterns of genetic divergences between species of
Amytornis examined suggest that the taxa occurring in
central and western Australia diversified 100 000 years ago while those forms
restricted to the rocky outcrop regions around the periphery of the continent
diverged much earlier (some 2-3 million years ago). The Eyrean grasswren,
A. goyderi, was part of an assemblage that included the
thick-billed grasswren, A. textilis (represented in this
study by the forms myall and
modestus), the dusky grasswren,
A. purnelli, and possibly the black grasswren,
A. housei. The white-throated grasswren,
A. woodwardi, appeared to be related to the striated
grasswren, A. striatus (represented in this study by the
forms striatus and merrotsyi)
although this association was not consistent across all tree-building methods.
The high genetic distance recorded between the two forms of
A. striatus examined (0.184) was at the higher end of
the range for interspecific comparisons within the genus (0.021-0.316). The
two forms were not identified as sister taxa in any of the distance-based and
discrete character-state trees. It is recommended that
A. merrotsyi be recognised as a species separate from
A. striatus, a conclusion supported also by
morphological characters.
Thermoregulation and ventilation in the tawny frogmouth, Podargus strigoides: a low-metabolic avian species
Authors: Bech Claus , Nicol Stewart C.
Published: January 2006

Oxygen consumption (VO2) and body temperature
(Tb) were measured during daytime (corresponding to the
normal resting phase) in the tawny frogmouth
(Podargus strigoides, mean body mass of 341 g) at
ambient temperatures (Ta) between -1ºC and
30ºC. Mean body temperature (over this range of Ta)
was 37.8ºC and there was only a small (0.4ºC), and insignificant,
day-night variation in Tb. Mean
VO2 within thermoneutrality (25-30ºC) was 0.59 mL
O2 g-1 h-1 ,
corresponding to a basal metabolic rate (BMR) of 3.32 W
kg-1 . This value is only 61% of the predicted
value for a non-passeriform bird. The minimal thermal conductance attained at
Ta below thermoneutrality was 0.156 W
kg-1 ºC-1, a value which is
very close to the allometrically predicted value. The relatively low
VO2 was paralleled by a low total ventilatory volume.
This, in turn, was mainly the result of a low respiratory frequency (10.2
breaths min-1, only 52% of that expected for a
similar-sized bird) whereas tidal volume (6.6 mL [BTPS]) was
107% of the expected value. Thus, our results suggest that the changing
ventilatory needs during the evolution of the low VO2 in
the tawny frogmouth have been met primarily by changes in respiratory
frequency.
Atmospheric ozone concentration and the colour vision of insect pollinators
Authors: Dyer Adrian G. , Dyer Adrian G.
Published: January 2006

Using a theoretical model of honeybee colour vision, and considering direct
and diffuse illumination conditions, it is shown that a large reduction in
atmospheric ozone concentration would have a minimal effect on bee colour
vision over the whole of their colour space.
Energetic consequences of metabolic depression in tropical and temperate-zone lizards
Authors: Christian Keith A. , Bedford Gavin S. , Schultz Timothy J.
Published: January 2006

One response of ectothermic animals to periods of inactivity is inverse
acclimation, or metabolic depression, which results in the conservation of
energy. Most studies of metabolic depression and acclimation have involved
temperate-zone species, and the information from tropical species has been
largely restricted to laboratory studies that failed to demonstrate thermal
acclimation of metabolism. Recently, metabolic depression has been shown in
several species of reptiles from the wet-dry tropics of northern Australia
during the dry season. We review existing data on the energy budgets of
temperate and tropical species during periods of inactivity and make
calculations of energy saved due to metabolic depression across a range of
temperatures. Because tropical species experience relatively high temperatures
during periods of inactivity, they have a greater potential for energy
savings, any enhancement of their metabolic depression is disproportionately
advantageous with respect to energy savings, and in some species metabolic
depression is probably essential for survival. Thus, we would expect metabolic
depression to be well developed in some tropical reptiles. The lack of thermal
acclimation in laboratory studies indicates that environmental parameters
other than temperature (such as food or water) may initiate metabolic
depression in tropical species. Higher temperatures, however, magnify the
energy savings accomplished by metabolic depression.
Sminthopsis griseoventer boullangerensis (Marsupialia:Dasyuridae), a new subspecies in the S. murina complex from Boullanger Island, Western Australia
Authors: Crowther M. S. , Dickman C. R. , Lynam A. J.
Published: January 2006

A new subspecies from the Sminthopsis murina complex,
Sminthopsis griseoventer boullangerensis,
subsp. nov., is described from Boullanger Island, off
the coast of Western Australia. This subspecies was considered previously to
be identical to S. griseoventer griseoventer, which is
common on the mainland of south-western Western Australia, but differs from it
with fixed differences at three of 18 isozymes screened. It also differs from
S. griseoventer griseoventer in having a relatively
longer tail and no entoconids on the second and third molars, and being
completely separated from it in a canonical variates analysis. It has not been
given full species status as it differs very little in mitochondrial DNA
control region sequences from
S. griseoventer griseoventer. It differs from other
members of the S. murina complex in its grey ventral
pelage, distinctive tail morphology, relatively small palatal vacuities (with
correspondingly greater inter-palatal vacuity distance), relatively larger
bullae, and more brachycephalic skull.
Sminthopsis griseoventer boullangerensis has a small
population and extremely limited known distribution, and is considered
endangered. Potential threats include competition from a high-density
population of house mice on Boullanger Island, the possibility of fires and
feral predators being introduced to the island, and the increased risk of
stochastic extinction that is consequent on small population size.
The composition of the milk of antarctic (Arctocephalus gazella) and subantarctic (A. tropicalis) fur seals at Macquarie Island
Authors: Goldsworthy Simon D. , Crowley Helen M.
Published: January 2006

The composition of milk collected from 36 antarctic
(Arctocephalus gazella) and 17 subantarctic fur seals
(A. tropicalis) breeding sympatrically at Macquarie
Island was examined over the first 100 days of lactation in the 1990/91
season. The mean composition of milk in A. gazella and
A. tropicalis was 41.3% and 44.6% water,
39.8% and 38.6% lipid, 18.1% and 16.1% protein,
and the estimated gross energy content of milk was 19.9 and 18.9 kJ
g–1, respectively. Neither the composition of milk
nor its energy density differed significantly between species, despite a
difference of 4–6 months in lactation length. Water content of milk
could be used to predict lipid (r2
= 0.67) and protein (r2
= 0.57) content, but was most accurate at predicting gross energy
content (r2 = 0.97). These
relationships were the same for each species. The water content of milk
decreased throughout the first 100 days of lactation in both species, while
lipid, protein and energy content all increased. The addition of maternal mass
into regression analysis with days post-partum increased the significance of
models predicting the content of lipid and proteins in the milk, but not those
predicting the water or gross energy content. Milk collected on the first day
of 2-day attendance bouts had, on average, 9% greater lipid content,
and 5% greater protein content than milk collected on the second day.
The growth rates of subantarctic fur seal pups were significantly lower than
those of antarctic fur seal pups over the first month of growth, suggesting
that (despite similar milk composition, attendance patterns and diet of the
two species of fur seal) the overall rates of energy transfer from mother to
pup in subantarctic fur seals is lower than in antarctic fur seals.
Morphogenesis of shell and scutes in the turtle Emydura macquarii
Authors: Alibardi Lorenzo , Thompson Michael B.
Published: January 2006

Formation of the scutes and dermis of the embryonic shell of the turtle
Emydura macquarii was studied using light and electron
microscopy. Shell morphogenesis begins at embryonic stage 15 and the shape of
the shell is mostly completed by embryonic stage 19. The carapace anlagen
arises as a thickening of the skin in the dorsal part of the mid-trunk region
between the anterior and posterior limbs. This thickening extends
ventro-laterally to form ridges at the margins of the carapace. Each ridge
forms as a thick epidermal placode over a condensation of mesenchymal cells.
The epidermis behind the advancing margins of the carapace is cuboidal or
columnar but does not form placodes. The margins of the carapace expand
rapidly in all directions. The plastron anlagen is derived from epidermal
cells localised in the latero-ventral regions between the fore- and
hind-limbs. Plastron placodes are present laterally, while the mid-ventral and
central epidermis remains cuboidal or columnar but does not form placodes at
embryonic stage 16. The plastron thickening rapidly moves from a
latero-ventral position to a flat ventral position between embryonic stages 16
and 19. Dermal–epidermal anchoring complexes occur throughout placodes
of both the carapace and plastron, but are rare in non-placode areas. The
accumulation of a dense mesenchyme beneath the shell epidermis forms a dermal
cushion that surrounds the body cavity. The superficial dermis close to the
epidermis is made of mesenchymal fibroblasts at embryonic stage 19, although
the inner-most areas contain bipolar fibroblasts and extracellular fibrils.
Scutes with serrations at their borders form as invaginations of the epidermis
into the dermis in the mid-dorsal areas of the embryo at embryonic stages
18–19. Dermal–epidermal anchoring complexes are located around the
infoldings that form the scutes of the hinge region. The epidermis of the
shell has 2–3 suprabasal cells at embryonic stages 19–22, and
lacks keratinisation before embryonic stage 22 when it has 4–6
suprabasal layers with 2–3 external layers made of flat cells. The
dermis thickens and has numerous collagen fibrils after embryonic stage 19.
The formation of dermal bones begins at embryonic stage 18–19 in the
plastron. Only small areas of the carapace near to the bridge have begun to
form dermal bone at embryonic stage 19. Calcification begins at embryonic
stage 19, but is still incomplete at embryonic stages 24–25.
A study of Albericus (Anura : Microhylidae) of New Guinea
Authors: Menzies J. I.
Published: January 2006

I examined a collection of approximately 230 frogs referable to the genus
Albericus on account of four synapomorphies (long fifth
toes, short legs, absence of clavicle and origin of the mandibular depressor
muscles). Morphometric analysis coupled with call characteristics suggests
three or four distinct clades within the genus. The status of
Albericus variegatus is examined and found to be
equivocal. Two recognised species (A. darlingtoni and
A. tuberculus) are redefined and eight new species are
described. I comment on several other specimens that cannot be accommodated
within those species described.
Estimating the weight of the Pleistocene marsupial lion, Thylacoleo carnifex (Thylacoleonidae:Marsupialia): implications for the ecomorphology of a marsupial super-predator and hypotheses of impoverishment of Australian marsupial carnivore faunas
Authors: Wroe S. , Myers T. J. , Wells R. T. , Gillespie A.
Published: January 2006

Using demonstrated relationships between body mass and humeral and femoral
circumferences, we calculate the weight of the only specimen of
Thylacoleo carnifex known from a near-complete skeleton.
Body weights of 112–143 kg were estimated for this individual, from
Moree, north-western New South Wales. Extrapolating on the basis of geometric
similtude, we further estimated the weight of the largest
T. carnifex for which we had cranial data at
128–164 kg. Moreover, estimates for at least three of the thirteen
available specimens exceeded 124–160 kg, suggesting that individuals of
this size were common. Our estimates of average weight for the species range
from 101 to 130 kg. These results clearly show that Pleistocene Australia had
a 'large' cat equivalent and that 'large' terrestrial
predator niches were not then occupied exclusively by reptiles.They may also
diminish the argument that soil-nutrient deficiency constrained the evolution
of large mammalian carnivores on this continent in the Pleistocene. Similarly,
we posit that prima facie evidence for reptilian
domination of terrestrial carnivore niches during the Miocene is wanting,
although it is conceded that far more detailed investigation is required to
comprehensively test these hypotheses. Earlier studies have drawn parallels
between T. carnifex and sabre-toothed predators, thought
to have specialised in hunting particularly large and powerful prey. Taken in
the context of upwardly revised weight estimates, we argue that Pleistocene
marsupial lions may have dispatched even
Diprotodon-sized animals. But again, more comprehensive
study, including thorough biomechanical design analysis of the post-cranial
skeleton in particular, will be required to thoroughly illuminate the
predatory habitus and general ecology of Australia's largest and most
specialised marsupial carnivore.
Metabolism and evaporative water loss of Western Australian geckos (Reptilia : Sauria : Gekkonomorpha)
Authors: Withers P. C. , Aplin K. P. , Werner Y. L.
Published: January 2006

Resting metabolic rate (RMR) and evaporative water loss (EWL) were measured,
and resistance (R) to evaporative water loss and water use index (WUI =
EWL/RMR) were calculated, for 22 species of Western Australian gecko. For
all available gecko data, body mass and temperature explained 85% of
the variability in RMR (=14.5 mass0.833
100.0398 Ta µL h–1),
and 70% of the variability in EWL (=0.126
mass0.539 100.049 Ta mg
h–1 ). For Western Australian geckos, RMR and EWL
were significantly influenced by body mass, using conventional regression and
phylogenetic analyses. Resistance to evaporative water loss (R) was not
significantly affected by body mass. Water use index was inversely related to
body mass: WUI = 21.9 M–0.344 mg mL
O2–1. There were significant
differences between species for R and for standardised residuals of RMR, EWL
and WUI. R was not correlated with phylogeny, and was significantly higher
(P = 0.020) for saxicolous geckos (1467 s
cm-1) than terrestrial geckos (797 s
cm–1); arboreal geckos had an intermediate R (977
s cm–1). Species that ate termites had lower
standardised linear regression residuals (P =
0.003) for RMR than did species that ate more general diets. Standardised
residuals for EWL were almost significantly related to microhabitat
(P = 0.053). Standardised residuals for WUI were
significantly related to microhabitat (P =
0.016); saxicolous species had lower WUI than terrestrial species.
Standardised linear regression residuals of the residuals from autoregression
(which should be independent of both mass and phylogeny effects) still
significantly correlated RMR and diet, but not EWL or WUI with microhabitat.
Longevity, reproductive effort and movements of three sympatric Australian arid-zone geckos
Authors: Read John L.
Published: January 2006

Three sympatric diplodactyline geckos were studied in chenopod shrubland over
a six-year period in northern South Australia. Females of each species were
significantly larger than males. Rhynchoedura ornata and
Diplodactylus conspicillatus, both termite specialists,
consistently produced multiple clutches of two eggs in a long breeding season
each year, whereas the reproductive output of
D. stenodactylus, a dietary generalist, was more
erratic. Females of the two Diplodactylus species bred
in three consecutive years, whilst R. ornata seldom
lived for more than two years. Mean relocation distances ranged from 26 to 35
m, which suggests that some individuals of all species maintained home ranges.
However, many individuals of each species, especially
R. ornata, were apparently transitory over areas greater
than the 1-ha study site.
Phylogenetic relationships among the Australian and New Zealand genera of freshwater crayfishes (Decapoda : Parastacidae)
Authors: Crandall Keith A. , Fetzner, Jr James W. , Lawler Susan H. , Kinnersley Margie , Austin Christopher M.
Published: January 2006

We sequenced approximately 500 base pairs of DNA from the 16S region of the
mitochondrial genome to estimate relationships among the freshwater crayfish
genera of Australia and New Zealand. In total, 35 sequences were obtained,
representing 32 species and all 10 genera native to Australia and New Zealand.
From these sequences, maximum likelihood, minimum evolution and parsimony
estimates of phylogenetic relationships among the genera were obtained and
compared with previous hypotheses concerning the relationships among the
crayfish genera. Our results support the monophyly of each genus (except
perhaps Euastacus) and the organisation of these genera
into three major clades: the first clade contains the genera
Engaeus, Tenuibranchiurus,
Geocharax, Gramastacus, and
Cherax; the second clade contains the genera
Paranephrops, Parastacoides,
Euastacus, and Astacopsis; and the
third clade contains the genus Engaewa. We reject the
ecological hypothesis of Riek for two major clades of crayfish species.
Finally, we provide a checklist of the Australian and New Zealand species as
they are currently recognised.
Genetic evidence for species boundaries in frogs of the Litoria citropa species-group (Anura:Hylidae)
Authors: Donnellan S. C. , McGuigan K. , Knowles R. , Mahony M. , Moritz C.
Published: January 2006

The Litoria citropa species-group comprises several
small to medium-sized tree-frog species found from mid-eastern Queensland to
eastern Victoria in a variety of habitats along streams associated with the
Great Dividing Range. The smaller members of the
Litoria citropa species-group,
Litoria phyllochroa and
L. pearsoniana, have a confused taxonomic history with
the taxonomic status of several populations, some regarded as endangered,
still in doubt. Multi-locus allozyme electrophoretic profiles and nucleotide
sequences of a portion of the mitochondrial
16S ribosomal RNA gene were used to examine the
evolutionary relationships of populations that are a geographically
comprehensive and morphologically representative sample of the species-group.
These data demonstrate the presence of a minimum of three species:
L. nudidigitus, L. phyllochroa and
a third species whose taxonomic name is yet to be resolved. This third taxon
encompasses a wide range of allozyme and mitochondrial nucleotide diversity
and can be divided into at least four evolutionarily significant units (ESUs)
that replace each other in a linear sequence from north of the Hunter Valley
in New South Wales to the Kroombit Tops in central Queensland. A possible zone
of hybridisation between the southernmost pair of these ESUs was identified in
northern New South Wales. The fourth ESU, a northern outlier of the range of
the species-group, is confined to Kroombit Tops, central Queensland.While its
phylogenetic relationship with the other three ESUs was not resolved precisely
by the present analysis, it nevertheless comprises a distinct and very
divergent mitochondrial lineage of considerable antiquity.Resolution of the
status of a further name applied to the species-group,
L. piperata, awaits a morphological analysis that
includes the relevant type material.
Molecular and morphological evolution in the south-central Pacific skink Emoia tongana (Reptilia : Squamata): uniformity and human-mediated dispersal
Authors: Austin Christopher C. , Zug George R.
Published: January 2006

Human-mediated and waif dispersal are both responsible for the distribution of
lizards on tropical Pacific islands. The component of each of these dispersal
modes to the Pacific herpetofauna, however, is unclear. Morphological
conservatism of Pacific lizards, the poor paleontological record on tropical
Pacific islands, and minimal research effort in the Pacific (compared with
other island systems) has hampered our understanding of waif versus
human-mediated patterns. We examine morphological and genetic variation of
Emoia concolor and E. tongana
(formerly E. murphyi), two scincid lizards, from the
south-central Pacific, to assess modes of dispersal and population structure.
Emoia tongana from Tonga and Samoa is genetically
uniform, suggesting that these are synanthropic populations recently
introduced, presumably from Fiji. Relatively large genetic divergence is
evident for populations of E. concolor within the Fijian
archipelago, suggesting prehuman intra-archipelago dispersal and isolation.
Birth in the northern brown bandicoot, Isoodon macrourus (Marsupialia:Peramelidae)
Authors: Gemmell Robert T. , Veitch Colleen , Nelson John
Published: January 2006

The ability of the newborn marsupial to move from the uterus to the pouch and
locate the teat is still not fully understood. Birth has now been observed in
a number of species of marsupial. However, filming this event, which occurs
over a few minutes, allows for a greater understanding of the mechanisms
involved. In this study, birth was filmed in 4 northern brown bandicoots,
Isoodon macrourus. Before birth the bandicoot lay on one
side with one hind leg facing upwards. The mother licked around the urogenital
sinus, around the pouch and along the inside of the hind legs. There was no
release of fluid just prior to birth of the first young, which appeared
covered in membranes. The mother licked the young vigorously to remove the
membranes. Young were born singularly or in groups of up to four young.
Contrary to the situation in the red kangaroo the pathway of the newborn of
the bandicoot was mainly downwards, with the newborn having to travel only
about 1 cm to reach the pouch. The newborn of the bandicoot do not have a
definite crawl to the pouch, as is seen in macropodids – they move with
a snake-like wriggle down a moist 1-cm pathway between the urogenital sinus
and the pouch. The mother bandicoot cleans the young, removing the membranes,
and lies on one side then on the other, positioning the pouch so that the
young nearly ‘fall’ into the pouch. As with the macropodids, the
transfer from the urogenital sinus to the attachment to the teat in the pouch
takes about 5 min. It is obvious that there are several marsupial ‘birth
positions’, and several methods are used by marsupial species to allow
the newborn to attach to the teat.
Morphology of the brown tree snake, Boiga irregularis, with a comparison of native and extralimital populations
Authors: Whittier Joan , Macrokanis Conrad , Mason Robert T.
Published: January 2006

We conducted an analysis of the morphology of specimens of the brown tree
snake, Boiga irregularis, from the native range of
eastern and northern Australia, Papua New Guinea and the Solomon Islands.
First, a cluster analysis was conducted to determine natural groupings in the
data; however, no groupings based on morphological characters were found. Then
the importance of additional factors such as geographical groupings and
coloration was analysed in a nonparametric analysis of variance. Significant
differences were found in the mean rankings of key characters such as dorsal
mid-body, ventral and subcaudal scale counts. However, the amount of variation
and the degree of overlap among populations and groupings precluded separating
animals on the basis of these features. Our data support the recognition of a
single species with two subspecies based on colour variation. We also compared
the morphology of a sample of brown tree snakes from an extralimital
population on Guam to that of this species in the areas of the native range.
Our data supported suggestions of alliances of the Guam population with
northern Papuan populations. However, the Guam population of the brown tree
snake was found to be less variable than were localised natural populations.
Morphologically, the Guam population is distinctive, suggesting that it has
undergone significant morphological change since its introduction.
Assessing the usefulness of histone H3, U2 snRNA and 28S rDNA in analyses of polychaete relationships
Authors: Brown S. , Rouse G. , Hutchings P. , Colgan D.
Published: January 2006

DNA sequence data from for histone H3 (34 species), U2 snRNA (34 species) and
two segments (D1 and D9–10 expansion regions) of 28S rDNA (28 and 26
species, respectively) have been collected to investigate the relationships of
polychaetes. Representatives of all of the major morphologically identified
clades were used, as well as members of the Sipuncula, Echiura, Turbellaria,
Clitellata and Siboglinidae (formerly the phyla Pogonophora and
Vestimentifera).
Maximum parsimony analyses of the separate data sets gave conflicting results
and none conformed closely to previous results based on morphology. Instead
each data set provided corroboration of a few of the morphological groupings,
usually pairing, though inconsistently, members of the same family. Higher
groupings proposed on morphological grounds were rarely recovered.
Maximum parsimony analysis of the combined data, excluding areas of uncertain
alignment, recovered some morphological groupings such as Cirratulidae,
Terebellidae, scale worms and eunicimorphs, and did not significantly
contradict others. However, some expected groupings were not recovered.
Surprisingly, the fanworms (Sabellidae and Serpulidae) were not shown as
sister taxa, and monophyly of Phyllodocida, a morphologically well
corroborated clade, required four more steps than most parsimonious trees.
Aciculata was not seen in our analyses, although it was the most strongly
supported large clade in Rouse and Fauchald (1997, Cladistics and polychaetes.
Zoologica Scripta 26,
138–204). Trees constrained to show Aciculata as monophyletic were 18
steps longer than the most parsimonious trees. If trees are rooted on
sipunculans rather than the nematode, Aciculata is nearly recovered, being
rendered paraphyletic by the inclusion of the sister-pair of Oweniidae and
Chaetopteridae.
As suggested by some recent morphological and molecular analyses, Siboglinidae
and Clitellata may well have sister groups among polychaetes. The
morphologically aberrant Sternaspidae are closest to members of Terebellida in
the present analyses, supporting the placement of Rouse and Fauchald.
Interesting results deserving further assessment concern the placement of
Chaetopteridae, Oweniidae and Sipuncula.
Life history characteristics of two Australian honeyeaters (Meliphagidae)
Authors: Ford Hugh A. , Trémont Steve
Published: January 2006

Most endemic Australian passerines that have been studied display long
breeding seasons, multiple nesting attempts, small clutches, low annual
productivity, high longevity and a high incidence of cooperative breeding. We
compare the life histories of two large endemic honeyeaters (Meliphagidae)
near Armidale, New South Wales. Red wattlebirds,
Anthochaera carunculata, have a long breeding season,
with many nesting attempts and clutches of two eggs, similar to other
honeyeaters whose breeding biology has been studied. Noisy friarbirds,
Philemon corniculatus, which are spring and summer
visitors to the study area, have shorter breeding seasons, usually making one
attempt and have a modal clutch size of three. Both species had incubation and
nestling periods of about 16 days. Friarbirds apparently have a laying
interval of 24 hours, the same as other honeyeaters, but unlike some other
endemic passerines, which have laying intervals of 48 hours. Breeding success
did not differ between the species, with young fledging from 32.7% of
wattlebird nests and 40.9% of friarbird nests. The reproductive
strategy of the noisy friarbird thus differs quantitatively from the apparent
norm for other honeyeaters and many other Australian endemic passerines.
The chronobiology of the brushtail possum, Trichosurus vulpecula (Marsupialia:Phalangeridae): tests of internal and external control of timing
Authors: Herbert P. A. , Lewis R. D.
Published: January 2006

The chronobiology of the brushtail possum
(Trichosurus vulpecula) was investigated in a vivarium
and in light-controlled cabinets to determine what controls the timing of
natural patterns of activity and rest. It is proposed that the timing of
natural behaviour of the possum is not regulated entirely by direct response
to environmental factors, but that it may have an element of internal control.
Unless perturbed by wind and/or rain, the onset of activity is precisely
timed each day, beginning as light intensity declines following sunset. In
tests of an internal clock hypothesis, possums in constant darkness exhibited
free-running circadian rhythms of activity with periods initially slightly
shorter than 24 h, spontaneously reducing to c.22 h 40
min after c. 40 days. The internal rhythm of the possum
could be entrained by 24-h light/dark cycles with activity initiated at
the onset of the dark phase. We propose that the timing of the onset of
natural behaviour of the possum is controlled through the output of a
circadian clock that may be modulated by direct responses to wind and rain.
Temporal variation in skull size and shape in the southern brown bandicoot, Isoodon obesulus (Peramelidae:Marsupialia) in Western Australia
Authors: Cooper Marie L.
Published: January 2006

Isoodon obesulus exhibits geographic variation in body
size and shape, which appears to be adaptive. The geographic range of this
species is declining, so the presence of adaptive divergence is of concern for
the conservation of this species, both in the long term (loss of diversity
decreasing evolutionary potential) and short term (choice of source
populations for translocations). In this study, skulls of
I. obesulus, both recent (animals alive within the last
100 years) and fossil (a few thousand years old), were examined and a range of
measurements obtained. Comparisons were made between the two data sets to see
whether skull morphology has changed over this relatively short period. Such a
change may indicate rapid evolution of these characters and therefore the
potential for fast regeneration of any lost geographic variation. Fossil
skulls were smaller than their recent counterparts, had shorter
‘snouts’ relative to skull width and depth, and displayed no
geographic variation in size and shape, whereas recent skulls were
geographically differentiated. Because of the apparent rapid evolution in
these characters, the implications of adaptive variation in size and shape
inI. obesulus with regard to its conservation may be
strictly short term, since any geographic variation lost may be quickly
recovered if suitable conditions exist.
The limits of the Araneoidea (Arachnida : Araneae)
Authors: Schütt Karin
Published: January 2006

A comparative morphological study of the following spider families is
presented: Anapidae, Microphol-commatidae, Textricellidae, Mimetidae,
Malkaridae, Archaeidae and Pararchaeidae. The results provide strong evidence
for the placement of Textricellidae and Micropholcommatidae in the Araneoidea.
Among others, probably the best autapomorphic character for the Araneoidea,
the triad (three spigots together producing the gluey capture thread) could be
found in all six species of micropholcommatids and textricellids in both
females and males. Within the Araneoidea, these two families share many
characters with the Anapidae, thus their assignment to the higher
symphytognathoids is most likely to be correct. The presence of a labral spur
in the Micropholcommatidae is also verified.
Mimetidae and Malkaridae are most probably araneoid. The position and
monophyly of the Archaeidae s.l. remains doubtful.
The Palpimanoidea, which was considerably enlarged in a revision by Forster
and Platnick (1984), is therefore here cut back to its original size.
Multiple feeding in wolf spiders: the effect of starvation on handling time, ingestion rate, and intercatch intervals in Lycosa lapidosa (Araneae : Lycosidae)
Authors: Framenau V. W. , Finley L. A. , Allan K. , Love M. , Shirley D. , Elgar M. A.
Published: January 2006

Multiple prey capture, the behaviour of a predator attacking prey whilst
handling a previously caught item, occurs in a variety of spiders that do not
build webs. The effects of recent feeding history on the frequency of multiple
prey attacks, handling time, ingestion rate, and intercatch intervals were
examined experimentally in the wolf spider
Lycosa lapidosa McKay. Juvenile spiders were subjected
to two different feeding regimes (starvation for 14 and 28 days) and then
provided with two different prey types (blowflies,
Lucilia cuprina, and crickets,
Acheta domestica). These two starvation levels or prey
types had little effect on the frequency (75%) of multiple prey
attacks. Spiders ingested approximately half the weight of any captured prey,
regardless of how many prey items they attacked. At the same time, the
handling time per prey item decreased with an increasing number of prey
attacked. This indicates a more efficient ingestion rate when more prey are
consumed. While the attacking time for the first prey was the same for all
treatments, the first intercatch interval was longer for spiders that were
starved longer. Chronically starved L. lapidosa appear
to secure a previously caught item rather than optimise their capture rate by
attacking further available prey.
Heterogeneous shedding ofEscherichia coliO157 in cattle and its implications for control
Authors: Matthews L. , Low J.C. , Gally D. L. , Pearce M. C. , Mellor D. J. , Heesterbeek J. A. P. , Chase-Topping M. , Naylor S. W. , Shaw D. J. , Reid S. W. J. , Gunn G. J. , Woolhouse M. E. J.
Published: January 2006

Identification of the relative importance of within- and between-host variability in infectiousness and the impact of these heterogeneities on the transmission dynamics of infectious agents can enable efficient targeting of control measures. Cattle, a major reservoir host for the zoonotic pathogenEscherichia coliO157, are known to exhibit a high degree of heterogeneity in bacterial shedding densities. By relating bacterial count to infectiousness and fitting dynamic epidemiological models to prevalence data from a cross-sectional survey of cattle farms in Scotland, we identify a robust pattern: ≈80% of the transmission arises from the 20% most infectious individuals. We examine potential control options under a range of assumptions about within- and between-host variability in infection dynamics. Our results show that the within-herd basic reproduction ratio,R0, could be reduced to <1 with targeted measures aimed at preventing infection in the 5% of individuals with the highest overall infectiousness. Alternatively, interventions such as vaccination or the use of probiotics that aim to reduce bacterial carriage could produce dramatic reductions inR0by preventing carriage at concentrations corresponding to the top few percent of the observed range of counts. We conclude that a greater understanding of the cause of the heterogeneity in bacterial carriage could lead to highly efficient control measures to reduce the prevalence ofE. coliO157.
Peripheral cannabinoid receptor, CB2, regulates bone mass
Authors: Ofek Orr , Karsak Meliha , Leclerc Nathalie , Fogel Meirav , Frenkel Baruch , Wright Karen , Tam Joseph , Attar-Namdar Malka , Kram Vardit , Shohami Esther , Mechoulam Raphael , Zimmer Andreas , Bab Itai
Published: January 2006

The endogenous cannabinoids bind to and activate two G protein-coupled receptors, the predominantly central cannabinoid receptor type 1 (CB1) and peripheral cannabinoid receptor type 2 (CB2). Whereas CB1 mediates the cannabinoid psychotropic, analgesic, and orectic effects, CB2 has been implicated recently in the regulation of liver fibrosis and atherosclerosis. Here we show that CB2-deficient mice have a markedly accelerated age-related trabecular bone loss and cortical expansion, although cortical thickness remains unaltered. These changes are reminiscent of human osteoporosis and may result from differential regulation of trabecular and cortical bone remodeling. TheCB2–/–phenotype is also characterized by increased activity of trabecular osteoblasts (bone-forming cells), increased osteoclast (the bone-resorbing cell) number, and a markedly decreased number of diaphyseal osteoblast precursors. CB2 is expressed in osteoblasts, osteocytes, and osteoclasts. A CB2-specific agonist that does not have any psychotropic effects enhances endocortical osteoblast number and activity and restrains trabecular osteoclastogenesis, apparently by inhibiting proliferation of osteoclast precursors and receptor activator of NF-κB ligand expression in bone marrow-derived osteoblasts/stromal cells. The same agonist attenuates ovariectomy-induced bone loss and markedly stimulates cortical thickness through the respective suppression of osteoclast number and stimulation of endocortical bone formation. These results demonstrate that the endocannabinoid system is essential for the maintenance of normal bone mass by osteoblastic and osteoclastic CB2 signaling. Hence, CB2 offers a molecular target for the diagnosis and treatment of osteoporosis, the most prevalent degenerative disease in developed countries.
Cytokinin-mediated control of leaf longevity by AHK3 through phosphorylation of ARR2 in
Arabidopsis
Authors: Kim Hyo Jung , Ryu Hojin , Hong Sung Hyun , Woo Hye Ryun , Lim Pyung Ok , Lee In Chul , Sheen Jen , Nam Hong Gil , Hwang Ildoo
Published: January 2006

Cytokinins are plant hormones with profound roles in growth and development, including control of leaf longevity. Although the cytokinin signal is known to be perceived by histidine kinase receptors, the underlying molecular mechanism and specificity of the receptors leading to delayed leaf senescence have not yet been elucidated. Here, we found that AHK3, one of the three cytokinin receptors in
Arabidopsis
, plays a major role in controlling cytokinin-mediated leaf longevity through a specific phosphorylation of a response regulator, ARR2. This result was obtained through identification of a gain-of-function
Arabidopsis
mutant that shows delayed leaf senescence because of a missense mutation in the extracellular domain of AHK3. A loss-of-function mutation in
AHK3
, but not of the other cytokinin receptors, conferred a reduced sensitivity to cytokinin in cytokinin-dependent delay of leaf senescence and abolished cytokinin-dependent phosphorylation of ARR2. Consistently, transgenic overexpression of wild-type, but not an unphosphorylatable mutant ARR2, led to delayed senescence of leaves.
Allosteric changes of the NMDA receptor trap diffusible dopamine 1 receptors in spines
Authors: Scott Lena , Zelenin Sergey , Malmersjö Seth , Kowalewski Jacob M. , Markus Eivor Zettergren , Nairn Angus C. , Greengard Paul , Brismar Hjalmar , Aperia Anita
Published: January 2006

The dopaminergic and glutamatergic systems interact to initiate and organize normal behavior, a communication that may be perturbed in many neuropsychiatric diseases, including schizophrenia. We show here that NMDA, by allosterically modifying NMDA receptors, can act as a scaffold to recruit laterally diffusing dopamine D1 receptors (D1R) to neuronal spines. Using organotypic culture from rat striatum transfected with D1R fused to a fluorescent protein, we show that the majority of dendritic D1R are in lateral diffusion and that their mobility is confined by interaction with NMDA receptors. Exposure to NMDA reduces the diffusion coefficient for D1R and causes an increase in the number of D1R-positive spines. Unexpectedly, the action of NMDA in potentiating D1R recruitment was independent of calcium flow via the NMDA receptor channel. Thus, a highly energy-efficient, diffusion-trap mechanism can account for intraneuronal interaction between the glutamatergic and dopaminergic systems and for regulation of the number of D1R-positive spines. This diffusion trap system represents a molecular mechanism for brain plasticity and offers a promising target for development of antipsychotic therapy.