bluuebunny/crossref_metadata_2025 huggingface dataset:
Control of feral cats for nature conservation. III. Trapping
Authors: Short Jeff , Turner Bruce , Risbey Danielle
Published: March 2003

We present comparative success of various trapping methods trialed during control of feral cats at a site for the reintroduction of threatened mammals at Shark Bay, Western Australia. Our results come from 31 703 trap-nights that caught 263 cats (an average of 0.83 per 100 trap-nights). Cats differed markedly in their vulnerability to trapping depending on whether they primarily scavenged at rubbish tips or around human settlement or whether they hunted for their food in the bush. Cage traps were an effective means of controlling the former, with 9.4 cats captured per 100 trap-nights. Scavenging cats included a higher proportion of sub-adults and kittens and lower proportion of adult males than hunting cats. Variation between years in capture success for hunting cats was largely explained by the abundance of rabbits relative to that of cats and whether the rabbit population was increasing or decreasing. These factors accounted for a nine-fold difference in trap success. The number of cats caught in any particular trapping session could be explained by location (rubbish tip or town versus bush), trapping effort (typically greater effort yielded higher captures), abundance of cats at the site (captures were highest when cats were abundant), and season (captures were highest in the first half of the year when the young of the year were becoming independent). Concealed foot-hold traps, in a range of possible sets, provided effective methods for capturing cats that hunt, except where capture of non-target species was a critical limiting factor. Cage traps caught cats at a comparable rate to foot-hold traps for standard sets, but caught a significantly different cohort. Concealed foot-hold traps caught a higher percentage of adult cats, particularly males, than did cage traps. Mouse carcases and rabbit pieces were significantly more effective as lures when rabbits (the major food of cats at the site) were at low densities, whereas the success of commercial scent lures was unrelated to food availability. Significantly more cats than expected were caught using food as an attractant at times of food shortage (late summer, autumn and early winter) for both scavenging and hunting cats. In contrast, scent lures caught significantly more cats than expected in spring and summer when cats were defending access to mates and/or territory. Hence, no single trap type, trap set, or lure provided unequivocally superior performance over others. Control is likely to be best achieved by a variety of trapping methods and lure types used in combination, supplementing well timed poisoning efforts. Trap success is likely to be maximised by trapping at times when the dominant prey of cats are scarce relative to the number of cats and are decreasing in abundance.
Social and genetic analysis of a population of free-living cats (Felis catus L.) exploiting a resource-rich habitat
Authors: Denny Elizabeth , Yakovlevich Paul , Eldridge Mark D. B. , Dickman Chris
Published: March 2003

Free-living cats (Felis catus L.) exploiting a waste-disposal site in rural Australia were studied for two years to investigate population structure and dynamics, and the relatedness of constituent individuals. The density of the population was equivalent to 700–750 cats km–2, the sex ratio was heavily skewed towards males, breeding occurred from July to April, and kitten survival rates were low. A combination of observational data, biometrics and microsatellite loci analyses was used to assess the relatedness of individuals in the population; these methods yielded highly congruent results. Thus, a female kin-group of three was identified, there was no female immigration, the average relatedness amongst the population was high and there was no indication of male dominance. The results indicate that cats at the site formed a tightly structured group, rather than an ad hoc collection of individuals. The stable, resource-rich habitat of waste-disposal sites may generally support high densities of group-forming cats in rural Australia, and pose broad-scale but previously unrecognised problems for effective management of free-living cats.
Seasonal changes in the ovarian structure ofthe Cape fur seal, Arctocephalus pusillus pusillus
Authors: P. N. Odendaal  , Bester M. N. , van der Merwe M. , Oosthuizen W. H.
Published: March 2003

The annual reproductive cycle of the female Cape fur seal (Arctocephalus pusillus pusillus) was described by noting monthly gross changes in ovaries from 159 females, histological changes in 46 females and placental scars in 119 females. The size and weight of an ovary containing a corpus luteum was significantly greater than that of an ovary containing a corpus albicans for most of the year, the latter only approaching, or exceeding the former during the breeding season. Follicular activity initially increased in ovaries containing either a corpus luteum or a corpus albicans; however, it declined in the ovary containing a corpus luteum after implantation, while in that containing a corpus albicans it increased, reaching a maximum in December of 32.0 ± 10.08 follicles, averaging 5.41 ± 0.73 mm. The corpus luteum increased in size following ovulation, attaining a maximum size of 22.28 ± 3.38 mm in August (eight months after ovulation). Thereafter, it gradually decreased in size, generally becoming invisible to the naked eye by 30–32 months after ovulation. Luteal cells increased until seven months after ovulation, reaching a maximum size of 34.36 ± 1.26 μm before regressing, disappearing from the corpus luteum by 18 months after ovulation. Using placental scarring and CA counts in 119 females, a pregnancy rate of 77.4% was calculated, with 6.5% abortions and 16.1% non-implantations making up the remainder.
The effects of tooth wear on the activity patterns of free-ranging koalas (Phascolarctos cinereus Goldfuss)
Authors: Logan M. , Sanson G. D.
Published: March 2003

The free-ranging activity patterns of five adult males and one sub-adult male koala (Phascolarctos cinereus) with varying degrees of tooth wear were investigated using acoustically sensitive radio-telemetry. Increased tooth wear was found to be associated with a significant decrease in the amount of time spent sleeping and being inactive. Furthermore, compared with individuals with low degrees of tooth wear, individuals with high tooth wear were found to spend considerably less time moving within and between trees, and had home ranges an order of magnitude smaller. Hence, feeding compensations were found to come at the expense of other activities such as sociality and therefore have important consequences for reproductive output. Individuals with high tooth wear also spent longer feeding per bout, and spaced feeding bouts out more evenly throughout a 24-h period, thereby exhibiting reduced degrees of nocturnality. The sub-adult was found to range over a disproportionately large area and spend a relatively large amount of time moving between trees, indicative of a dispersing individual. Moreover, the activity patterns of this individual were found to differ slightly from the adult trends and were perhaps affected by the extra energetic demands associated with dispersal.
Foraging ecology and organisation of a desert bat fauna
Authors: McKenzie N. L. , Start A. N. , Bullen R. D.
Published: March 2003

Airframe design parameters related to flight performance, stability and control had tight, functionally appropriate relationships with the foraging niches and echolocation parameters of nine species comprising the bat fauna of the Little Sandy Desert, Australia. The airframe parameters segregated into two near-independent groups, one related to microhabitat use, the other to foraging strategy. The structure of the desert's bat fauna is displayed in these terms, and its organisation is compared with the faunas of surrounding regions. A diversity–productivity model of faunal structure is revealed, with an organisation that conforms with the 'specialisation' hypothesis. Clear family-level relationships between phylogeny and foraging ecology imply that ecological specialisations occurred early in the evolution of bats.
Morphological variation within Antechinus agilis and Antechinus stuartii (Marsupialia : Dasyuridae)
Authors: Crowther M. S.
Published: March 2003

A study of morphological variation within and between Antechinus stuartii and A. agilis was undertaken to assess whether previously described diagnostic features of these taxa apply across their ranges. This also allowed resolution of the identity of Antechinus populations from southern New South Wales and Victoria, and identification of areas of sympatry between these two taxa. Morphological variation within both of these taxa was also quantified. Both species are extremely variable in size, and the characters used to diagnose the taxa do not appear to be consistent across the species' ranges. It was confirmed that all populations studied within Victoria are A. agilis. In addition to Kioloa on the south coast of New South Wales, another area of sympatry was identified in the Newnes Plateau, west of Sydney. There is some latitudinal and altitudinal variation in morphology and nipple number, which may be related to the seasonal availability of resources between different geographical areas.
The association of tooth wear with sociality of free-ranging male koalas (Phascolarctos cinereus Goldfuss)
Authors: Logan Murray , Sanson Gordon D.
Published: March 2003

The sociality (as measured by the degree of bellowing and amount of tree use) of five adult male koalas and one sub-adult male koala (Phascolarctos cinereus), with varying degrees of tooth wear, were investigated using acoustically sensitive radio-telemetry. Initial increases in tooth wear that coincide with an increase in age to maturity were associated with an increase in reproductive effort. Advanced tooth wear was found to be associated with a decrease in reproductive effort. This trend in reproductive effort is consistent with life-history predictions, and suggests that tooth wear has the potential to impose limitations on the reproductive longevity and fecundity of free-ranging male koalas.
Geographic dimorphism in the mountain brushtail possum (Trichosurus caninus): the case for a new species
Authors: Lindenmayer D. B. , Dubach J. , Viggers K. L.
Published: March 2003

The morphological and genetic characteristics of the mountain brushtail possum (Trichosurus caninus) are described for animals from a range of locations throughout its known geographic distribution in eastern Australia. Although there is considerable variation among populations, unequivocal morphological and genetic differences exist between northern and southern populations of the species. Specimens from southern populations (from Victoria) have a significantly (P < 0.001) larger ear conch, a significantly (P < 0.001) longer pes, and a significantly (P < 0.001) shorter tail than do specimens from northern populations (from New South Wales and Queensland). Animals can be clearly distinguished using a simple index based on these three morphological measures, which are gathered from live animals. North–south dimorphism is strongly supported by patterns in genetic data that show genetic distances of 2.7–3.0% between the southern and northern populations. The combined outcomes of morphological and genetic analyses suggest the existence of two distinct species. We recommend that the northern form, distributed from central New South Wales north to central Queensland, retain the name Trichosurus caninus; the southern form from Victoria is described here as Trichosurus cunninghami, sp. nov. The common names of these new species should be the 'short-eared possum' and the 'mountain brushtail possum', respectively.
Naso mcdadei, a new species of unicornfish (Perciformes : Acanthuridae), with a review of the Naso tuberosus species complex
Authors: Johnson J. W.
Published: March 2003

An immaculate square-nosed acanthurid fish of the genus Naso, previously misidentified as N. tuberosus, is described as a new species, N. mcdadei. The species is widespread, but appears uncommon, being known from only 10 specimens and five underwater photographs. It is described from specimens from tropical eastern and western Australia, southern Indonesia, Mauritius, and Natal, South Africa. Its occurrence is confirmed from off western Sumatra, the Maldives, Chagos Archipelago and southern Taiwan by photographs. It differs from N. tuberosus (Lacèpede, 1801) and N. tonganus (Valenciennes, 1835) most notably through smaller, more numerous teeth and a generally uniform greyish colouration. The head, body and fins all lack numerous small dark spots that are variously present in the latter two species. In adults, it also differs through a squarish rather than rounded tuberosity on the snout, a shorter straighter nasal groove, lack of a discernible hump in the dorsal profile, smaller-scale tubercles, non-prominent jaws, and first rather than last dorsal spine longest.The species previously recognised as N. tuberosus is split into two closely related taxa, N. tonganus (Valenciennes) from the western Pacific and Indian Oceans and N. tuberosus Lac�pede from the central and western Indian Ocean. These species differ mainly in the size and shape of the nasal tuberosity, dorsal profile, body depth, and colouration.
Geographic variation in skull characters of fur seals and sea lions (family Otariidae)
Authors: Brunner S. , Shaughnessy P. D. , Bryden M. M.
Published: March 2003

Geographic variation was observed in skulls of several otariid species, with a general change in size corresponding with a change in latitude and primary productivity. The largest specimens were from cool temperate localities, conforming mostly to Rensch's rule. Skulls of Australian sea lions from Western Australia were generally smaller in condylobasal length, but were more robust than those from South Australia. The subantarctic fur seal did not conform to Bergmann's rule: skulls from Amsterdam Island (37�55´S) were largest, those from Gough Island (40�20´S) intermediate and those from Marion Island (46�55´S) the smallest. For both sexes, skulls of southern sea lions from the Falkland Islands were smaller than their equivalents from mainland South America. Similarly, skulls of South African fur seals from south-east South Africa appeared smaller than those from the west coast of South Africa and Namibia; skulls from Namibia grouped separately from those of south-east and west coast, South Africa. We postulate that the Otariidae are in the process of species divergence, much of which may be driven by local factors, particularly latitude and resources.
Mycobiota as acute and chronic cloacal contaminants of female sea turtles
Authors: Phillott A. D. , Parmenter C. J. , Limpus C. J. , Harrower K. M.
Published: March 2003

To determine the potential for intra-oviductal contamination of sea turtle eggs with fungi accumulated during nesting, turtles were sampled for cloacal fungi. Pre-gravid females had a low incidence (17%) of cloacal fungi (Acremonium, Cladosporium, Penicillium). A higher occurrence (30%) of these same fungi in courting animals, that had not bred for ≥2 years, was probably the result of transfer during intromission. Nesting (75%) and inter-nesting (100%) turtles had the greatest occurrence and diversity of cloacal fungi (Acremonium, Aspergillus, Chrysosporium, Fusarium, Mucor, Penicillium, Phialophora, Sporothrix, Stachybotrys). The incidence of cloacal fungi rapidly decreased after nesting, to 28% within one year (Acremonium, Penicillium) and 13% in animals that bred at least two years earlier (Acremonium, Cladosporium, Penicillium). The other species of fungi are probably lost during defaecation.If fungal spores can be transported and maintained in the sea turtle oviduct by the same mechanisms as for spermatozoa, acute intra-seasonal contamination of eggs by fungi may be possible. The potential for chronic inter-seasonal contamination of the oviduct appears to be low.
A taxonomic assessment and redescription of Polydactylus multiradiatus (Günther, 1860), with a synopsis of other Australian species in the genus (Perciformes : Polynemidae)
Authors: Motomura H. , Johnson J. W. , Iwatsuki Y.
Published: March 2003

The taxonomic status of three nominal species of Polydactylus, viz. P. multiradiatus (Günther, 1860), P.�specularis (De Vis, 1883) and P. auratus McKay, 1970, is revised. A comparison of the type series of Polydactylus auratus and the original description of Polynemus specularis with the holotype of Polynemus multiradiatus and 63 additional specimens from northern Australia has shown them to be conspecific. Polydactylus multiradiatus is characterised by its: 7 (rarely 6 or 8) pectoral filaments, not extending to posterior tip of pectoral fin; 14–17 (modally 15) pectoral fin rays; 13–15 (modally 14) dorsal fin soft rays; 16–18 (modally 16) anal fin soft rays; 49–56 (modally 52) pored lateral line scales; 7 or 8 (modally 8) scale rows above lateral line and 14 or 15 (14) below; 11–14 (modally 12) gill rakers on upper limb, 15–20 (modally 17) on lower and 27–33 (modally 30) in total; and vomerine teeth present. A synopsis of other Australian Polydactylus species and a key to known Australian Polydactylus are provided.
Evidence for the use of magnetic cues in mound construction by the termite Amitermes meridionalis (Isoptera : Termitinae)
Authors: Jacklyn P. M. , Munro U.
Published: March 2003

The termite Amitermes meridionalis builds meridionally elongated mounds. We removed the tops of such mounds and then allowed the termites to repair their mounds in the natural geomagnetic field and in artificial magnetic fields with different magnetic declinations. Cross-sections of repaired mounds were taken and the arrangement of the small, elongated cells that form the basis of mound architecture was assessed. The results suggest that the termites align mound cells along the existing axis of the mound and the cardinal axes of the horizontal component of the applied magnetic field.
Systematics of the Egernia whitii species group (Lacertilia : Scincidae) in south-eastern Australia
Authors: Donnellan Stephen C. , Hutchinson Mark N. , Dempsey Paula , Osborne William S.
Published: March 2003

Allozyme electrophoresis was used to assess the taxonomic significance of colour pattern variation within and between populations of the Egernia whitii species group from 41 locations in south-eastern Australia. Analysis of the products of 39 presumed loci revealed that a minimum of three species are present in southern New South Wales among populations previously referred to Egernia whitii. Fixed allelic differences were maintained where pairs of species were sympatric. One of these three species is wide-ranging and is the one to which the name E. whitii is properly applied. The other two are more restricted ecologically and geographically and are described here as new. The three species are genetically and morphologically distinct from the other three eastern Australian members of the species group, E.�margaretae, E. modesta, and E. multiscutata. Genetic data and a review of the morphological evidence provide no support for the recognition of subspecies within either E. whitii (sensu stricto) or E. multiscutata.
Growth patterns of two widely distributed freshwater turtles and a comparison of common methods used to estimate age
Authors: Spencer Ricky-John
Published: March 2003

Turtles are long lived and demographic models requiring estimates of age, growth, fecundity and survival are central for management. Most studies that estimate age and growth of freshwater turtles use annuli as an index of age without estimating its error and very few studies that use growth models include many juveniles, where growth is often large and variable. In this paper, I compare the reliability of growth annuli and common models in determining age and growth of two widely distributed turtles in Australia. Most turtles are carnivorous during the juvenile stage but many species shift to a lower-quality omnivorous diet prior to maturing. Patterns of growth are often characterised by this dietary shift and I compared the growth of a common omnivorous turtle (Emydura macquarii) and a vulnerable sympatric species that is an obligate carnivore (Chelodina expansa). Mark–recapture programs were established in three lagoons on the Murray River. In total, 1218 hatchling E. macquarii were released into two of the lagoons and growth annuli were found to be unreliable in estimating their age by Year 2. The von Bertalanffy and logistic growth models can reliably estimate age of both male and female E. macquarii and C. expansa respectively. Growth is extremely rapid during the juvenile stage of E. macquarii, but is highly variable in C. expansa, with rapid growth occurring only beyond three years of age. Hence growth models fail to predict age when juveniles are excluded from the analyses. Female E. macquarii delay maturity until 9–12 years of age because clutch size is positively related to body size and they can produce only one large clutch per year. Female C.�expansa mature later (at ~14 years) than female E. macquarii and both species are sexually dimorphic, as males mature earlier at smaller sizes than females. Common growth models describe the growth of two widely distributed freshwater turtles, but different patterns of growth and age at maturity relate to quality of diet and reproduction.
Diets and predictions of feeding rate of house mice and Lakeland Downs short-tailed mice inhabiting an arid-zone island in Western Australia
Authors: Moro D. , Bradshaw S. D.
Published: March 2003

An analysis of the faecal pellets of two species of arid-zone mouse, the house mouse (Mus domesticus) and Lakeland Downs short-tailed mouse (Leggadina lakedownensis), inhabiting Thevenard Island in Western Australia was conducted to ascertain their dietary requirements, and to use this information to predict their feeding rates in the field. Both species consumed seed, monocotyledon and dicotyledon plant material and invertebrate material, although the relative frequency-of-occurrence of these items varied throughout the year. Invertebrate material formed the highest proportion of dietary intake for both rodent species at all times, suggesting that this dietary strategy is advantageous for rodent species that inhabit environments where plant seeding is seasonal and rainfall dependent. The dry-matter intake (DMI) of free-ranging M.�domesticus and L. lakedownensis was predicted and compared using information from two sources: their isotopic water fluxes and the water content of their diet, and their isotopic sodium fluxes and the sodium content of their diet with and without corrections for non-dietary (exogenous) sources of sodium. The DMI derived from the water turnover was high for both species, suggesting that the mice were drinking and that assumptions inherent in this calculation were violated. Feeding rates were also high if no correction was made for exogenous, non-dietary sodium. When corrections were made, however, M. domesticus was predicted to ingest 4.62 ± 0.20 g dry matter day–1 compared with 3.86 ± 0.23 g dry matter day–1 for L.�lakedownensis. When DMI was scaled on the basis of allometric predictions for desert eutherians, only estimates of DMI for M. domesticus fell outside the predicted 95% confidence intervals. The results presented suggest that M. domesticus were obtaining some sodium from sources additional to their diet. Taken together, this methodology provides a useful application for measuring the feeding rate of free-ranging species given known dietary requirements in the field.
Reassessment of the Early Cretaceous plesiosaur Cimoliasaurus maccoyi Etheridge, 1904 (Reptilia : Sauropterygia) from White Cliffs, New South Wales
Authors: Kear Benjamin P.
Published: March 2003

Cimoliasaurus maccoyi Etheridge, 1904 is a poorly known plesiosauroid from the lower Cretaceous (Aptian) opal-bearing deposits (Doncaster Member, Wallumbilla Formation) of White Cliffs, New South Wales. Characters used to define the taxon are found to be either uninformative beyond higher taxonomic levels, ontogenetically related or misinterpreted, suggesting that C. maccoyi is a nomen dubium. Provisional referral of the C. maccoyi remains to Elasmosauridae gen. et sp. indet. may be warranted on the basis the derived morphology of its cervical vertebrae. A review of 'cimoliasaurian' taxa described from the Callovian to Maastrichtian of Europe, North and South America, New Zealand and Australia indicates that all can either be reassigned or represent nomina dubia. The taxonomic status of Cimoliasauridae is also tenuous, with the family established on largely non-diagnostic characters.
Patterns of activity and inactivity in echidnas (Tachyglossus aculeatus) free-ranging in a hot dry climate: correlates with ambient temperature, time of day and season
Authors: Brice P. H. , Grigg G. C. , Beard L. A. , Donovan J. A.
Published: March 2003

Echidnas occur throughout Australia. They exhibit daily fluctuations in body temperature (Tb) and use torpor to various degrees throughout much of their range. Echidnas elsewhere are commonly diurnal except during hot weather. This study used temperature-sensitive radio-transmitters to investigate the activity patterns and temperature relations of echidnas in the relatively hot, dry climate of south-west Queensland with respect to temperature and photoperiod. During activity, echidnas were characterised by rising, but not necessarily high, Tbs. Activity was seen only within an ambient temperature range (as measured in a nearby Stevenson Screen: Tss) of 9–33�C so that activity was seen during the day and at night during the cool weather but only at night in summer. Echidnas used caves, burrows and logs when inactive. Tbs of inactive echidnas declined except when affected by rising ambient temperatures, as determined within these shelters (Ta). In summer, Tbs of echidnas in these shelters changed little or rose with increasing Ta to levels even higher than in active echidnas.Torpor was used by echidnas for periods up to nine days during winter and occasionally for up to one day during summer. Due to the difficulty of identifying the occurrence of torpor from Tb alone in warm conditions, the possibility that echidnas utilise torpor for less than one day remains inconclusive. Nevertheless, at least five bouts of torpor were identified in four (of eight) echidnas during winter/spring and two bouts of torpor from two echidnas in summer.
Rheotaxis by epaulette sharks, Hemiscyllium ocellatum (Chondrichthyes : Hemiscylliidae), on a coral reef flat
Authors: Peach M. B.
Published: March 2003

Rheotaxis (orientation to water currents) is commonly observed in fishes. Facing upstream is thought to be an element of shark behaviour during prey search and station-holding, but quantitative studies of rheotaxis by sharks in the wild are lacking. In this study, rheotaxis by the epaulette shark, Hemiscyllium ocellatum, was investigated on a coral reef flat at Heron Island, Great Barrier Reef, Australia. The orientation of 78 individuals in open areas (on sand or on top of coral heads, directly exposed to the prevailing current) was analysed with respect to current direction and velocity. H. ocellatum showed a significant (P < 0.05) preference for facing upstream (mean angle 1�, where the current origin was taken to be 0/360�) while resting on the substrate (n = 23), but showed no evidence of a preferred direction while swimming (n = 50). Observations of foraging were few (n = 5) but there was no indication of a preferred direction by these sharks. Resting H. ocellatum faced significantly more upstream at faster current velocities (P < 0.05), suggesting that rheotaxis may function in station-holding. There was no apparent relationship between rheotaxis and current velocity for swimming H. ocellatum.
Competition between tadpoles and mosquitoes: the effects of larval density and tadpole size
Authors: Mokany Allie , Shine Richard
Published: March 2003

Tadpoles and mosquito larvae compete for scarce resources in natural freshwater ecosystems, but factors determining the extent of competition between these two groups of organisms remain largely unstudied. Natural ponds display great variation both in the densities of larvae, and in the body sizes of tadpoles. We set up replicated artificial pond experiments to examine the effects of population density and tadpole size on interactions between tadpoles and mosquito larvae. We examined the effects of larval density in two systems of co-occurring tadpoles and mosquito larvae, one from brackish-water ephemeral ponds (Crinia signifera with Ochlerotatus australis) and one from permanent freshwater ponds (Limnodynastes peronii with Culex quinquefasciatus). In both systems, increasing densities of larvae suppressed growth and development both of conspecifics and of the competing taxon. In the C. quinquefasciatus–L. peronii system, larger tadpoles exerted more powerful suppression. Our results suggest that mosquito developmental rates and adult body sizes (and thus, the danger which mosquitoes pose to public health) may be reduced if natural water-bodies contain dense populations of large tadpoles.
Nest-site selection in a terrestrially breeding frog with protracted development
Authors: Mitchell N. J.
Published: March 2003

Metamorphosis of larvae of the Australian moss frog (Bryobatrachus nimbus) occurs in a terrestrial nest approximately one year after oviposition. Neither parent attends the eggs, thus selection of an appropriate nest site is critical to egg viability. This study examined the dynamics of nest-site utilisation over six years and the characteristics of nests chosen as oviposition sites. Nest cavities were located at ground level amongst heath within one of 10 species of bryophyte, lichen and lycopod. On average, 2.6% of nests contained a male B. nimbus during daytime monitoring during the breeding season, and 7.3% of nests contained an egg mass. Despite an abundance of potentially suitable nests from previous years, males constructed a small proportion (<10%) of new nests each year and new nests were more likely to be used as oviposition sites than older nests. Discriminant function analysis showed that moss nests used as oviposition sites were distinguishable from empty nests by their greater horizontal dimensions. Eggs deposited in wider nests are restricted to fewer layers, and a preference for wider nests may be adaptive because embryonic oxygenation is enhanced under such conditions. However, rather than demonstrating nest-site selection, the use of relatively large nests as oviposition sites may be an artifact of their occupancy by a breeding pair.
Dispersal patterns and population structure in a small marsupial, Antechinus agilis, from two forests analysed using microsatellite markers
Authors: Kraaijeveld-Smit F. J. L. , Lindenmayer D. B. , Taylor A. C.
Published: March 2003

Juvenile male agile antechinus (Antechinus agilis) are thought to disperse immediately after they leave the nest, whereas females are philopatric. However, no genetic data are available to support a hypothesis of male-biased dispersal, and the possible effects of habitat characteristics on dispersal are not known. We used five microsatellite loci to describe the dispersal patterns and population structure of A. agilis at two different forested sites (Mt Donna Buang and Mt Disappointment in central Victoria, south-eastern Australia). Within each site, DNA samples were collected from individuals from different trapping grids (four grids in Mt Donna Buang, collected over two years, and seven grids at Mt Disappointment, collected over one year). To assess levels of genetic structuring among the populations, Fst values (the proportion of genetic variance among populations) were calculated for each site and sex separately, and a test for isolation by distance was performed. Overall, Fst values were low, and did not increase with distance, and this may be the result of high levels of gene flow for both sexes at both sites, at least on the scale of less than 10 km. To investigate microsatellite patterns at a finer scale, we calculated pair-wise relatedness values separately for sites, years and sexes. By comparing these values for animals within and between grids, evidence was found for male-biased dispersal. A genetic assignment test provided further evidence for this: males were more likely to be assigned to grids other than their capture site. Most females had high assignment values for their capture site, although some of the females may have been immigrants. This result could be due to inaccuracies in the assignment test, or due to a higher frequency of dispersal of females than previously thought. The sex-biased dispersal was less pronounced at Mt Disappointment than at Mt Donna Buang. This may be related to the level of disturbance: logging patches, roads and fire-breaks (grass strips) disrupt the forest at Mt Disappointment more than at Mt Donna Buang.
Thermosensitive period for sexual differentiation of the gonads of the flatback turtle (Natator depressus Garman)
Authors: Hewavisenthi Suhashini , Parmenter C. John
Published: March 2003

Temperature-dependent sex determination has previously been reported for the flatback turtle (Natator depressus). The present study investigates the thermosensitive embryonic developmental stages for the sexual differentiation of this species. Groups of eggs incubated initially at constant temperatures of 26, 29 and 32�C were shifted once during incubation from either a constant masculinising temperature (26 or 29�C) to a constant feminising temperature (32�C) or vice versa. Findings from this study support the hypothesis that the effect of temperature and the timing of the thermosensitive period are dependent upon the specific temperature utilised during incubation. The thermosensitive developmental stages at masculinising temperatures were different to those of feminising temperatures. For the 26 to 32�C temperature shift, the thermosensitive period was confined to a single developmental stage (Stage 24). Ovarian development was determined at a later developmental stage than testicular development.
Sex identification and evidence of gonadal activity in the short-beaked echidna (Tachyglossus aculeatus) (Monotremata : Tachyglossidae): non-invasive analysis of faecal sex steroids
Authors: Oates J. E. , Bradshaw F. J. , Bradshaw S. D. , Lonsdale R. A.
Published: March 2003

The sex of three short-beaked echidnas (Tachyglossus aculeatus), part of a captive colony in which no successful births have occurred, was determined by measuring levels of faecal sex steroids over a period of two months. Levels of faecal oestradiol-17β were found not to differ between male and female short-beaked echidnas. However, measurement of the oestradiol : androgen ratio (E : A ratio) and androgen concentrations successfully identified one male and two female echidnas. Mean E : A ratios for the two females were 18 ± 6 and 23 ± 8, compared with 1.3 ± 0.6 for the male. The mean androgen concentration for the male was 10.1 ± 2.3 ng g–1 dried faeces, and 1.7 ± 0.5 and 2.2 ± 0.6 ng g–1 dried faeces for the two females. The E : A ratio allowed correct identification of the sex of the echidnas 80% of the time, whereas the androgen concentration correctly identified the sex 75% of the time but was reliable only during the breeding season. Both the male and female echidnas showed evidence of gonadal activity; lack of breeding in captivity was therefore not due to all animals being of the same sex or lacking reproductive activity. The study has demonstrated that faecal steroid analysis is an accurate method for sex determination in the short-beaked echidna and further monitoring of these hormones may elucidate many of the unknown aspects of their reproductive biology.
Evolutionary relationships among blue- and black-plumaged populations of the white-winged fairy-wren (Malurus leucopterus)
Authors: Driskell Amy C. , Pruett-Jones Stephen , Tarvin Keith A. , Hagevik Sarah
Published: March 2003

The white-winged fairy-wren (Malurus leucopterus) exhibits striking plumage colour variation between the Australian mainland and two islands (Dirk Hartog Island and Barrow Island) off the coast of Western Australia. Adult males on the mainland are bright blue with white wings and adult males on the two islands are black with white wings. To examine evolutionary relationships within this species, we sequenced 980 base pairs of two mitochondrial genes from 34 individuals from both islands and five mainland sites. Birds on Barrow Island were the most genetically distinct. Specimens from Dirk Hartog shared a unique character with, and were most similar to, birds from the Western Australian mainland. The black-and- white-plumaged subspecies from the two islands were not each other's closest relatives. Mapping of plumage evolution produced two equally parsimonious hypotheses: (1) black plumage arose from blue plumage convergently on the two islands, or (2) black plumage arose from blue plumage once and was followed by a re-evolution of blue plumage in mainland Western Australia birds. Levels of genetic differentiation in this species were low but genetic differentiation was discovered between morphologically identical eastern and western populations of the mainland subspecies, which is evidence for a current barrier to gene flow on mainland Australia.
Morphometric divergence among populations of Rhinonicteris aurantius (Chiroptera : Hipposideridae) in northern Australia
Authors: Armstrong Kyle N.
Published: March 2003

The isolation of the Pilbara population of the orange leaf-nosed bat, Rhinonicteris aurantius, from the Kimberley and the Northern Territory populations by the Great Sandy Desert, and the differences in climate and landscape between these regions, prompted a study of morphological divergence. Skull, noseleaf, ear and wing characters were used in a morphometric analysis of museum specimens. Univariate and multivariate analyses revealed subtle differences in the size of some snout and noseleaf measurements (condylocanine length, nasal breadth, rostral height, anterior leaf height and total noseleaf width) between the Pilbara and the northern populations, with smaller measurements in Pilbara animals. The species was otherwise morphologically conserved. Size differences may be indicative of a functional relationship with echolocation call frequency. Sexual dimorphism was identified in some skull measurements only (larger in males). Further study might confirm the subtle differences detected here in the snout and noseleaf and provide a functional basis for them. The isolation of R. aurantius in the Pilbara is part of a general pattern of allopatry, evolution and endemism in north-western Australia that resulted from the formation of the Great Sandy Desert.
The rete testis of acrobatid and burramyid marsupials
Authors: Woolley P. A. , Vanderveen A. E.
Published: March 2003

The form of the rete testis has been investigated in all members of two families of possums, the Acrobatidae and the Burramyidae. A simple rete like that found in members of many other families of marsupials was seen in Distoechurus pennatus, one of the two species of acrobatids. The rete in the six species of burramyids was only slightly different from that seen in Distoechurus. In Acrobates pygmaeus, the other acrobatid, the rete was found to be most like the horseshoe-shaped rete found in a phalangerid and in macropodids. On the basis of the form of the rete testis, Acrobates and Distoechurus do not appear to be closely related.
Secondary metabolites in Eucalyptus melliodora: field distribution and laboratory feeding choices by a generalist herbivore, the common brushtail possum
Authors: Wallis I. R. , Watson M. L. , Foley W. J.
Published: March 2003

We studied the influence of a group of plant secondary compounds, the sideroxylonals, on feeding by the common brushtail possum (Trichosurus vulpecula), a generalist herbivore. Possums were offered synthetic diets either with or without sideroxylonals or, in separate experiments, foliage from 28 individual Eucalyptus melliodora trees. Possums ate less of the synthetic diet at sideroxylonal concentrations of 4 and 7 mg g–1 when offered a choice or no choice, respectively. Possums fed foliage in no-choice protocols ate 12–61 g of dry matter per day. Sideroxylonal concentration was an essential determinant of feeding on foliage but the wide variation, particularly at intermediate sideroxylonal concentrations, suggests that other secondary plant chemicals, e.g. tannins, are important also. The normal distribution of sideroxylonal concentrations (mean = 27.7, s.d. = 7.85 mg sideroxylonals per g dry leaf) in a natural population of 150 E. melliodora trees shows that brushtail possums will rarely encounter highly palatable trees (<10 mg sideroxylonals per g dry leaf) nor highly unpalatable foliage (>40 mg sideroxylonals per g dry leaf). When foraging on E. melliodora, brushtail possums must contend with intermediate sideroxylonal concentrations (20–30 mg per g dry leaf), where variability in food intake is most noticeable.
Taxonomic status of the mardo, Antechinus flavipes leucogaster (Marsupialia : Dasyuridae): a morphological, molecular, reproductive and bioclimatic approach
Authors: Crowther M. S. , Spencer P. B. S. , Alpers D. , Dickman C. R.
Published: March 2003

This paper uses a combined morphological, molecular and ecological approach to assess the taxonomic status of Antechinus flavipes leucogaster from Western Australia, and its relationship to A. flavipes flavipes from eastern Australia. Morphological analyses show that A. flavipes leucogaster is smaller and finer than its eastern Australian counterpart in both cranial and dental dimensions. Phylogenetic analyses of partial cytochrome-b sequences showed that A. flavipes flavipes and A. flavipes leucogaster form reciprocally monophyletic clades that have a relatively high level of divergence (approximately 6%). Analysis of the timing of reproduction indicates that the two subspecies show opposite responses to latitude, with A. flavipes leucogaster ovulating later at high latitudes and A. flavipes flavipes ovulating later in more northerly parts of its range. The combined data and the entirely allopatric distributions of the two subspecies confirm their distinctive status. Bioclimatic analysis suggests further that A. flavipes leucogaster occupies wetter but seasonally more variable environments than its eastern relative. It is clear from the level of morphological, molecular, reproductive and distributional differences that A. flavipes flavipes and A.�flavipes leucogaster should be regarded as separate taxa for the purposes of conservation management, and their current subspecific status should be maintained.
Seasonal variation in body mass and blood oxygen carrying capacity of the superb fairy-wren (Malurus cyaneus)
Authors: Box J. , Lill A. , Baldwin J.
Published: March 2003

The responses of small birds to many seasonal energy challenges include enhancement of aspects of aerobic metabolism, sometimes involving an increase in the rate of oxygen delivery to the metabolising tissues. One such mechanism that enhances oxygen delivery seasonally is an increase in blood oxygen carrying capacity. This response is enhanced in birds because of their rapid erythrocyte turnover rate. Some small birds have also evolved winter fattening, which helps them to meet the energy challenge presented by winter conditions. Such adaptations, while well documented for North Temperate birds, have received little attention in birds inhabiting temperate Australia.
Over a two-year period, we examined seasonal changes in mass, an approximate indicator of fattening, and the parameters determining blood oxygen carrying capacity in a population of superb fairy-wrens (Malurus cyaneus) in outer Melbourne, Australia. Body mass did not vary significantly seasonally, but haematocrit and whole blood haemoglobin were significantly higher in the breeding season than at other times of year and the erythrocyte count was significantly higher in spring than in autumn. We conclude that the failure of the fairy-wrens to increase mass in winter (i.e. show marked winter fattening) was probably due to the comparative mildness of the climate and to the known fitness costs of fat storage. The significant 18% increase in blood oxygen carrying capacity in spring probably helped the birds to meet the additional energy requirements of breeding, particularly the likely increase in flight activity. However, given the magnitude of the increase, other mechanisms must have been involved in meeting breeding costs. The seasonal peak in blood oxygen carrying capacity did not coincide with the time when moulting was most pronounced.
Extra-pair paternity and mate-guarding behaviour in the brown thornbill
Authors: Green David J. , Peters Anne , Cockburn Andrew
Published: March 2003

We used multilocus DNA fingerprinting to assess parentage in the brown thornbill, Acanthiza pusilla, a socially monogamous Australian passerine. Extra-pair paternity was uncommon (6.2% of 178 offspring; 11.9% of 67 broods) and there was no evidence of intra-specific brood parasitism. Extra-pair paternity was limited because pairs spent more time together when females were fertile and males were able to evict intruding males before they could approach the female. Males were responsible for the close proximity of partners during the fertile period. Mate guarding therefore appears to be a male tactic aimed at preventing female infidelity rather than a cooperative behaviour of the pair aimed at preventing extra-pair copulations and/or female harassment. Females did not attempt to escape male guarding and were rarely observed to solicit copulations from intruding males. Nevertheless, females paired to smaller and younger males were more likely to cuckold their mates than females paired to larger and older males. This suggests that females may be more likely to seek or accept extra-pair matings when paired to small, young males or that old, large males are better at preventing their mates from engaging in extra-pair copulations. We found that male age but not male size influences mate-guarding behaviour. Older males tended to respond more aggressively to intruders. We therefore speculate that the relationship between male size/age and extra-pair paternity in brown thornbills may arise because female thornbills prefer large males as mates but are unable to express this preference as easily when paired to older males.