Australian Journal of Zoology

Published by CSIRO Publishing
Online ISSN: 0004-959X
Publications
Article
Observations on social relations between territorial adult male and adult female A. forsteri were made on the Open Bay Islands, Westland, New Zealand, during the breeding season 1970-71. Threats comprised about 80% of all social encounters between males and females. Attempted and successful olfactory investigations of females by males, herding of females by males, and 'peace-keeping' by males accounted for about 18% of all encounters, and such interactions usually had agonistic overtones. Less than 2% of all encounters were not agonistic from their inception. Herding responses of males were vigorous and frequent, and are interpreted as serving two functions: containment of females and communication of certain of the herding males' characteristics to the females. Because herding occurs throughout the Otariidae, and is rarely effective in containing females, the second function is probably more important. Males showed much individual variation in their herding tendencies. The frequency of herding behaviour was depressed at warm temperatures. Olfactory investigations of facial and perineal regions of females were common and were not restricted to peri-oestrous females. Only oestrous females were sexually receptive to and showed little aggression toward territorial males, and males detected their physiological state mainly through olfaction. A few oestrous females solicited males with mock threats or by rubbing against them. Precopulatory and early copulatory behaviour was characterized by a moderate amount of mutual contact-seeking behaviour, multiple mounts by the male, and 'activation' of the female by the male biting her. Copulations appeared to be terminated through physical resistance by the female, which resulted in ejaculation and subsequent dismounting by the male. At the time of female resistance, the male commonly had to physically control her. The sudden return to aggressive behaviour typical of non-oestrous females may be mediated through a neural inhibitory process resulting from cervico-vaginal stimulation, as has been proposed for the guinea pig.
 
Article
Reproductive biology was studied in captive N. alexis, N. fuscus, N. mitchellii and N, cervinus. All were polyoestrous, the oestrous cycle averaging 7.0-8.0 days in N. alexis and N. mitchellii and 9.0 days in N. fuscus. In N. cervinus there was a considerable variation in length; this species may be easily stressed and less adaptable to captivity. Gestation in the non-lactating animal lasted 32, 34-37 and 38-43 days in N. alexis, N. mitchellii and N, cervinus respectively; all three had post-partum oestrus and mating. Lactation appeared to delay implantation in N, cervinus and probably in N. mitchellii, but not in N. alexis; it lasted 3-4 weeks, during which time the young clung tenaciously to the teats. Oestrus was not always suspended during lactation in N. alexis, and conception may take place during suckling in this species. Interspecific variations in this pattern of reproduction are discussed, and the information compared with data from other Australian Muridae.
 
Article
Information about breeding seasons, litter sizes, gestation periods, post-partum oestrus, oestrous cycles, and the development of the young is given for Notomys alexis, Pseudomys albocinereus, P. shortridgei and P. desertor. Some data are also given for N. cervinus, N. mitchellii, P. australis and P. novaehollandiae. Published accounts of the reproductive biology of other conilurine rodents are briefly reviewed.
 
Article
Reproductive organs of female C. gouldii and changes in the ovaries, uterine horns, corpus uteri and vagina during the reproductive cycle are described. In the south-west of Western Australia, C. gouldii is monoestrous with pro-oestrus from January to March or April. Females are inseminated at the beginning of winter (a late winter insemination may also occur). Sperm is stored over winter in the core of a vaginal plug, in uterine glands, and in the uterine part of the oviducts. Ovulation and fertilization begin at the end of winter, from two to nine ova being shed from each ovary. Corpora lutea may be deeply embedded in the ovaries and ovulation apparently causes considerable break-down of capillaries at the point of rupture. Pregnancies occur in both horns and twinning is the rule. Gestation lasts about 3 months. After parturition there is a rapid involution of uterine horns and vagina, followed by a brief lactation anoestrus. The beginning of the period of births varies with latitude. In the south-west region it commences late November or early December; in the central region late (and possibly early) October or early November; in the northern region late September or early October.
 
Article
The reproductive and associated organs of both male and female T. georgianus are briefly described. In females, only the right ovary is functional and pregnancies occur only in the right horn. They are monovular and the corpus luteum occupies most of the ovary and is deeply embedded in its stroma. Females are monotocous and the gestation period is probably about 4 months, young being born from October to February. They are monestrous and there is an autumn and early winter dioestrousanoestrous period. Spermatozoa are not stored in the reproductive tract of females and copulation appears to coincide with the oestrous condition. In males, spermatogenesis proceeds throughout the year and spermatozoa are present in the epididymis and vas deferens in all months that males were collected (no records for December). Spermatozoa are also found in the ampulla of Henle and vesicula seminalis in most months of the year. The position of the testes varies with season: in summer they descend to the scrota1 sacs; in autumn, winter, and spring they are more abdominal.
 
Article
Eight stages of spermatogenesis, based on cellular association, have been found in four species of Australian marsupials: Macvopus eugenii, M. rufogriseus, Trichosurus vulpecula, and Perameles nasuta. The cellular association are similar to those in eutherian mammals, and the frequency with which these stages occur in these marsupials are also similar. Following [3H]thymidine injections directly into the testis or into a testicular artery, the length of one cycle of the spermatogenic epithelium was estimated by autoradiography to be 17, 16, and 15 days for M. rufogriseus, M. eugenii, and T, vulpecula respectively; labelled spermatozoa first appeared in the urine 61 and 56 days after injection in M. eugenii and T. vulpecula respectively. From these data the minimum transit time through the epididymis can be calculated to be 13 and 11 days respectively. From the number of cells labelled in tubular cross-sections at different stages of spermatogenesis 1 hr after an intra-arterial injection of [3H]thymidine, it was concluded that at least four synchronized peaks of mitosis occurred in the spermatogonia of M. rufogriseus.
 
Article
Reproduction in field populations of the five species and 13 of 14 subspecies of native Australian Rattus is compared, using both materials personally collected and museum specimens. We have separated each subspecies into juvenile and adult categories, the dividing point reflecting the approximate size at which sexual maturity is reached. Occurrence of pregnancies and juveniles, treated monthly, permit estimates of time and length of seasonal breeding for each subspecies. Information on gonads and accessory sex glands is given for both breeding and non-breeding adults and for juveniles. All Australian subspecies of Rattus have a fundamentally similar mechanism of reproduction. Those attaining high densities have the highest ovulation rates, the largest litter sizes, and the greatest number of teats. Furthermore, in the two subspecies of high reproductive potential for which we have evidence, females can be precocious in attaining sexual maturity under field conditions.
 
Article
A total of 2750 grey kangaroos were examined at Mt. Hope, N.S.W., over a period of 4 years, commencing in 1962. Two colour phases of grey kangaroo were recognized but it was not until late in the study that concurrent investigations revealed that two sympatric species occurred in the area in the approximate ratio 1 : 8. As it was not possible to distinguish the species accurately in retrospect, all the kangaroos were treated as one group. A few males became sexually mature at 20 months of age, most by 36 months, and all before they were 72 months old. Females generally became sexually mature when between 20 and 36 months of age but onset of breeding was dependent on the breeding season (September-March). Most females were breeding by their second summer, some by the third summer, and a few not until the fourth summer. Most births occurred between September and March but some occurred in all months of the year. Of the total females carrying pouch young, 5% had dormant embryos in the uterus and all of these had pouch young more than 180 days old. The highest per- centage of females carrying dormant embryos was found in late autumn, possibly because of improved nutrition after heavy rains. No western grey kangaroos apparently carried a dormant embryo but 30% of the total eastern grey females did. A significant excess of pouch young were attached to an anterior rather than a posterior teat in multiparous females. When an anterior teat was already being suckled by a young-at-foot, the posterior teat on the same side was apparently shielded and a significant excess of young born to such females attached to the anterior teat on the non-suckled side. If a posterior teat was enlarged, almost two-thirds of the newborn young attached to anterior teats; the greater number on the non-suckled side. One female had two young in the pouch, separated in age by the length of one gestation period, indicating that suckling by the first young had failed to inhibit the next expected ovulation. Disparity between 713 male and female young was not significant at 105: 100 for pouch young and 84: 100 for young-at-foot. For sets of pouch young through the age range 113-280 days there was an estimated constant mortality rate of 1.82% per 28 days. No between-sex or between season variation in the mortality rate was revealed.
 
Article
Reproduction was studied in eight female T. caninus held in captivity in Armidale, N.S.W., for up to 5 yr. Oestrus was diagnosed from the vast increase in epithelial cells in the vaginal smear, post-oestrus being detected by the appearance of many leucocytes and of some elongate epithelial cells. The mean of 17 oestrous cycles was 26.4+- 1.0 days and the mean of 10 gestation periods was 16.2+-0.2 days. The teats evert and the female first ovulates at the end of her 2nd year, but no captive female gave birth till near the end of her 3rd year. In the anatomy of the uteri and vaginae, T. caninus resembles T. vulpecula but the ovaries of T. caninus are markedly distinguished by the presence of up to seven large corpora lutea. Although the weight of the luteal tissue may contribute as much as 83.9 % of the total ovarian weight, there is no evidence from the uteri that these large corpora lutea are functional in hormone secretion. The luteal cells are large but vacuolated and are separated by a well developed network of connective tissue. As the corpora lutea persist throughout the life of the animal, it is suggested that their number be used to indicate the maximum age of the animal.
 
Article
The proliferation and secretory activity of the uterine endometrium in the marsupial T. vulpecula is examined at the cellular and subcellular levels throughout the 26-day oestrous cycle. The observations described are correlated with measured concentrations of progesterone in the peripheral blood plasma. Evidence cited indicates that there are no significant functional differences in the uterine endometrial secretory activity during the 17.5-day gestation period in pregnant females, compared with those in a normal oestrous cycle. Progesterone assays carried out on blood plasma taken from 20 staged animals throughout the oestrous cycle, five of which were at known stages of gestation, also supports the view that pregnancy does not significantly alter the physiological pattern of the reproductive cycle in this marsupial.
 
Article
Eastern grey kangaroos, M. giganteus, and the western grey kangaroos M. f. fuliginosus, M.J melanops and M. f, ocydromus were bred in enclosures over a period of 10 y. Testis biopsies indicated sexual maturity in males, as follows: in both species, changes in the tubules from age 15 months; some spermatozoa seen by 20 months; active spermatogenesis with sperm free in the lumen by 31 (some western greys) or 48 months (eastern greys). In females, onset of sexual maturation, indicated by eversion of the teats, was from 14 and 18 months in western and eastern greys respectively; initial mating at c. 16.4 and 19 months with births not less than 1 month later. Crosses occurred only between western males and eastern females. Male hybrids were sterile; females were fertile, invariably mated with western males but also twice with eastern males. Smears taken from the anterior urogenital sinus showed that in both species and in their hybrids oestrus was accompanied by a marked increase in long narrow epithelial cells ('long cells'). The cycle was 34.85+-4.42 days in western females, 38.06h+-3.51 days in hybrids and 45.58+-19.82 days in eastern females. Variation in cycle length between and within females in each species was not significant, although variation between fuliginosus and melanops was significant at the 5% level. Oestrus occurred in all months of the year but least often in winter when some females entered anoestrus. Variance ratios for cycle length in relation to month of year were not significant for eastern or hybrid females but were, at the 5 % level, for western females. On loss or removal of pouch young the mean delay in return to oestrus was 10.92f 4.78 days in eastern and 8.2515.84 days in western females, significantly different at the 5% level. Females which retain their young may return to oestrus by 150 days after the birth and may mate at any or all of up to nine oestruses before conceiving again. Differences between eastern and western females were not significant, but those between western subspecies were, particularly between fuliginosus and melanops at the 0.1 % level. Embryonic diapause was observed seven times, all in eastern females, and followed matings not less than 160 days after the birth of a current pouch young.
 
Article
Female M. parma in captivity reach sexual maturity at 11 1/2-16 months of age. Scrota1 size indicates that sexual maturity is attained in males at about 22 months. One male had spermatozoa at 19-20 months and another had a first fertile mating at 24-25 months. Mating behaviour is described and resembles that of other small macropodids. M. parma is monovular and polyoestrous. The oestrous cycle has a mean length of 4197810.72 days (n = 58; range 36-59 days) while the gestation period is 34.54*0.13 days (n = 28; range 33-36 days). Post-partum oestrus and mating occurred from 4 to 13 days after birth in a small proportion (16.7%) of those animals examined. However, most animals had an oestrus, while carrying a pouch young, between 45 and 105 days after birth. A few animals did not come into oestrus at all while carrying a pouch young. Removal of pouch young typically resulted in return to oestrus between 6 and 15 days later, in females that had not had a post-partum oestrus or an oestrus while carrying a pouch young. Females which mated at some stage during lactation prior to removal of pouch young gave birth 31.16 days later (n = 3; range 30.5-32.0 days). Three females at the Melbourne Zoo had estimated delayed gestation periods of 31, 31, and 32 days. The earliest observation of a young with its head out of the pouch was at 146 days of pouch life. Most young had left the pouch for short intervals by 175 days with the youngest observed out at 160 days. Young permanently leave the pouch at 211.9+-1.0 days (n = 10; range 207-218 days). Permanent exchange of pouch young has been observed in two cases, both at approximately the time young were first leaving the pouch for short intervals. Some females that mated while carrying a young in the pouch gave birth 6-11 days after permanent pouch exit of the primary young. Unmated females returned to oestrus 12-24 days after permanent pouch exit of their young. Young were weaned at 2 5 3 ) months after pouch exit. Most females entered anoestrus in 1968 following transfer of the animals into small holding pens. In 1969 only 5 of 24 matings resulted in young in the pouch, while in 1970 the corresponding figure was 21 of 44 matings. In both years there was evidence of young being born but apparently being lost during the climb from the urogenital opening to the pouch, probably because of overcrowding of the mothers. Evolution of embryonic diapause is discussed in relation to the reproductive pattern established for M. pavma. It is postulated that embryonic diapause first arose at the end of pouch life and has come to occupy the entire length of pouch life in most macropodids.
 
Article
total of 65 skulls of the Australian sealion, Neophoca cinerea, was examined to investigate the extent to which sexual dimorphism is reflected in cranial dimensions (n = 32) and skull growth, and to determine whether cranial sutures (n = 18) can be useful in age determination. All adult skull dimensions studied display significant sexual dimorphism. Skull growth ceases close to 4–7 years of age for females (Suture Fusion Rating, SFR 25–34) but skull growth in males continues until at least 16 years of age. In animals with a SFR ≥ 25, male skulls have a minimum condylobasal length of 272 mm, whereas female skulls have a maximum condylobasal length of 259 mm. The relatively early closure of the cranial vault sutures (cessation of brain growth) is balanced by the continued growth of the bony projections that provide muscle attachment (e.g. mastoid width). The later fusion of the snout and palate sutures corresponds with the continued growth of the snout and palate to match the prolonged growth of the mandibles. The upper sixth postcanine tooth was present in 43% of the adult female skulls, but only 15% of the adult male skulls. The data suggest that it may be possible to determine age(s) from examination of the sequence of fusion of cranial sutures as well as by calculation of an overall suture fusion rating for the skull. Yes Yes
 
Article
Freshwater fishes are the most common hosts of the glochidia (parasitic larvae) of freshwater mussels (Bivalvia: Unionoida: Unionoidea). Velesunio angasi (Sowerby, 1867) (Hyriidae), is the only known hyriid species recorded from the Fortescue River in the Pilbara region of Western Australia. Eleven species of fish (n = 516) were captured from pools of the Fortescue River in June 2010. Small, white, bladder-like cysts were observed on Neosilurus hyrtlii Steindachner, 1867, though not on any of the remaining 10 species examined. Light microscopy of sectioned cysts revealed that they contained glochidia that were of similar size and shape to those of V. angasi. Glochidia were found on 73.2% of 168 N. hyrtlii examined, with a mean intensity of 3.3 cysts per infested fish. Prevalence was significantly greater on smaller fish (P < 0.01); however, no relationship between size and intensity of infestation was observed. This represents the first record of glochidia infestation on fish from the Pilbara region. Yes Yes
 
Article
The inland robust scorpion, Urodacus yaschenkoi (Urodacinae, Scorpionidae), is a large (similar to3 g) semi-fossorial scorpion that is widespread in arid regions of Australia. It constructs spiralling burrows up to 1 m deep in sandy soils. This study determined the net cost of transport (NCOT) by burrowing, which represents the energy used in horizontally burrowing a given distance, excluding maintenance metabolism. A mathematical model generally applicable to semi-fossorial species was developed and used to estimate the total cost of burrow construction. The model incorporates (1) horizontal NCOT, (2) the cost of moving spoil and the animal's mass along the length of the tunnel, and (3) the cost of working against gravity to raise spoil and the animal's mass to the surface. The total cost of burrow excavation to a depth of 47 cm was estimated to be 350-530 J. This represents approximately 2% of an adult scorpion's yearly energy turnover. Interspecific allometric comparisons of published NCOT data from phylogenetically diverse burrowers (with body masses spanning over two orders of magnitude) showed that burrowing method and substrate are important determinants of NCOT. Specifically, the cost of constructing an open tunnel through damp or dry sand is higher than the cost of moving through wet sand or mud without forming a tunnel.
 
Article
Dual-energy X-ray absorptiometry (DXA) is a non-invasive technology for measurement of body composition that requires validation against reference methods when applied to a new species. The aim of this work was to validate DXA for the assessment of body composition of the echidna. Body composition was determined in the short-beaked echidna (Tachyglossus aculeatus aculeatus) using a Norland XR36 DXA scanner and validated by proximate chemical analysis for dry matter, ash, crude fat (FM) and protein (as 6.25 × N) and bone mineral content (BMC). Echidnas were opportunistically obtained as ‘road kill’. Body composition data were compared between techniques by correlation and limits of agreement (LOA) analyses. Twenty-eight echidnas (11 males, 13 females, 4 not determined), weighing 520–5517 g, underwent analyses. Mean FM was 489.9 ± 439.5 g and 448.5 ± 337.5 g, lean mass was 2276.0 ± 1021.4 g and 2256.0 ± 1026.0 g, fat-free mass was 2356.3 ± 1055.1 g and 2389.5 ± 1081.1 g and BMC was 80.3 ± 39.5 g and 79.9 ± 42.4 g by DXA and chemical analysis, respectively. The two methods were highly correlated (0.84 to 0.99) and not significantly different, although LOA were large. DXA has the potential to be used to assess body composition of echidnas although further work is required to improve accuracy of measurement.
 
Article
Extensive abundance surveys of microhylid frogs across altitudinal gradients within the Wet Tropics rainforests of north-eastern Australia were undertaken. Detailed patterns of abundance were resolved for nine microhylid species exhibiting differing associations within the altitudinal gradient. The position of altitudinal range boundaries was found to be largely consistent with previous accounts in the literature, providing confidence in established limits to species distributions. Microhylid frogs, in particular those species restricted to mountaintops, are considered among other endemic rainforest vertebrates within the region to be one of the groups most immediately threatened by climate change. The combined results establish important baseline data for assessing the impacts of climate change, including altitudinal shifts in distribution and localised declines in abundance, on microhylid frogs in the region. Yes Yes
 
Changes in (a) head length and (b) bodyweight with age of brush-tailed rock-wallabies reared by their natural mothers, between birth and Day 350 post partum. Trend line with 95% confidence limits is indicated.  
Changes in (a) head length and (b) weight, with age of brush-tailed rock-wallaby (BTRW) young reared on either tammar wallaby () or yellow-footed rock-wallaby () foster mothers, between birth and Day 350 post partum. Trend lines indicate growth curve for brush-tailed rockwallaby young reared on either their natural mothers (arrow) or surrogate mothers. Surrogate mothers indicated thus: TW = tammar wallaby and YFRW = yellow-footed rock-wallaby. Confidence limits (95%) are indicated for young reared by their natural mothers.  
Article
Pouch-young removal and cross-fostering trials were undertaken in the brush-tailed rock-wallaby, Petrogale penicillata, to assess whether this procedure could be used to accelerate breeding and recruitment in this threatened marsupial species. Basic reproductive data, lacking at the time of the study, were also collected. Eighteen pouch young, weighing 1 - 106 g, were fostered to either tammar wallaby, Macropus eugenii, or yellow-footed rock-wallaby, Petrogale xanthopus, surrogate mothers. Sixteen P. penicillata pouch young were transferred to surrogate mothers whose own young were greater or equal in size to the P. penicillata young being transferred. Fourteen of these young survived ( 88%). Two of the P. penicillata pouch young were transferred to surrogate mothers whose own young was smaller in size than the P. penicillata young being transferred. Neither survived. Growth curves for pouch young on mothers and surrogate mothers were estimated. P. penicillata young reared by surrogate mothers grew at a similar rate, and were weaned at a similar age, to the pouch young of the foster species. Like other rock-wallaby species, P. penicillata underwent embryonic diapause and had a gestation period of similar to 30 days. Permanent pouch exit occurred at similar to 200 days and young became sexually mature at similar to 23 months for males and no later than 21 months for females. This study clearly demonstrates that pouch young of P. penicillata, as small as 1 g (similar to 8 days old), can be removed and cross-fostered successfully. These procedures can be used to accelerate breeding and recruitment by up to six times in this threatened species provided an adequate source of surrogate mothers is available.
 
Article
Six juvenile Neoceratodus of convenient size for respirometry (27-51 g) were available for study. Fish of this size are very rarely taken and the opportunity was used to examine the ability to examine the ability of Neoceratodus to undergo metabolic acclimation. Metabolic rate-temperature curves were constructed for fish with cold (18 degrees C) and warm (25 degrees C) thermal histories, using oxygen consumption as a measure of the rate of metabolism. The Q10 of fish with warm history (Q10 = 2.42) was higher than that for fish with cold history (Q10 = 1.55) and it was seen that there was partial thermal acclimation over the range investigated.
 
Acrodipsas cuprea specimen data and preservation methods DMSO, dimethyl sulphoxide. Morphotype relates to the upper-side wing colour on males: DC, dark form with variable areas of copper scales; DB, dark form with variable areas of blue scaling; PB, pale form often with blue scales; PC, pale copper coloured
Summary of nested clade results for the geographical distance analysis of Acrodipsas cuprea haplotypes. Test statistics are shown on the left. Haplotype designations (zero-step clades) and nested clades are shown in italics. Spatial distribution of A. cuprea haplotypes is shown in Fig. 1 together with clade designations. All clade and nested clade distances (great circle) are shown in kilometres following each clade identification. Significantly large (↑) or small (↓) clade ( c ), nested clade ( n ), and interior vs tip (I–T) distances (D) are highlighted in boldface type. Interior clades are shaded. Alongside nested clades in which there were significant values, a series of numbers corresponds to the sequence of questions in the inference key (Posada 2001). Biological inferences generated by the analysis, Fr. = past fragmentation, ID = restricted gene flow with isolation by distance.  
Relationship between pairwise genetic distances measured in nucleotide substitutions and great circle distances (km) for A. cuprea haplotypes. Mantel's original comparison based on Pearson's correlation test detected a significant relationship (P < 0.001).  
Article
Acrodipsas cuprea is the only polymorphic species in an uncommon myrmecophagous radiation within the Lycaenidae in Australia. A small cryptic butterfly, it is found almost exclusively on hilltop sites in eastern Australia where several geographically localised morphotypes are recognised. This study used mitochondrial DNA sequences extracted from museum specimens to reveal whether A. cuprea morphotypes evolved in isolation, such that intermediate populations resulted from secondary contact, or whether the distribution of morphotypes was maintained solely by selection across a primary contact zone. Genetic data were also used to assess the species' dispersal ability and to explain the historical processes resulting in its extant distribution. Analysis of molecular variance found that 81% of genetic variation was distributed among colour morphs, suggesting that different wing colours had evolved in isolation. Mixed haplotypes and morphotypes in a zone separating the otherwise discrete morphological populations, particularly along the Great Dividing Range in south-east Queensland, suggests a more recent secondary admixture. Isolation by distance detected by nested clade analysis and pairwise comparisons confirmed the limited dispersal ability of A. cuprea, which was more evident in the southern part of its range. Genetic relationships among haplotypes suggest that the species originated in the drier inland areas of central Queensland, before expanding to the coast and south to Victoria. Yes Yes
 
T b of echidnas (points) and available T a of their shelters (lines) at Idalia. (a) IB3 during summer when active and at rest in logs and burrows with a possible torpor event (grey bar). (b) IB4 during winter/spring when activity could be deduced from signal variability. (c) IB6 during winter/spring when inactive in different logs, implying activity in between. (d) IB7 in summer inactive in different caves. Tick points indicate midnight, horizontal black bars indicate nighttime.
Frequency of rest periods and activity bouts by average T ss throughout these periods in all echidnas during (a) winter/spring, and (b) summer. (c) Probability of activity at given T ss from logistic modelling (GLM: ln(p/(1-p) = f(T ss + T ss 2 )) using average T ss for each period of rest and activity.
Frequency of observed and deduced activity of echidnas by time of day with (a) frequency of T ss < 9°C in winter/spring, and (b) frequency of T ss > 33°C in summer. Horizontal bars indicate hours of darkness (averaged over the seasons).
Article
Echidnas occur throughout Australia. They exhibit daily fluctuations in body temperature (T-b) 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, T(b)s. Activity was seen only within an ambient temperature range (as measured in a nearby Stevenson Screen: T-ss) of 9-33degreesC 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. T(b)s of inactive echidnas declined except when affected by rising ambient temperatures, as determined within these shelters (T-a). In summer, T(b)s of echidnas in these shelters changed little or rose with increasing T-a 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 T-b 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.
 
Article
This study continues the collection of data on the anterior adhesive areas and secretions of monopisthocotylean monogenean (flatworm) parasites and begins an investigation of their phylogenetic usefulness. Here, two species of parasitic worms from an elasmobranch, Troglocephalus rhinobatidis (Monocotylidae: Dasybatotreminae) and Neoheterocotyle rhinobatidis (Monocotylidae: Heterocotylinae), are compared and contrasted. It has been suggested in recent literature that these two taxa are more closely related than is currently recognised. Our data support this view. Both species have multiple apertures on the ventral anterior margin through which adhesive is secreted. Two types of secretion exit from multiple adjacent duct endings terminating in each aperture: rod-shaped (S1) and spherical-shaped (S2) bodies. S1 bodies of both species show nano-banding of similar size and are membrane bound. Ultrastructure of the glands, ducts, duct endings and secreted adhesive is similar for both species, but aperture shape differs. Away from the adhesive areas, tegumental inclusions are found to differ between the two species and another, apparently non-adhesive, secretion is found in N. rhinobatidis.
 
Transverse sections through lingual salt gland in the posterior region of the tongue of Crocodylus porosus. Haemtoxylin and eosin stain. (a) A low-power shot of salt gland that has been sectioned through the dorsally located excretory pore (ep), possible gustatory receptors (r) and excretory duct (d). The gland is situated within connective tissue (ct), below which is a layer of adipose tissue containing elements of muscle (m) and blood vessels (bv). Numerous secretory tubules (s) can be seen within the gland complex. (b) A high-power shot of a transverse section through a salt gland lobule. Thin sheets of collagen fibres (ct) surround the secretory tubules (s). Small blood vessels (bv), erythrocytes (e), and the epithelial cells of the secretory tubules can be seen.
Transverse sections through a lingual salt gland, treated with Bielschowsky's silver stain for nerve fibres and dendrites. (a) A low-power shot of the gland. Bundles of unmyelinated nerve fibres containing axons (encircled) occur throughout the stroma. (b) A high-power shot of silverstained cells in salt gland lobule. A nerve fibre bundle (b) containing neuronal axons has cut transversely. Networks of small nerve fibres (f) penetrate the interstitial tissue of the secretory tubules (s).
Transverse sections through a lingual salt gland that have been stained for the presence of acetylcholinesterase (AchE) activity (dark stain). (a) A low-power shot showing a rich network of AchE-positive nerves (arrows) that encircle the secretory tubules (st). Small AchE-positive fibres branch inward to the secretary epithelium (arrowhead). (b) A high-power shot of AchE-positive nerve fibres (arrow).
Fluorescence photomicrographs of transverse sections of a lingual salt gland detecting the presence of catecholamines (using the SPG method). (a) A low-power shot of the salt gland showing networks of fluorescing nerve fibres (open arrows) surrounding the secretory tubules (s). Relatively high background fluorescence occurred in all sections. (b) Nerve fibres (open arrows) can be seen surrounding blood vessels and penetrating the spaces between the secretory epithelial cells. Variscosities (closed arrows) were a common feature in the nerve networks.
Article
Many marine reptiles and birds possess extrarenal salt glands that facilitate the excretion of excess sodium and chloride ions accumulated as a consequence of living in saline environments. Control of the secretory activity of avian salt glands is under neural control, but little information is available on the control of reptilian salt glands. Innervation of the lingual salt glands of the salt water crocodile, Crocodylus porosus, was examined in salt water-acclimated animals using histological methods. Extensive networks of both cholinergic and adrenergic nerve fibres were identified close to salt-secreting lobules and vasculature. The identification of both catecholamine-containing and cholinergic neurons in the salt gland epithelium and close to major blood vessels in the tissue suggests the action of the neurotransmitters on the salt-secreting epithelium itself and the rich vascular network of the lingual salt glands.
 
Article
The biology of the Australian wasp Taeniogonalos venatoria Riek was investigated using populations in the Adelaide Region during 1986-90. This species is unusual for a trigonalyid because it is a primary parasitoid of a pergid sawfly and can act facultatively as a hyperparasitoid. The wasp oviposits onto foliage, eggs are ingested by host larvae, eggs then hatch, and the larva penetrates the gut wall. Saline, acid saline, cathepsin and physical manipulation were effective in triggering eclosion. Eggs were viable on foliage for up to 5 months. Larval instars 1-3 are endoparasitic; 4-5 are ectoparasitic. Populations are univoltine, and adults emerge between February and April in synchrony with early-stage host larvae. Adult wasps are relatively short lived (8 days), but survival is increased by access to water and food. Female wasps contain over 6000 eggs at emergence. Aspects of the biology of T. venatoria are discussed in relation to other species of trigonalyid wasps.
 
Article
The present observations on the now-extinct Thylacinus are based on the reproductive system of an adult thylacine discovered among the specimens of the Hill collection at the Hubrecht Laboratory in the Netherlands. As in other marsupials, the reproductive tract was characterised by the presence of a uterus duplex and a vaginal complex where the ureters passed dorsally over each lateral vaginal canal to enter the bladder. The lateral vaginal canals each entered a urogenital sinus that terminated in a shallow cloaca. The gross dimensions of the reproductive tract of the thylacine were greater than those of any extant dasyurid marsupial. The distance from the rostral pole of the ovaries to the most caudal extremity of the urogenital sinus measured 25 cm. The distinctive aspects of the reproductive tract included a disproportionate enlargement of the corpus uteri that is without parallel in any other marsupial species. The bodies of the right and left uteri measured 10.4 cm x 1.2 cm x 0.9 cm and 9.1 cm x 0.8 cm x 0.7 cm respectively. The rostro-caudal length of the right and left cervices measured 2.7 cm and 1.7 cm respectively. The cervical canals entered the vaginal complex by way of a thick median vaginal septum. The elongated caudal component of the vaginal culs-de-sac lacked a median vaginal septum. As in other dasyurid marsupials, the lateral vaginae and associated vaginal complex were of diminutive proportions in relation to the typical marsupial pattern. The histology of the tract was remarkably good for tissue preserved since 1902 and indicated that the tissues were free of pathological changes. A characteristic marsupial pattern of ovarian folliculogenesis was evident where all but a thin peripheral zone of the cytoplasm of the primary oocyte became vacuolated during the pre-antral stage of ovarian follicle development.
 
Article
In air-breathing aquatic animals, predation is a strong selection pressure that may be reduced by modification to diving patterns. The risk of predation increases with time spent at the surface, thus shorter, more frequent surfacing events or longer, less frequent surfacing events would decrease predation risk. A reduction in time spent on the surface can be achieved by use of bimodal respiration, which is an ability to extend dive duration using dissolved oxygen to supplement aerially acquired oxygen. Air is a more efficient respiratory medium; however, under predation pressure, the cost of surfacing increases and the reliance on aquatic gas exchange should therefore increase. We tested whether the bimodally respiring filesnake (Acrochordus arafurae) changed its diving behaviour under simulated aerial (model bird) and aquatic (large fish) predation. Aerial predation did not alter dive or surface duration, percentage time surfacing or activity. However, a greater number of longer dives were observed with fewer long surface intervals, suggesting an increase in the use of aquatic gas exchange. The diel diving patterns (short night dives, long day dives) may provide an in-built antipredatory response to aerial predation. The threat of aquatic predation produced atypical antipredator behaviour, with longer surface intervals, shorter dives and increased activity, indicating that piscivorous filesnakes may have identified the predatory fish as prey rather than a predator.
 
Article
Knowledge of factors affecting the survival of individuals and their reproductive success is essential for threatened species management, but studies assessing these factors are lacking for many threatened rock-wallaby species. In this study we investigated the factors influencing the breeding performance of females and the survival of pouch young in a wild colony of the threatened brush-tailed rock-wallaby. Individuals were trapped between October 2000 and April 2004. More than 50% of the females in the colony were breeding below their full potential and giving birth to only one offspring per year. Most females within the colony bred in synchrony, with a substantial birth peak evident during autumn. Pouch young born in autumn left the pouch during spring and were weaned during summer and autumn when forage was most abundant. Pouch young born during the autumn birth peak or in winter had a substantially higher probability of surviving through to pouch emergence than those born during spring or summer. This study provides demographic parameters that may be used in population models and for comparison with other populations, particularly those that are small and declining. To optimise reproductive success in reintroduction programs, females in good condition and with small pouch young should be released at the end of the wettest season.
 
Article
Genetic relationships among nominal subspecies of the lycaenid butterfly Ogyris amaryllis were investigated in eastern Australia. High levels of variation and population differentiation observed for allozyme markers were not consistent with subspecies boundaries. Partitioning of allozyme variation was explained better by arranging populations according to their larval host plant. Mitochondrial sequence data recovered a polyphyletic inland subspecies, with several peripheral subspecies showing reduced variation within this topology. Nonparametric topology tests rejected monophyly of the nominal subspecies and suggested that allopatric divergence is unlikely to account for the evolution of this complex. Genetic data, combined with information on distribution and ecology, are more consistent with a pattern of peripheral isolation associated with host-plant specialisation of coastal populations. Yes Yes
 
Multidimensional scaling plot of pairwise F st differences between populations of H. albopunctatus (stress value = 0.09). Population abbreviations are listed in Table 1.
Allele frequencies for 22 populations of H. albopunctatus for the 4 variable loci detected
Article
We report on the genetic structuring of populations of a large burrowing frog, Heleioporus albopunctatus, from the central wheatbelt of Western Australia. This region has been highly fragmented by vegetation clearance for agriculture since the early 1900s. Genetic variation at four variable loci in twenty-two populations was analysed using cellulose acetate electrophoresis. Analysis across all populations showed a moderate, but significant degree of subdivision (Fst = 0.087 ± 0.049, p<0.05) and high levels of heterozygosity (H = 0.133, SE = 0.084). Several small populations had higher Fst values in pair-wise comparisons. A mantel test revealed no significant relationship between genetic distance and geographic distance (r = -0.136, p = 0.34) and this combined with data from multidimensional scaling analyses, reveal that geographic isolation of populations is not a significant determinant of genetic structuring. Despite this, the presence of high levels of subdivision as a result of the erosion of genetic diversity indicates that regional persistence may be dependent on the maintenance of metapopulation structures that allow gene flow.
 
Article
Chicks of megapodes, including the Australian brush-turkey, Alectura lathami, live independently, without parents to show them where and what to eat. This paper represents the first investigation of how megapode chicks find and identify food. The specific questions addressed are: whether naive brush-turkey hatchlings are able to differentiate between food and objects that do not give a nutritional reward; whether they possess a preference for certain types of food; and which factors are most likely to trigger feeding in hatchlings. The three questions were approached by pairwise choice tests of two types. In Type 1, chicks were offered mealworm larvae, fruit cubes, seeds and non-nutritious objects (pebbles); in Type 2, chicks were offered beads of four different colours (red, green, blue and yellow). The median peck rate at pebbles was always significantly lower than that at mealworms, fruit or seeds. Mealworms received significantly more pecks than seeds or pebbles. Chicks showed no clear preference for any colour. All chicks also directed some pecks at 'other items' that appeared to display a strong contrast against the background of the box they were kept in, either in colour (e.g. dark knotholes in light brown wood) or in shape (three-dimensional, such as claws and faeces). Hatchlings seem to direct their initial pecks at objects that have certain characteristics in common, such as contrast, movement (for live prey) and reflective surfaces (for fruit or seeds). Preference for these rather general characteristics may be adaptive considering that chicks can hatch in various habitats and different months of the year, making the types of food available at hatching unpredictable.
 
Article
Twelve estuarine crocodiles (6-51 kg) were fitted with recording back packs in order to study the longevity, frequency and daily/tidal rhythm of natural dives by crocodiles free-living in their familiar habitat. Despite disinterest shown by captive crocodiles in removing their jackets in tank trials, all but one of the seven crocodiles recaptured 5-16 days after release had shed their jackets and recorders. Results from the 9.75 kg animal showed that it had a prolonged emergence during each daylight low tide (basking?), that it dived mainly in daylight hours (feeding?), predominantly in the upper half of the tide and that most dives were of very short duration (1-5 minutes). Even the longest dive, 30 minutes, was well within the aerobic capabilities of a crocodile this size. Although these results are from a single animal, and may turn out to be quite atypical, if attachment problems are solved, the method has clear potential for revealing much about the daily activity patterns of free-ranging crocodiles and other animals.
 
Article
Using implanted radiotransmitters, we monitored body temperatures in five platypuses ranging freely in the Thredbo River in Australia's southern alps between April and October 1988, where the water gets as cold as any that a platypus is likely to encounter. Activity pattern showed a distinct daily cycle. No evidence of hibernation or even brief periods of torpor was found, all individuals maintaining body temperatures close to 32 degrees C throughout the winter (mean s.d., 32.08 0.75 degrees C, range 29.2 34.6 degrees C, n = 2237). No differences were found between the means or the variances of body temperatures of animals during day-time rest in stream-bank burrows and those during night-time foraging in winter at temperatures as low as 1.0 degrees C.
 
Article
Two new leprocreadiid digeneans are described from the intestine of the long-finned freshwater eel in the Brisbane River, Queensland, and from Australian bass Macquaria novemaculeata in the Richmond River in New South Wales. Both lepocreadiids use the prosobranch gastropod Posticobia brazieri as their first intermediate host. Cercariae of T. blepta penetrate and encyst in the pharyngeal muscle, external muscle, and viscera of fishes in the genera Gobiomorphus and Hypseleotris, and in several species of tree frog tadpoles. The cercariae of S. callista are often eaten or accidentally inhaled by several small fishes, including Retropinna, Craterocephalus, Pseudomugil and Ambassis, and encyst in the pharyngeal muscle and viscera. -from Author
 
Article
A study was undertaken in the south-west of Western Australia to investigate potential vertebrate hosts of Barmah Forest virus (BFV), Sindbis virus (SINV) and Trubanaman virus (TRUV) following isolation of these viruses from mosquitoes collected during routine surveillance for arboviruses. Over 3000 animal and human sera collected between 1979 and 1995 were tested for the presence of neutralising antibodies to each of the viruses. The overall prevalence of antibodies to BFV, SINV and TRUV was 0.4%, 0.3% and 1.6%, respectively. Antibodies to BFV were detected only in quokkas (3.2%), horses (1.2%) and humans (0.9%). No definitive evidence of infection with BFV was detected in samples collected prior to 1992, supporting previous suggestions that BFV was introduced into the region after this time. Antibodies to SINV were detected in western native cats (16.7%), emus (4.5%), rabbits (0.8%) and horses (0.7%), and evidence of TRUV infection was most common in western grey kangaroos (21.1%), feral pigs (3.6%), rabbits (2.4%), foxes (2.3%), quokkas (1.6%) and horses (1.6%).
 
Article
This study was based on the development of a non-invasive glucocorticoid enzyme-immunoassay for the assessment of stress in wild and captive endangered Fijian ground frogs (Platymantis vitiana). Enzyme-immunoassays were developed and validated for thefirst time to non-invasively measure both cortisol and corticosterone metabolites in frog urine. Frog urine showed parallel displacement with corticosterone but not cortisol standards, therefore corticosterone enzyme immunoassays were used to examine stress in wild and captive frogs. Urinary corticosterone metabolite concentrations increased in frog urine (n = 4) at 6 h, 1 day and 2 days after injection with adrenocorticotropic hormone (0.44 mgg–1 bodyweight), indicating that the corticosterone enzyme-immunoassay could detect changes in circulating orticosterone in frogs. Urinary concentrations of corticosterone were measured in wild frogs (n = 18) after capture in the field. The first measurement beyond the initial sample was at 2–3 h. Mean urinary corticosterone concentrations rose after the initial sample and were significantly elevated in samples collected 3–4 h after capture. This is the first demonstration of a urinary corticosterone response to capture in amphibians. Urinary corticosterone metabolite concentrations for all months combined were lower in captive males than in wild males, and differed between vitellogenic, non-vitellogenic and captive females. Concentrations did not differ between captive and wild females. In conclusion, urinary corticosterone enzyme immunoassays can be used in frogs for assessing stress responses to capture and natural stress profiles of both captive and wild populations. Additional keywords: adrenocorticotropic hormone, capture, stress, urine Yes Yes
 
Article
This paper evaluates the systematic status of the Antechinus populations of northern New South Wales and southern Queensland, using a combined morphological and molecular (allozymes and mitochondrial DNA) approach. Analysis of the d-loop section of the mitochondrial DNA control region revealed two highly supported clades within A. stuartii sensu lato that were sympatric in the Border Ranges of northern New South Wales. However, genetic distances between these clades were small ( approximately 3%), indicating that time of divergence was probably relatively recent. Allozyme electrophoresis also showed very small differences between clades/ species. Analyses of cranial and dental characters showed that the members of each of these clades differed morphologically and that the clades corresponded to A. stuartii and the recently described A. subtropicus. The combined results support the species status of A. stuartii and A. subtropicus, and suggest that speciation was likely a result of a recent vicariant event.
 
Mean abundance (±s.e.) of life stages of ectoparasite species found on brown antechinus over the entire study period Data are shown for the three study sites and are given for all animals captured and examined (sample sizes: Lagoon, 77; Kioloa, 79; Creek, 65) 
Article
We studied ectoparasite infestation patterns in a wild population of brown antechinuses, Antechinus stuartii (Dasyuridae) at three sites in south-eastern New South Wales, over a period of seven months. Ectoparasite diversity on brown antechinuses was particularly high for a small mammal: 18 species of ectoparasites were recorded, including one undescribed species of mite. Ectoparasite infestation varied between study sites and changed seasonally. Variation between sites was related to habitat and environmental parameters, and the highest ectoparasite infestations were encountered in the coolest habitat with greatest depth of leaf litter. Host population densities varied only slightly between sites, and host density was not considered to be a primary factor influencing ectoparasite infestation. This is the first study to provide a host record of ectoparasites of Antechinus stuartii sensu stricto.
 
Map of the study area showing native vegetation suitable for antechinuses, and cleared areas, beach, dunes and ocean. Arrows represent dispersal movements of individual males. 
The dispersal distance of males versus the index of population density at the natal site (number of individuals captured within 50 m in February 2004). Three pairs of brothers are indicated by a, b and c.
The dispersal distance of males versus the difference in density index of females between the natal and settlement sites.
The distance moved by the daughter in a litter that moved the furthest versus the distance moved by the mother of the litter. Only litters with surviving mothers and at least one daughter are represented.
Article
In common with most mammals, the frequency of natal dispersal in antechinuses is strongly male-biased. Inbreeding avoidance has been put forward as the most likely explanation, with juvenile dispersal being driven by the mother. Dispersal distances and factors affecting emigration and immigration of each sex have not previously been studied in antechinuses, because of the difficulty of following the fates of individual dispersers. I studied a dense population of brown antechinuses ( Antechinus stuartii) of known parentage in linear habitat that could be comprehensively trapped, and determined the fate of 27 females and 14 males that survived to dispersal age. Juvenile males dispersed not only more frequently than females (71% v. 11%), but also much further ( maximum known distance: 1230 m v. 270 m). Males dispersed further if they had been raised in an area of low population density, and were more likely to immigrate into an area with a higher density of females than the natal site. Death of the mother disrupted normal home-range establishment, resulting in frequent philopatry of sons and dispersal of some daughters. Some females emigrated after young were weaned, and this also prompted dispersal of daughters. There was no evidence that daughters with surviving, philopatric mothers were more likely to survive to breed. I conclude that male-biased dispersal appears to result not only from costs of inbreeding, but also partly by the benefits of finding a site with more mating opportunities.
 
Collection locations for Litoria examined in the present study. See the Appendix for key to the OTU designations.
Strict consensus tree of the 100 equally most parsimonious trees found after heuristic searches showing relationships among partial mitochondrial 16S rRNA sequences of Litoria. Numbers in parentheses indicate the frequency of that haplotype in an OTU. Bootstrap proportions among 2000 maximum parsimony (left) and Neighbour-joining/Jukes–Cantor distances (right) pseudoreplicates are in bold above branches. See the Appendix for the key to the OTU designations.
Article
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.
 
Apparatus used to monitor activity of rainbow trout and Murray River crayfish.  
Article
Studying biological rhythms of activity and determining the external factors that influence behaviour of animals can be challenging in many aquatic habitats. We investigated the validity of using variations in radio-signal strength to quantify changes in activity of radio-tagged aquatic fauna on a small spatial scale under controlled conditions in the field. We monitored short-term activity (<1 min) of two aquatic species, rainbow trout (Oncorhynchus mykiss) and Murray River crayfish (Euastacus armatus), that differ markedly in their primary mode of movement. Simultaneous video monitoring confirmed that active and inactive periods for both species could be accurately determined by radio-telemetry, as were specific behaviours exhibited by trout. We were also able to quantify activity based on different radio-tag (coil and trailing whip antennas) and receiving antenna configurations (yagi and gap-loop antennas); however, we recommend use of control tags to provide reference data. Variation in radio-signal strength represents a valid means of monitoring activity of moderately site-attached aquatic species. Yes Yes
 
Article
Semi-aquatic animals represent a transitional locomotor condition characterised by the possession of morphological features that allow locomotion both in water and on land. Most ecologically important behaviours of crocodilians occur in the water, raising the question of whether their 'terrestrial construction' constrains aquatic locomotion. Moreover, the demands for aquatic locomotion change with life-history stage. It was the aim of this research to determine the kinematic characteristics and efficiency of aquatic locomotion in different-sized crocodiles (Crocodylus porosus). Aquatic propulsion was achieved primarily by tail undulations, and the use of limbs during swimming was observed only in very small animals or at low swimming velocities in larger animals. Over the range of swimming speeds we examined, tail beat amplitude did not change with increasing velocity, but amplitude increased significantly with body length. However, amplitude expressed relative to body length decreased with increasing body length. Tail beat frequency increased with swimming velocity but there were no differences in frequency between different-sized animals. Mechanical power generated during swimming and thrust increased non-linearly with swimming velocity, but disproportionally so that kinematic efficiency decreased with increasing swimming velocity. The importance of unsteady forces, expressed as the reduced frequency, increased with increasing swimming velocity. Amplitude is the main determinant of body-size-related increases in swimming velocity but, compared with aquatic mammals and fish, crocodiles are slow swimmers probably because of constraints imposed by muscle performance and unsteady forces opposing forward movement. Nonetheless, the kinematic efficiency of aquatic locomotion in crocodiles is comparable to that of fully aquatic mammals, and it is considerably greater than that of semi-aquatic mammals.
 
Map of Australia showing historical and present distribution of the greater bilby and the location of captive breeding and reintroduction sites.  
Primer sequences developed to analyse portions of the bilby nuclear and mitochondrial genome
Position of primers used to amplify portions of the bilby mtDNA control region from the tRNA proline end.  
Microsatellite diversity for three populations of M. lagotis from eight loci n(I) = initial number of samples genotyped, n(D) = number of samples after removal of duplicates, A = allelic richness corrected for population size, H E = expected heterozygosity
(a) Nested clade phylogenetic network of bilby mtDNA control region haplotypes showing the 0-, 1-and 2-step clades. (b) Nesting design of the 2-, 3-, 4-, and 5-step clades for bilby mtDNA control region haplotypes.  
Article
The greater bilby, Macrotis lagotis, is a species of conservation significance in the arid and semiarid zones of Australia. A species recovery program has been underway since the mid-1990s but the incorporation of molecular genetic data within the program has been difficult due to the problems of obtaining regular, population-wide samples of this trap-shy and sparsely distributed species. In this study, we demonstrate that faecal pellets collected from around burrows in the dry, arid habitat of western Queensland provide a viable source for DNA extraction and analysis. Faecal DNA was used to generate population-level estimates of microsatellite and mtDNA diversity for comparison with previous estimates for the natural population derived from tissue samples. Data were used to assess both the reliability of faecal-derived genotypes and the extent of any diversity loss since the previous study. Microsatellite diversity recorded from eight polymorphic markers for the natural population (A = 4.31 ± 0.30, HE = 0.76 ± 0.03) was comparable with the previous study, indicating little change in genetic diversity for the natural population in the 10-year interim. Faecal genotypes generated for the recently reintroduced population matched the known number of founders as well as a known genotype, providing support for the reliability of the faecal DNA approach. The captive and reintroduced populations had significantly lower diversity levels than the natural population (A = 3.59 ± 0.28, HE = 0.68 ± 0.03; A = 3.57 ± 0.20, HE = 0.65 ± 0.03 respectively). Mitochondrial control region analysis, incorporating nested clade phylogeographic analysis (NCPA), agrees with earlier findings that populations of bilbies across the arid zone in Australia have only recently become fragmented, but the case for Queensland bilbies being strongly differentiated from other regions is diminished. Implications from this study include the need to further supplement the captive and reintroduced populations with additional out-bred individuals and that faecal DNA can be used effectively for ongoing monitoring and management of this species. Yes Yes
 
Comparison of broad-scale food categories from the faecal pellets of Leggadina lakedownensis (open bars, n = 73) and Mus domesticus (hatched bars, n = 75) across all trips combined. Each bar represents the mean ± standard error of a food item present in the faecal pellets of a species. Comparisons using Mann-Whitney U-tests: ns, not significant (P > 0.05).
Article
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.
 
Article
Using a tethered-insect technique, we investigated within- and between-population variation in the post-alighting host-plant preference and specificity of female Helicoverpa armigera from four populations. No significant difference occurred among populations in host-plant preference. Differences in host-plant preference existed among female moths within a population, and these differences are under genetic control and heritable. Most females ranked maize, sorghum and tobacco highest, followed by cotton varieties DP90 and HG660. The least-preferred plants were cowpea and lucerne. A few females (20%) differed from this general pattern and among each other, and reversed the rank order of host plants. Within a population, individual female moths differed in their host-plant specificity, with some individuals being more generalist than others. Similarly, significant differences occurred in host-plant specificity among populations. The relevance of these findings are discussed in relation to polyphagy in H. armigera.
 
Article
Amphidromous stream-cling-gobies of the genus Stiphodon comprise an important component of the fish communities in insular streams of tropical Indo-Pacific high islands. We aimed to develop an effective and rapid method of surveying Stiphodon atratus in a continental stream and then apply the method in an untested stream. Triple-pass snorkelling of a single pool revealed the reliability of single-pass estimates of the abundance of S. atratus. Single-pass survey of a reach in each of two streams then confirmed the presence of S. atratus, Stiphodon semoni and Stiphodon rutilaureus, in Australia. However, Stiphodon were in low abundance (S. atratus, Cooper Creek, n = 38, Pauls Pocket Creek, n = 45; S. semoni, Cooper Creek, n = 4, Pauls Pocket Creek, n = 14; S. rutilaureus, Cooper Creek, n = 0, Pauls Pocket Creek, n = 38). Preliminary indications are that particular streams provide critical habitat for newly discovered assemblages of Stiphodon within the Australian Wet Tropics. Small population sizes, coupled with the attractiveness of Stiphodon as aquarium pets, warrants that national protective status is provided to this genus until a comprehensive understanding of species distribution, abundance and population genetic structure is achieved. Yes Yes
 
Article
Abstract The nomenclature, systematic position and diagnostic characters of the family are discussed and information on techniques of collection and study are given. Taxonomic and faunistic data for 43 of the 56 known Australian species of Cholevidae are presented, based on abundant previously unstudied material. The distinctive characters of most species are illustrated. Only Agyrtodini and Nemadini occur in Australia. Choleva macleayi Blackburn is not a member of Anemadinae, but of Nemadinae : Nemadini. Agyrtodini are considered to be the probably the sister-group of all other Cholevidae, instead of being a tribe of subfamily Nemadinae. A key to the Australian genera of Nemadini is provided. After study of types, Pseudonemadus nigricornis Portevin is removed from the synonymy of P. integer (Portevin) and placed into the synonymy of P. adelaidae (Blackburn). The erroneous diagnosis of genus Catoposchema Jeannel is corrected and C. semota Szymczakowski is transferred to genus Austronargus. The following new taxa are described: Agyrtodes tasmanicus, sp. nov.; A. decoratus, sp. nov.; A. eucalypti, sp. nov.; A. crassus, sp. nov.; Pseudonemadus (Pseudonemadus) irregularis, sp. nov.; P. (P.) pusillus, sp. nov.; LEPTONEMADUS, subgen. nov. of Pseudonemadus, with type-species P. (L.) transvestitus, sp. nov. and P. (L.) elegans, sp. nov.; AUSTROCHOLEVA, gen. nov., with type-species A. platypus, sp. nov., and A. williamsi, sp. nov.; AUSTRONARGUS, gen. nov., with type-species A. tidbinbillae, sp. nov., and A. semota (Szymczakowski); Austronemadus, gen. nov. (type-species: Choleva macleayi Blackburn); A. neboissi, sp. nov.; Paranemadus, gen. nov., with type-species P. striatopunctatus, sp. nov.; Rangiola (?) rubrifasciata, sp. nov.; Nargiotes procerus, sp. nov.; Nargomorphus crassicornis, sp. nov.; N. acutangulus, sp. nov.; N. catopoides, sp. nov.; and N. ornativenter, sp. nov.
 
The sigmoidal curve relating sex ratio and incubation temperature at constant temperature from six clutches of loggerhead turtle nesting at Mon Repos and Heron Island with asymptotes at 0 and 100% female. The vertical solid line indicates the pivotal temperature. The data are from Limpus et al. (1985). The pivotal temperature estimating from this curve is 28.3 ± 0.1°C.
Sand temperatures and rainfall at Mon Repos during the 2005-06 and 2006-07 nesting seasons. Sand temperatures were recorded every 2 h and then averaged over 24 h to calculate a daily mean. Air temperature and rainfall data were obtained from a weather station located 20 km from the study site. (a) Daily means for 2005-06. (b) Daily means for 2006. Top panels are the means from the first and second sand dunes at each depth; bottom panels are the means from all depths for each dune site.
Daily range of fluctuation in the nest and sand temperature at 50 cm depth in the first sand dune in 2005-06 and 2006-07.
Article
Sand temperatures and loggerhead turtle nest temperatures (Caretta caretta) at Mon Repos rookery (Australia) were monitored over the 2005–06 and 2006–07 nesting seasons and hatchling sex ratios of clutches were estimated using the Constant Temperature Equivalent method. Nest temperatures were positively correlated with the sand temperature and air temperature in both seasons. Both seasons produced a female-biased sex ratio, especially the 2005–06 season, when almost all hatchlings were predicted to be female. Hatch success rate was not affected by nest temperature and averaged 85%, but hot nests from 2005–06 had a reduced emergence success compared with other nests. Daily cyclic temperature fluctuations of 0.5–1.5°C were a feature of nests, with a tendency for greater daily amplitude in the 2005–06 season when the average daily temperature was hotter. These daily temperature fluctuations increased the constant temperature equivalent temperature by 0.1–0.5°C above mean nest temperature during the sex-determining period and resulted in an increased female bias in the estimated hatchling sex ratio.
 
Article
Effective management of tree-hollow-dependent wildlife requires a sound knowledge of the characteristics of the trees used for shelter or breeding. We used radio-tracking to identify the den trees of squirrel gliders (Petaurus norfolcensis) in south-east Queensland (Qld) and north-east New South Wales (NSW). Squirrel gliders used dead trees as well as 13 species of living tree for dens across the two locations. Dead trees accounted for a large percentage of dens (54% of 48 dens in Qld, and 50% of 18 dens in NSW) despite comprising only 3-10% of the forest (trees >20 cm diameter at breast height (dbh)) at each location. This preference is largely due to dead trees being more likely to contain hollows, accounting for 26-44% of available hollow-bearing trees. Mean den tree size (dbh) was 48.9 ± 2.4 cm in Qld and 62.8 ± 5.6 cm in NSW. Den entrance height averaged 6.8 ± 1.2 m in Qld and 11.9 ± 1.3 m in NSW. Fissures in the trunk and holes in branches were the most common of six hollow types used. At one location branch end hollows were ignored relative to their availability. Den entrances varied in size (2.5-12 cm wide) but most were ≤5 cm in diameter. Entrance size of hollows appears to be the hollow attribute of most importance to squirrel gliders. Monitoring of these den trees over several years revealed the collapse of three dead den trees at each location, which is equivalent to an annual loss of 3% of den trees. Further research is needed to determine whether this will lead to a future shortage of den trees. © CSIRO 2008.
 
Article
Incubation temperature influences embryonic development and the morphology of resultant hatchlings in many species of turtle but few studies have addressed its effect on oxygen consumption and total embryonic energy expenditure. Eggs of the Australian broad-shelled river turtle, Chelodina expansa, were incubated at constant temperatures of 24 degrees C and 28 degrees C to determine the effect of temperature on oxygen consumption, embryonic energy expenditure and hatchling morphology. All embryos at both incubation temperatures experienced a period of developmental diapause immediately after oviposition. Once this initial diapause was broken, embryos underwent a further period of developmental arrest when the embryo was still very small and had minimal oxygen consumption (<20 mu L h(-1)). However, once rapid embryonic growth started, development appeared to be continuous. Rate of increase and peak rate of oxygen consumption were temperature dependent, both being highest at 28 degrees C. Net production efficiency (total oxygen consumed during incubation divided by yolk-free hatchling mass) was 120 mL O-2 g(-1) at 24 degrees C and 111 mL O-2 g(-1) at 28 degrees C. Hatchling mass and yolk-free hatchling mass were independent of incubation temperature, but hatchlings from 28 degrees C had larger residual yolks and smaller head widths than hatchlings from 24 degrees C.
 
Top-cited authors
David John Colgan
  • University of Magdalena
Gerasimos Cassis
  • UNSW Sydney
Philip Withers
  • University of Western Australia
George D. F. Wilson
  • Saugatuck Natural History Laboratory, LLC
Gregory D Edgecombe
  • Natural History Museum, London