Time filter

Source Type

South Perth, WA, United States

Tapley B.,Zoological Society of London | Rendle M.,Zoological Society of London | Baines F.M.,Greenfield | Goetz M.,Durrell Wildlife Conservation Trust | And 5 more authors.
Zoo Biology | Year: 2014

Conservation breeding programmes are a tool used to prevent amphibian extinctions. The husbandry requirements of amphibians are complex. Ongoing research is needed to ensure optimal management of those captive-bred animals destined, in particular, for reintroduction. The UV-B and vitamin D3 requirements of amphibians are largely unknown. Metabolic bone disease has been reported in a number of species. These include the Critically Endangered mountain chicken frog (Leptodactylus fallax) reared in captivity on diets supplemented with a high-calcium multivitamin and mineral supplement containing vitamin D3 but without UV-B provision. Captive-bred L. fallax being reared for reintroduction to Montserrat were provided with UV-B radiation from metamorphosis and were fed on insects supplemented with vitamins and minerals. Overlapping heat, light and UV-B gradients were provided, mimicking what we believe best represents the natural situation and thereby facilitated self-regulation of UV-B exposure. A subset of 10 frogs was periodically radiographed to assess skeletal health. Radiographic bone density and anatomical integrity appeared unremarkable when compared with a wild caught L. fallax. In addition to other routine health-screening, we recommend that radiography be performed to a structured schedule on a subset of all captive-bred and reared amphibians to assess skeletal health and to gauge the appropriateness of captive husbandry. We demonstrate here that, through the appropriate provision of a combination of both UV-B radiation and dietary supplementation, L. fallax can be bred and reared in captivity with healthy skeletal development. Zoo Biol. 34:46-52, 2015. © 2014 Wiley Periodicals, Inc. Source

Willers N.,University of Western Australia | Willers N.,Bentley Delivery Center | Martin G.B.,University of Western Australia | Matson P.,Perth Zoo | And 3 more authors.
Animals | Year: 2015

Populations of Australian marsupials can become overabundant, resulting in detrimental impacts on the environment. For example, the threatened black-flanked rock-wallaby (Petrogale lateralis lateralis) has previously been perceived as overabundant and thus ‘unwanted’ when they graze crops and cause habitat degradation. Hormonally-induced fertility control has been increasingly used to manage population size in other marsupials where alternative management options are not viable. We tested whether deslorelin, a superagonist of gonadotropin-releasing hormone (GnRH), would suppress reproduction in free-living adult female rock-wallabies without adversely impacting body condition. We trapped, synchronised reproduction and allocated female rock-wallabies to a placebo implant (control, n = 22), one (n = 22) or two (n = 20) subcutaneous implants of deslorelin. Females were then recaptured over the following 36 months to monitor reproduction, including Luteinising Hormone levels, and body condition. Following treatment, diapaused blastocysts reactivated in five females and the resulting young were carried through to weaning. No wallabies treated with deslorelin, conceivede a new young for at least 27 months. We did not observe adverse effects on body condition on treated females. We conclude that deslorelin implants are effective for the medium-term suppression of reproduction in female black-flanked rock-wallabies and for managing overabundant populations of some marsupials. © 2015 by the authors; licensee MDPI, Basel, Switzerland. Source

News Article
Site: http://www.scientificamerican.com

Feral cats have scratched up another victim. Earlier this month the Western Australia (WA) government listed a rare marsupial called the numbat, also known as the banded anteater (Myrmecobius fasciatus), as endangered. The colorful squirrel-like critters—literally the emblem of Western Australia—only grow to about 45 centimeters in length and have no defense against hungry felines. As a result of this predation, the wild population of numbats—which only live in the state of WA—has fallen to an all-time low of about 1,000. Surveys conducted earlier this year found the animals now have a population density of just 0.24 animals per 100 square kilometers. That’s pretty darned low. Conserving numbats has so far relied on two distinct programs. The first involves baiting and killing another invasive species, red foxes (Vulpes vulpes), which were introduced to Australia nearly two centuries ago and have been linked to other extinctions. WA Environment Minister Albert Jacob announced that state agencies will now step up its fox poisoning program and expand it to include cats. “Control of feral cats is one of our biggest challenges in protecting our threatened animal species,” he said in a prepared statement. The program uses a recently approved concoction called Eradicat, which was developed in WA and contains a mix of kangaroo mince, chicken fat and a deadly poison called 1080. The other program is more positive: captive breeding. Perth Zoo has the world’s only numbat captive breeding program and so far more than 200 of the animals have been released back into the wild to supplement the remaining populations. Last month 15 numbats—10 juveniles and five adults—wearing radio collars were released into an area called the Dryandra Woodland. Ten more were released into the same region on December 7. A conservation organization called Project Numbat helped to raise the money for the radio collars. Despite their risks, numbats are doing better than some other species. The same day the numbat was declared endangered four other long-lost mammals were finally identified as extinct: the desert bettong (Bettongia ogilbyi penicillata), inland burrowing bettong (Bettongia lesueur graii), south-western rufous hare-wallaby (  Lagorchestes hirsutus hirsutus) and Gould's mouse (Pseudomys gouldii). All were probably wiped out by invasive predators like foxes, cats, mice or rats. None of them have been seen for at least 50 to 100 years. Photo by S J Bennett. Used under Creative Commons license

Hogan L.A.,Perth Zoo | Hogan L.A.,University of Queensland | Lisle A.T.,University of Queensland | Valentine L.,Murdoch University | And 2 more authors.
Animal Reproduction Science | Year: 2012

The reproductive endocrinology of the highly endangered numbat (Myrmecobius fasciatus) is described for the first time. Patterns of faecal steroid secretion (progesterone [PM], oestradiol-17β [E2] and testosterone [TM] metabolites) were examined within a captive numbat population over 1 year and revealed a highly synchronized seasonal pattern of reproduction. TM secretion increased progressively from September to November, peaked in December and then decreased in February. All females displayed luteal phases (1-3), between late-November to late-March, in association with pregnant (Pr, n= 4), non-productive mated oestrous cycles (NMEC, n= 8) and non-mated oestrous cycles (NEC, n= 6). The mean oestrous cycle length was 30.2 ± 1.1. d (n= 11) and was comprised of a mean follicular (n= 11) and luteal (n= 18) phase length of 16.2 ± 1.6. d and 14.0 ± 0.8. d, respectively. No variation in mean luteal phase length or PM concentration according to cycle type (Pr, NMEC, NEC) or cycle number (1st, 2nd or 3rd cycle) was detected. Longitudinal profiling of PM secretion confirmed that the female numbat is seasonally polyoestrous and that the luteal phase occurs spontaneously. Changes in the secretion of E2 provided little instructive information on oestrous cycle activity. Mating success was 31%, with age and subject having no effect on mating success. Timing of introduction, of male to female, appeared to impact mating success, with paired animals introduced for a shorter time frame (≤14. d) prior to the first observed mating successfully producing young. Collectively, results of the present study confirm that PM and TM can be reliably used to index numbat reproductive activity. © 2012 Elsevier B.V. Source

Hogan L.A.,Perth Zoo | Hogan L.A.,University of Queensland | Lisle A.T.,University of Queensland | Johnston S.D.,University of Queensland | Robertson H.,Perth Zoo
General and Comparative Endocrinology | Year: 2012

Annual patterns of faecal cortisol metabolite (FCM) secretion were examined in six captive numbats (Myrmecobius fasciatus). The use of enzyme-immunoassay for the measurement of FCM in the numbat faeces was validated using an adrenocorticotropic hormone (ACTH) challenge and the resultant FCM measurements represent the first description of adrenal endocrinology in this species. Total overall, baseline and peak FCM mean concentrations varied according to individual, but not gender. For males, mean baseline and overall FCM secretion was higher in spring in summer (compared to winter and autumn) and was elevated during the breeding season. For females, mean baseline FCM secretion did not differ by season or breeding season, but mean overall FCM secretion was elevated during the breeding season. Thus, male (but not female) numbats display an annual change in FCM secretion that is strongly linked to their seasonal pattern of reproduction. Significant FCM elevations (n = 178) were observed in response to 20 different stressors, with these stressors being allocated to one of six categories: ANIM, ENVIRO, HAND, HEALTH, MAN and UNK. The mean proportion of positive responses to each category varied according to category, season and breeding season, but did not vary by individual or gender. ANIM and HEALTH stressors elicited a higher response rate than all other categories and an increase in the number of ANIM, ENVIRO, and HEALTH stressors were observed during the breeding season. Although there were multiple stressors within the captive environment that the numbats reacted to, this did not translate into a welfare issue. © 2012 Elsevier Inc. Source

Discover hidden collaborations