No abstract

Changes in life history are expected when new sources of extrinsic mortality impact on natural populations. We report a new disease, devil facial tumor disease, causing an abrupt transition from iteroparity toward single breeding in the largest extant carnivorous marsupial, the Tasmanian devil (Sarcophilus harrisii), in which males can weigh as much as 14 kg and females 9 kg. This change in life history is associated with almost complete mortality of individuals from this infectious cancer past their first year of adult life. Devils have shown their capacity to respond to this diseaseinduced increased adult mortality with a 16-fold increase in the proportion of individuals exhibiting precocious sexual maturity. These patterns are documented in five populations where there are data from before and after disease arrival and subsequent population impacts. To our knowledge, this is the first known case of infectious disease leading to increased early reproduction in a mammal. The persistence of both this disease and the associated life-history changes pose questions about longer-term evolutionary responses and conservation prospects for this iconic species.carnivorous marsupial ͉ infectious cancer ͉ wildlife disease ͉ precocious breeding ͉ semelparity

An emerging infectious facial cancer threatens Tasmanian devils with extinction. The disease is likely to occur across the range of the devil within 5 years. This urgent time frame requires management options that can be implemented immediately: the establishment of insurance populations, in captivity, wild-living on islands, and aiming for eradication in areas that can be isolated. The long-term options of the spontaneous or assisted evolution of resistance or development of a field-deliverable vaccine are unlikely to be available in time. The disease's characteristic allograft transmission through intimate contact simplifies isolation of insurance populations and breaking transmission in suppression trials. Better knowledge of contact matrices in wild devils will help focus timing and demographic targets of removals. A metapopulation approach is needed that integrates captive and wild-living island and peninsula (disease suppression) populations to minimize the loss of genetic diversity over 50 years until either extinction and reintroduction can occur, resistance evolves or a fielddeliverable vaccine is developed. Given the importance of the insurance populations and the low genetic diversity of devils, a conservative target for retention of 95% genetic diversity is recommended. Encouraging preliminary results of the first disease-suppression trial on a large peninsula show fewer late stage tumors and no apparent population decline. Limiting geographic spread or suppressing the disease on a broadscale are both unlikely to be feasible. Since the synergy of devil decline and impending fox establishment could have devastating consequences for Tasmanian wildlife, it is crucial to manage the dynamics of new and old predator species together.

No abstract

Female Tasmanian devils (TDs) Sarcophilus harrisii and spotted-tailed quolls (STQs) Dasyurus maculatus were monitored to assess changes in plasma progesterone and faecal oestrogens/progestagens, vaginal smears and qualitative changes in pouch appearance during the oestrous cycle. Pouch condition was characterized based on size, colour and secretions, and was found to accurately reflect reproductive status, being significantly correlated with changes in both sex steroids and vaginal cytology. During the follicular phase, pouch redness and secretions were maximal, and associated with increased sex steroid concentrations, a karyopyknotic index of 490% and the onset of copulation. Post-ovulation, pouches became wet and deep and developed a glandular appearance; plasma progesterone/faecal progestagen concentrations remained high and sustained throughout the luteal phase. These features were identical during the pregnant and non-pregnant oestrous cycle. This study demonstrated that pouch appearance is a reliable physical indicator of the stage of oestrous in the TD and STQ, and provides an alternative non-invasive method for evaluating the ovarian cycle of these threatened species. This technique can be readily applied to monitor individuals in free-ranging or captive populations, and will aid as a practical tool for improved breeding management.

Fecal steroid monitoring was applied as a non-invasive method to investigate testicular cycles and seasonality in the Malayan Sun bear (Ursus malayanus), an endangered ursid from South East Asia. Fecal testosterone was analyzed by radioimmunoassay in samples collected from male Sun bears (n ¼ 8) housed in zoological parks in North America and New Zealand, over periods of o27 months. Testosterone levels were often, but not exclusively, elevated during mating periods with peaks accompanying breeding behavior and copulation. There was a significant effect of age with older bears having clearly higher concentrations of fecal testosterone (Po0.001). Testosterone concentrations fluctuated throughout the year, with no significant effect of season (P40.05). All bears did, however, share a common pattern of annual excretion that suggests a potential role for non-photoperiodic seasonal influences on testicular cycles. Levels were generally lower early in the year with regular increases occurring at 3-4-month intervals. Grouped data suggest an association between cycles of testosterone production in males and months of peak reproductive activity in captivity.

Improved knowledge of the breeding biology of carnivorous marsupials is warranted given their heightened conservation status. Past studies have focused on smaller dasyurids and little is known of male reproductive physiology in the larger species. This study aimed to characterize the pattern of androgen concentrations in male devils and spotted-tailed quolls and to evaluate fecal steroid measurement as a practical, alternative technique for monitoring reproductive activity. Blood and fecal samples were collected from captive adult devils (n=6) and adult quolls (n=8). Plasma and fecal androgen concentrations were significantly positively correlated. In both species there was a significant effect of season on androgen concentrations; and the annual increase preceded female estrus activity. For devils, fecal androgens were elevated during the austral summer: peak concentrations were observed in January-February, and copulation occurred from late February-late May. In quolls, fecal androgen concentrations were highest during austral autumn/winter: the annual increase began in April and copulation occurred from mid-May to early October. The lengthy period of elevated plasma and fecal androgens and protracted annual period of mating activity implies a period of extended spermatogenesis in both species.

Deflighting is used to prevent large captive birds from escaping by limiting their ability to fly. This practice deprives birds of this normal behaviour, but can allow them to express other behaviours that would be suppressed if they were confined to cages or aviaries. The potential negative welfare issues associated with deflighting include the stress of capture and restraint, pain and discomfort associated with the procedure and during recovery, risk of post-operative infections, risk of neuroma formation which could lead to pain, and loss of the ability to fly. The potential practical and welfare advantages of deflighting include a reduction in the need to closely confine or cage birds to prevent them from escaping, and deflighting may be the only way of keeping particular birds in an open situation for display, such as in parks or zoos. In these respects, there must be a balance between the requirement for this practice and the welfare compromises it introduces for birds. By outlining temporary and permanent methods and the complications involved, the following review highlights potential welfare problems and discusses ways of avoiding them. It also evaluates the necessity of deflighting and the need for careful risk assessment.