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Australia has lost two species and one subspecies of ratite due to historical persecution and anthropogenic changes to their habitats. Two additional ratites, the Southern Cassowary (Casuarius casuarius johnsonii) and Coastal Emu (Dromaius novaehollandiae), are following this trajectory and will require human intervention to prevent further population decline or extinction. Advanced reproductive technologies offer promising avenues for the management of genetic and demographic diversity, both in-situ and ex-situ. Here, we review two important techniques and their efficacy in the conservation management of Australian ratites. The first is the sexing of an embryo in-ovo. This technique is central to developing technologies, however, is presently problematic in species producing thick and heavily pigmented eggs (i.e. Cassowary and Emu). Developments including the reduction of the shell membrane may promote light refraction and thus render the technique able to be used safely with developing embryos of Australian ratites. The supplementation of natural hormone during early embryonic development is another tool for sex regulation in ratite embryos. This was previously trialled in the Ostrich to influence a preferred gonadal sex, however, it will be trialled in the Emu and Cassowary for the first time. The use of these advanced reproductive technologies will complement current conservation efforts for Australian ratites, and facilitate the establishment and maintenance of robust captive populations. [ABSTRACT FROM AUTHOR]

BACKGROUND Currently in Australia there are no standardised recommendations regarding the age at which dogs and cats should be desexed and there is a lack of clear evidence to support desexing at any particular age. The purpose of this study was to determine Australian veterinarians’ opinions and practices in relation to dog and cat desexing. METHODS A cross-sectional survey was emailed to all members of the Australian Veterinary Association in March 2013. Chi-squared test analysis was used to examine the association between demographic variables of respondents and the recommended (≤ 16 weeks, 20 weeks or ≥ 6 months) and minimum desexing age (≤10 weeks, 12−16 weeks or ≥ 20 weeks). RESULTS Respondents most commonly recommended desexing dogs and cats at the age of 6 months (24 weeks) before they have a season or a litter. The mean recommended age for desexing dogs was 21.9 weeks and for cats it was 20.8 weeks. The most common minimum age that veterinarians would desex dogs and cats if requested was 12 weeks. The mean minimum age for desexing dogs was 14.2 weeks and for cats was 13.5 weeks. A large proportion of respondents reported that they would perform early age (< 16 weeks) desexing if requested. A smaller proportion reported that they would perform very early age (< 10 weeks) desexing if requested. Anaesthetic risk was a major concern that inhibited respondents from desexing earlier. Respondents reported they would be more inclined to recommend earlier desexing with greater support from the scientific literature. CONCLUSION Respondent age, university of graduation, year of graduation, sex and current employment played significant roles in veterinarians’ recommended and minimum ages for desexing. [ABSTRACT FROM AUTHOR]

Contents Flow cytometric sexing of spermatozoa followed by application in artificial insemination or in vitro fertilization provides a unique opportunity to predetermine the sex of offspring and might enhance the conservation management of endangered species in captivity such as the elephant and rhinoceros. To obtain an indication of the sortability of spermatozoa from these species, the relative DNA differences between X and Y chromosome bearing spermatozoa (fresh, frozen thawed, epididymal) from three rhinoceros species [white ( Ceratotherium simum), black ( Diceros bicornis), Indian ( Rhinoceros unicornis)] and both elephant species, the Asian and the African elephant ( Elephas maximus, Loxodonta Africana), were determined through separation of spermatozoa into X and Y chromosome bearing populations, using a modified high speed flow cytometer. The head profile areas of spermatozoa from all five species were measured using light microscopy. By multiplying the relative DNA differences and the head profile areas, the sperm sorting indices were calculated to be 47, 48 and 51 for white, black and Indian rhinoceros respectively. The calculated sorting index for the Asian elephant was 66. In the African elephant, we determined the highest sorting index of 76. These results indicate the practicability of flow cytometric sex sorting of spermatozoa from the tested rhinoceros species and both elephant species. The lower sorting indices in rhinos indicate that sex sorting of spermatozoa from the rhinoceros will be more challenging than in elephants. [ABSTRACT FROM AUTHOR]

Since 1980, 856 Sooty Oystercatchers (Haematopus fuliginosus) have been caught and banded in Australia by the Victorian Wader Study Group (n=801, from southern Australia) and the Australasian Wader Studies Group (n=55 birds, all from north-western Australia). The biometric data collected were analysed for differences between sexes and ages and for geographical differences. Females were larger than males in all biometric dimensions, in all age-groups and in both geographical regions. For both subspecies – H. f. fuliginosusin south-eastern Australia and H. f. opthalmicusin north-western Australia – length of bill (exposed culmen) was the most discriminating parameter for determination of sex. Weights of adult females increased markedly towards the end of the moulting period. In south-eastern Australia, adult males considerably outnumber adult females in catches. Furthermore, adult males also outnumbered adult females in late autumn–early winter samples; at other times, and in other age-groups, the sex-ratio was more evenly balanced. Differential survival or spatial distribution of females and males are proposed as the mechanisms causing male-biased tertiary sex-ratios in catches. South-eastern Australian birds were larger and heavier than their northern counterparts. Furthermore, comparisons between Sooty Oystercatchers and the sympatric congener, the Australian Pied Oystercatcher (H. longirostris) showed the former to be significantly larger and heavier in both parts of the country. [ABSTRACT FROM AUTHOR]