Kate A. Bryant

Opportunistic breeding in the polyandrous honey possum, Tarsipes rostratus

Honey possums, Tarsipes rostratus, tiny (7-12 g) flower-dependent marsupials, were trapped in three areas of south coastal heathland in Western Australia on 5-8 occasions each year from 1984 to 1995. Mark-recapture estimated annual mortality at 86%, with only a few individuals living for more than one year. Most females breed for the first time while not yet fully grown and may produce up to four litters in a year. Maximal litter size is four, but usually only two or three young are reared. The small litter size and relatively slow growth of pouch young is attributed to the time needed for the mothers to harvest pollen, upon which T. rostratus relies for its nitrogen requirements. Females with pouch-young were recorded in all months, but with a higher frequency over winter when nectar was most abundant, and at a lower frequency (in some years, none) when food was scarce in autumn. Young are in the pouch for about 60 days and some females give birth to the next litter soon after pouch exit, presumably from delayed blastocysts. We suggest that T. rostratus females are polyandrous and that the smaller males compete by searching for females in oestrus. The multiple paternity of several litters, confirmed by single-locus microsatellite profiling, supports this model.

Genetic isolation between coastal and fishery-impacted, offshore bottlenose dolphin (Tursiops spp.) populations.

The identification of species and population boundaries is important in both evolutionary and conservation biology. In recent years, new population genetic and computational methods for estimating population parameters and testing hypotheses in a quantitative manner have emerged. Using a Bayesian framework and a quantitative model‐testing approach, we evaluated the species status and genetic connectedness of bottlenose dolphin (Tursiops spp.) populations off remote northwestern Australia, with a focus on pelagic ‘offshore’ dolphins subject to incidental capture in a trawl fishery. We analysed 71 dolphin samples from three sites beyond the 50 m depth contour (the inshore boundary of the fishery) and up to 170 km offshore, including incidentally caught and free‐ranging individuals associating with trawl vessels, and 273 dolphins sampled at 12 coastal sites inshore of the 50 m depth contour and within 10 km of the coast. Results from 19 nuclear microsatellite markers showed significant population structure between dolphins from within the fishery and coastal sites, but also among dolphins from coastal sites, identifying three coastal populations. Moreover, we found no current or historic gene flow into the offshore population in the region of the fishery, indicating a complete lack of recruitment from coastal sites. Mitochondrial DNA corroborated our findings of genetic isolation between dolphins from the offshore population and coastal sites. Most offshore individuals formed a monophyletic clade with common bottlenose dolphins (T. truncatus), while all 273 individuals sampled coastally formed a well‐supported clade of Indo‐Pacific bottlenose dolphins (T. aduncus). By including a quantitative modelling approach, our study explicitly took evolutionary processes into account for informing the conservation and management of protected species. As such, it may serve as a template for other, similarly inaccessible study populations.

Do preservation methods affect the identification of dietary components from faecal samples? A case study using a mycophagous marsupial

We tested whether four preservation methods for faecal samples affected the identification of dietary components from the mycophagous woylie (Bettongia penicillata ogilbyi). All storage techniques identified fungi as the most abundant food type (>69%), followed by plant material (9-17%) and invertebrates (<5%). Between 8 and 13% of material from each technique was unidentifiable. Despite these general similarities in the results from the different techniques, there were small but statistically significant differences in the relative importance of the food types estimated using the different preservation techniques. Individual researchers will need to decide on a case-by-case basis whether these small differences can be disregarded given the general aims of their study or whether a correction factor is appropriate if small differences in diet are important to their objectives.

Quantifying the internationality and multidisciplinarity of authors and journals using ecological statistics

Authors or journals often claim internationality or multidisciplinarity based on assertion or qualitative evidence, while scientometric studies employ sophisticated analyses or software beyond the resources of occasional users to assess these concepts. This paper demonstrates how statistics used to describe ecological communities can be applied to bibliometric data to quantify internationality or multidisciplinarity for individuals and journals, enabling tests of statistical significance using graphical user interface freeware accessible to even occasional users. Margalef Richness, diversity and evenness or equitability can be calculated to indicate whether papers or citations come predominantly from a small group of countries or disciplines, or are more widely distributed. Tests of statistical significance for differences in Margalef richness, diversity or evenness between authors or journals enable testing of diverse hypotheses including, for example: differences in internationality or multidisciplinarity between authors or between journals; or changes over time in these variables for authors or journals (perhaps in response to career changes or changes in editorial policy). Quantifying internationality and multidisciplinarity in an accessible way for many potential users, with the possibility of statistical hypothesis testing, is a significant advance over assertion and qualitative description on the one hand or conceptually and practically complex analysis on the other.

Diet of the critically endangered woylie (Bettongia penicillata ogilbyi) in south-western Australia

Abstract. To assist the management of the critically endangered woylie (Bettongia penicillata ogilbyi), a quantitative study of its diet was conducted across five of the larger subpopulations in south-western Australia. There was a close match between dietary composition established from foregut contents and faecal pellets. Woylies were predominantly mycophagous in all subpopulations, but consumed a broad diet including invertebrates, seeds and other plant material. Individuals in a high-density, fenced subpopulation ate significantly less fungi than free-ranging animals from lower-density subpopulations. Dietary composition did not vary significantly amongst subpopulations in the Upper Warren region, where a range of population densities was observed. Altogether, 79 fungal spore classes were identified, including at least 15 genera from 14 families. Sampling across one year showed that fungi made up a larger fraction of the diet in autumn or winter, and greater diversities of fungi were consumed at these times than at other times of year. This information is essential to provide valuable ecological context for effective population management of woylies, as well as identification and conservation of important habitats.