No abstract

Large numbers of metallic starlings (Aplonis metallica) migrate annually from New Guinea to the rainforests of tropical Australia, where they nest communally in single emergent trees (up to 1,000 birds). These aggregations create dense and species-rich faunal “hot-spots”, attracting a diverse assemblage of local consumers that utilise this seasonal resource. The starlings nested primarily in poison-dart trees (Antiaris toxicaria) near the rainforest-woodland boundary. Surveys underneath these colonies revealed that bird-derived nutrients massively increased densities of soil invertebrates and mammals (primarily wild pigs) beneath trees, year-round. Flying invertebrates, nocturnal birds, reptiles, and amphibians congregated beneath the trees when starlings were nesting (the wet-season). Diurnal birds (primarily cockatoos and bush turkeys) aggregated beneath the trees during the dry-season to utilise residual nutrients when the starlings were not nesting. The abundance of several taxa was considerably higher (to > 1000-fold) under colony trees than under nearby trees. The system strikingly resembles utilisation of bird nesting colonies by predators in other parts of the world but this spectacular system has never been described, emphasizing the continuing need for detailed natural-history studies in tropical Australia.

No abstract

Article impact statement: Wallach et al.’s framing of compassionate conservation is flawed and impractical and could be dangerous for people, wildlife, and ecosystems.

Sustainability of wildlife harvests is critical but difficult to assess. Evaluations of sustainability typically combine modelling with the measurement of underlying abundances. For many taxa harvested in developing countries, however, abundances are near-impossible to survey and a lack of detailed ecological information impedes the reliability of models. In such cases, repeated surveys of the attributes of harvested individuals may provide more robust information on sustainability. If the numbers, sizes and other demographic attributes of animals taken for the commercial trade do not change over biologically significant time intervals (decades), there is a prima facie case that the harvest is indeed sustainable. Here, we report the results of examinations of > 4,200 reticulated pythons (Python reticulatus) taken for the commercial leather industry in northern and southern Sumatra, Indonesia. The numbers, mean body sizes, clutch sizes, sizes at maturity and proportion of giant specimens have not decreased between our first surveys (1995) and repeat surveys (2015). Thus, despite assumptions to the contrary, the harvest appears to be sustainable. We use our data to inform the design of future monitoring programs for this species. Our study underpins the need for robust science to inform wildlife trade policy and decision-making, and urges wildlife managers to assess sustainability of difficult-to-survey terrestrial wildlife by drawing inferences directly from the harvest itself.

Overexploitation is a key driver of biodiversity loss but the relationship between the use and trade of species and conservation outcomes is not always straightforward. Accurately characterizing wildlife trade and understanding the impact it has on wildlife populations are therefore critical to evaluating the potential threat trade poses to species and informing local to international policy responses. However, a review of recent research that uses wildlife and trade-related databases to investigate these topics highlights three relatively widespread issues: (1) mischaracterization of the threat that trade poses to certain species or groups, (2) misinterpretation of wildlife trade data (and illegal trade data in particular), resulting in the mischaracterization of trade, and (3) misrepresentation of international policy processes and instruments. This is concerning because these studies may unwittingly misinform policymaking to the detriment of conservation, for example by undermining positive outcomes for species and people along wildlife supply chains. Moreover, these issues demonstrate flaws in the peer-review process. As wildlife trade articles published in peer-reviewed journals can be highly influential, we propose ways for authors, journal editors, database managers, and policymakers to identify, understand, and avoid these issues as we all work towards more sustainable futures.

No abstract

Prey selection in many species is known to change ontogenetically, suggesting that associated changes in trophic structure may also be important. Several studies have examined relationships between prey selection and the size of trophic structures; however, few have explored these changes over ontogeny or the effects that they may have on a species broader ecology. The present study addressed this issue by examining relationships between changes in head size and prey selection in juveniles and adults from three populations of the python Morelia viridis and related them to changes in sexual maturity and ontogenetic changes in colour (OCC). Our scaling data for head size showed that juveniles and adults scaled mostly with negative allometry, and allometric slopes were significantly different before and after OCC. The change in head shape allometry was strongly associated with changes in prey selection from ectothermic to endothermic prey and with OCC in two of the three populations studied. OCC in the other population varied widely and may be the result of isolation on an oceanic island. Negatively allometric head growth is common in vertebrates and may serve a functional role in M. viridis by reducing the maximum ingestible prey size in adults, thus aiding arboreality. Our data do not allow us to test which of these changes have causal or resultant effects on one another; however, we suggest they may be part of an overall evolutionary defence–foraging strategy that circumvents costs imposed by restricting foraging opportunities to certain habitats. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, ••, ••–••.