Trouble in paradise: When two species of conservation and cultural value clash, causing a management conundrum

Threatened species throughout the world are in decline due to various causes. In some cases, predators of conservation or cultural value are causing the decline of threatened prey, presenting a conservation conundrum for managers. We surveyed marine turtle nests on K'gari (formally known as Fraser Island), Australia, to investigate dingo predation of green and loggerhead turtle nests, where each of these species is of conservation value. Our monitoring revealed that 84% of nests were predated by dingoes. Only 16% of nests were not consumed by dingoes, and only 5.7% of nests were confirmed to have successfully hatched. Up to 94% of nests were consumed in some areas, and predation rates were similar across different dingo packs. Information on the available numbers of nests and dingoes in the area indicated that turtle nests alone are sufficient to support extant dingoes over the summer. These results indicate that marine turtle eggs represent a previously unquantified but important food source for dingoes on K'gari, and that turtle nests at this rookery site are under serious threat from dingoes. This research should highlight the importance of prioritising the protection of turtle nests from dingoes or risk losing the entire rookery forever in the near future.

The current state of carnivore cognition

The field of animal cognition has advanced rapidly in the last 25 years. Through careful and creative studies of animals in captivity and in the wild, we have gained critical insights into the evolution of intelligence, the cognitive capacities of a diverse array of taxa, and the importance of ecological and social environments, as well as individual variation, in the expression of cognitive abilities. The field of animal cognition, however, is still being influenced by some historical tendencies. For example, primates and birds are still the majority of study species in the field of animal cognition. Studies of diverse taxa improve the generalizability of our results, are critical for testing evolutionary hypotheses, and open new paths for understanding cognition in species with vastly different morphologies. In this paper, we review the current state of knowledge of cognition in mammalian carnivores. We discuss the advantages of studying cognition in Carnivorans and the immense progress that has been made across many cognitive domains in both lab and field studies of carnivores. We also discuss the current constraints that are associated with studying carnivores. Finally, we explore new directions for future research in studies of carnivore cognition.

The killer’s toolkit: remarkable adaptations in the canine teeth of mammalian carnivores

Often the first point of contact between predator and prey, mammalian canine teeth are essential for killing, dismembering and consuming prey. Yet despite their importance, few associations among shape, function and phylogeny are established. We undertook the first comprehensive analysis of canine tooth shape across predatory mammals (Carnivora, Didelphimorphia and Dasyuromorphia), integrating shape analysis with function of this fundamental feature. Shape was quantified using three-dimensional geometric morphometrics and cross-sectional sharpness. Canines vary in three main ways (sharpness, robustness and curvature) which vary with diet, killing behaviour and phylogeny. Slender, sharp canines are associated with carnivores such as felids that target the neck of their prey and primarily consume the ‘softer’ parts of a carcass. Robust, blunt canines are found in mustelids and dasyurids that typically consume ‘harder’ materials, such as bone, or bite into skulls. Differences in the killing behaviours of felids and canids probably result in more curved canines in the latter, which act as hooks to hold prey. We find functional specialization in the upper and lower canines of individuals and across the major mammalian clades. These patterns demonstrate how canine teeth are adapted to suit diverse diets and hunting styles, enabling mammals to become some of nature's most successful predators.