Reproductive failure in mammals due to exposure to polychlorinated biphenyls (PCBs) can occur either through endocrine disrupting effects or via immunosuppression and increased disease risk. To investigate further, full necropsies and determination of summed 25 polychlorinated biphenyls congeners (∑PCBs lipid weight) in blubber were undertaken on 329 UK-stranded female harbour porpoises (1990-2012). In sexually mature females, 25/127 (19.
View Article and Find Full Text PDFFear of predation produces large effects on prey population dynamics through indirect risk effects that can cause even greater impacts than direct predation mortality. As yet, there is no general theoretical framework for predicting when and how these population risk effects will arise in specific prey populations, meaning that there is often little consideration given to the key role predator risk effects can play in understanding conservation and wildlife management challenges. Here, we propose that population predator risk effects can be predicted through an extension of individual risk trade-off theory and show for the first time that this is the case in a wild vertebrate system.
View Article and Find Full Text PDFCulturally transmitted tool use has important ecological and evolutionary consequences and has been proposed as a significant driver of human evolution. Such evidence is still scarce in other animals. In cetaceans, tool use has been inferred using indirect evidence in one population of Indo-Pacific bottlenose dolphins (Tursiops sp.
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