The welfare and ethics of research involving wild animals: A primer

1. Wild animals are used in scientific research in a wide variety of contexts both in situ and ex situ. Guidelines for best practice, where they exist, are not always clearly linked to animal welfare and may instead have their origins in practicality. This is complicated by a lack of clarity about indicators of welfare for wild animals, and to what extent a researcher should intervene in cases of compromised welfare. 2. This Primer highlights and discusses the broad topic of wild animal welfare and the ethics of using wild animals in scientific research, both in the wild and in controlled conditions. Throughout, we discuss issues associated with the capture, handling, housing and experimental approaches for species occupying varied habitats, in both vertebrates and invertebrates (principally insects, crustaceans and molluscs). 3. We highlight where data on the impacts of wild animal research are lacking and provide suggestive guidance to help direct, prepare and mitigate potential welfare issues, including the consideration of end-points and the ethical framework around euthanasia. 4.We conclude with a series of recommendations for researchers to implement from the design stage of any study that uses animals, right through to publication, and discuss the role of journals in promoting better reporting of wild animal studies, ultimately to the benefit of wild animal welfare.