This dataset comprises cast reconstructions of brain cavity space in 60 extant avian species, derived from X-ray micro computed-tomography scan image stacks. Each reconstruction was made using Materialise Mimics 14.11 to create volumetric models (brain cavity casts) that were then transformed into the polygon mesh stereolithograph (STL) files archived here. Brain cavity cast models are in most cases accompanied by casts of main vascular features (e.g., carotid arteries) and the olfactory nerves (CN I). A data file (Data_TableComma Separated Values) based on values reported in Table 1 of Walsh et al. (2013: doi:10.1371/journal.pone.0067176) is included that records volume values used in the original analysis, and coding of cerebellar flocculus morphology. Full details about this nonGeographicDataset can be found at https://doi.org/10.5285/4e15f483-5b05-409e-acc0-5117fc24e90b

Data comprise measurements of carcass condition (age, sex, length, mass and fat score), age (from stable isotope analysis of whiskers and Cementum aging of teeth) and rodenticide concentrations (bromadiolone, difenacoum, brodifacoum, flocoumafen and difethialone) in liver tissues for 68 polecats found dead in Great Britain between 2013 and 2016. All carcasses were stored frozen until necropsy examination at the National Museum of Scotland (with support from The Negaunee Foundation). Liver samples were frozen and transferred to the Centre for Ecology & Hydrology (CEH) for rodenticide analysis. Funding for the rodenticide analysis was provided by the People's Trust for Endangered Species and CEH. PhD funding from The Vincent Wildlife Trust and the University of Exeter. Full details about this dataset can be found at https://doi.org/10.5285/2f49911c-192c-4f09-a1a2-72a21f20706c