Protocol for: Beyond glucocorticoids: A scoping review of hormones in keratinized tissues of non-human mammals.

Hormonal measurements in keratinized tissues of animals (i.e. hair, claws) are useful tools to assess long-term physiological process and overall health. However, existing research has mostly focused on the link between glucocorticoid levels and stress. In this scoping review, we aim to describe the extent of research and highlight the gaps in knowledge of hormonal measurements, other than glucocorticoids, in the keratinized tissues of non-human mammals Eligible studies will include non-human mammals, regardless of species or living conditions, in which keratinized tissues (i.e. hair, hooves, claws, horns, baleen) are used for the extraction and quantification of hormones besides glucocorticoids (cortisol, corticosterone). Studies must investigate associations between hormone concentrations and intrinsic (i.e. age, sex, reproductive status) and/or extrinsic factors (i.e. seasonality, environmental disturbance). The key information sources that will be searched are MEDLINE All (Ovid), Web of Science and CAB Abstracts (Ovid). All identified references will be screened and extracted through Covidence independently by two reviewers. Extracted data will be synthesized descriptively to provide an overview of the hormones, tissues, species, investigated association, and research gaps in this field.