Non-invasive endocrine monitoring applied to conservation, welfare and behavioral studies of wildlife.

CANTARELLI V; MASTROMONACO G; GILMAN C; PONZIO M.F

virtual

Congreso; 54th International Congress of the International Society for Applied Ethology (ISAE).; 2021

International Society for Applied Ethology (ISAE).

Traditionally, studies on reproductive biology and the response to stress have been based on the determination of endocrine activity of hormones associated with these processes in plasma, along with behavioral studies. However, the collection of blood samples itself constitutes a procedure that can modify plasma glucocorticoid levels and in turn, negatively impact the expression of the hypothalamic-pituitary-gonadal/adrenal axis and in turn the behavioral activity of the studied animals. In addition, plasma levels of certain hormones fluctuate widely as a result of pulsatile secretion and/or circadian rhythms and therefore, each blood sample provides a static data of a parameter that is changing, so multiple samples would be needed to have a reliable notion of long-term hormonal secretory activity. Non-invasive hormonal monitoring allows us to measure the metabolites of steroid hormones in different matrices, such as feces, urine, saliva, hair, feathers, egg yolk etc. The steroids of interest are extracted from the matrices using methanol, and the resulting supernatant is assayed using polyclonal antibodies in an enzyme immunoassay. The main benefit of these techniques lies in the fact that its use completely avoids the stress of animal handling and restraint associated with the collection of blood samples and the risks associated with repetitive venipuncture. This is particularly important when dealing with wild animals in captivity or when also recording behavioral data. Furthermore, sample collection can be performed during long periods of time and finally, the type of assay used is relatively simple, efficient and easy to adapt from one species to another.Using these techniques, we were able to evaluate, both in the wild and in captivity, aspects as diverse as reproductive cycles, seasonal variations, sexual and behavioral differences associated with hormones, association between hierarchical positions, effects of environmental toxins on the endocrine function, stress and, even more, the effects of human activities on animal welfare. However, the implementation of laboratory techniques associated with this discipline emphasizes their prior validation, aspects that will be considered in this dissertation.