Page 74 - University of Pretoria RESEARCH REVIEW 2016

HEALTH
SEARCHING FOR THE DIRTY TRUTH
REPRODUCTION, HEALTH AND WELLBEING OF WILDLIFE
Wildlife endocrinology provides valuable information about the mechanisms regulating reproduction and the responses to stressors, thereby contributing to conservation
efforts. Research provides insights into
the influence of environmental factors on reproduction and supports the development of assisted reproductive technologies.
The Endocrine Research Laboratory (ERL) at UP addresses questions concerning the regulative endocrine mechanisms in mammals, reptiles and birds, with the focus on developing and validating non-invasive tools to monitor the reproductive functions and responses to stressors in wildlife, and in domestic animals. Since its establishment in 2009, the ERL has developed numerous non-invasive tests for a wide range of species, and has been pioneering techniques in Africa. The core work of the laboratory involves non-invasive endocrine monitoring of faecal samples from a wide variety of animals.
Professor André Ganswindt, recently appointed Director of the Mammal Research Institute in
the Faculty of Natural and Agricultural Sciences, writes that monitoring reproductive functions and responses to stressors in wildlife can be challenging, especially when working with elusive and dangerous animals. Capturing wildlife to collect blood samples usually causes a stress response, making it difficult to determine natural cause-and-effect relationships. Furthermore, frequent blood sampling may be harmful, particularly to small animals such as Spiny mice, Elephant shrews, or African lesser bushbabies. Non-invasive methods have gained popularity over the past 30 years as a more practical approach for assessing ovarian, testicular and, more recently, adrenocortical activity in wildlife. The alternative hormone matrices now most commonly used are urine, saliva, feathers, hair, and especially faeces.
Faeces are the best hormone matrix that can be collected without disturbing the animal. Faecal hormones can provide useful information on
female and male reproductive status, as well as adrenocortical function as a measure of stress. For example, Professor Ganswindt’s team is able to determine pregnancy in free-ranging white rhinos by monitoring the levels of progestogens. The group is able to examine the welfare implication of dehorning by measuring glucocorticoid concentrations, an approach that contributes towards efforts to protect endangered species like the rhino.
Hormone metabolism and excretion are highly species-specific processes, and this specificity
even applies to closely related species. Tests must therefore be validated for every new species studied. Professor Ganswindt explains that only certain types of hormone, or rather their metabolites, can be quantified. The ERL focuses on quantifying steroids, and to a lesser extent amine hormones, because other compounds, such as protein hormones,
are completely degraded by the time defecation takes place.
Adapted from text by Louise de Bruin, http://www.up.ac.za/en/news/post_2141307-searching-for-the-dirty-truth 72 | UP Research Review 2016
Stefanie Ganswindt