Using Positive Reinforcement Conditioning to Collect Samples From Unanaesthetized Lions (Panthera leo) for Reproductive Studies
Assisted reproduction techniques (ARTs) have incredible potential in wildlife conservation, but are vastly unexplored.1,2 African lions (Panthera leo) represent an accessible model for the study of the reproductive biology of large, non-domestic felids, and the applicability of ARTs within their conservation programs. Thus, there is a need to achieve a better understanding of this species‘s reproduction physiology and to develop accurate and field-friendly protocols for techniques such as artificial insemination (AI) during both natural and induced estrus for this species.
Hereby, as part of a broader research project focusing on these matters, six female African lions held at Ukutula Conservation Center (North West Province, South Africa) were trained by means of habituation, desensitization, and positive reinforcement conditioning to voluntarily allow blood collection from the lateral coccygeal vein, as well as collection of vaginal cytology samples, and vulva pictures. In parallel, scan and continuous behavior monitoring was performed, two hours a day, five days per week, for nine months, to record and describe any sexual activity and estrous signs present in these females.
All animals showed great interest in the training sessions, and remained calm and cooperative during the sampling procedures. The use of this methodology makes reproductive cycle monitoring easier, allowing frequent sample collection (i.e., every 1–2 days). Around 350 blood samples and 400 cytology samples and pictures have been collected from the lionesses since the training was first implemented in June 2017. To date, a total of 16 estrous cycles have been identified by the presence of specific signs such as purring, flirting, lordosis, rolling, and increased anogenital grooming, as well as by enlarged and separated vulvar lips and hyperemic vaginal mucosa, and a high incidence of superficial cornified vaginal cells. This information, together with the results of the endocrine tests currently taking place will allow in-depth description of the reproductive cycle of the African lion, and to identify the precise moment for artificial insemination in this species.
In comparison with traditional chemical restraint, our sampling methodology using positive reinforcement training reduces the psychologic stress component associated with anesthesia and its possible physiologic effects (e.g., hypoventilation, hypotension), and opens up a new research approach to felid reproduction physiology.
The authors would like to thank Ukutula Conservation Center for their assistance throughout this study, specially to the ranger‘s team for their cooperation during the training sessions and sampling procedures.
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2. Swanson WF. Application of assisted reproduction for population management in felids: the potential and reality for conservation of small cats. Theriogenology. 2006;66:49–58.