Characterization of Ovarian Steroid Patterns in Female African Lions (Panthera leo), and the Effects of Contraception on Reproductive Function

RESEARCH ARTICLE Characterization of Ovarian Steroid Patterns in Female African Lions (Panthera leo), and the Effects of Contraception on Reproductive Function Sarah B. Putman1,2, Janine L. Brown1, Ashley D. Franklin1,3, Emily C. Schneider1,4, Nicole P. Boisseau1, Cheryl S. Asa5, Budhan S. Pukazhenthi1* 1 Smithsonian Conservation Biology Institute, Front Royal, Virginia, United States of America, 2 George Mason University, Fairfax, Virginia, United States of America, 3 Point Defiance Zoo and Aquarium, Tacoma, Washington, United States of America, 4 Shady Grove Fertility, Rockville, Maryland, United States of America, 5 AZA Wildlife Contraception Center, St. Louis, Missouri, United States of America * OPEN ACCESS Citation: Putman SB, Brown JL, Franklin AD, Schneider EC, Boisseau NP, Asa CS, et al. (2015) Characterization of Ovarian Steroid Patterns in Female African Lions (Panthera leo), and the Effects of Contraception on Reproductive Function. PLoS ONE 10(10): e0140373. doi:10.1371/journal. pone.0140373 Editor: Nei Moreira, Federal University of Parana (UFPR)—Campus Palotina, BRAZIL Received: March 30, 2015 Accepted: September 24, 2015 Published: October 13, 2015 Copyright: This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication. Data Availability Statement: All relevant data are within the paper and its Supporting Information files. Funding: This work was supported by ASLAN Fund National Zoo and Ritz Carlton. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Abstract Because of poor reproduction after the lifting of an 8-year breeding moratorium, a biomedical survey of female lions in U.S. zoos was initiated in 2007. Fecal estrogen (FEM), progestagen (FPM) and glucocorticoid (FGM) metabolites were analyzed in samples collected 3–4 times per wk from 28 lions at 17 facilities (0.9–13.8 yr of age) for 4 mo—3.5 yr and body weights were obtained ~monthly from 17 animals at eight facilities (0.0–3.0 yr of age). Based on FEM, estrous cycle length averaged 17.5 ± 0.4 d in duration, with estrus lasting 4.4 ± 0.2 d. All but one female exhibited waves of estrogenic activity indicative of follicular activity; however, not all females expressed estrous behaviors (73%), suggesting silent estrus was common. Female lions experienced puberty earlier than expected; waves of estrogenic activity were observed as young as 1.1 yr of age, which may be related to a faster growth rate of captive vs. wild lions. Mean gestation length was 109.5 ± 1.0 d, whereas the non-pregnant luteal phase was less than half (46.0 ± 1.2 d). Non-mating induced increases in FPM were observed in 33% of females housed without a male, consistent with spontaneous ovulation. A number of study animals had been contracepted, and the return to cyclicity after treatment withdrawal, while variable, was ~4.0 yr and longer than the 1-yr expected efficacy, especially for those implanted with Suprelorin. For FGM, there were no differences in overall, baseline or peak mean concentrations among the age groups or across seasons, nor were there any relationships between reproductive parameters and FGM concentrations. Overall, results suggest that poor reproduction in lions after the breeding moratorium was not related to altered adrenal or ovarian steroid activity, but for some females may have been a consequence of individual institutions’ management decisions. Competing Interests: The authors received funding from Ritz Carlton, a for-profit organization. The funders did not have any influence on content or interpretation of the data presented in this PLOS ONE | DOI:10.1371/journal.pone.0140373 October 13, 2015 1 / 27 Female African Lion Endocrinology and Effects of Contraception manuscript. Hence, this does not alter the authors' adherence to PLOS ONE policies on sharing data and materials. Introduction Globally, African lions (Panthera leo) are listed as vulnerable with a decreasing population trend [1], although in western and central Africa, lions are considered endangered [2]. In 2004, the total number of lions in Africa was estimated to be 16,000–30,000 individuals, a reduction of >97% over a 200-year period [3]. Today, only seven countries in Africa have more than 1,000 lions [4] and most populations exist only in small areas of dry forests, grasslands and protected reserves [5,6]. Pressures from persecution [7,8], disease [9,10] and habitat loss [11] are main causes of wild lion population declines. Conserving this species long-term likely will require improved in situ management in combination with establishing ex situ ‘insurance’ populations as part of overall conservation efforts [12,13]. Natural mating is an important aspect of captive breeding, but when that fails or more intensive genetic management is needed, zoos often rely on assisted reproductive technologies (ART), like artificial insemination (AI) and in vitro fertilization (IVF). To do so, a thorough knowledge of species reproductive mechanisms is required so that species-specific protocols can be developed [14–17]. Female lion reproductive biology appears to be similar to other Felidae in that females exhibit variable estrous cycle lengths, non-pregnant luteal phases (NPLP) that are shorter than the length of a pregnancy, and they are considered induced ovulators but can ovulate spontaneously [18]. Historically, African lions have bred relatively well in captivity [19–21], especially when compared to other felids [22–26]. As a result, reproduction has often exceeded available space. In one instance, between ~1990 and 1998, the North American African Lion Species Survival Plan (SSP) program instituted a breeding moratorium to better manage animal spaces, as well as to remove African/Asiatic hybrids and individuals of unknown pedigree from the breeding population. New founders were imported from Africa to bolster the genetics of the population. However, after the moratorium was lifted in 1999, the captive population experienced a 6-year period of low fecundity. Only 35.4% of reproductive-age females produced offspring between 1999 and 2005, compared to 68% between 1990 and 1998 [27] when breeding was limited to new founders. Thus, in 2007, the SSP requested a reproductive assessment of both male and female lions, including gonadal hormone activity, to determine underlying causes of poor reproduction. At that time, surprisingly little was known about lion endocrine function. The majority of extant studies were based on behavioral observations only [28,29]. Few had collected biological data and these involved only a small number of captive animals [30,31], post-mortem examinations of culled individuals in the wild [32] or short-term (< 3 hr) blood sampling [33]. Wit (...truncated)