Animal Reproduction Science 144 (2014) 38–47 Contents lists available at ScienceDirect Animal Reproduction Science journal h om epa ge: www.elsevier.com/locate/anireprosci Factors influencing breeding success, ovarian cyclicity, and cub survival in zoo-managed tigers (Panthera tigris) Sarah P. Saunders a,∗ , Tara Harris b , Kathy Traylor-Holzer c , Karen Goodrowe Beck d a Conservation Biology Graduate Program, University of Minnesota, 2003 Upper Buford Circle, Suite 135, St. Paul, MN 55108, USA b Minnesota Zoo, Conservation Department, 12101 Johnny Cake Ridge Road, Apple Valley, MN 55124, USA c IUCN SSC Conservation Breeding Specialist Group, 12101 Johnny Cake Ridge Road, Apple Valley, MN 55124, USA d Point Defiance Zoo & Aquarium, 5400N Pearl Street, Tacoma, WA 98407, USA a r t i c l e i n f o Article history: Received 12 May 2013 Received in revised form 10 November 2013 Accepted 18 November 2013 Available online 28 November 2013 Keywords: Breeding success Cub survival Ovarian cyclicity Panthera tigris Tiger Zoo-managed a b s t r a c t Understanding factors that influence reproduction and offspring survival in zoo popula- tions is critical for management of threatened and endangered species. Examination of long-term data (1989–2011) compiled from the Association of Zoos and Aquarium’s zoo- managed tiger breeding program provides the basis for a more thorough understanding of reproduction and scientifically based decisions for effective population management in this endangered felid. Biological and management-related factors that could influence tiger breeding success and cub survival were evaluated using logistic mixed models. Breeding success improved with female age until approximately age five, then declined thereafter. Experienced female breeders had greater breeding success than inexperienced females. Litter size was most predictive of cub survival, with average-sized litters (3–4 cubs) expe- riencing the highest proportional survival. Management-related factors, such as whether the breeding institution had a recent tiger litter and whether both animals were already located at the same institution, also influenced breeding success and cub survival. These results highlight the importance of institutional husbandry experience and the need to retain knowledge through staff turnovers to achieve optimal reproductive success. Using fecal estrogen data, frequency of ovarian cyclicity and mean cycle length did not differ by female age or parity; thus, lack of cyclicity and/or increased cycle duration are not likely explanations for declining breeding success with age. These results provide valu- able reproductive information that should improve scientific management of zoo-based tiger populations. © 2013 Elsevier B.V. All rights reserved. 1. Introduction Understanding factors that influence reproduction and offspring survival can be important for zoo-based manage- ment of threatened species, as they impact reproductive ∗ Corresponding author at: 2003 Upper Buford Circle, Suite 135, St. Paul, MN 55108, USA. Tel.: +1 708 220 6590. E-mail addresses: saund196@umn.edu (S.P. Saunders), tara.harris@state.mn.us (T. Harris), kathy@cbsg.org (K. Traylor-Holzer), karen.goodrowe@pdza.org (K.G. Beck). success and population growth rate (Owen et al., 2010). Intensively managed breeding programs use these data to make scientifically based, strategic recommendations that aim to achieve the goal of demographically stable and genetically diverse populations (Ballou et al., 2010). Though highly endangered in the wild, tigers (Panthera tigris) are one of the most commonly exhibited species in zoos worldwide. Cooperative breeding programs for tigers are coordinated by numerous regional zoo associations around the world, and serve as a “genetic lifeboat” by mak- ing breeding recommendations aimed at retaining genetic 0378-4320/$ – see front matter © 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.anireprosci.2013.11.006