Reproductive Physiology of Ethiopian wolves (Canis simensis) A thesis submitted for the degree of MSc by Research Freya van Kesteren Wildlife Conservation Research Unit, Department of Zoology The Queen’s College, University of Oxford Hillary Term 2011 1 Abstract Reproductive physiology of Ethiopian wolves, Canis simensis Freya van Kesteren, Queen’s College MSc by Research, Hillary 2011 Cooperative breeding can be defined as a breeding system in which more than a pair of individuals help rear young from a single litter. Ethiopian wolves, Canis simensis, like many other canids, breed cooperatively. However, unlike most group living canids, they specialize in hunting rodents and forage solitarily. Their unusual social system, which combines cooperative breeding, intense sociality and solitary foraging, makes Ethiopian wolves a suitable species in which to study the physiology of cooperative breeding. There are no Ethiopian wolves in captivity, but advances in reproductive science have enabled researchers to study the reproductive physiology of wild populations non-invasively by extracting and assaying hormones in faecal samples using radio/enzyme immunoassays. Using these methods I studied the reproductive physiology of Ethiopian wolves in Bale Mountains National Park, Ethiopia, the largest population of these rare endemic canids. Faecal samples must be preserved almost immediately after defecation to prevent bacterial degradation of hormones. Freezing is the preferred storage method under controlled conditions, but is often infeasible when studying wild populations. Comparison of three alternative storage methods determined that desiccating samples was a reliable method of preserving Ethiopian wolf samples in field conditions. Analysis of faecal samples collected from 14 dominant and nine subordinate female Ethiopian wolves revealed that dominant females came into oestrus and showed oestradiol peaks during the annual mating season, whereas subordinate females did not, suggesting a hormonal mechanism of reproductive suppression. However, two subordinate females came into oestrus outside the annual mating season. Both dominant and subordinate females had increased levels of progesterone during the duration of the dominant’s pregnancy, and three subordinate females showed signs of pseudopregnancy, including lactation. These results suggest that some subordinate females come into oestrus outside the mating season and become pseudopregnant, as pseudopregnancy in canids follows an infertile ovulation. Dominant females did not prevent subordinate females from mating, and cortisol levels of dominant and subordinate females did not differ significantly during the mating season, suggesting that reproductive suppression in female Ethiopian wolves was unrelated to aggression or stress hormones. No seasonal patterns in testosterone levels in samples collected from male Ethiopian wolves were found. Subordinate males were observed engaged in mating behaviour, including with their pack’s dominant female, but dominant males would prevent subordinate males from mating with the dominant female, suggesting a behavioural method of reproductive suppression. Dominant males had higher cortisol levels than subordinates, which may be related to the stress of maintaining dominant status and/or mate guarding. In summary, seasonal patterns in progesterone and oestradiol levels were found in female Ethiopian wolves, but not in testosterone levels in males. There was evidence for hormonal and behavioural reproductive suppression of subordinate females and males respectively, but in neither sex was reproductive suppression mediated through stress hormones. As well as providing an insight into the reproductive physiology of a rare cooperatively breeding canid, this study provides needed reproductive biology information for a hitherto unstudied species, and sets the basis for making a contribution to future reproductive management initiatives for the conservation of this charismatic canid. i Acknowledgements This research could not have been carried out without the support and input of many people, and I am grateful to many colleagues, institutions, friends and family. Firstly I would like to thank my main supervisor, Dr. Claudio Sillero-Zubiri, and co- supervisors Prof. David Macdonald, Prof. Bob Millar and Dr. Monique Paris for providing me with the opportunity to study the Ethiopian wolves in Bale and for your supervision and guidance. Special thanks go to Claudio for sharing his knowledge of and passion for the wolves with me, to David for his academic input and support, to Bob for help with the laboratory analyses, input and support and to Monique for very helpful discussions and moral support. This research could also not have been carried out without funding provided by the Institute for Breeding Rare and Endangered African Mammals, Dr. Mervyn Jacobson, Queen’s College Oxford and the Prins Bernhard Cultuurfonds. Funding for the Ethiopian Wolf Conservation Programme was generously provided by the Wildlife Conservation Network and the Born Free Foundation. I would also like to thank the Ethiopian Wildlife Conservation Authority, and especially Dr. Kifle Agraw, the Oromia Bureau for Agriculture and Rural Development, and the Bale Mountains National Park staff and especially warden Berhanu Jilcha for permission to carry out this research in Bale. Special thanks go to my field team in Bale; Gedlu Tessera, Muzeyen Turkee, Tamam Mohammed, Yussuf Emeno, Antennah Girma and Hussein Savi for their hard work in collecting the faecal samples and behavioural data. We not only worked side by side for three years but also shared our meals, celebrated holidays and had some great times together. Thanks go to Henrietta Chilton and Stephanie Graham for agreeing to be my volunteers. I am sorry both your visits to Bale were cut short by injuries and wish you better luck in future exploits! Thanks to Melody Kelemu, who volunteered for me only very briefly but became a friend and impressed me with her wisdom at such a young age! I would like to thank all of the EWCP team, including Anne-Marie Stewart, Chris Gordon, Edriss Ebu, Fikre Getachew and Wegayo Worku for their help and support in Bale. Special thanks go to Anouska Kinnahan and Thadeigh Baggallay from the Frankfurt Zoological Society. I am very grateful for your support and kindness, and for being there for me to turn to when I needed help. Thank you to Charlie Watson and Flavie Vial, the other two Bale firengi gals, both strong, intelligent, and wonderful women. I am happy we shared some experiences in Bale and I’m grateful for your friendship and support. Thanks should also go to the wolves, who became very dear to me and tolerated my endlessly following them and collecting their faecal samples. Individuals such as Orange, White-White, Nafanta and many others enriched my life and if I have made any contribution to the conservation of this species I have accomplished something worthwhile. At the HRSU in Edinburgh I would like to thank Nancy Evans and Ian Swanston for your help with the lab work, and for your patience and friendliness. Special thanks go to Krissy Nichols, for being another ‘poo person’, for your help in the lab, and for your friendship. I would like to thank Phil Allcock from Zoology Stores in Oxford for help in sourcing the necessary lab equipment. Thanks go to Prof. Wenche Farstad and Tucker Murphy for comments on earlier drafts, and to Prof. Franz Schwarzenberger for some of the assays. ii For the last few years I have been a part of WildCRU, and I have never known such a wonderful, intelligent, dedicated and kind group of people. I found support, acceptance and friendship at WildCRU, and shared stimulating conversations, laughs and good times with everyone here. In particular I would like to thank the following people for their kindness and support: Michelle Lee, Ros Shaw, Alison Poole, Rosie Salazar, Joelene Hughes, Tom Moorhouse, Tom Hart, Merryll Gelling, Sandra Baker, Thomas Merckx, Adam Dutton, Chris Sandom, Christos Astaras, Hanna Tuomisto, Femke Broekhuis, Nic Elliot, Rannveig Magnusdottir, Ruthi Brandt, and Zinta Zommers. Special thanks go to Dawn Burnham and Lynne Larkman for your help and support. Thank you to Lucy Tallents and Jorgelina Marino for helpful discussions about Ethiopian wolves. Special thanks to Erika Cuellar for keeping me company in the paradise! A very special thank you to Paul Johnson. I owe you gratitude not only for help with stats and proof reading, but for your friendship, support and tireless efforts to integrate me into British society through Viz, Carry On, double entendres and cricket. I will miss your humour and wit. Special bonds develop between office mates at Tubney and I would like to thank my ‘original’ office mates Joanna Bagniewska and Tucker Murphy. You have shown me what true friendship is and have always been there for me to offer me a shoulder to cry on when I was upset or a dungeon to crash in when I had nowhere to go. You made writing up a lot more tolerable with deep discussions about Lolita and less deep business time songs. I will always be grateful for your love and support and you will both always have a friend in me. But more recent officemates should also not be forgotten. I thank Ewan Macdonald for being a great officemate (who bakes!) and Amy Dickman for great anecdotes and lemons. There are many friends in Edinburgh whom I’d like to thank, starting with Arno Proeme, an old friend who took me in when I needed a place to live. Thank you