Abstract
Following the introduction of DNA fingerprinting in the 1980s, studies have repeatedly revealed mismatches between the mating system inferred from social behaviour and the mating system revealed through genetic relationships. In this study, we examined the occurrence of extragroup paternities (EGPs) in gelada monkeys at Guassa, Ethiopia and explored how EGPs may be acquired in this species, which is conventionally considered to have a single breeding male (‘leader’) per social group (‘unit’). We found that while leaders sired most offspring, a substantial proportion (17 of 88 offspring, 19%) were sired by extra-unit males. Offspring were more likely to be sired by extra-unit males when they were: (1) conceived in the 6 months following the start of peak rainfall (July–December) and (2) the first successful conception for a mother. Furthermore, eight of the 17 extra-unit paternities were directly or indirectly the result of a single infertile leader, indicating that infertility plays an important role in the occurrence of EGPs. Compiling published data revealed that the 19% EGP rate observed among Guassa geladas was also the median for polygynous nonhuman primates (range 0–57%, N = 5 populations), in contrast to geladas in the Simien Mountains, where EGPs are absent or rare. Thus, intraspecific variation in EGP rates in geladas encompasses much of the range described across polygynous primates more broadly. The Guassa gelada EGP rate was similar to the median rate reported for mammals. Primates generally had a lower median rate of EGPs, more similar to the median rate reported for birds. Understanding variation in EGP rates requires understanding the outcomes of competing interests of males and females within the same species, as well as how these features contribute to the evolution of social systems and influence variation in EGP rates at higher taxonomic levels.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 277-301 |
| Number of pages | 25 |
| Journal | Animal Behaviour |
| Volume | 177 |
| DOIs | |
| State | Published - Jul 2021 |
Bibliographical note
Funding Information:We thank the Ethiopian Wildlife Conservation Authority, Amhara Regional Government and Mehal Meda woreda for permission to conduct this research. We are grateful for the support that the Guassa Gelada Research Project (GGRP) has received from Dean Gibson and the San Diego Zoo, CSU Fullerton, the Leakey Foundation, Margot Marsh Biodiversity Foundation, Primate Conservation Inc., Gisela and Norman Fashing, Joe and Pat Healey, Anita and Hans-Peter Profunser and the Christopher Schroen Memorial Fund. We thank M. Charpentier, M. Huck, R. Jacobs, L. Moscovice and S. Rosenbaum for providing additional information from their own studies of EGPs in nonhuman primates. We also thank members of the Wilson Lab at the University of Minnesota (in particular Nisarg Desai for statistical advice and Kristin Crouse and Maud Mouginot for their helpful comments), Tung Lab at Duke University (in particular Tawni Voyles) for support in lab work and members of the GGRP (in particular Jacob Kraus and Evan Beierschmitt) for assistance in sample collection. In addition, we thank the GGRP field staff (Metikay Basasen, Badiloo Muluyee, Ngadaso Subsebay, Bantilka Tessema, Shoafera Tessema and Tasso Wudimagegn) for providing logistical support. C.M.M. thanks the Leakey Foundation, the Wenner-Gren Foundation and the University of Minnesota for funding her work at Guassa. The University of Minnesota also supported M.L.W.‘s visits to Guassa. M.L.G. was supported by grants from the National Geographic Society (no. 9122-12), and University of Michigan. P.J.F. and N.N. thank the US-Norway Fulbright Foundation for their support.
Funding Information:
We thank the Ethiopian Wildlife Conservation Authority, Amhara Regional Government and Mehal Meda woreda for permission to conduct this research. We are grateful for the support that the Guassa Gelada Research Project (GGRP) has received from Dean Gibson and the San Diego Zoo , CSU Fullerton , the Leakey Foundation , Margot Marsh Biodiversity Foundation , Primate Conservation Inc. , Gisela and Norman Fashing, Joe and Pat Healey, Anita and Hans-Peter Profunser and the Christopher Schroen Memorial Fund . We thank M. Charpentier, M. Huck, R. Jacobs, L. Moscovice and S. Rosenbaum for providing additional information from their own studies of EGPs in nonhuman primates. We also thank members of the Wilson Lab at the University of Minnesota (in particular Nisarg Desai for statistical advice and Kristin Crouse and Maud Mouginot for their helpful comments), Tung Lab at Duke University (in particular Tawni Voyles) for support in lab work and members of the GGRP (in particular Jacob Kraus and Evan Beierschmitt) for assistance in sample collection. In addition, we thank the GGRP field staff (Metikay Basasen, Badiloo Muluyee, Ngadaso Subsebay, Bantilka Tessema, Shoafera Tessema and Tasso Wudimagegn) for providing logistical support. C.M.M. thanks the Leakey Foundation , the Wenner-Gren Foundation and the University of Minnesota for funding her work at Guassa. The University of Minnesota also supported M.L.W.‘s visits to Guassa. M.L.G. was supported by grants from the National Geographic Society (no. 9122-12 ), and University of Michigan . P.J.F. and N.N. thank the US-Norway Fulbright Foundation for their support.
Publisher Copyright:
© 2021 The Association for the Study of Animal Behaviour
Keywords
- extragroup paternity
- gelada monkey
- infertility
- limited control
- mate quality
