TY - JOUR
T1 - Social parasitism as an alternative reproductive tactic in a cooperatively breeding cuckoo
AU - Riehl, Christina Pauline
AU - Strong, Meghan J.
N1 - Funding Information:
Acknowledgements We thank C. Arvind, L. Carabbia, L. Jara, A. Savagian, Z. Smart, J. Touchton and W. Webber for assistance in the field, and E. Jiang and M. Smith for assistance in the laboratory. We are grateful to S. Bogdanowicz and the Cornell Laboratory of Ornithology for support in genotyping and in developing genetic markers, and to the Smithsonian Tropical Research Institute for their continued support of the Barro Colorado Island field station. Z. Volenec assisted with the preparation of Figs. 1, 2. D. T. Baldassarre, M. E. Hauber, D. I. Rubenstein and A. G. Savagian provided comments on earlier drafts and presentations of this work. Funding for this project was provided by the Smithsonian Tropical Research Institute, the Harvard Society of Fellows, the William F. Milton Fund at Harvard University, the Department of Ecology and Evolutionary Biology at Princeton University, the Program in Latin American Studies at Princeton University and the Princeton Environmental Institute at Princeton University.
Publisher Copyright:
© 2019, The Author(s), under exclusive licence to Springer Nature Limited.
Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2019/3/7
Y1 - 2019/3/7
N2 - Cooperatively nesting birds are vulnerable to social parasites that lay their eggs in host nests but provide no parental care1–4. Most previous research has focused on the co-evolutionary arms race between host defences and the parasites that attempt to circumvent them5–9, but it remains unclear why females sometimes cooperate and sometimes parasitize, and how parasitic tactics arise in cooperative systems10–12. Here we show that cooperative and parasitic reproductive strategies result in approximately equal fitness pay-offs in the greater ani (Crotophaga major), a long-lived tropical cuckoo, using an 11-year dataset and comprehensive genetic data that enable comparisons of the life-histories of individual females. We found that most females in the population nested cooperatively at the beginning of the breeding season; however, of those birds that had their first nests destroyed, a minority subsequently acted as reproductive parasites. The tendency to parasitize was highly repeatable, which indicates individual specialization. Across years, the fitness pay-offs of the two strategies were approximately equal: females who never parasitized (a ‘pure cooperative’ strategy) laid larger clutches and fledged more young from their own nests than did birds that both nested and parasitized (a ‘mixed’ strategy). Our results suggest that the success of parasites is constrained by reproductive trade-offs as well as by host defences, and illustrate how cooperative and parasitic tactics can coexist stably in the same population.
AB - Cooperatively nesting birds are vulnerable to social parasites that lay their eggs in host nests but provide no parental care1–4. Most previous research has focused on the co-evolutionary arms race between host defences and the parasites that attempt to circumvent them5–9, but it remains unclear why females sometimes cooperate and sometimes parasitize, and how parasitic tactics arise in cooperative systems10–12. Here we show that cooperative and parasitic reproductive strategies result in approximately equal fitness pay-offs in the greater ani (Crotophaga major), a long-lived tropical cuckoo, using an 11-year dataset and comprehensive genetic data that enable comparisons of the life-histories of individual females. We found that most females in the population nested cooperatively at the beginning of the breeding season; however, of those birds that had their first nests destroyed, a minority subsequently acted as reproductive parasites. The tendency to parasitize was highly repeatable, which indicates individual specialization. Across years, the fitness pay-offs of the two strategies were approximately equal: females who never parasitized (a ‘pure cooperative’ strategy) laid larger clutches and fledged more young from their own nests than did birds that both nested and parasitized (a ‘mixed’ strategy). Our results suggest that the success of parasites is constrained by reproductive trade-offs as well as by host defences, and illustrate how cooperative and parasitic tactics can coexist stably in the same population.
UR - http://www.scopus.com/inward/record.url?scp=85062584625&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85062584625&partnerID=8YFLogxK
U2 - 10.1038/s41586-019-0981-1
DO - 10.1038/s41586-019-0981-1
M3 - Article
C2 - 30814729
AN - SCOPUS:85062584625
SN - 0028-0836
VL - 567
SP - 96
EP - 99
JO - Nature
JF - Nature
IS - 7746
ER -