Mar 2020 – From playmates to wingmen, new paper on alliance formation

The most recent issue of Behavioral Ecology features our latest paper, tracking the ‘careers’ of more than 50 sub-adult males through early adulthood as they form second-order alliances.

Title: Affiliation history and age similarity predict alliance formation in adult male bottlenose dolphins

Authors: Gerber L, Connor RC, King SL, Allen SJ, Wittwer S, Bizzozzero MR, Friedman WR, Kalberer S, Sherwin WB, Wild S, Willems EP, Krützen M.

Abstract: Male alliances are an intriguing phenomenon in the context of reproduction since, in most taxa, males compete over an indivisible resource, female fertilization. Adult male bottlenose dolphins (Tursiops aduncus) in Shark Bay, Western Australia, form long-term, multilevel alliances to sequester estrus females. These alliances are therefore critical to male reproductive success. Yet, the long-term processes leading to the formation of such complex social bonds are still poorly understood. To identify the criteria by which male dolphins form social bonds with other males, we adopted a long-term approach by investigating the ontogeny of alliance formation. We followed the individual careers of 59 males for 14 years while they transitioned from adolescence (8–14 years of age) to adulthood (15–21 years old). Analyzing their genetic relationships and social associations in both age groups, we found that the vast majority of social bonds present in adolescence persisted through time. Male associations in early life predict alliance partners as adults. Kinship patterns explained associations during adolescence but not during adulthood. Instead, adult males associated with males of similar age. Our findings suggest that social bonds among peers, rather than kinship, play a central role in the development of adult male polyadic cooperation in dolphins.


Full citation: Gerber et al. 2020. Affiliation history and age similarity predict alliance formation in adult male bottlenose dolphins. Behav Ecol 31: 361-370.

Supplementary material and acknowledgements: Supplementary material can be found at Behavioral Ecology online. We thank the RAC Monkey Mia Dolphin Resort, Monkey Mia Wildsights, and the DBCA’s Shark Bay Rangers for their continued support and assistance. We also thank all field assistants for their help during this study. We thank the anonymous reviewers and the editor for their insightful comments on the manuscript.

Funding: This study was supported by a Swiss National Science Foundation grant (31003A_149956) to M.K. Further financial assistance was provided by grants from the Australian Research Council (A19701144, DP0346313), National Science Foundation (1316800, BNS 8601475), Eppley Foundation for Research, National Geographic Society, W.V. Scott Foundation, SeaWorld Research and Rescue Foundation, A.H. Schultz Stiftung, Ann & Gordon Getty Foundation, Francis V.R. Seebie Charitable Trust, US National Institutes of Health Fellowship, Fulbright Fellowship to Australia, Rackham pre-doctoral Grant, University of Michigan, and the University of Zurich. S.L.K. was supported by The Branco Weiss Fellowship – Society in Science. W.R.F. was supported by a Graduate Fellowship in Anthropogeny from the University of California, San Diego.

Data Accessibility: Analyses reported in this article can be reproduced using the data provided by Gerber et al. (2019) at Behavioral Ecology online.

Watch this blog space for a couple more forthcoming papers. 🙂