Publication Date:
2022-07-19
Description:
© The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Sun, R., Barbraud, C., Weimerskirch, H., Delord, K., Patrick, S., Caswell, H., & Jenouvrier, S. Causes and consequences of pair‐bond disruption in a sex‐skewed population of a long‐lived monogamous seabird. Ecological Monographs, (2022): e1522, https://doi.org/10.1002/ecm.1522.
Description:
Many animals form long-term monogamous pair bonds, and the disruption of a pair bond (through either divorce or widowhood) can have significant consequences for individual vital rates (survival, breeding, and breeding success probabilities) and life-history outcomes (lifetime reproductive success [LRS], life expectancy). Here, we investigated the causes and consequences of pair-bond disruption in wandering albatross (Diomedea exulans). State-of-the-art statistical and mathematical approaches were developed to estimate divorce and widowhood rates and their impacts on vital rates and life-history outcomes. In this population, females incur a higher mortality rate due to incidental fishery bycatch, so the population is male-skewed. Therefore, we first posited that males would show higher widowhood rates negatively correlated with fishing effort and females would have higher divorce rates because they have more mating opportunities. Furthermore, we expected that divorce could be an adaptive strategy, whereby individuals improved breeding success by breeding with a new partner of better quality. Finally, we posited that pair-bond disruptions could reduce survival and breeding probabilities owing to the cost of remating processes, with important consequences for life-history outcomes. As expected, we showed that males had higher widowhood rates than females and females had higher divorce rates in this male-skewed population. However, no correlation was found between fishing effort and male widowhood. Secondly, contrary to our expectation, we found that divorce was likely nonadaptive in this population. We propose that divorce in this population is caused by an intruder who outcompetes the original partner in line with the so-called forced divorce hypothesis. Furthermore, we found a 16.7% and 18.0% reduction in LRS only for divorced and widowed males, respectively, owing to missing breeding seasons after a pair-bond disruption. Finally, we found that divorced individuals were more likely to divorce again, but whether this is related to specific individual characteristics remains an important area of investigation.
Description:
We acknowledge all the field workers involved in long-term demographic studies since 1960 on Possession Island for their invaluable help with data collection and Dominique Joubert for help with data management, as part of Program 109, “Seabirds and marine mammals as sentinels of global changes in the Southern Ocean,” funded by the French Polar Institute Paul-Émile Victor (IPEV; PIs H. Weimerskirch, C. Barbraud, P. Jouventin, J.L. Mougin). We acknowledge Institut Polaire Français, Paul-Emile Victor (IPEV), Terres Australes et Antarctiques Françaises, and Zone Atelier Antarctique et Terres Australes for logistical and financial support. SJ thanks Jimmy Garnier for earlier development of the two-sex model. We thank Rubao Ji, Michael G. Neubert, Serguei Savedra, and Joanie Van de Walle for thoughtful discussions and comments on an earlier version of the manuscript. SJ thanks Jimmy Garnier for constructive discussions on the conceptualization of the project. HC acknowledges support from the European Research Council, ERC Advanced Grant 788195. This work was supported by the National Science Foundation Office of Polar Programs Grant 1840058.
Keywords:
bycatch
;
capture–mark–recapture
;
divorce
;
life-history outcomes
;
Markov chain models
;
sex-biased
;
vital rates
;
wandering albatross
;
widowhood
Repository Name:
Woods Hole Open Access Server
Type:
Article
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