Does habitat structural complexity influence the frequency of extra-pair paternity in birds?
- 501 Downloads
Several studies have suggested that vegetation structural complexity can influence the frequency of extra-pair copulations, especially by reducing mating-guarding efficiency. Here we investigate if habitat structural complexity affects broad patterns of extra-pair paternity (EPP) and extra-pair broods (proportion of nests presenting at least one extra-pair young—EPB), specifically testing the prediction that species living in habitats with denser vegetation would have a higher frequency of EPP or EPB. We reviewed studies reporting EPP and EPB levels and categorized structural complexity of vegetation for the study population into five habitat categories. Using both phylogenetic ANOVA and phylogenetic generalized least squares (PGLS), we found no significant effects in either EPP or EPB rates. Under the mating-guarding point of view, possible explanations for the lack of support are (i) trade-offs between the possibilities for females to escape from male surveillance and the difficulty to encounter neighbor extra-pair males by visual orientation in areas with dense vegetation; (ii) the predominance of passerine birds in most categories of vegetation complexity, which are small and agile, such that even less vegetated areas may allow extra-pair copulation to be concealed; (iii) environmental components other than vegetation, such as rocks and cliffs, also could provide concealment opportunities for extra-pair copulation; and (iv) the performance of predawn forays, when habitat complexity may play a weak role on guarding effectiveness. A macroecological understanding of EPP and EPB is a continuing challenge for understanding variation in avian mating systems. Our results contribute to improving the knowledge of the impact of habitat in sexual selection.
Although a vast literature on avian extra-pair paternity (EPP) and its causes exists, the influence of a number of environmental parameters remains poorly addressed. One such parameter is habitat structural complexity. Scattered pieces of evidence from single-species studies have supported the idea that in more complex habitats, i.e., dense vegetation, extra-pair copulation (EPC) is facilitated by concealment opportunities. Here we provide a broad review on studies reporting EPP and EPB (proportion of nests presenting at least one extra-pair young) levels, and we classified study sites into five habitat categories, which were then compared. After controlling for phylogenetic effect, we found no significant effect. Possible explanations for the nonsignificance under a mating-guard perspective can involve trade-offs between the possibilities for females to escape from social surveillance and the difficulty to encounter neighbor extra-pair mates, the availability of habitat components other than vegetation providing concealment for EPC, and the use of strategies such as predawn forays to avoid mate-guarding consequences. Our results further expand the role of habitat in avian sexual selection.
KeywordsCuckoldry Extra-pair copulation Infidelity Social monogamy Mate system Review
We are grateful to Universidade Federal de São Carlos and the University of Kentucky for logistical support and to L.J. Revell, L. Harmon, and M. Alfaro for important discussions on the statistical methods applied here. CB received fellowships from Fundação do Amparo à Pesquisa do Estado de São Paulo—FAPESP (#2014/15456-2 and #2013/21209-5). We also especially thank two anonymous referees for comments on the manuscript.
Compliance with ethical standards
Ethical statement and ethical approval
As this is a review article, the statement on the welfare of animals is not applicable.
This study was funded by Fundação do Amparo à Pesquisa do Estado de São Paulo—FAPESP (#2014/15456-2 and #2013/21209-5). FAPESP is a public foundation, funded by the taxpayers of the State of São Paulo, Brazil. The grant proposals are peer-reviewed blindly by area researchers.
Conflict of interest
The authors declare that they have no conflict of interest.
Data availability statement
The datasets analysed during the current study are available in the Supplementary material.
- Abouheif E (1999) A method for testing the assumption of phylogenetic independence in comparative data. Evol Ecol Res 1:895–909Google Scholar
- Bennett PM, Owens IPF (2002) Evolutionary ecology of birds: life histories, mating systems and extinction. Oxford University Press, OxfordGoogle Scholar
- Black JM (1996) Partnerships in birds: the study of monogamy. Oxford University Press, New YorkGoogle Scholar
- Del Hoyo J, Elliott A, Sargatal J, Christie DA (2016) The handbook of the birds of the world alive. Lynx editions, http://www.hbw.com
- Dias RI, Macedo RH (2011) Nest predation versus resources in a Neotropical passerine: constraints of the food limitation hypothesis. Ornis Fennica 88:30–39Google Scholar
- Gotelli NJ, Ellison AM (2004) A primer of ecological statistics. Sinauer Associates, SunderlandGoogle Scholar
- Griffith SC, Stewart IRK, Dawson DA, Owens IPF, Burke T (1999) Contrasting levels of extra-pair paternity in mainland and island populations of the house sparrow (Passer domesticus): is there an “island effect”? Biol J Linn Soc 68:303–316Google Scholar
- Lack D (1968) Ecological adaptations for breeding in birds. Methuen, LondonGoogle Scholar
- Ligon JD (1999) The evolution of avian breeding systems. Oxford University Press, New YorkGoogle Scholar
- Paradis E (2014) An introduction to the phylogenetic comparative method. In: Garamszegi LZ (ed) Modern phylogenetic comparative methods and their application in evolutionary biology, 1st edn. Springer, New York, pp 3–18Google Scholar
- Pinheiro J, Bates D, DebRoy S, Sarkar D (2017) nlme: linear and nonlinear mixed effects models. CRAN, https://cran.r-project.org/web/packages/nlme/nlme.pdf
- Westneat DF, Sherman PW, Morton ML (1990) The ecology and evolution of extra-pair copulations in birds. Curr Ornithol 7:331–369Google Scholar
- Xiao H, Hu Y, Lang Z, Fang B, Guo W, Zhang Q, Pan X, Lu X (2016) How much do we know about the breeding biology of bird species in the world? J Avian Biol. doi: 10.1111/jav.00934