Does habitat structural complexity influence the frequency of extra-pair paternity in birds?

• Published in: Behavioral ecology and sociobiology 2017-07, Vol.71 (7), p.1-8, Article 101
• Main Authors: Biagolini, Carlos, Westneat, David F., Francisco, Mercival R.
• Format: Article
• Language: English
• Subjects: Animal Ecology; Animal reproduction; Behavioral Sciences; Biomedical and Life Sciences; Birds; Categories; Cliffs; Complexity; Copulation; Efficiency; Extra-pair copulation; Extra-pair paternity; Females; Habitat availability; Habitats; Least squares method; Life Sciences; Males; Mate guarding; Monogamy; Nests; Orientation; Orientation behavior; Paternity; Phylogenetics; Phylogeny; Population studies; REVIEW; Reviews; Rocks; Sexual selection; Social behavior; Surveillance; Tradeoffs; Variance analysis; Vegetation; Zoology
• ISSN: 0340-5443; 1432-0762
• DOI: 10.1007/s00265-017-2329-x

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.