Does Social Mating System Influence Nest Defence Behaviour in Great Reed Warbler (Acrocephalus arundinaceus) Males?

Abstract

In birds with biparental care, males and females often conflict over how much care to provide to their offspring and it may be substantially influenced by increased level of polygamy. In accordance with sexual conflict theory, males of socially polygynous bird species provide much less care to their nestlings than do males of most socially monogamous species. Most of previous studies, however, have used feeding behaviour as an index for variations in male parental care only. However, this may be skewed if polygynous males compensate for lower feeding assistance through the provision of other parental care such as protection of nests from predators. In this paper, we examine nest defence behaviour in the facultatively polygynous great reed warbler with respect to sex and type of social mating system. We recorded latency to the first arrival, distance from the predator and defensive reaction of each parent towards a human intruder. Socially polygynous males with two simultaneously active nests defended primary females’ nests less vigorously than socially monogamous males, whereas no differences were found between monogamous and primary females. Generally, however, they took a bigger role in nest defence than males in all cases. Our results support an idea that sexual conflict is driven by polygamy and that type of social mating system can influence nest defence behaviour of facultatively polygynous birds. This finding should be taken into consideration when studying nest defence parental care in polygynous mating systems.

Repeatability of Host Female and Male Aggression Towards a Brood Parasite

“…In accordance with these findings and with the fact that great reed warbler females play an important role in both antiparasitic and antipredator nest defences (Požgayová et al. ; Trnka & Prokop ; Trnka & Grim ), we predicted high between‐year repeatability (i.e. relatively low within‐individual variance compared with high between‐individual variance) of antiparasitic behaviour for females and low repeatability for males (i.e.…”

“…This suggests that great reed warbler females are more consistent in their aggressive responses than males that are more flexible. Moreover, both male and female great reed warblers show high levels of interindividual variation in the intensity of nest defences (Trnka & Prokop ; Požgayová et al. ).…”

Habitat use and nesting success of the Great Reed Warbler (Acrocephalus arundinaceus) in different reed habitats in Serbia

“…Although this species usually builds its nests at the reed edge adjacent to the water (Báldi 1999, Báldi and Kisbenedek 1999, Prokešová and Kocian 2004a, Báldi and Batáry 2005, Trnka et al 2009, Trnka and Prokop 2010, it can build nests in reed edges adjacent to the banks in reed habitats with no or little water surface (e.g., in Pista and Bager, Table 1; Mérő et al 2014). Beside the edges, reed stem density and reed stem diameter significantly affect nest site selection (Graveland 1998, Mérő and.…”

Color plumage polymorphism and predator mimicry in brood parasites

“…We avoided some potential confounders by experimental design; all dummy presentations were done on the first day of the incubation period, in the morning (7:00–11:00 CET), at non-parasitized nests, and only at nests of monogamous males, thus excluding nesting stage [42], daytime [41], parasitism status [39] and mating status [43] as confounders. We statistically controlled for other potentially relevant factors that could not be avoided in this study design, namely experiment date in the season (continual; including its squared term to test for non-linear seasonal patterns), clutch size (continual) as a surrogate of reproductive value [42], first attacking sex (categorical; male, female, both at once) and host arrival direction for the first arriving pair member (categorical; “central” = first host arrived directly at the nest with a chance to see both dummies simultaneously, “focal” = dummy side, i.e., host first saw the focal dummy and “opposite” = opposite dummy side, i.e., host first saw the dummy paired with the focal dummy).…”