Cooperative nest building in wild jackdaw pairs

Abstract

Animals create diverse structures, both individually and cooperatively, using materials from their environment. One striking example are the nests birds build for reproduction, which protect the offspring from external stressors such as predators and temperature, promoting reproductive success. To construct a nest successfully, birds need to make various decisions, for example regarding the nest material and their time budgets. To date, research has focused mainly on species where one sex is primarily responsible for building the nest. In contrast, the cooperative strategies of monogamous species in which both sexes contribute to nest building are poorly understood. Here we investigated the role of both sexes in nest building and fitness correlates of behaviour in wild, monogamous jackdaw pairs (Corvus monedula). We show that both partners contributed to nest building and behaved similarly, with females and males present in the nest box for a comparable duration and transporting material to the nest equally often. However, while females spent more time constructing the nest, males tended to invest more time in vigilance, potentially as a means of coping with competition for nest cavities. These findings suggest a moderate degree of division of labour, which may facilitate cooperation. Moreover, some aspects of behaviour were related to proxies of reproductive success (lay date and egg volume). Females that contributed relatively more to bringing material laid earlier clutches and pairs that spent less time together in the nest box had larger eggs. Thus, selection pressures may act on how nest building pairs spend their time and cooperatively divide the labour. We conclude that cooperative nest building in birds could be associated with monogamy and obligate biparental care, and provides a vital but relatively untapped context through which to study the evolution of cooperation.

Interspecific variation in cooperative burrowing behavior byPeromyscusmice

“…Our study revealed that only the monogamous P. polionotus demonstrated cooperative burrowing behavior. Although an association between monogamy and cooperation has been previously noted (Dillard and Westneat 2016;Hahn et al 2021), in this study, these species also differ ecologically, and therefore we cannot rule out the contributions of such factors to interspecific variation in cooperative burrowing. For example, both P. leucopus and P. maniculatus occupy structured habitats, such as forests and grasslands, and nest in a variety of locations, including rock crevices, brush piles, fallen logs, and tree cavities (Nicholson 1941;Madison et al 1984;Sharpe and Millar 1990).…”

Nest-Building Effort is Not An Indicator of Male Quality In Bonelli’s Eagles, Aquila fasciata

“…In some bird species where both partners put similar effort into nest construction, the pair may reduce their effort as the laying date approaches 93,94 . In other taxa, the parents carry material to the nest throughout the entire breeding season (until after the chicks edge 9 ).…”