Department of Biological Sciences, Center for Biodiversity Research, Edward J. Meeman Biological Station, University of Memphis, Memphis, TN, 38152, USA.
Department of Biological Sciences, Purdue University, West Lafayette, IN, 47907, USA.
Anim Cogn. 2021 May;24(3):613-628. doi: 10.1007/s10071-020-01453-5. Epub 2021 Jan 3.
In addition to food and protection, altricial young in many species are ectothermic and require that endothermic parents provide warmth to foster growth, yet only one parent-typically the female-broods these young to keep them warm. When this occurs, reduced provisioning by males obliges females to forage instead of providing warmth for offspring, favoring the temporal mapping of male activities. We assessed this in a wild house wren population while experimentally feeding nestlings to control offspring satiety. While brooding, females look out from the nest to inspect their surroundings, and we hypothesized that this helps to determine if their mate is nearby and likely to deliver food to the brood (males pass food to brooding females, which pass the food to nestlings). Females looked out from the nest less often when their partner was singing nearby and when his singing and provisioning were temporally linked, signaling his impending food delivery. Females also left to forage less often when their mate was nearby and likely to deliver food. Nestling begging did not affect these behaviors. Females looking out from the nest more often also provisioned at a higher rate and were more likely to divorce and find a new mate prior to nesting again within seasons, as expected if females switch mates when a male fails to meet expectations. Our results suggest anticipatory effects generated by male behavior and that brooding females temporally map male activity to inform decisions about whether to continue brooding or to leave the nest to forage.
除了食物和保护，许多物种的晚成性幼仔都是变温动物，需要恒温的父母提供温暖来促进生长，但只有一个父母——通常是雌性——孵化这些幼仔以保持它们温暖。当这种情况发生时，雄性提供的资源减少迫使雌性去觅食而不是为后代提供温暖，这有利于雄性活动的时间映射。我们在一个野生的画眉鸟种群中评估了这一点，同时通过实验给巢内的雏鸟喂食来控制后代的饱腹感。在孵卵期间，雌性会从巢中探出头来检查周围环境，我们假设这有助于确定它们的伴侣是否在附近并可能给幼仔喂食（雄性将食物传递给孵卵的雌性，雌性再将食物传递给巢内的雏鸟）。当它们的伴侣在附近唱歌，并且它的唱歌和喂食行为具有时间关联，表明它即将送食物来时，雌性从巢中探出头来的次数会减少。当它们的伴侣在附近且可能会送食物来时，雌性离开巢穴去觅食的次数也会减少。雏鸟的乞食行为不会影响这些行为。如果雌性在雄性未能达到期望时更换伴侣，那么从巢中探出头来的雌性更频繁、提供食物的速度更快、更有可能在再次筑巢前离婚并找到新伴侣，这与预期相符。我们的研究结果表明，雄性行为产生的预期效应，以及孵卵的雌性会根据是否继续孵卵或离开巢穴去觅食的决定来对雄性活动进行时间映射。
