Why do hoarding birds gain fat in winter in the wrong way? Suggestions from a dynamic model
In winter, small birds should be fat to avoid starvation and lean and agile to escape predators. This means that they face a tradeoff between the costs and benefits of carrying fat reserves. Every day they must gain enough fat to survive the coming night. Food-hoarding species can afford to carry less fat than nonhoarders because they can store energy outside the body. Furthermore, hoarders should