Increasing energy expenditure for a deep-diving bird alters time allocation during the dive cycle
How foraging animals respond to changes in energy costs is poorly understood. Energy costs are especially important for central-place foragers because they determine transit costs as well as foraging costs. For example, oxygen consumption during diving determines the minimum surface pause for a given oxygen store, dive depth and dive duration. A theoretical model based […]
Rush and grab strategies in foraging marine endotherms: the case for haste in penguins
The speed at which air-breathing marine predators that forage by diving should swim is likely to depend on a variety of factors that differ substantially from those relevant in animals for hich access to oxygen is unlimited. We used loggers attached to free-living penguins to examine the speed at which three species swam during periods […]
Pushed to the limit: food abundance determines tag-induced harm in penguins
The energetic costs of animal movement change with body condition, although the consequences of this for foraging efficiency are rarely considered. We deployed externally attached devices to Magellanic penguins (Spheniscus magellanicus), known to increase the costs of swimming via increased drag in a consistent manner, and noted, however, that foraging behaviour and efficiency varied dramatically […]