Visual trail following in colonial seabirds: theory, simulation, and remote observations

Seabirds have long been thought to exploit social information when searching for their prey, the distribution of which is often patchy and variable. The fact that most seabirds breed colonially has led to speculation that colonies serve as “information centers,” allowing their inhabitants to learn about the distribution of food by observing or following other successful foragers, though this hypothesis is controversial and the evidence for it is mixed. However, several recent studies have documented behaviors that suggest some seabirds do exploit social orientation cues at or near their colonies in order to orient toward food. In this paper, I explore in‐depth one such social orientation behavior, which I call “visual trail following.” I derived a simple model of information transfer and showed that trail following should be favored over other commonly hypothesized foraging behaviors. An individual‐based simulation model was then used to test this theoretical prediction against several other foraging strategies while varying prey patchiness and colony size. The model's results showed that trail following was the optimal strategy across a wide range of conditions. Finally, I used radar data recorded at a tern colony in coastal New York to demonstrate evidence for trail following in the movements of wild seabirds. These results show that trail following and similar behaviors are effective foraging strategies that are likely important for seabirds and other colonial animals.