“Imagine you are in a new city and looking for a place to have a good meal, what do you do? You can walk around and see what restaurants you encounter, but chances are that this will take a lot of time and you might still end up at a mediocre place. Alternatively, you can see where others are going. When you have incomplete information about your environment, taking advantage of the information of others can be incredibly helpful.” Many animals find themselves in situations of incomplete information about where to find resources. One such animal is the Trinidadian guppy. Guppies that live in resource-poor sections of rainforest streams can benefit from high-quality food resources, such as fruits and insects, that fall sporadically into the water. But such resources are difficult to find without a little help.
Here we study the link between guppy social behaviour and foraging success. By studying animal behaviour in the wild, we maximize the ecological-relevance of our findings. Often such field experiments come at the cost of experimental rigour, especially when studying vertebrates. Due to their small size and their naturally plastic spatial and social life, Trinidadian guppies offer the best of both worlds. We can causally test social factors (such as group size and group composition) by conducting group-level manipulations and we can disentangle effects of the immediate environment by doing translocations, all without trading off ecological relevance.
