Photo: Eric Bégin (flickr)
Everyone is familiar with the sight of robins hopping around the yard, peering into the grass or “head-cocking” to locate a nice juicy worm. In no time, they find their prey and fly off with a mouthful.
Cues to find prey
Birds are known to use visual, auditory, and possibly vibrations or tactile cues to find prey, but vision is predominant.
The way the robins turn their head when searching for food suggests they could be using visual or auditory cues, but it wasn’t until scientists tested robins in the lab that we really knew for sure how they find worms.
Testing the birds
Birds were placed in aviaries where they could be given buried mealworms in trays of dirt.
To test if they were using scent to locate their prey, birds were offered trays with buried live, moving worms and dead ones. Robins found the live worms more often, suggesting they were not using scent.
In the next test, they were given hanging food trays to keep them from touching the soil with their feet and detecting the worm’s vibrations. The trays did not affect their ability to find the worms, suggesting they do not use tactile cues.
When cardboard was used as a barrier to block visual cues, the birds could still find the worms. That meant they were using another sense. A last experiment used white noise to block sound cues and the birds had more difficulty finding the worms.
The research concluded that robins could use either visual or auditory cues alone to find worms in the soil, but probably use both. So the next time you see a robin “head-cocking” you can be fairly sure it’s listening and looking for those mouthwatering treats!