Scientists aren’t sure whether robins rely more on sight or sound. A robin probably uses its eyes in open areas with good visibility. Or when noise, like high winds or traffic, make it harder to hear. If the worms are hidden by grass or rocks, a robin may use its ears more.
Scientists don’t think robins use their other senses to hunt, like feeling vibrations in the soil or sniffing out worms.
It turns out the robins I see outside may not be hunting worms at all. Worms are only about 20% of a robin’s diet. They mostly eat fruit and other tiny invertebrates like insects. But there are times when robins eat lots more worms.
“Worms are a particularly important part of the diet during the breeding season, so spring into summer,” Watts said.
That’s when adult robins are feeding hungry chicks. Worms are a nutritious snack for growing birds.
So, when a robin scans the ground, it might not even be looking for worms. It could be searching for beetles or other tasty finds.
I guess you could say there’s a lot of wiggle room in the process.
Sincerely,
Dr. Universe
Ask Dr. Universe is a science education project based out of University Marketing & Communications at Washington State University.