ROBINS: WORM PREDATORS
By Sally Blanchard(Robin sculpture by Sally Blanchard) The American robin is one of the most recognizable birds throughout the United States. People who aren't that interested in birds usually know what a robin looks like and a lot of people also know that they eat earthworms. My mother told me that at one time when I was a kid, I went around the yard with a jar and collected worms to feed the robins. Evidently, I tried to get the robins to come over to me to get a worm by dangling it from my fingers. She didn't remember that I had any takers. Perhaps the birds thought that they didn't need my help and maybe even saw me as competition. I just thought that since my Budgie came to me to get food, then a robin would come to me to get a worm. About 15% to 20 % of a robin's diet is earthworms. So does the Robin hear the worm, see the worm, smell the worm or feel the worm vibrations? For years, sources told us that the robin heard the worm, but in the 1960s experiments were done that showed that the robin cocks his head sideways and sees the worm or evidence of the worm being there. Have you ever noticed how a robin seems to get quite excited after it rains? They hop around the yard, placing the side of their head to the ground in various places. Evidently, after a good rain, the worms let the tips of their bodies hang out from their burrows or if the burrows become flooded, the worms come to the surface of the lawn. This makes it easy for the robin eye to spy the worm, stab their beak into the burrow and pull the worm out for a tasty snack. Worms also leave castings in the dirt at the mouth of their burrows and an astute robin figures out that this is evidence of a worm underneath in the dirt. While vision is the main means of worm finding, they might also hear the worm from time to time. So does the early bird get the worm? My guess is that is true only if the bird has really good eyesight. I am curious if robins use the same eye each time they search for a worm or do they switch eyes to find one? I am going to have to watch my neighborhood robins more closely. Our American robin was given the name Robin by English settlers who missed their little red-breasted robin. The European Robin is not related to ours at all. We have always been told that robins (Turdus migratorius) are a sign of Spring, but they actually live all year round throughout the United States. Perhaps the robins that we see in the winter, go farther north in the summer and the ones we see in summer have come to our area from farther south. During winter time, they do form large flocks and eat berries and whatever insect matter that they can find. (See the story about Drunken Waxwings)
Speaking of WormsBy the way, there is a bird called a Worm-eating Warbler. It actually eats caterpillars and not the earthworms that robins dine on. The genus and species of the worm-eating warbler are Helmitheros vermivorus - the vermivorus part means worm eating. It is a fairly plain bird with a couple of stripes on its head and the worm-eating warbler lives in wooded areas of eastern North America and winters in Central America. It takes a sharp eye to find one. Interestingly the word Vermicelli means little worm. Hope that doesn't change your taste for noodles.