The Early Bird Gets the Worm (so, do we want him in our garden?)
on March 12, 2009
On an early March day when Mother Nature had blessed us with warm balmy weather I notice a large number of robins foraging in my lawn and garden. Of course we have had a variety of winter birds visit us all winter but the sight of the robins on their migratory route north seemed proof that spring had come to stay. As I watched the robins hop around busily extracting their dinner from the soil I began to wonder about what they were eating; seeds? grubs? worms?
The image of a robin pulling an earthworm from the soil is one of the icons of spring. But if robins really do eat earthworms, do I really want the robins in my yard, or worse still, in my garden? In the Piedmont area of North Carolina where I live, the red clay soil is a major foe and I have to work very hard at amending it to make my vegetables, flowers, shrubs and trees grow. On the advice of the local county extension agent I have added and dug in huge amounts of organic matter with the assurance that the earthworms would gradually mix the clay and organic matter on a level unequalled by any shovel. The idea of losing my key helpers, the earthworms, is unsettling so I have been reading up on American robins, especially their diet.
Robin feeding earthworm to young
According to Wikipedia the American robin’s diet consists of about 40% invertebrates such as beetle grubs, caterpillars, and grasshoppers, and 60% wild and cultivated fruits and berries and it “ finds worms by sight, pouncing on them and then pulling them up.”
The Cornell Lab of Ornithology states that earthworms are an important part of their diet during the breeding season, but that fruit is the main diet during the winter. The time of day also affects what robins eat, earthworms being favored early in the day while fruit is favored in the later on. Bill Thompson, III, in North Carolina Bird Watching, mentions nothing but earthworms in his entry on feeding.
So, what am I to believe? Are the robins, the harbingers of spring and beloved by all, actually robbers in my garden, taking my hardworking earthworms and thereby denying my plants the soil they so richly deserve? This is a hard one! For the time being I will enjoy the robins in my yard and hope that they are eating their fill of Japanese beetle grubs and other pests I don’t even know about.