If you feed birds in your backyard, eventually you will either see or find evidence that one or more of the birds drawn to your backyard bird cafe fell victim to a hawk. Thanks to the data collected by thousands of volunteers that have participated in Project FeederWatch since 1987, ornithologists are now able to provide us with a better understanding of this activity.
The ongoing Project FeederWatch study is sponsored by the Cornell Laboratory of Ornithology, Bird Studies Canada, National Audubon Society and the Canadian Nature Federation.
You might find it surprising to learn the leading cause of death in and around bird feeders is actually window strikes. In fact, birds being killed when they fly into windows is estimated to less than one percent of the birds that fly south in the fall. Roughly, half of all deaths documented by Project FeederWatch volunteers were attributed to window strikes.
In comparison, cats were responsible for 30 percent of the reported mortality. Hawks were involved in roughly a third of the bird deaths tallied. Sharp-shinned and Cooper’s hawks were linked if some 50 percent of these cases.
Although sharp-shinned and Cooper’s hawks are similar in appearance, they have different feeding preferences. The diet of the sharp-shinned hawk consists primarily (95%) of small birds. During the study, sharp-shinned hawks were reported to feed on 28 species of birds. The six birds most commonly caught were European starlings, house sparrows, house finches, dark-eyed juncos, pine siskins and mourning doves. It is interesting to note, three of these birds (the European starling, house finch and house sparrow) are not native to Georgia.
For some reason, during the reporting period, sharp-shinned hawks were most often seen hunting in suburban yards than those located in urban or rural areas.
On the other hand, birds comprise only about fifty percent of the diet of the Cooper’s hawk. Out of the 22 birds captured at feeders by this hawk, by far, its favorite food was the mourning dove. Other birds preferred by the Cooper’s hawk were house sparrows, European starlings and dark-eyed juncos.
The study emphasized hawk predation was not a common occurrence.
In fact, an analysis of the data collected found each winter during the study period neither of the hawks was ever seen in most of backyards.