Observation on the Food Habits of a Desert Sparrow Hawk
Observation on the Food Habits of a Desert Sparrow Hawk
After all that has been written in favor of the Sparrow Hawk (Falco sparverius phalaena) it is interesting to note that the frequent response, that is, alarm or warning calls, of small birds when one appears near at hand is, sometimes at least, justified.
On the afternoon of April 30, 1928, about 4:30, while watching some Black Phoebes that were nesting under the eaves of a house in South Pasadena, I saw them suddenly exhibit signs of fear; and a moment later a Sparrow Hawk (there could be no mistake in its identity) hovered for a moment near the nest, then flew in under the eaves and, taking one of the young from the nest, flew away carrying the bird in its claws. The Phoebes made no particularly desperate efforts to drive off the enemy.
About twenty minutes after the first observed visit, the hawk appeared again, but seeing human beings quite close at hand flew away. During the next hour it made several appearances, but each time it was frightened away by our too close proximity. Suspecting from the Phoebe's actions that the last fledgling had been taken, the nest was examined and found to be empty. Soon after examining the nest we moved to a greater distance and within a few minutes the hawk reappeared, went to the nest, searched for young, taking almost a minute to make sure that nothing had been overlooked, then flew away and did not appear again during the next hour.
A few minutes after the hawk's first visit, a Mockingbird, attracted no doubt by the distress calls of the Phoebes, flew close to the nest. Both Phoebes attacked furiously, one seeming to ride the Mockingbird’s back for a moment. The Mockingbird made no attempt at retaliation so far as could be observed.
Raymond B. Cowles
University of California at Los Angeles, Los Angeles California, May 15, 1928
