Homing Instinct in Cowbird
Homing Instinct in Cowbird.-On ,May 9, 1950, -at Benicia, Solano County, ~California; I banded two male Cowbirds (Molotkrus ater), and two days later, on May 11, a female of the same species. These three birds remained through June and departed early in July. They occupied a territory equal to some six square blocks, in which area my home is located.
From the middle of April to the middle of July, 1951, these same three cowbirds again frequented my banding traps, repeating so frequently that they became a nuisance. The bait used was ordinary canary bird seed which I was using to catch linnets and other seed-eating birds.
The female appeared to be mated with the two males, as the three were seldom far separated, and no other cowbirds were in evidence except three one-time visitors to my traps.
As an experiment, I took one of the two male cowbirds with me in my car from Benicia to Sacramento, sixty miles distant, on May 20, 1951. After exhibiting him at a meeting of the Western Bird-banding Association, I released him. Two days later this same bird was repeating again in my traps in Benicia, direct evidence of attraction either to its customary haunts or to its mate, or to both. -EMERSON A. STONER, Benicia, California, February 29,1952.