Vertebrate Pest Conference Proceedings collection


Date of this Version

March 1967


A knowledge and understanding of a bird's habits and behavior patterns is prerequisite to any intelligent approach toward solving problems created by that species. This also applies to associated species commonly observed with it. Since my subject today is blackbirds I will confine my observations to species in this group, particularly red-winged blackbirds. The Red-Winged Blackbird, (Agelaius phoeniceus) is numerically and economically the most important. Several sub-species or races are recognized and in California the most important of these is the Bi-colored Blackbird, (A. p. californica). The ranges of subspecies commonly overlap, particularly in the Southeast, and field identification is often difficult. In the central valley of California the Tri-colored Blackbird, (Agelaius tricolor) is responsible for much of the depredation in crops, particularly rice. Another typically western species is the Yellow Headed Blackbird, (Xanthocephalus xanthocephalus) which commonly winters in the Southwest and Mexico. This is a large blackbird easily recognized by the black plumage and yellow head. A common blackbird of the West and North-central States is Brewer's Blackbird. The males are black with yellow eyes while the females are grayish with dark eyes. Grackles, (Quiscalus quiscula), are large shiny blackbirds with a long wedge-shaped tail and are more common in the East. A common associate of all the above species during the fall and winter months is the Brown-headed Cowbird (Molothbus ater). The well-known Starling, (Sturnus vulgaris) is also found associated with all of the above species, particularly in their fall and winter concentrations. Red-wing, grackle, cowbird, and starling combinations comprise many of the enormous winter concentrations in the Southeast. In the Southwest, redwings, yellow-headed, and Brewer's blackbirds commonly associate with cowbirds and starlings during the winter months. These associations are usually dissolved in the spring during the breeding season. All of the above species, plus several more, are often indiscriminately referred to as "blackbirds". Since the habits and behavior patterns differ with each species correct identifications are necessary before a control program is planned, I have frequently recommended control procedures by mail which were unsuccessful because of incorrect identification of the offending species. Starlings and red-wings are often confused and several times control procedures for starlings were recommended when actually only red-wings were involved. In recent years, the starling has achieved considerable notoriety and to many people any dark-colored bird is a starling. It is important that the correct identification of the offending species be established, preferably by direct observation.