Date of this Version
The avicide, DRC-1339, is used to cull populations of spring-migrating blackbirds in eastern South Dakota to reduce damage to ripening sunflower in late summer. We investigated non-target bird hazards associated with using various grain mixtures to attract blackbirds (Icteridae), especially red-winged blackbirds (Agelaius phoeniceus), to avicide-treated bait broadcast in harvested cornfields. During spring 1997 and 1998, we recorded the species and numbers of birds attracted to 0.2-ha plots baited with cracked corn and brown rice, fine-chipped sunflower meats and brown rice (1997 only), and unsupplemented brown rice. Unbaited plots were used as reference sites. In 1997 and 1998, non-target birds showed no preference among bait mixtures (P's > 0.16). In 1997, blackbird preference did not differ among bait mixtures (P> 0.12); whereas, in 1998, blackbirds preferred the cord rice mixture over rice (P= 0.02). Our data show that augmenting brown rice with cracked corn or sunflower meats poses little additional risk to non-target birds and may help attract blackbirds to the baitsite.