Northern Cardinal Cardinalis cardinalis
Attacks Juvenile Brown- headed Cowbird Molothrus ater
5 July 2013
This evening, while sitting on the patio after dinner we were watching a Chipping Sparrow Spizella passerina feeding a juvenile Brown-headed Cowbird, when the cowbird was suddenly attacked by a male Northern Cardinal. The attack was quite ferocious and sustained, and the Chipping Sparrow attempted to defend its putative offspring as best it could. The attack by the cardinal eventually ended and the young cowbird flew up onto a fence rail, apparently little the worse for wear. We have never witnessed this behaviour before and we are left wondering whether the cardinal inherently recognized the latent threat of nest parasitism by a cowbird, and instinctively attacked the juvenile based on some kind of genetic imperative.