White-throated Sparrow Killed by Copperhead
A striking demonstration of one of the haxards to which bids are exposed, namely, attack by snakes, was witnessed about 2:30 p.m. on February 27, 1938, at Alum Creek in the Bastrop State Park, near Bastrop, Texas. I had just killed a White-throated Sparrow (Zonotrichia albicollis) which, with five or six others, had been scratching for food in the leaf litter under a yaupon bush (Ilez vomitoria) at the edge of a clearing. When I went over to retrieve the bird, my attention was attracted to a second bird of the same species that was thrashing about among the dead leaves. At first I thought I had wounded it; but when I reached over to pick it up I discovered that it was struggling to escape from a copperhead snake (Agkistrodon mokasen). The snake had the bird by the back of the head, holding on tenaciously, and periodically clamping its jaws tighter as if trying to sink its fangs and teeth deeper.
Approximately three minutes elapsed from the time the struggle first was observed until the bird relaxed, apparently dead. The snake, still holding to its intended prey, then attempted to drag its kill farther back into the pile of litter. Curious to see what would happen if I interfered, I took a stick and attempted to drag the snake into the open. Evidently the instinct of self preservation overcame that of hunger; for the snake released its kill immediately and attempted to escape by burrowing into the pile of leaves. Finally it was captured.
An autopsy revealed that the sparrow had not been wounded by my gun-shot and that apparently it had been captured while in sound condition. The fangs of the snake had penetrated the cranium and pierced the brain, causing a slight hemorrhagic condition. Death, of course, doubtless resulted from the poison injected.
The fact that the copperhead captured and killed an apparently normal bird leads one to wonder how severe this type of predation is on small birds which habitually scratch among leaf litter for food. The copperhead is so colored that it is discernible when motionless among dead leaves only by close scrutiny; hence it is admirably adapted, as far as color is concerned, to feed, upon birds with such habits. Also, the tendency the snake exhibited to conceal itself under the leaves leads me to suspect that it may have lain in hiding and “pounced” upon the unsuspecting bird.
William B. Davis
Agricultural and Mechanical College, College Station, Texas, March 14, 1938