Chatfield July 8 - two interesting behavioral observations

[David Suddjian]

The evening of July 7 brought a big thunderstorm with some intense winds. The road to the Plum Creek Nature Area passes between some tall cottonwoods before it ends at a washout. As I drove to those trees soon after sunrise on July 8 I noticed about 50-60 birds feeding on the asphalt and adjacent dirt edge. There were leaves and twigs blown down on the road, and I figured some invertebrates must have blown down from the trees in the storm; the rest of the roadway had no feeding birds. I was delighted to see the diversity of species feeding very intently on the road surface, and then humbled to be unbale to determine what they were so busily eating. The asphalt assemblage included Western Kingbird, Eastern Kingbird, House Wren, American Robin, Gray Catbird, European Starling, Yellow Warbler, Lark Sparrow, Blue Grosbeak, Red-winged Blackbird, Brown-headed Cowbird, and Bullock's Oriole! Starlings, blackbirds and cowbirds were most abundant, but I was surprised to see so many species that would not usually visit a road surface to forage. The pair of catbirds out in the open road was most striking. So I closely examined the road and dirt edge, but all I could find were 3 or 4 termites. Even when I scrutinized the exact areas where birds were busy feeding moments before I couldn't find anything!

Later along the road to the horse corrals I came upon a mob of magpies crowded into a willow and raising a ruckus like only corvids can. Several were focusing attention near the base of the tree amid the grasses. Maybe they were alarmed by a big snake. I walked in close and couldn't see the target of their interest amid the dense willow foliage and grasses. I was thinking, do I really want to get a close look at a rattlesnake? As I closed in, out flushed an adult female Cooper's Hawk dragging a limp magpie in her talons! It was the only quiet magpie in the bunch. She winged off toward the reservoir with a train of outraged magpies on her tail. Literally. As far as I could see she held her prize tight in her talons all the way over.

David Suddjian

Littleton, CO