Friday, May 1, 2015

Transition in the Valley

Over the past week, there has been a significant transition in the South Platte Valley.  The last of the winter birds have departed for northern latitudes or for their summer range in the mountains; in concert,  an increasing variety of summer residents have returned to the Valley, having wintered well to our south.

Yesterday, only a few tardy female buffleheads remained on the ponds at South Platte Park, while double-crested cormorants, American white pelicans, western grebes and snowy egrets had settled in for the summer.  In the riparian woodlands, house wrens, yellow warblers, gray catbirds, northern orioles, western pewees and yellow-breasted chats joined the permanent residents.  On our farm, which sits on the west wall of the valley, broad-tailed hummingbirds, house wrens, Say's phoebes, willow flycatchers, mourning doves and chipping sparrows have all made an appearance and Swainson's hawks, back from Argentina, have rejoined our year-round raptors.

Late migrants, such as western tanagers, common nighthawks, lesser goldfinches and violet-green swallows may not appear for another week or so but the great majority of summer residents are now in place.  We'll enjoy their presence until October, when the autumn chill and waning daylight send them south once again.