Black Terns On Land Prowers County

[Dan Stringer]

A large variety of fun species are still being seen in SE CO. Among 91 sp. on the 14th were a pair of Rose-breasted Grosbeaks at Hasty GC (Bent), a White-eyed Vireo in Lamar CC Woods (Prowers) ID'd by Dave L, and an Indigo Bunting at Holly rest area. On the 15th a Chestnut-sided Warbler was at Melody Tempel Grove (Bent) ID'd by Dave L (not a bad guy to run into). On the north end of Thurston Reservoir (Prowers) there's an inlet canal where I found a Worm-eating Warbler going between a willow tree with catkins and skulking around in the ditch below. There's a huge miller-moth hatch everywhere down here and the birds are taking full advantage.

The highlight of both days was going south from Prowers CR UU on CR 75/10 to the S end of Thurston, at about 5 p.m. I watched 22 Black Terns floating over an alfalfa field. On the reservoirs I'd noticed that they don't typically plunge-dive like other terns, mostly skimming the water's surface for insects or small aquatic prey at the subsurface. Their foraging behavior in the alfalfa was the same, dipping down to glean moths with their talons. It was mesmerizing, just like a water scene but over bright green fields. 

Dan Stringer

Larkspur, CO

[Dan Stringer]

I was so caught up with this Black Tern green scene, after reviewing photos, they were actually gleaning the small moths and other bugs in the alfalfa fields with their bills, not their claws.