Birding Blacks Creek Reservoir


WC spent a morning walking around Blacks Creek Reservoir. Blacks Creek is a small, mostly seasonal irrigation reservoir located a few miles southeast of Boise. The reservoir is a patchwork of ownership interests, but an effort led by Golden Eagle Audubon Society a few years ago has created a birding gem.

The reservoir varies from approximately 80 to 200 acres, depending on seasonal precipitation and irrigation demands. It has been identified as an Important Bird Area; it’s a stopover spot for migrating waterfowl and shorebirds during spring and fall migration, as well as supporting some breeding birds.

It isn’t much to look at. Sagebrush and mud, mostly, with the Boise Front in the background. But the birding can be very good. Here are a few bird photos taken at Blacks Creek on July 29, just as fall migration was getting under way.

Long-billed Dowitcher, Blacks Creek Reservoir, July 2017

Long-billed Dowitcher, Blacks Creek Reservoir, July 2017

Long-billed Dowitchers don’t breed or winter in Idaho, but they do move through on migration. This fellow is a little early, which suggests he is probably a male. The migration patterns of this species are not well known to science.

Western Sandpipers, Blacks Creek Reservoir, July 2017

Western Sandpipers, Blacks Creek Reservoir, July 2017

The odds are good WC has seen these birds in the Copper River Delta. Western Sandpipers are especially interesting for two reasons. First, they were one of the species that alerted ornithologists to the importance of biofilm – pond scum – as a food source. And they appear to have evolved a migration strategy that minimizes their exposure to sandpiper-eating raptors. Pretty cool to see them in the sagebrush steppe.

Savannah Sparrow, Blacks Creek Reservoir, July 2017

Savannah Sparrow, Blacks Creek Reservoir, July 2017

Unlike the dowitcher and sandpipers, Savannah Sparrows breed in the sagebrush. This bird has lost some of his tail feathers, but has still captured a mouthful of insects for his or her hatchlings. Sparrows are primarily seedeaters, but the young need the proteins from bugs.

Swainson's Hawk, Blacks Creek Reservoir, July 2017

Swainson’s Hawk, Blacks Creek Reservoir, July 2017

Finally, a resident raptor, a Swainson’s Hawk. This is a dark morph, the darkest of this variable species. This bird was ljkely roosting – this photo was taken at 6:45 AM – but there were countless grasshoppers in the air and ground, and Swainson’s Hawks are enthusiastic bug eaters.

As fall migration picks up, bird and species counts at Blacks Reservoir are likely to pick up, especially with the higher water levels this year. WC will be back to Blacks.

Special props to the Golden Eagle Audubon Society for its hard work in preserving and restoring this site. It’s a gem.

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