Monday, July 4, 2016

Once rare, blue grosbeak sightings increase throughout Ohio

The blue grosbeak is expanding its range north.

July 3, 2016

NATURE
Jim McCormac

The blue grosbeak has long been a coveted bird in Ohio.

Until relatively recently, the best chance at seeing one was to cruise the back roads of rural Adams County, which is along the Ohio River between Cincinnati and Portsmouth. There, a bird-watcher might see this exotic songbird among unkempt pastures.

A male blue grosbeak is bedecked in rich cobalt feathering, punctuated by cinnamon wing bars. Its massive bill looks like it belongs on something else. The bird's song is a melodious warbling, as if the songs of a purple finch, indigo bunting and orchard oriole were fused into one.

Small wonder that those of an avian bent would want to view this bird.

In the early 1900s, naturalists eagerly reported Ohio blue grosbeak sightings. Perhaps the first indisputable sighting dates to 1925 in Lake County, when Edward Doolittle published a note about a bird he found in Painesville in the Wilson Bulletin.

Sightings were sparse until 1940, when ornithologist Lawrence Hicks found the first Ohio nest, in Adams County.

Adams County is a biological hot spot, well-known for hosting animals and plants rare or nonexistent elsewhere in the state, many at the northern limits of their ranges. Hicks’ inaugural grosbeak nesting was near the only established Ohio breeding locale for chuck-will’s-widow, which was discovered in 1932. This large nightjar is at its northern limits in Adams County.

By the 1980s, blue grosbeaks were obviously expanding north. Ohio sightings became more widespread and frequent. They could be expected in appropriate habitat in Ohio River counties from Cincinnati upriver to Gallipolis.

The expansion continues unabated, and now it would not be surprising to find a blue grosbeak anywhere, although southern Ohio remains the stronghold.

Birds appear annually as far north as the Oak Openings west of Toledo and routinely occur in central Ohio. Glacier Ridge Metro Park near Dublin hosted a singing male last summer.

The recently published Atlas of the Breeding Birds in Ohio (field work conducted from 2006 to '11) documented a 237 percent increase from the first atlas, which took place from 1982 to '87. Only seven other species showed greater increases between atlases.

Why the spike in blue grosbeaks? No one knows exactly, but it’s probably a combination of factors. This species favors open meadows interspersed with brushy fence rows and scattered trees, a habitat that greatly increased after the deforestation of much of Ohio. Steadily increasing mean temperatures may also be beneficial to this southern species.

Blue grosbeaks breed extensively across the southern United States and north in the Great Plains to the Dakotas. This highly migratory bird winters throughout Mexico and Central America.
Nonetheless, it is considered an uncommon species, and the North American population is estimated at 18 million birds; about one-fifth of that is its better-known relative, the indigo bunting.

Amazingly little is known of basic life history elements of the blue grosbeak. If someone with ornithological inclinations is looking for a master’s or doctoral thesis, this beautiful bunting would be a good candidate.

Naturalist Jim McCormac writes a column for The Dispatch on the first, third and fifth Sundays of the month. He also writes about nature at www.jimmccormac.blogspot.com.

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1 comment:

Lisa Greenbow said...

We found this to be true here in our Indiana county as we did the last Breeding Bird Survey.