Meeting in the middle

The Great Plains states are a meeting ground of eastern and western-occurring bird species. Breeding activity was in full swing in the South Dakota Black Hills this past week, with birds dashing around, fighting, singing, and completely uncooperative as far as photography was concerned.

Bullocks Oriole are the western counterpart of the eastern Baltimore Oriole, but look quite different.

Bullocks Oriole are the western counterpart of the eastern Baltimore Oriole, but look quite different, with their black eyestripe (instead of an all black head).

The white on the wing is more of a large patch than a wing bar (as it is in the Baltimore Oriole.

The white on the wing is more of a large patch than a wing bar (as it is in the Baltimore Oriole.

The Baltimore Oriole occurs in South Dakota, but doesn’t seem to breed in the Black Hills, which is the eastern limit of breeding range for Bullock’s Oriole.

baltimore oriole

These two species do occasionally overlap in breeding areas and can make mistakes and pair with the wrong species, which is why ornithologists once lumped them as one species, the Northern Oriole.  However, DNA comparisons of the two species show that they don’t even share a recent common ancestor.

Western Kingbirds are similar in size and habits to their eastern counterparts, the Eastern Kingbirds.

Western Kingbirds are similar in size and habits (flycatching from a perch) to their eastern counterparts, the Eastern Kingbirds.

Both eastern and western kingbirds hunt for insects in the open prairie, but nest in the protection of shrubs and trees.

Both eastern and western kingbirds hunt for insects in the open prairie, but nest in the protection of shrubs and trees.

With completely overlapping ranges and similar foraging strategies throughout the Dakota prairie, Western and Eastern Kingbirds would seem to be in direct competition with one another, but apparently avoid it with minor differences in their specific habitat preferences for nesting and hunting.  Western Kingbirds were very common in towns, parks, and camping areas where there were very large, widely dispersed cottonwood trees, which they prefer for nesting.  Eastern Kingbirds were only seen in lower vegetation (shrubs) near the prairie edge.

We saw Mountain Bluebirds as we were driving along in the Black Hills, but not close enough to photograph.

Photo from Wikimedia Commons by Elaine

Photo from Wikimedia Commons by Elaine Wilson.

Eastern Bluebirds may also breed in parts of the Great Plains states, although they are rare in the Black Hills. Mountain Bluebirds prefer higher elevations (e.g, in the Black Hills), while Eastern Bluebirds are more common in the river valleys on the prairie itself.  These two species probably don’t interact, being completely separated in habitat choice.

South Dakota, with its varied landscapes — desert, mountain, and prairie — is a great place for birding!

4 thoughts on “Meeting in the middle

  1. Love the informative post and the photos, Sue. It’s complicated enough to identify birds in a single range, but when you are at a place where ranges overlap, it has to be absolutely maddening.

    • Well, on the “up-side”, you get to see more birds that way. I think the most interesting part is how they share the environment, when each would normally take over the whole niche in the absence of the other.

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