It is a great pleasure to present to you a guest contribution which I hope is one of many by Hemant Kishan, Director of Strategy and Planning, with the General Motors Company . . .
Finding Vireos at Corkscrew Swamp Sanctuary, Naples, Florida
Two species of vireo are common at Corkscrew Swamp -- the White-Eyed and the Blue-Headed. Both can be found with relative ease but photographing them is another story as they tend to be secretive and inconspicuous; especially the white-eyed vireo.
The blue-headed vireo, as seen above, is the larger of the two. Its appearance is distinctive with prominent "white spectacles" and a blue/grey head. Unlike the white-eyed, the blue-headed is not a resident breeder at Corkscrew and prefers, like the many "snow birds" who live seasonally in Florida, to spend only the winters here; leaving for its breeding grounds in the Northern reaches of the US and Canada in the Summer.
The blue-headed vireo can often be found in mixed feeding flocks at Corkscrew Swamp with gnatcatchers and warblers. It is, however, not a flocking bird and does not nest in colonies. It moves quickly through the greenery, picking off insects for food.
Curiously, it was only in 1997 that the Blue-Headed Vireo (seen in the above three images) was recognized as a true species. Earlier, what we now know as the blue-headed, Cassin's and Plumbeous vireos were lumped into a single species known as the "Solitary Vireo". Thanks to genetic and song analysis, all three now have full species status.
No prizes for guessing the origins of this vireo's name! The white-eyed vireo (as seen in the image directly above and the four below) is a small, secretive vireo with dazzling white eyes. The white eyes are a sign of maturity with the juveniles of the species having a dark iris instead. They are a strictly monogamous species that attaches its nest to trees using spider webs!
The white eyed vireo has yellow spectacles with a white throat and two white bars on its wings. Like many other vireo species, the coloration is subdued with a combination of green, olive, white and grey.
White-eyed vireos can turn up anywhere along the boardwalk at Corkscrew. I have usually found them singly but also infrequently in mixed flocks. Early mornings are best and, if you're lucky like I was, sometimes, the best technique is to be absolutely still and let them approach you as they feed.
White-eyed vireos are usually found in low thickets at Corkscrew. They are one of only two perching bird species found in the United States that have white eyes; so their name is also a diagnostic identifying feature of these handsome, small vireos that are found widely in Florida -- from mangroves to scrubland habitat.
In the picture immediately above, a white-eyed vireo has just caught a "daddy long legs," and if you look carefully you can see one of its wings and legs. While predominantly insectivorous, white-eyed vireos will also consume berries in Winter.
Next time you're out birding, look for this attractive neotropical bird and a great place to find it is at Corkscrew Swamp Sanctuary.