Although my 420 mm telephoto lens system (an EF300mm f/4L IS USM coupled with a 1.4x extender) provides approximately the same magnification as 8 power binoculars, its viewfinder offers a far less adequate image. In the first place, the field of view is restricted by the camera’s telescopic lens, making it more difficult to find and track the movement of an active target. The view is not nearly as bright as that provided by binoculars. Further, the camera’s image is only in two dimensions, so it is impossible to “see around” the leaves and twigs that may obstruct important identifying features of a small bird. The camera’s auto-focus feature presents an additional challenge, as it will sometimes pick out a little twig that you failed to see in front of the bird, turning the intended target into nothing but a blur.    

Case in point. This week, in Kane County, Illinois, I photographed a Philadelphia Vireo for the first time, but did not know this until after I got home. I had heard its song, which I find hard to distinguish from that of the Red-eyed vireo, and then caught a glimpse of what I thought to be just another Warbling Vireo. After taking a few hasty shots, I returned to my search for migrating warblers.

The “Gilvus” group of vireos includes these three rather similar species. Here is a recent photo of the locally common Warbling Vireo, Vireo gilvus.

Take a close look at my next photo, of the overlooked Philadelphia Vireo, Vireo philadelphicus. It is quite similar to the Warbling vireo, but shows a brighter yellow breast and the black line through its eye extends out in front of the eye. I noticed this only after seeing its image displayed on the computer screen.

Bell’s Vireo, Vireo bellii, also included in the Gilvus group, has more subdued plumage. Its normal range is the Central and Western US, but I found this one in Florida, also in my “Fake Hammock.”

I thought vireos got their name from their songs, which are usually rather brief and disconnected phrases that sometimes sound like “vireo… vir-de-lee-o… viree-ee…” However, In Latin, “vireo” means “to be green.”

Although all vireos display a more or less greenish cast to their plumage,  the “Green-backed” group is aptly named. It includes the  Red-eyed Vireo, Vireo olivaceus.

The Black-whiskered Vireo, Vireo altiloquus, resembles a Red-eyed with a penciled Fu Manchu mustache. This was my first sighting and only photo opportunity, in what I called the “Fake Hammock” near our South Florida home.

Members of the “Eye-ringed” group of vireos appear to be wearing spectacles. This is a Blue-headed Vireo, Vireo solitarius, photographed in direct sunlight, which accents the cool blue color of its head and legs. In poor light the head often looks more gray, as the blue is due to scattering of blue light by the structure of its feathers, not a blue pigment. Unlike the bright blue iridescence of peacocks and grackles, which is caused by reflection of light, the structural blue color is present under nearly all lighting conditions.     

The White-eyed Vireo, Vireo griseus, is common as a breeder and winter visitor in South Florida.

Here is a Yellow-throated Vireo, Vireo flavifrons (my poor, and only photo), taken a couple of weeks ago near my NE Illinois home.