In forests, birds are less numerous in the middle of the woods than they are on the edge, where the trees meet open areas. This is an example of the edge effect. Where 2 ecosystems meet, there tends to be more variety and greater numbers of living things taking advantage of both areas. However, the large amount of interior forest is a ready home for some species, a definite niche to fill. And one of the most common birds to be found deeper in the North American forest in the warm season is the Red-Eyed Vireo.
But first- what is a vireo?
Vireos are the wood warbler’s lesser-known, plainer cousin.
They like the treetops- forests are ideal habitats for them. Much like wood warblers, they comb endlessly through the leaves for insects to eat. They winter in Central or South America. Unlike warblers, they tend to be a bit larger, have bigger bills, and are less colorful. And they are not as easy to see. So warblers tend to get more attention.
The Red-Eyed Vireo is a record-breaking singer. This species holds the world record for most bird songs in a day- 20,000! It sings constantly from dusk to dawn in the summer woodland, sounding very much like a bland Robin. If one is singing in an area of the forest, you tend to notice more its absence when it stops than the constant singing, which is almost a background soundtrack.
This bird isn’t the easiest bird to get a good look at, either. It often is in the midst of the leafy upper levels of tall trees, foraging for food. And it blends in fairly well with its surroundings, being olive-colored, though it does have striking red eyes and an eye-stripe on the face- if you can get a good look.
These birds build nests in the forks of branches, made from various materials and held together by spider web. The following picture shows a vireo with a possible spider web in its beak.
One morning this last May, I paused in a hike at a local Metro Park. I sat on a bench along the path in a mature patch of woods, and gazed straight upwards for several minutes (I bet I made quite a sight for the bicyclists pedaling by). After a while I noticed birds moving through the treetops far above me- they were larger than warblers and moved and perched in a different fashion- they were Red-Eyed Vireos. It struck me how different their world was, how relatively isolated these birds were from the point of view of us ground-dwellers, or even from birds who lived closer to the ground. They went about their search for insects, examining leaves methodically. They’ve adapted well to this environment.
It’s always a treat to get a good photograph of one of these birds. They are true forest dwellers who call the sun-dappled treetops home. And it looks like a serene life, at least from the ground.