Birds that buzz…

Two words that are usually said together:  bird song, or better yet songbirds, those usually small birds in your garden that produce the wonderful, lilting, sometimes piercing, often warbling, unique collection of notes that identifies each species.

But not all songbirds sing, or sing exclusively — some of them have adopted a buzz as part or all of their song. In fact, their soft buzzes or wheezes are remarkably similar and difficult to pinpoint when looking for that buzzing bird that you’re not really sure isn’t some sort of insect.  Why would male birds want to buzz instead of sing?

Take the Blue-winged Warbler for example; wouldn’t you assume from its name that its song would be a melodious warble, rather than a two-note “bee-buzz“?

blue-winged warbler-

A beautiful Blue-winged Warbler sitting out on the edge of the forest overlooking a prairie grassland, buzzing away.

blue-winged warbler-

A better look at the blue wing of the Blue-winged Warbler. He was little and mighty far away.

Just 20 feet away, a Clay-colored Sparrow is buzzing away, with a very similar, low frequency, raspy buzz call.

clay-colored sparrow-

Pale-colored, but with distinctive stripes on its head and face, the Clay-colored Sparrow blends in well to its usual background of dry grass.

clay-colored sparrow-

Its pink bill resembles that of a Field Sparrow, but its buzzing “song” makes it easy to identify.

Buzzing seems to be a common characteristic of “song” in grassland birds, like Grasshopper Sparrows and Savannah Sparrows.  So, one wonders if these birds are trying to avoid detection in prairie habitat by mimicking insects when they “sing”, or whether female birds just find buzzing particularly enticing?

It turns out that buzzing sound made with the bird equivalent of a larynx (called a syrinx), is actually quite physically challenging, and therefore could be an indicator to females of the quality of a potential mate.  German researchers* found that larger, more robust male Nightingales incorporated more buzzes in their song, and enjoyed greater attention from females than their less robust or younger competitors.

Another possible explanation for buzzing birds found in grassland habitats is that low frequency buzzing notes apparently carry long distances, and can be heard throughout and beyond the male’s territory.  Banded Wrens incorporated more buzzing notes in their early morning song that was directed toward other males in the nearby vicinity, at times before females were present.**

*Citation: Weiss M, Kiefer S, Kipper S (2012) Buzzwords in Females’ Ears? The Use of Buzz Songs in the Communication of Nightingales (Luscinia megarhynchos). PLoS ONE 7(9): e45057. https://doi.org/10.1371/journal.pone.0045057

**Citation: P.L. Trillo and S.L. Vehrenkamp. Anim Behav. Song types and their structural features are associated with specific contexts in the Banded Wren. 2005 Oct; 70(4): 921–935. https://dx.doi.org/10.1016/j.anbehav.2005.02.004

A surplus of yellow

After looking at the hundreds of photos I took over the last few days, I have come to the conclusion that yellow is a very popular color in the bird world.  Is this because of the evolutionary relationships of the many yellow warbler species, or is it the availability of carotenoid-containing foods that produce the yellow and red colors in birds, or is yellow simply a highly desirable color in the bird’s eye?  A Google search yields no answers.

Here are a few of my yellow favorites from past few days:

Against a dull background of leafless trees, the American Goldfinch really stands out.

Against a dull background of leafless trees, the American Goldfinch really stands out.

Chestnut-sided Warblers have brilliant golden yellow helmets.

Chestnut-sided Warblers have brilliant golden yellow helmets.

A Magnolia Warbler lights up the green foliage he tries to hide in with his yellow breast.

A Magnolia Warbler lights up the green foliage he tries to hide in with his yellow breast.

Nashville Warblers comb the underside as well as the topside of the foliage.

Nashville Warblers comb the underside as well as the topside of the foliage, showing off an entirely yellow breast and belly.

The female Northern Parula Warbler shows off an unusually rich yellow throat color.

The female Northern Parula Warbler shows off an unusually rich yellow throat color.

A very cold little Blue-winged Warbler has puffed up his yellow feathers to stay warm during these last couple of chilly days.

A very cold little Blue-winged Warbler puffed up his bright yellow feathers to stay warm during these last couple of chilly days.

A Yellow-throated Vireo sedately waits on a branch until I can take its photo -- unlike those pesky warblers that flit.

A Yellow-throated Vireo waited sedately on a branch until I took its photo — unlike those pesky warblers that flitted around continuously.

Great Crested Flycatchers are not only larger than most other flycatchers but show off their lemon yellow bellies.

Great Crested Flycatchers are not only larger than most other flycatchers but show off gorgeous lemon yellow bellies.