Friday, June 29, 2012

Singing the Wrong Song

At the nature preserve - a Feild Sparrow belts out the typical song of his species  

You might think that sometimes birds are deliberately trying to deceive you, but really, it could just be the way that they were raised.

A male Prairie Warbler sings at the preserve in 2011

In 20 years of identifying birds by their songs, I have been fooled many times. I recall being deceived by a Field Sparrow that instead of singing the typical Field Sparrow "bouncing ball" song, he performed a perfect rendition of a Prairie Warbler's song. Interestingly, the normal songs of the 2 species are not in the least bit similar. The Field Sparrow's song is a series of clear whistled notes that become increasingly short as it progresses (hence the bouncing ball effect). The Prairie Warbler, by contrast, sings a toneless song that consists of short buzzy notes given in a rapid volley.

One thing that these 2 unrelated birds have in common is their habitat, which is overgrown pasture land. It is thought that during a particularly impressionable time in his development, a juvenile songbird can be greatly influenced by the songs of other birds that are nesting in his immediate neighborhood. So it’s possible to imagine a young Field Sparrow, that instead of growing up to sing his father's traditional song, rebels and proudly belts out some kind of bohemian rhythm –like that produced by the freewheeling warblers in the next bush over. That's the way to break your father's heart, boy!
Who are you to tell me I'm singing the wrong song?
Well, probably not, but trying to secure a mate of your own species when you’re not speaking the same language is at best problematic. It’s likely that a female Prairie Warbler would be as confused as I was when she gets a gander at who is singing. And a female Field Sparrow would have no incentive to even get close enough to find out that this confused soul is one of her own kind. However, it has been shown that birds with aberrant songs can succeed in holding territories and even securing mates of their own species.

The Golden-winged Warbler that sang the wrong song for 5 years

For about 5 consecutive breeding seasons we had a male Golden-winged Warbler at the nature preserve that sang exactly like a Blue-winged Warbler. This is more understandable than the former case with the Field Sparrow, since the Golden-winged and Blue-winged are so closely related, and In fact the 2 species regularly interbreed. Their standard songs are also quite similar and the notes are of a similar pitch and quality. The Golden-winged Warbler sings (typically) 4 hearty buzz notes, while the Blue-winged’s song consists of just 2 buzzy notes.

A male Blue-winged Warbler
Most recently we’ve had an Eastern Towhee whose song is very strange indeed. To me it sounded ever so vaguely like a Red-winged Blackbird’s song, and definitely nothing like a Towhee’s normal song (often characterized by the phrase: “Drink… your… tea”.) Based only on the habitat that I was hearing the song emanate from, I had thought it possible that a Towhee was producing the song, but I couldn’t be sure on the identification until I actually saw the bird singing.
This Eastern Towhee will not be having any tea this morning

In this case, I don’t think the Towhee had been influenced by neighboring birds to sing this aberrant song. I think it’s more likely that this bird’s syrinx (voice box) is not working properly. Or maybe this is just his far out interpretation of the classic Drink...your…tea. Hey, it’s also possible that he just might not want any tea.
His rendition may ultimately catch on. Perhaps someday in Central New York, all of the Towhees will sing like him –and the great towhee tea boycott will begin.

Unlike most female songbirds, the Female Northern Cadinal does sing

Regional accents occur with some bird species. A resident Cardinal singing in New York State may not be singing precisely the same song as its cousin in Michigan. Regional accents can be even more local. For years I noted a peculiar sounding alarm call given by Baltimore Orioles living around the Utica Marsh and Mohawk River floodplain area. Orioles in other parts of the County, though they give an equivalent alarm call, do not give the same calls as their lowland counterparts.
The male Baltimore Oriole

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