13 replies to this topic

[spok4]

[PanHanNE]

Hi spok4! Welcome to the forum.
I am not good enough to identify your bird myself, but I think that those who are might ask the date and location where your pictures were taken. That is information you should generally provide with any photos of birds you want help to identify here..

[spok4]

Hey! You!

Now as I was saying, this is all the same bird here. I snapped it from a distance down our treeline with full zoom. July 2, 2012 during the day in eastern WI. I went down the WI wiki list, paged through some books, and I has nothing! It looks bigger than a warbler or sparrow--it isn't no thrasher me thinks. IDK

[creeker]

That is a young Brown-headed Cowbird. They are a brood parasite. The female Brown-headed Cowbird lays it's eggs in another birds nest (usually one per nest.) They generally pick smaller species than themselves, so the baby cowbird quickly outgrows and dominates it's foster nestlings, usually leading to their demise. In your third pic, you can see the cowbird begging food from the smaller warbler type above it (it's foster mother.)

[TheBillyPilgrim]

Agree with Brown-headed Cowbird

[jdeitsch]

Brown-headed Cowbird thirded. The little bird above it looks like a Hooded Warbler maybe?

[JimBob]

Brown-headed Cowbird thirded. The little bird above it looks like a Hooded Warbler maybe?

It's hard to be 100% sure on the warbler in his picture, but Hooded was my thought as well. Location and date would help though. Guessing mid summer.

[cestma]

That is a young Brown-headed Cowbird. They are a brood parasite. The female Brown-headed Cowbird lays it's eggs in another birds nest (usually one per nest.) They generally pick smaller species than themselves, so the baby cowbird quickly outgrows and dominates it's foster nestlings, usually leading to their demise. In your third pic, you can see the cowbird begging food from the smaller warbler type above it (it's foster mother.)

Wow, nice catch! Just to be annoying, I might add that the parent bird could also be the foster father. (Unless you're seeing much more in it than I am, and are sure of its sex!)

http://imageshack.us...59/img2730u.jpg (Zoom in.)

[blackburnian]

agree with cowbird

[spok4]

I was sort of thinking cowbird after I posted, but I never knew its chest was such a gold color. I've only seen them from above when they are on the ground below a feeder. I have a whole new perspective now for these birds that nobody likes. I started learning my birds and flowers this spring after a hernia restricted my activities, and now I do my best to capture each bird--I have a whole new respect. From what I can see, the cowbird is protected in the state. I did well all summer identifying, but I usually miss the obvious, so thank you all for the comments.

[cestma]

The whole idea of nest parasitism is fascinating when you think about it. If you look into it just a bit, you'll find the hypothesis that this adaptation evolved in cowbirds because the adults followed roaming herds of buffalo, and could not afford to linger in one place long enough to raise young.

[psweet]

Actually, cestma, if you look a bit farther, you'll find that the entire genus of Cowbirds are nest parasites -- and most of them are tropical. There's also been some phylogenetic comparative stuff that suggests that the process starts as specialists and expands to generalists (at least that's the direction I think it went in). Which implies, to me at least, that the nomadism we find in Brown-headed Cowbirds wasn't the pressure that started the parasitism, but may well have been part of the transition to the ultra-generalist pattern we see in them.

[cestma]

Actually, cestma, if you look a bit farther, you'll find that the entire genus of Cowbirds are nest parasites -- and most of them are tropical. There's also been some phylogenetic comparative stuff that suggests that the process starts as specialists and expands to generalists (at least that's the direction I think it went in). Which implies, to me at least, that the nomadism we find in Brown-headed Cowbirds wasn't the pressure that started the parasitism, but may well have been part of the transition to the ultra-generalist pattern we see in them.

I stand corrected! Thank you--nothing worse than purveying misinformation. I did attempt to look further, only to run into the paywall fortress, so grabbed my Gill textbook and, whaddaya know, in addition to a nice discussion of brood parasitism in general it has sidebar devoted to exactly what you mention, complete with a phylogenetic tree. Ultra-generalist, indeed! By a couple of orders of magnitude from the one-host species. Wow. The more you look, the more fascinating it gets.

[psweet]

I wouldn't say you were purveying misinformation -- you're right, that hypothesis is out there to be found. And you're right, it just keeps getting more and more interesting!