Baby bird question/ ID Philadelphia, PA (1 Viewer)

[smallonion]

Hi! In my yard all day, a big, fat fluffy baby bird has been following another bird around - and the one he is following is a lot smaller. He is gaping for the smaller bird. The smaller bird is some sort of LBJ - I think it's a song sparrow as opposed to the normal house sparrow. I can't tell if the smaller bird is actually feeding the baby, or is just bemused at this big fat gaping baby.

Is there any time during a fledgling sparrow's development that he should be bigger than his parent?

 

[jmepler]

Could it be a Brown-headed Cowbird? Cowbirds are brood parasites. They lay their eggs for other birds to incubate and raise. I believe Song Sparrows are one of the more common "host" birds.

Mike

 

[JamesA]

Juv house sparrows here often appear larger than the parents, and though this may just be them being more "fluffed up" I suppose they could genuinely be fattened up by parent birds who themselves are thinned down from all the effort. Perhaps.

 

[KC Foggin]

And on the other side of the coin, it may be a juvie Cowbird that the Sparrow has unwittingly raised.

 

[smallonion]

I am so excited to think that it might be a baby cowbird. I volunteer at a wildlife rehab and currently we have a cowbird fledgling around the same age, which suggests that fledgling cowbirds are around in the area. I will look much more closely tomorrow!

 

[Gretchen]

I guess looking at the fat baby's markings should make it clear, as well as size (young cowbirds are quite a bit larger than sparrows I believe). I too have noticed that baby sparrows can look larger than their parents - they are much fluffier (and perhaps their parents are "stuffing" them to aid growth) - I think this is quite natural.

(By the way, you're not at the Schulylkill Center are you? I visited there once.)

 

[Destined to Fly]

Brown-headed Cowbird nestlings and fledglings

I volunteer for Sandy Pines Wildlife Centre and this is what Brown-headed Cowbird nestling and fledglings look like. In Ontario, Canada fledglings are here right now and we can see them as late as the end of July. Their begging call is very different from any sparrow, it is buzzy like!

 

[Jeff Hopkins]

Song sparrows are (IMO) the most common victim of cowbird parisitism in SE PA.

Odds are it's a baby cowbird.

 

[smallonion]

(By the way, you're not at the Schulylkill Center are you? I visited there once.)

I am a volunteer at the Schuylkill Center - when did I see you? Did you bring a bird in?

I haven't seen the baby and his 'parent' yet today, but I'm on the lookout.

Thanks everyone!

 

[Gretchen]

I am a volunteer at the Schuylkill Center - when did I see you? Did you bring a bird in?

Just visited for a look around a few years ago. No idea if you were there then - just figured it was in the area you were in and it might be where you were helping out. (Have sent PM)

Look forward to hearing about another sighting