When it is a cowbird!
I went to Jamaica Bay National Wildlife Refuge this morning, part of the Gateway National Park in New York City (you mean you've got a national park in NYC!!! Who would have known?) Doing my annual "census" of yellow warbler (another Dendroica, this one Dendroica petechia) and other fine feathered friends. Well I did see some...
And they were feeding a cowbird.
(sorry but I'll keep this a short diary- haven't got the time to do my usual 1000-1500 words)
Cowbirds are brood parasites- they lay their eggs in the nests of other birds. Not very sporting, but it is a very damned successful breeding strategy. Well successful for them, not for the other birds as the young cowbird will easily outweigh the other chicks, and it will kick them out of the nest one by one, until it is the only chick remaining. The parents will regrettably be unable to distinguish between the parasite and their own (now this is not always true. Sometimes they will detect the egg before they hatch the nest out, and they will simply build another nest ON TOP of the original one. They'll abandon their already laid eggs, and form new ones. I've heard that yellow warblers (who are generally good at detection, but these guys were numbskulls) have laid up to 5 additional nests on top of the original, discarding each "contaminated" batch of eggs.
Laying an egg is a day or two's work, but rearing chicks lasts two weeks in the nest, another two outside of the nest "educating" and protecting the fledglings. So it is easier to start again, than go through the entire 1-month process raising Arizona.
Just look at the size difference! The little darling is huge in comparison to the parent (looks like the adopted-mother from here) bird.
And it's hungry too!
So all in all, I was a bit disappointed in the yellows this summer. I've seen anywhere from a low of about 12 birds (remember, for every one I see there are a few I miss- so "12" could mean 12, could mean much more) to about 100 yellows in 2002. This year is a touch below last year, with about 15 birds seen. Again, seen isn't all the birds out there. I didn't see that many chicks, which was quite a surprise. So it is possible that they are already hatched and fledged early, and the adults might be preparing for a second brood. Isn't that common, but it does happen. Also possible that they are late this year, in which case there might be many more in another two weeks.
I've been saying for the last three years that contrary to "official" wisdom, we've got breeding American Redstarts in NYC. Some people say we do, some say we don't. I say, let the birds speak for themselves. I saw more redstarts today, than yellow warblers!
Now before I leave, let me end it with this rather spectacular photograph. In a day full or surprises, this one takes the cake. At about 9 in the morning, in the middle of a salt marsh, there's this raccoon sifting through the mud in search of terrapin eggs. Us humans are prohibited from entering the area, but someone forgot to tell the masked bandit.
Note- as I type this, dxo is still going through the editing process, and I might easily find even better photos than this- they'll be added. I'll maintain this diary as well as I can seeing my busy schedule today. If there are any questions I forget to address, I'll get it later tonight.
Edit- More photos!
Caught the female flying away. These shots were in relatively low light, with a 400mm 5.6 lens, and even at ISO400 the shot is only 1/60th. So you'd normally "discard" a shot like this, but the abstract blur is rather nice. I have so many shots like this- should be thrown away, but they are subtle and fascinating.
Now this is simply such a fantastic photo that I had to include it- One of these days I'll have to do a photoblog of flowers. Note the fly on the cactus flower - this is one of three shots taken, the only one with the insect (greenbottle fly? is this a solitary wasp?) in flight hovering over the flower. Yes NYC has cactus- we've got native and "planted" native prickly pear cactus.