The White-crowned Sparrows of Golden Gate Park

This past week I set out independently to target net, band, and bleed white-crowned sparrows in Golden Gate Park. It has ended up being a very successful endeavor so far - we caught 17 birds in 4 days! A special thank you to Dave and Justin for helping me out.

This is just a small screenshot of net locations. The green x's are where we successfully caught birds. (The other points are from my initial site visits and mark where I heard birds)

The toughest part to learn was the bleeding - it's nerve-wracking pricking such a small vein! I was worried that I would poke the birds too hard with needle so most of the first few birds hardly bled at all. Turns out I just wasn't pricking in the right place. By day 4 I felt much more comfortable and was able to get a great sample from each bird.

The first bird I banded at GGP! (S/YKB):

But my favorite bird was this male, "RBM/S":

As you can see he is still pretty young. White-crowned sparrows have a brown crown in their first year of life. Chicks hatch in the spring so if you find a bird in the latter part of the year with a brown crown you can pretty confidently call it a hatch year bird. On January 1st all birds turn 1, no matter what day they were born. This male is an after hatch year since he obviously wasn't born this year but hasn't fully developed his black and white crown yet.

Despite his younger age, this male has managed to secure and defend a great territory. It encompasses a wide area as well as a water source. It even crosses a road, which can be risky. He was conspicuously and consistently singing from multiple perches. I set up the net and playback and within 30 seconds he was caught. If another male were actually in his territory, you can be sure he wouldn't be there for long.

The blue outlines a small lake and waterfall, the red circle is roughly the outline of his territory, and the green x is where I caught him. 

After processing and release most birds take a moment to regain their composure. They ruffle their feathers and investigate their new color bands (and usually try to pick them off.) Imagine yourself after giving blood, you need a moment to build energy back up. Not this guy though. After a quick preening he was back on his perches and singing within one minute. If will be really interesting to find out if he is infected with malaria!

I plan to continue Golden Gate Park this week and weekend and then begin audio recording. Stay tuned!