Collecting Data in the Field

In this first stage of my research, I'm going out to the city parks of San Francisco and collecting initial data on Nuttall's white-crowned sparrows, as well as marking them for later identification. Here's a photo summary of the steps.

First we scope out the landscape - both visually and listening for a singing white-crown.

Jenny and Kathleen spotting white-crowns at Lake Merced. 

If we spot a white-crown:

We set up a mist net:

Dave raising a net in the Presidio.

Ravinder and Jasper untangling a net.

Then we set up a playback underneath the net.

And sometimes a decoy bird:

Jenny's amazing white-crowned sparrow decoy.

Then we wait and hopefully a bird flies into the net. As soon as a bird is caught we rush up to remove him or her and stop the playback to minimize stress. The bird is placed in a cloth bag before we take measurements. 

We first band the bird. As I mentioned in the last post there is a unique sequence of color bands that get applied to each individual so we can identify them with binoculars later on. 

Here I'm applying a silver USGS band to a white-crown.

Then we take morphological measurements:

Weight

Wing

Tail

And more that aren't pictured.
Then we take a blood sample. Using an alcohol swab or water we wet the feathers around the brachial vein that runs across the bird's "elbow."

 Using a small needle, bevel up, parallel to the vein and at a 45° angle, we quickly and shallowly puncture the vein.

We collect a very small amount of blood in a capillary tube. Using gravity to our advantage the natural blood flow of the bird quickly fills the tube. 

A clear view of the brachial vein.

We use the collected blood to make a couple microscope slides and store the rest for later DNA processing in the lab.

Ravinder is very good at making blood smears. I'm still learning the nuances of this technique.

This concludes the "processing" of the bird. We take him back to the net where he was captured and let him go. He is ruffled but after a quick preening and exploration of his new color bands and he flies off.

Up next I'll provide a rundown of the tools necessary for ornithology field work - banding pliers, special rulers, etc. including some of the items your generous donations have allowed me to purchase. Thank you thank you thank you!