Field Work with ACR: Learning the Building Blocks of Their Shorebird Research Projects

BY: Emily Dewing

Audubon Canyon Ranch (known by many as “that bird organization”), is an environmental conservation organization notorious for its long history of shorebird research. Over many decades, they have researched, documented, and published many papers on all kinds of bird in the Bay Area. During a research project, you can find groups of Audubon Canyon Ranch scientists along the coast, capturing and tagging birds.

I was recently fortunate enough to join them for such an event. As a GrizzlyCorps member, and not a seasoned bird tagger, I was mostly there to observe and learn. And I did just that.

We started the evening by gathering all sorts of supplies; nets, net poles, bird tags, hip waders, blood sampling kits- the works. A group of about 8 of us caravanned with these supplies to Walker Creek Delta, which is a portion of coastal land owned by ACR to ensure no development happens on shorebird habitat.

After putting on our hip waders to enter the coastal stretch of land, we set out into the delta. A ten-minute walk through the low-lying marshy plants had us at the shoreline, right where all the bird action was happening.

We set up two large nets in the same way you would set up a volleyball net: two poles on either side and a large rectangular net in the middle. These nets had panels in them that would trap a bird that flew into the netting. After setting up these two nets, we camped out about 100 yards away from them, kneeling low, so as not to alert any birds of our presence. Within minutes, a bird - a Dunlin, the exact bird we were looking to capture- landed inside of the first net. The whole crew sprang into action. One of us quickly (but not too quickly, as that would scare off other birds), made their way to the captured bird. As they did this, another crew member prepared the radio tag that would be put on the bird like a harness. A different crew member readied the blood sampling kit, and yet another was grabbing the measuring devices to assess the bird  (we documented the beak length, fat level, weight, and age). Someone else grabbed the small metal ID tag/ring that would go around the bird’s ankle. Everyone else was preparing the holding containers for the birds where they would be put in between stages of the assessments.

The eight of us set out into the marshy land to set up our nets and prepare for the birds.

One crew member with us that day was there to gather blood samples for a study on bird stress response to drought. Their project involved getting corticosterone (a stress hormone) levels from birds all over northern California and seeing the impact that drought has on bird stress levels. The birds we were getting samples from that day were the control group. The thing is, birds get very stressed out when they are suddenly caught in a net- a very understandable reaction. So, in order to get base level corticosterone levels from this control group, we had to get blood samples within 3 minutes of the bird hitting the net. Any longer than 3 minutes, and the bird’s corticosterone levels in their blood would be reflective of their stress from being captured. Hence, we tried to move as quickly as possible when processing these birds.

As the sun set over Tomales Point, the birds were unable to see the netting, and we captured more birds than we could handle. At the end of the capture, we had a very successful day of documenting the bird health of Dunlins in the area, tagging them for MOTUS Towers to track their activity, and getting blood samples for a control group.

Nils Warnock, Cypress Grove Research Center Biologist and Director, about to measure the Dunlin's wing.

We made our way back to the cars, drove back to the offices, and unpacked the blood samples. The blood sampler and I grabbed a centrifuge, and I put all of the blood samples inside. I ran it for a few minutes, and then we measured all sorts of characteristics of each sample. I documented everything for them, and then we had some pastries to celebrate the successful capture.

This experience was so educational and really peeled back the layers of mystery that shroud what a research project truly looks like on the ground level. It only solidified that this is the kind of work I want to do, and I cannot wait to learn more about this type of research and fieldwork.