Wood Duck Box Outing

I got to the office around 7:00 am and then after work, I accompanied my coworker Charlotte and our new HPA Coordinator Jordan on a trip to the Conaway Ranch.   The ranch, UC Davis, and the California Waterfowl Association had joined forces to host a duck-box outing at the ranch.  PhD students and interns from the college are conducting a 4-year study on Wood Ducks that nest on the ranch, and they took us around to the various duck box locations to show us what they do on a daily basis.  About 20 people showed up to participate in the outing.

When we arrived at the ranch I was alerted right away to the sounds of killdeer screeching around us, so I looked around and actually spotted TWO of their nests on the ground.  They make little shallow depressions in the ground and surround them with rocks and gravel, so they’re sometimes hard to see.  (One of the UC Davis guys, John, said he’d accidentally stepped on some of them during earlier excursions, because he wasn’t paying attention to where he was walking.)  When you get too close to a nest, the mother flies off of it, and then rolls around on the ground, pretending her wing is broken to distract you from the nest.  It’s so funny to watch them do this.  One of the nests we found had 4 speckled eggs in it, and the other had three.  We also saw three different kinds of egrets, Great Blue Herons, Black-Crowned Night Herons, Black and White-Faced Ibises, Red-Winged and tricolored Blackbirds, Barn Swallows, and all sorts of other birds as we drove around the ranch.

To get to the duck-box destinations, we had to car pool, and I went with my coworkers in a huge 8-passenger van.  The step up into the van was so high that I had trouble getting in (and out) of it.  I actually had to get onto the floorboard, on my knees (which hurt like hell), and then climb up into the seat.  I was sore by the end of the day; used muscles and pulled muscles I didn’t know I had.  My poor old body…

At the ranch, all but a very narrow strip of riparian habitat had been destroyed in the past — (Conaway is seeking ways to restore a lot more of it now; and Tulyome is hoping to be able to help them with that.) — so the trees that the Wood Ducks would normally use to nest in don’t exist anymore.  To give them spots to nest, though, the ranch has sent up a series of boxes for them… and they seem to have adapted well to using them.  They like the area so much, actually, that many of the ducks never venture too far from it, and those that do migrate return to it to breed again the following year.  They’ve found nests, for example, with moms and daughters, or a pair of sisters, sitting on the same nest, incubating the eggs together…

We found eggs in two of the boxes we checked, and also found a female Wood Duck sitting on the eggs in one of them.  We had to climb up a ladder to look into the boxes — which was again tough on my knees, but I really wanted to see what the inside of the box looked like…  The eggs we saw were pale tan, but one of the UC Davis folks, Tez, said that he had a photo of a nest with many different colored eggs in it.  It’s not uncommon for Wood Ducks to “parasitize” one another’s nests; that is, the females will lay eggs in their own nests AND other nests as well.  And Tez theorized that the different colors of eggs correspond to the mother who laid them (but he can’t be certain without seeing the chicks hatch, giving them a blood test, and then matching the DNA to the moms).  He said that sometimes the females will lay eggs in several nests before actually claiming one particular nest as their own and then sit to incubate the eggs — no matter whose eggs they are.

Sometimes, to “salt” the nests, the grad students will put fake eggs into the nests with the hopes that parasitizing females will lay “live” eggs on top of the fake ones.  They’ve had pretty good success with that…

Tez lifted the eggs out of the nest that didn’t have a mom in it — he figured she had fled when she heard the vans coming but would be back later to continue to incubate her brood — , and put each egg to his ear to listen to them.  When the ducklings are about ready to hatch, you can hear them pecking.  None of these eggs were that far along yet.

After everyone had a chance to look into the boxes, one of the students lifted the female out of her box and showed us how they weigh, measure and check the birds.  They can tell the age of the female by several different factors:  if she has a leg band, they know she’s at least a year old (and if she doesn’t have one, they give her one); older females have more white on their heads and wing feathers (like “gray hair”) and the shoulder feathers are more iridescent; and older females have an orange ring around their eyes whereas the younger ones have a yellow ring.  Based on this stuff, they figured the female they had in hand was at least 2 years old.  I got to hold her for a while (inside the net bag they put her in so she didn’t freak when they weighed and measured her).  She weighed next to nothing, and I could feel her little heart pounding away inside her chest.  I was worried we were stressing her out too much — all these people looking at her and handling her.  So, the grad student put her back in her nest — through the front door rather than the top, so it was more like she normally returned to her nest.  Within a few minutes she was calm again, sitting on her eggs…

It was a very interesting and educational outing.  I enjoyed it, despite the fact that it was 98° outside (ugh) and I was sore from muscle pulls.  I’m glad I went.