Quack!
Fellow GGRO intern Emma's sister Rosa is currently working on a waterfowl banding project in a natural area called Siusun, about an hour and a half north of San Francisco. Waterfowl have the highest recovery rate of any banded birds, due to hunting. So there has been a recent push in California to band more waterfowl and find out how many ducks born in the Golden State actually stay here.
In the last year, I've gotten a chance to observe songbird banding, hawk banding, and owl banding, so it was fascinating to see the similarities and differences that exist in duck banding. As the head of the Minnesota Zoo bird show once told me: "ducks are just really funny animals and always make people laugh." The light-hearted and jovial attitude that seemed to pervade our duck banding experience seems to only confirm that theory.
To catch the ducks, Rosa sets up traps in the water, full of lots of delicious bait (in this case, wheat). The ducks can get in through a narrow entrance, but it is designed so that escape is a much trickier ordeal, although as I witnessed today, not altogether impossible. Every morning and evening, Rosa (or another waterfowl banding technician) checks the traps, and uses a net to extract the ducks, placing them in a carrying case, which she uses to transport them back to her truck where the bands await.
The duck traps, located in the middle of the pond.
Extracting the ducks from the trap.
Ducks, waiting for some bling.
The ducks in this habitat are typically either mallards of gadwalls - the first task when removing a duck from the crate is to decide which one. As ducklings, the only way to tell is to measure the diameter of the leg as each species wears a different sized band. As they continue to get their first full juvenile molt, mallards will begin to show the characteristic blue/green, iridescent bands on their wings. Once the species is determined, the band is affixed to the left leg of the duck.
Ooh, shiny.
Affixing a band to a female mallard (and you will notice that I'm stupidly putting it on the wrong leg).
Throughout this process, the ducks would show varying levels of passivity. For the more boisterous of the bunch, Rosa showed us how to put the ducks into a "burrito hold" to calm them down. Essentially, we would stick the duck's head under its wing, and it would immediately stop flailing so much.
Once the band is on, the next step is to determine the sex. There are sometimes clues on the feathers and bill. For example, female mallards sometimes show speckling on their yellow bill. However, to be sure there's no confusion, we had to check between the legs. As it turns out, ducks are the only birds to actually exhibit penises, so if a penis is found dangling out of the duck's cloaca, that's pretty conclusive evidence that it is a male.
Female mallard bill. To protect the privacy of the ducks, no cloaca photos have been posted.
Next up is age. While trapping ducks this summer, Rosa has yet to trap a non-hatch-year duck (meaning that all of the ducks trapped were born this spring). Whether this has to do with there being just so many more hatch-years than non-hatch-years, or whether the adults leave earlier for migration, or whether the adults are just smarter, Rosa could not say. As the ducklings molt into ducks, they would slowly replace their down with feathers. We examined how much down the ducklings had to see how far along they were in molting. If a duck was fully molted, we checked the tail feathers. Notched tail feathers indicated a hatch-year duck, like all the ducks we saw today.
Notched tail feathers - this duck was born this spring.
Lastly, we needed to get a weight. The obtainment of the ducks' weights was a great example of their resiliency throughout the process compared to other birds I've seen banded.
Anna weighs a duck.
Once all the data is collected and recorded, the ducks are free to be released back into their habitat.
It was pretty cool to dip my toes into waterfowl banding today. In addition to the ducks, we saw a ton of other great wildlife including a number of great egrets, Northern harriers, white-tailed kites, a common moorhen, and a herd of ten elk! While I enjoyed banding the ducks, it also made me all the more excited to get going with the raptor research. Three weeks until the migration season begins!
