|Posted by Brian on March 26, 2018 at 11:10 PM|
It’s been an interesting couple of weeks since the field season began. Field work is nothing if not unpredictable. Broken laptop, broken recorder, snow in northern California, snow on the Oregon coast. I woke up a couple mornings ago, nearly slipping and falling in the slush at my feet, then looked around and saw that snow was falling from the sky. Unfortunately, after leaving northern California a couple weeks ago due to excessive snow, birds had not yet arrived in Florence, OR, so we decided to sample the center of the hybrid zone some more while we wait for those slackers to arrive up north. We just finished up working at the South Slough reserve (which is a beautiful place!), and started working at New River, an “Area of Critical Environmental Concern”. After that, we will try again north in Florence, and then head to northern California for the inland transect. I’m not in a hurry to leave, as we’ve been lucky enough to have a research station and yurt all to ourselves. Through the first eight days, we caught a total of zero birds…however, in the last few days, we’ve caught 16, so things have gone pretty well overall! And today was the first day that was saw the sun for more than a few minutes, so things are headed in the right direction.
It’s always funny to watch people’s faces as they walk by while we’re working. A female hummingbird flying around in a cage, a weird dude with a microphone, and a strange trap set up at a feeder. Everybody always looks so confused. We catch wild females because they elicit courtship displays from a territorial male. We observe and record the male behavior with a shotgun microphone, catch the male, sample his DNA, and take a bunch of measurements to go alongside our behavioral data. Then, not only can we map out the hybrid zone and assess phenomena such as selection, but with enough samples, we can correlate specific components of courtship displays with the genes behind them, using recombination occurring in the hybrid zone. Recombination is when the genes of one species, say, Allen’s Hummingbird, and the genes of another, Rufous Hummingbird, recombine as a result of interbreeding (hybridization). As a result, their genetic material gets rearranged, and their hybrid offspring has a genome representative of both parent species. Thus, the hybrid might perform bits and pieces of courtship displays from each parent species, and with high enough sampling, we hope to correlate the portions of the genome that trigger certain components of courtship displays, namely the pendulum display in Allen’s Hummingbird.
Finally…we are in the center of the hybrid zone sampling, even though we have a lot of samples from here already. Why? Well, variation is the highest in the center of a hybrid zone, where there is the greatest interaction of parental phenotypes (physical expressions of traits). Thus, to try and account for all of the variation present, its important to sample the center of the zone as much as possible. Thanks for reading! I’ll try to update at least once a week from this point forward.
Wildlife thus far: not too much! Some garter snakes, tree frogs, Bald Eagle, and a Varied Thrush (life bird for me, and a really, really cool one!). My field assistant (Zach) saw a bobcat unsuccessfully ambush a squirrel…I wasn’t too happy I missed that.