My mornings in the field begin, incongruously, with Michael Jackson. At 4:10 each morning he blasts from my roommate and fellow research assistant’s phone, never failing to startle me awake. I force myself up and begin to stumble around the apartment pulling on hiking pants, inhaling granola, and stuffing equipment into my bag.
By 5:15 the crew is out the door and headed to the mountains. The sun is way ahead of us, already peeking out over the peaks. As we make our way out of town, a local fox typically yawns good morning at us from the side of the road. Nearing the mountains, the paved roads turn to gravel, rattling us awake as we listen to a podcast or two – New Heads for New People is my favorite.
Once at our study site, either Mt. McIntyre or Grey Mountain, we lay out the plan for the day. Until the nestlings hatch we have three objectives – banding males, searching for nests and analyzing males’ responses to song playbacks.
Early on in the field season, banding the birds was our highest priority. By placing colored bands on the birds’ legs we can identify who’s who for the entirety of the season. To band the birds we first catch them in a mistnet, a nylon net stretched between two poles (like a volleyball net) that is very difficult for birds to see. It isn’t easy for humans to see either; when banding birds this past year in Miami, I had to stop a sleepy gardener from driving a golf cart right through one.
The birds, thinking calls played on a hidden speaker are intruding males from other territories, fly into the net and get tangled. That’s when we swoop in, untangle them and begin the process of measuring and banding the bird. A regulation metal band is placed on every bird along with a distinct combination of color bands. We measure their wings, legs, and three separate measurements of their beak – length, width, and depth. Then we snap a quick picture of their crown, the coloration of which is thought to be correlated with the social status of the bird. Finally we take a quick blood sample (to determine relatedness and gender) and set them free.
Once the birds have been banded and released, new leg jewelry in tow, we try to determine the extent of their territory and possible nest locations. Nest searching is like an Easter egg hunt except with real eggs and much, much harder. It consists of long stretches of time watching birds who appear to have no interest whatsoever in building a nest. Then, suddenly, right as you begin to lose hope, the female of the pair will beeline for a low stand of willows, make a quick seet call, and fly out of sight.
That’s the signal for our field crew to move in. We search the clumps of grass in the section of willows where the bird was last seen, looking for a small cup shaped nest made of grass. Usually we come up empty handed in this first round of searching, so we back off and wait for the female to make another appearance. Eventually, after a few back and forths like this, a shout will go up as the nest is found.
Every banded male is subjected to a series of song playbacks – their own dialect, a foreign dialect and a white-crowned sparrow song. We make note of how close the males get to the speaker and the vocalizations they make. By analyzing their behavior during these playbacks we can compare their levels of response to that of the nestlings. This allows us to determine whether the levels of response change as the birds age. Similar playbacks will be done with the nestlings right before they’re ready to fledge.
Over the past few weeks the mountain has slowly shifted from spring into summer. Snow has melted into muddy puddles, purple patches of lupine are slowly replaced by yellow cinquefoil, and the number of layers we strip off throughout the day has increased. We’ve slipped into a comfortable routine of long morning hikes to the furthest territories, nest-searching lunch breaks and casual bird watching on our hike back to the car.
By the time we finish we’re usually sun-burned, bug-bitten and exhausted from traipsing up and down mountains all day. Yet, with few exceptions, there’s a strong feeling of accomplishment as the car bounces its way down the mountain. The rest of the afternoon will be spent reading, meandering through the woods or, more typically, passed out on the couch. Once dinner is cooked and eaten it isn’t long till I’m back in bed, sunlight still streaming through the window, ready to start it all over again at 4:10 the next morning.
Stay tuned as I continue to share stories from my sparrow-filled summer in the Yukon. A quick intro to the work I’m doing can be found here.