American robins captured, banded, and released in Lesser Slave Lake Provincial Park were used in a scientific study sponsored by NASA. The study tracked birds with GPS for three months and compared 25 years of data from the Lesser Slave Lake Bird Observatory (LSLBO). It found that robins are migrating earlier, some crossed the Rocky Mountains, and snow on the ground impacts when they fly.
The birds were captured during spring migration in 2016 to 2018. One of the birds from the study returns to Lesser Slave Lake each year.
“Last spring, I saw him,” says LSLBO executive-director Patti Campsall. He had the little backpack on. The battery was dead, but it shows that the GPS units don’t bother the birds.
The study was published by Dr. Ruth Oliver, Nicole Krikun, and others.
Krikun is a former assistant bander at LSLBO. Oliver is currently a Yale University postdoctoral associate at the Centre for Biodiversity and Global Change. They banded and put GPS on 77 robins.
“Robins are a common bird we don’t know a lot about,” says Oliver. Robins were chosen because they are very common and one of the biggest songbirds.
The paper is entitled ‘Behavioral responses to spring snow conditions contribute to long-term shift in migration phenology in American robins’ by Ruth Oliver et al. 2020.
Merriam-Webster Dictionary defines this use of phenology as “periodic biological phenomena that are correlated with climate conditions,” which include bird migration and when plants bloom.
“The northern Rocky Mountains represent a significant geographic feature of the landscape, which several individuals traversed in the course of their migration,” says the research paper.
Bird’s don’t like flying over large bodies of waters or hills, says Oliver. She chose LSLBO because Lesser Slave Lake (to the east) and Marten Mountains (to the west) funnel a tremendous number of birds through the park.
Another consideration was Lesser Slave Lake is on the southern edge of the boreal forest. This was the southern edge of the geographic area eligible for NASA’s Arctic-Boreal Vulnerability Experiment. This was a variety of linked studies done at the same time in the boreal forest and arctic.
Another important factor was technology improvements, she continues.
The new GPS technology weigh about as much as a nickle. Older GPS were too big to put on songbirds. These were attached to the birds backs with strings under the wings, which are designed to break after a few months.
The battery life of the GPS is about three months, which was enough time for the birds to get from the southern edge of the boreal forest where they were captured to their nesting ground.
Some birds in the study, including the one that comes back to the Boreal Centre each year, nested near Lesser Slave Lake, others further north in the boreal forest, and some reached the arctic.
Robins spend the winter in places as far south as Mexico, Oliver says. Many of the birds in the study nested in Alaska in the summer. One flew to northwestern Alaska – near the Noatak National Preserve, which is well past Nome, Alaska.
Nome Alaska is 2,920 km as the crow flies from Slave Lake, says an online distance calculator.
Krikun was critical to the research, says Oliver.
“It was a super interesting study,” says Krikun. Capturing the birds in nets had a “different setup and style.”
The differences included the location, size of the net, and use of lures and decoys.
The nets were set up around the open areas by the Boreal Centre for Bird Conservation instead of amid the trees a few kilometres north at LSLBO.
Robins like foraging for food in open areas, says Krikun. Krikun and Oliver removed snow, used bird decoys, bird calls, and walked through the meadow to flush the birds toward the nets.
It was fun thinking up creative ways to attract the birds, says Krikun, but very few of them worked. The normal LSLBO banding uses passive netting without any lures.
At the time, Krikun was the assistant bander at LSLBO, but her work didn’t start until May 1. As the study was from mid-April to early May, it worked well with her schedule.
Only birds over 70 grams were used in the study, says Krikun. Each bird was banded by putting a band with a unique number on its leg. The birds were sexed, weighed, and aged.
The net also caught other birds.
Krikun says an exciting one was a sharp shinned hawk. It would have been the first captured in Lesser Slave Lake Provincial Park, but she didn’t have the right size band and as the location was different it wouldn’t have been included in the LSLBO numbers.
The target was 30 birds a year. The study tracked 15 birds in 2016, 27 in 2017, and 13 in 2018.
The research article is available in Environmental Research Letters.