by Dr. Oakleigh Thorne, II
Dr. Thorne holding a male Red-winged Blackbird.
When the COVID-19 virus hit the United States this year and in mid-March we were told to work from home, it was interesting to see how nature went on as usual as if nothing had ever happened. As always, the male Red-winged Blackbirds set up their territories around Sombrero Marsh, just west of the Thorne Nature Experience office. Their song sounds like my first name: “Oak-alee,” loud and clear! When I hear it, I know that spring is finally here.
I’ve been able to go out to Sombrero Marsh every day and it was fun to see the spring migration of ducks during March and April. There were a lot of Northern Shovelers and Gadwall. I also saw Green-winged and Cinnamon Teal. I even saw some Wilson’s Phalaropes. These are small robin-sized birds that swim like a duck on the surface of the water.
Later in the spring I started to hear Meadowlarks and Chorus Frogs. When a bunch of Chorus Frogs start to sound off, it indeed makes a chorus! Their call sounds like running your fingernail along a comb.
In March, when the first stay-at-home orders came out, there was much less car traffic in Boulder. As a result, we had some unusual wildlife coming into town from the foothills. There were three Mountain Lions seen in North Boulder. Where I live at Spruce and 21st Streets, we had a flock of Cassin’s Finches for the first time in many years.
The end of April and early May marked the arrival of Common Grackles, Mourning Doves, Say’s Phoebes, and various kinds of swallows. We have a dozen nesting boxes at our Thorne office and these are mainly occupied by Tree Swallows. We also had a pair of nesting American Robins this year.
As I have mentioned before in other articles, we have a Federally-licensed bird banding station at Thorne Nature Experience. Besides blackbirds, grackles, and doves, we usually catch and band a few Brownheaded Cowbirds and House Finches. At the end of June I was able to band nineteen baby Tree Swallows in our nesting boxes! They were well feathered-out and almost ready to fly.
My favorite bird is the Cliff Swallow. We usually band several hundred of them each year with my bird banding class, which was unfortunately cancelled this year because of the virus. This made me very sad. Cliff Swallows are amazing birds. They nest in colonies with one nest next to the other, made of small balls of mud mixed with saliva. In the wild they nest under sandstone cliffs, but they also nest under human-made bridges and road culverts (where a stream goes under a street or highway). Cliff Swallows have a square tail, a buffy-colored rump, and a light crescent moon on their forehead. All swallows feed on flying insects, such as mosquitoes and gnats, so they migrate south in our winter because they need to be where there is “perpetual summer” with plenty of their flying-insect food. Cliff Swallows migrate all the way to Brazil and Argentina in South America!
We also have many Barn Swallows here in the summertime. They have a forked tail and rusty-colored breast and belly. You will often see them flying through traffic intersections, dodging cars, and feeding on flying insects that somehow are attracted to these areas. One theory is that mosquitoes are attracted to these intersections by the CO2 (Carbon dioxide) from the cars that are stopped at the traffic lights.
During this difficult time, I hope you are getting outside for fresh air, exercise, and the enjoyment of nature. Will we ever get back to some kind of “normal?” I hope so. At least nature is always there for us!
Dr. Thorne is founder and honorary president of Thorne Ecological Institute in Boulder. They have helped “connect kids to nature” for more than 55 years. For more information about Thorne Natural Science School classes for children, check www.thornenature.org or e-mail info@thornenature.org or call (303) 499-3647.