Phenology Report, April 5 2022
Oh boy/girl/nonbinary person, is it a busy time of year for phenology! The summer birds are returning to Minnesota- John reports that robins, killdeer, red-winged blackbirds, grackles, sandhill cranes, and great blue herons are back in Grand Rapids. John reports that the great blue herons have a very regular schedule, almost always arriving between March 27th and April 4th, a range of about a week. Robins, those flighty lil’ friends, are the opposite: their range spans a whole month and a half, from March 6th (in 2012) to April 15th (2013). Those two years were unusual ones- 2012 was one of the earliest springs in John’s records, and 2013 was one of the latest.
Barred owls are messing with John’s head! On April 1 (April fool’s day, depending on how mischievous you’re feeling), John heard a barred owl going through its whole musical repertoire two hours before sunset (around 4:50pm). Initially, he suspected that his good friend Harry Hutchins was playing a prank on him. Harry is an excellent barred owl mimic, imitating all their sounds with ease (even the screams and laughter that ends their typical spring hootstravaganza). However, he heard the same owl again the next night (at around 5:50), so it’s probably actually an owl, not a prankster. Barred owls, as you may know, have a hoot that sounds like who cooks for you, who cooks for you all. I’ll insert it here:
The students in our phenology talkbacks this week have been seeing great horned owls, and John heard the northern saw-whet owl last night! The tiny saw-whet owl has a call that sounds like a truck backing up, a repetitive whistle, or the process of sharpening a saw’s teeth (hence the name, saw-whet). Here is the call of the saw-whet owl:
In other raptor news, John reports seeing male northern harriers, a raptor known for its distinctive low-flying flight pattern and the bright white patch on its rump. The females, according to John’s records, will be just a few days behind. This is in contrast to red-winged blackbirds, where the males arrive a good three weeks before the females.
The snow is slowly decreasing (despite the best efforts of the snowfall this week). When John observed the snowpack last week, the fields were about 20% covered and the forests are still about 90% snow-covered. Still a lot of snow for April 1st!
In a cool atmospheric sighting, John saw a circumhelical arc (a rainbow entirely circling the sun), caused by uniform ice crystals in the sky. In order to form this rainbow, the crystals have to be low enough in the sky for the top of the circle is only offset from the sun by 22 degrees- it's pretty unusual, and spectacular!
We’re getting lots of reports of red squirrels chasing each other around; keep an eye out, it’s definitely the season for it! The female leads the chase, and the male (or males) follow- if she goes fast, they go fast, if she slows down, they slow down too. This is all part of their courtship display. John was out and accidentally surprised a pair during this process. They ran up a tree and began to mate, and it “went on for a much longer time than [John] would’ve imagined”. The female squirrel seemed less than enthused about the process, and John gave up watching after about 15 minutes.
Moving right along, the Canada geese are out and about, and there’s finally some open water on the creek near Crooked Lake, where John lives. The geese and trumpeter swans are enjoying the open water. At his birdfeeder, John has seen huge flocks of common redpolls, as well as purple finches, red-winged blackbirds, blue jays, “all of the woodpeckers”, nuthatches, chickadees, and the rest of the ‘usual crowd’ that stays through the winter. He must be going through birdseed quickly!
The speckled alder (a deciduous tree with fruiting cones resembling small brown pine cones) has male flowers hanging down from the branches. The flowers are a burgundy color and a little under two inches long. They are soft and bendable right now, but last week they would have been hard and rigid. This indicates they are on the cusp of being ready to release pollen- in an average year, this occurs around April 2nd. The timing is pretty variable depending on the year, but this is normally the time of year they begin to show!
John’s resident female bald eagle is sitting comfortably on her nest, and John is doing his best not to disturb her. Because they’ve moved back to the older nest in an aspen tree, John’s view of the nest isn’t as good as it has been in previous years, but he’s keeping an eye out! He’s also seen and heard his resident sand hill cranes, who he believes are looking for a nesting site.
Speaking of big ol’ birds, John sends us off with some information on trumpeter swans. We’ve been seeing a lot of posts on trumpeter swans on the Season Watch page, and it’s great to see the species doing so well after being extirpated from the state in the 1880s. John informs us that trumpeter swans were reintroduced to Minnesota in 1983, with 24 eggs that were brought in from Alaska. They began the reintroduction near Tamarac National Wildlife Refuge (close to the White Earth reservation). They also released some near Nicollet Lake near Mankato, where they were very successful. The stated goal of the project was to have 30 nesting pairs; they achieved that goal in only 4 years! Trumpeter swans are very aggressive and territorial, easily driving off predators such as foxes, minks, otters, and raccoons. Nobody wants to take on a four-foot tall, 35lb bird with wings spanning 8 feet and a 'fight on sight’ approach to the world. Unsurprisingly, researchers found only one egg in two summers of observation that was taken by a predator (I’d add that those are some brave researchers)!
So, trumpeter swans have found Minnesota a perfect spot to prosper. Current estimates suggest that the population numbers around 30,000 swans, and other states are beginning to follow our example! In the northern U.S., there are estimated to be about 63,000 swans, a huge success for the conservation program. Now you know why there are trumpeter swans “all over your backyard” (I wish, John)- enjoy them! Here's what they sound like:
That does it for this week: keep your eyes out, and enjoy the onset of spring!