Loons you see in summer may be casing the joint

Q: A group of eight loons, all appearing to be adults, suddenly showed up in late July at our lake in north central Minnesota. They were swimming in a close-knit group, and we’ve never seen anything like this before. This lake already has three or four nesting pairs, each with chicks. Do you know what those loons were doing?

A: Excellent question with a fascinating answer, according to an organization called the Loon Project. It turns out that this is a well-studied and frequent phenomenon in the loon world, with small groups of loons dropping down on lakes long after the breeding season has gotten underway. Since I’ve never observed this myself, I turned to the Loon Project, which has been studying loons for decades.

Most of the drop-in loons you saw were probably birds not ready to breed, either too young or just getting ready to pair up. They’re said to be exploring your area, looking for a possible nesting territory for next year or later. These visiting loons are checking to see if there are young loons on the lake, a sign that it’s a high-quality territory, capable of sustaining chicks. For this reason, the resident loons try to hide their chicks during such visits, so the scouting loons might not choose it as a possible territory. This lessens the chances for battles next spring between established loons and interlopers. The resident loons on a given lake may join the visitors and leave with them, too, probably to draw them away from their chicks. Some of the visiting loons may even be parent loons from other lakes visited by scouting loons, attempting to lead the scouting loons away from their own lake. They leave their own chicks in hiding to do this, betting that the visitors will be fooled into thinking they don’t have offspring.

So, while the group of loons swirl around in the water and even engage in a kind of square dance, making it resemble a social gathering, the Loon Project feels there are some pretty strong dynamics behind their activity, with each bird having its own goals for the visit. We Minnesotans love our loons, and it’s fascinating to learn more about them. You may be interested in the Loon Project: https://loonproject.org/2020/09/27/understanding-social-gatherings-the-basics/.

Q: We were paddling on Lake Como in St. Paul in late July and saw an unusual bird. I thought at first it was a green heron, but checked the herons in a field guide and no match. It was about 23 inches tall, any ideas?

A: The photo you sent shows a double-crested cormorant standing on a tree branch over the water. These aquatic birds live on a fish diet, and are adept at swimming underwater in pursuit of their prey, using their wings to steer. Some fisherpeople dislike cormorants, feeling they reduce sport fish populations. “Cormies” are sometimes mistaken for loons on the water, but they have a much slimmer head and longer beak. You can learn more here:

www.allaboutbirds.org/guide/Double-crested_Cormorant/.

A: Robins in our region raise two families each summer, but they almost always build a new nest for each brood. As you can imagine, the chicks take a toll on their nest, leaving behind a stretched-out, poopy mess. A few robins might build their second nest on top of the old one, saving themselves the effort of making a mud base.

Q: What kind of hawk is this [in photo sent by reader]? It stands on top of the bird feeder and has been catching little birds. Is there anything I can do to stop it?

A: Regrettably, your photo shows a Cooper’s hawk, a species that feeds on smaller birds. It has discovered it’s much easier to haunt your feeders than to find prey out in nature. At the time you took the photo, early July, these hawks were very busy trying to feed their nestlings. To foil the Cooper’s from decimating your feeder birds, the best thing to do is to take your feeders down for a week or two. The hawk should move off when it can’t easily make a catch.

Q: There’s a crow that comes to my suet feeder on a regular basis. It takes a big chunk, then goes to the birdbath and dunks it a couple times before flying off with it. What’s up with that?

A: Sounds like the crow is “softening up” the suet before presenting it to its youngsters in the nest (even though suet probably doesn’t need this treatment). Some crows seem to get in the habit of dunking food items in water during nesting season: They’ll dunk roadkill, chunks of rabbit killed by another predator, bits of dead birds, etc. This might also be a way to keep nestlings hydrated.

A: It’s not all that easy to spot a scarlet tanager, and when we do, it’s usually during spring migration. The astonishingly bright red males and the greenish females rush through our area on their way to nesting sites, primarily in the north central part of the state. Look for them in forests and woodlands, near the top of the canopy. Learning to recognize their distinctive, burry song will help guide you to male tanagers on migration (hear their song here: allaboutbirds.org/guide/Scarlet_Tanager/sounds).

Q: I enjoy seeing woodpeckers and like the fact that they’re here summer and winter. I’m wondering if any migrate?

A: That’s a good question, and you’re right, some kinds of woodpeckers can be spotted at feeders and in forests and woodlands every month of the year. This is true of species like the pileated, red-bellied, hairy and downy woodpecker. But there are woodpeckers that migrate, and these include Northern flickers, yellow-bellied sapsuckers and red-headed woodpeckers. Just to complicate things, a few of these latter three species can be found in our area in winter.

Note to readers: Several readers wrote in with concerns about common grackles dominating their feeders, gobbling up all the food and keeping other, more desirable birds away. Grackles are a nuisance at feeders in summer but luckily tend to disappear after the nesting season is over with, usually by mid-July.

St. Paul resident Val Cunningham, who volunteers with bird organizations and writes about nature for local, regional and national newspapers and magazines, can be reached at valwrites@comcast.net.