While they took awhile to arrive, the hummingbirds when they finally appeared did so in numbers I’ve not seen before. Perhaps it was the cooler spring that made for few natural sources of food, as flowers were delayed in blooming.

The frenzy at the feeders has been almost constant, nearly draining the two dry of nectar within a day or so. But it does ensure the feeders get cleaned frequently and filled with fresh nectar.

And it’s lovely to watch, like an aerial ballet, as the groups — sometimes up to eight — seem to drink and back off in sync, allowing each a turn at the tap.

They’re not always that civil, though. One male perches like an eagle atop one of the feeders, ready to drive away any that dare to drink there. Sometimes he relents, though, and the other feeder is spaced far enough away that it provides enough juice for the others.

(Phyllis Carlson photos)

It seems like the right time to reprint some of the advice offered last year by Laura Erickson of Duluth, Minn., an author who was science editor at the Cornell Lab of Ornithology and has a podcast, blog at www.lauraerickson.com and long-running public radio program, “For the Birds.”

She recommends:

— Don’t use hummingbird nectar that is dyed red. It’s unnecessary to attract the birds and can harm them, as it can take days for the dye to clear their system. If opting for store-bought nectar, pick one that is clear.

— It’s better — and less expensive — to make nectar at home. Erickson recommends a mix of 4 parts water to 1 part sugar. Use white table sugar, not raw sugar or brown sugar, as they can have minerals that can affect the birds. Some people insist cane sugar is best, but Erickson doubts it makes a difference; buy beet sugar if it’s cheaper. Honey might seem like a natural choice, being derived from nectar, but it gets contaminated too quickly, she said. If the weather turns significantly cooler, a 3-to-1 mix might be used to provide more carbs, but the nectar should be no sweeter than that.

— While some nectar recipes call for bringing the mixture to a boil, presumably to make it more sterile, Erickson said that’s not needed. “The moment a hummingbird’s tongue touches the water, it’s injecting germs into it.” The better route is make small batches and change what’s in the feeder frequently; nectar, especially on warm and sunny days, can go bad quickly. In cooler climates, it might hold up for several days; in the heat, consider swapping it out daily. One definite warning sign — if the nectar goes cloudy, toss it and clean the feeder.

— Rather than one feeder with multiple ports, Erickson recommends several smaller feeders for hummingbirds. Highly territorial and pugnacious, hummingbirds will lay claim to a feeder and chase off rivals — see the example listed above — so having feeding sites placed far enough apart they can’t see each other can draw in more hummingbirds without the conflict, Erickson said.

Finally, continue feeding through the summer and fall if possible. While other food sources certainly will be available, the feeders provide an easy morning energy boost for the hummingbirds and during migration can be crucial pit stops to keep them fueled for the flight south. And no, it won’t keep hummingbirds from migrating.

*****

I promised her I would not say the “q” word, but during what should be the busy time of year for a wildlife rehabilitator, Phyllis Carlson said she hasn’t had that many calls.

It has, however, been a little squirrelly at her Quinnesec home, with numerous grays, one red that didn’t make it — and now three northern flying squirrels.

In 30-plus years, they’re the first babies she’s raised of this, “the smallest and cutest” of the region’s native tree squirrels, Carlson said.

The cuteness factor is enhanced by the large “Bambi” eyes that also indicate this species is nocturnal. That’s just one unique trait that distinguishes it from other squirrels that mostly prefer moving during the day.

The main difference is, of course, the flaps of skin — known as patagium — from wrist to ankle that when extended allows the flying squirrel to glide from tree to tree. Though not true flight, it also is more than Buzz Lightyear in “Toy Story” “falling with style,” as the squirrel uses its tail as a rudder in the air and to slow its speed when coming in for a landing. It also has a special piece of wrist cartilage that allows it to even further extend the furry skin flaps.

Couple big eyes with a small size and very soft fur — “they feel luxurious,” Carlson said — and, yeah, they’re pretty attractive little animals, she said.

The trio came to her May 22 after someone cut down a tree and found them inside, the mother dead — another reminder this is the time of year to avoid felling trees if possible. Though they had eyes open and were fully furred when discovered, they spent most of the initial weeks with her sleeping and being bottle-fed formula. Now, they’re starting to eat some solid food — grapes, walnuts, blueberries — and showing more interest in their surroundings.

She’s moved them to a larger aquarium, with a log to climb that has holes to hide in, and eventually will shift them to a pen outdoors. In the new quarters, they’ll start to gain back some of the wildness, Carlson said.

“Within a week and a half, they won’t want anything to do with me,” she predicted.

While they’re likely northern flying squirrels, the southern species has been advancing north with climate change, with northern Wisconsin being the southernmost point for the northern species. The northern and southern are very similar — northern slightly larger, more cinnamon-colored and with a gray base to its white belly fur — and hybridization is known to occur where the species overlap. The northern flying squirrel is listed as a species of special concern in Wisconsin, according to the Wisconsin Department of Natural Resources.

North America has three species of flying squirrel — the northern, which can range through Canada and into Alaska; the southern, primarily in the eastern U.S. but also in small pockets of Mexico and Central America; and the Humboldt’s, a Pacific Northwest variety only recently classified as separate from the northern.

They have a varied diet that sounds gourmet — truffles and mushrooms, lichens, acorns and other hardwood nuts and mast, conifer seeds, fruit, tree buds, insects, bird eggs and probably chicks if they can find them, as they “readily consume meat when available,” according to the Wisconsin DNR.

Carlson’s group is the average for the species, which typically give birth to two or three pups between May and July. She figures they’re about six weeks old now, which would put them close to weaning age, according to the DNR. But young flying squirrels may remain with their mother — or Carlson — for several more months.

Betsy Bloom can be reached at 906-774-2772, ext. 240, or bbloom@ironmountaindailynews.com.