A Northwoods Almanac for 4/30 – 5/13/21
Ravens
Last week, Mary and I celebrated our 42nd anniversary by taking a 3-day trip to Minnesota’s North Shore and hiking and birding in as many places as we could squeeze in. One of the many highlights we shared was seeing four raven chicks being fed by an adult raven in a cliff-side nest along one of the whitewater rivers in the area. From the trail, we were able to look down into the ledge nest along the cliff-face and watch as the adult flew in and stuck its bill down each of the chick’s throats, regurgitating a morning meal.
The chicks were mostly naked and just getting their pin feathers, so they were perhaps two weeks old. One researcher describes them as “grotesque gargoyles” when they are this age and younger, which, while a bit harsh, does describe how big they already are while still being mostly featherless and uncoordinated. They won’t be fully feathered until 5 weeks or so of age, at which point they can fledge. Once fledged, the juveniles may leave in a week or so, or they may stay in the area for up to 6 weeks and be fed by the parents. Usually by July or August, they’re independent.
This seemed a bit early for the chicks – it was April 22. Given the likely age of the chicks and the 20 to 25 day incubation period, the eggs had to have been laid a month or more earlier in mid-March.
We first saw this nest with chicks in the exact same place back in 2010. This is the only raven nest we’ve ever seen, so we have to rely on research studies for our background information. The research says there’s circumstantial evidence that the same birds return to the same nest site, but there’s no long-term studies to confirm this. Apparently ravens may renest on the same site, or they may have multiple nest sites relatively nearby, or sometimes they alternate between nest sites from year to year.
Ravens also appear to be monogamous, but no long-term study with marked birds exists to support this either.
So, while we’d like to believe this is the same raven pair that produced young in this nest 11 years ago, we have no evidence. But the fact that the same nest site is still being used suggests it may be the same pair. The record life span for a banded, wild bird is just over 13 years, but captive birds are reported to have lived more than 44 years.
Horned Grebes, Harlequin Ducks, and Long-tailed Ducks
Besides the ravens, we had some other wonderful sightings during our trip. The most numerous waterfowl we encountered on Lake Superior were horned grebes, a species we rarely see, but which we saw this trip on three different occasions, and each time in large flocks. In their breeding plumage, horned grebes display a yellow, swept-back and erectable plume of feathers on either side of its head, a bright red eye, and rufous neck. In other words, they’re stunning!
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| horned grebe range map |
They’re a circumpolar species, meaning they breed in northern regions across the world, in this case from Greenland to Scotland to Scandinavia to Russia to Alaska and western Ontario. Around our area, I’ve seen them only a few times over three decades of birding here.
There was more. In the harbor at Grand Marais, we were amazed by continual excellent views of a pair of rare harlequin ducks, another northern breeder but one that occupies a unique niche among North American waterfowl – it feeds and breeds in fast-flowing rivers and moves with great agility in raging white water, diving to river bottoms to pick larval insects, snails, crabs and other small creatures from rocky substrates. The literature says they’re relatively tame and can be approached, and that was certainly our case in the very calm water of a sheltered bay.
The male is crazy colorful with a large white crescent in front of the eye, and a white circle behind its dark eye that one would think was its eye. Two broad stripes mark the base of its neck and upper chest, and its sides and flanks are a lovely chestnut – oh, just look at their picture! Their name derives from a character of traditional Italian comedy and pantomime, the harlequin, who appeared in costumes of multicolored triangular patches.
harlequin pair, photo by Bob Kovar
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| harlequin duck range map |
And finally, also at Grand Marais but out on the lake bouncing in the waves, was a flock of long-tailed ducks. This species is a true circumpolar Arctic species, breeding as far north as 80°N around the globe. What I find most interesting about them is their ability to dive to impressive depths. They’re probably the deepest diver among waterfowl and have been recovered from nets and hooks set up to 66 meters deep in Lake Michigan.
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| long-tailed duck range map |
Counting Cranes and Bank Beavers
For our part in the annual sandhill crane count on 4/17, Mary and I paddled a stretch of the Manitowish River that we do every year. And like every year, we put-in at around 5:45 a.m. It was a beautiful morning, but the difference this year was that it was 21°, and while we thought we had warm enough gloves, well, such was not the case. You know that feeling when your hands are so cold that when they finally warm-up, they just ache and ache? We’ve done the count for over three decades now, and in all kinds of weather, so you’d think we would have it all figured out by now. Still learning, I guess.
Despite being really cold, we had a great morning for wildlife sightings. The water level on the river was exceedingly low because of the refilling of the Manitowish Chain of Lakes. We were scraping bottom regularly, but the lack of water in the adjacent wetlands forced waterfowl to feed and loaf directly on the river, which certainly helped our observations.
We not only saw two pairs of sandhill cranes, but we also observed trumpeter swans, blue-wing teals, green-wing teals, common mergansers, hooded mergansers, wood ducks, mallards, Canada geese, bald eagles, and one lone shorebird – a greater yellowlegs.
Perhaps most interesting of all, and disturbing, were the number of exposed bank beaver holes in the shorelands that were high and dry. We’d never seen so many. Thus, we saw more active beavers on the river than we’ve ever seen before, because they didn’t have homes below water where they would be secure.
If you aren’t aware, beavers not only live in lodges that they build, but some also live in bank holes. They dig these bank holes underwater, then tunnel up and create a den above the waterline.
The dramatic drawdown of the Manitowish every spring to refill the Chain exposes both the entrance holes to lodges as well as the entrances to bank dens. It also leaves any muskrats, minks, and otters who have dens/lodges on the edge of the water higher and drier. For any waterfowl that are trying to build nests along the river edge, they, too, are left well above the waterline. And for fish that have spawned early in the wetlands after ice-out, like northern pike, their eggs are left to dry in the mud.
But that’s the long-standing management strategy. Once the Chain fills, the river will be apportioned its minimum share of water based on keeping the Chain at its maximum fill.
Back to the birds: I’ll report the results of the crane count when they’re available, but as usual, it was a wonderful morning!
Voyageurs Wolf Project
The Voyageurs Wolf Project is a University of Minnesota research project that was started to address the question of what do wolves do during the summer? Their goal is to provide a comprehensive understanding of the summer ecology of wolves in an area that includes Voyageurs National Park in northern Minnesota, and specifically to understand the predation behavior and reproductive ecology of wolves (e.g., number of pups born, where wolves have dens, etc.) during the summer.
They learned quickly that the only feasible way to understand where wolves are traveling and hunting prey during summer is by attaching GPS-collars to wolves, so they’ve done that now for over three years. Their latest video comes from the first-ever camera collar footage from a wild wolf (see https://www.youtube.com/watch?v=8JxN33fl6bs). It’s notable because this lone wolf knew how to hunt and catch fish. On the video, he can be seen eating three different fish, which were all killed and consumed along the Ash River.
The collar only took videos for 30 seconds at the beginning of every hour of daylight, so the researchers only got 7 total minutes of video footage each day (14 hr of daylight x 30 second per hour), so it’s a random sample of wolf behavior.
In previous years, the researchers documented wolves from a single pack hunting and killing fish. However, this footage clearly demonstrates that other wolves know how to hunt fish and they do so in different areas. See https://www.voyageurswolfproject.org for additional information and videos.
March Global Temperatures
March and April seem to have flipped their positions in the calendar – March was warmer than April in our area of the Northwoods, and as I write this, snow is falling on 4/26. What began as a very early, warm spring has fallen back into more of what we usually expect in the Northwoods – wild temperature fluctuations with snow and heavy frosts heading into May.
However, what any one of us sees out our windows is a very tiny view of the world. It takes a global perspective to understand what is taking place regarding the climate, and for March, the average global land and ocean-surface temperature was 1.53 degrees F (0.85 of a degree C) above the 20th-century average of 54.9 degrees (12.7 degrees C). This ranks the month as the eighth-warmest March in NOAA's 142-year global temperature record.
Given how unusually warm March felt here in the Northwoods (according to NOAA, March 2021 was at least 3.6 degrees F warmer than average across southern and eastern Canada and the eastern half of the contiguous U.S., so the statistics back up our experience), I would have thought the rest of the world had to be experiencing record warm temperatures, but such was not the case. Still, March 2021 was among Earth’s top-10 warmest, and it was the 45th-consecutive March and the 435th-consecutive month with temperatures above the 20th-century average.
I’ll be curious to see what the global averages are for April, because at the moment out my window, the Northwoods continues to experience below-average temperatures.
Celestial Events
For planet-watching in May, look after dusk for both Mercury and Venus very low in the WNW twilight. Look also for Mars in the west.
Before dawn, look for Jupiter in the SE and Saturn in the SSE.
May 5 marks the midpoint between spring equinox and summer solstice. We’re now up to 14.5 hours of daylight!
The Eta Aquarid meteor shower peaks before dawn on 5/6.
New moon on 5/11. The moon will be at apogee – the farthest away from Earth that it will be in 2021 (252,594 miles).
Thought for the Week
It’s time for spring ephemeral wildflowers to be blossoming in profusion: Where flowers bloom, so does hope . . . Almost every person, from childhood, has been touched by the untamed beauty of wildflowers. Lady Bird Johnson
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