A Northwoods Almanac for November 25 – December 8, 2011
Swans Migrating
Tundra swans have been migrating through northern Wisconsin in the last few weeks. Thousands will congregate on the Mississippi River near Winona, MN until the winter gets truly serious, and they have to complete their migration to Chesapeake Bay.
In Wisconsin, we have two native species of swans – tundras and trumpeters – and one exotic species, the mute swan. The mutes comprise a very tiny population in northern Wisconsin, while the trumpeters number only in the hundreds. Thus, from a statistical probability point of view, when someone calls me at this time of year with a sighting of a large number of swans, my default reaction is to say they are very likely tundras.
Over the last three weeks, Missy and David Drake have been treated on Round Lake to a growing flock of swans. Two small groups of swans initially appeared, one group comprised of three adults and four gray juveniles and the other with four adults and five juveniles. A week later, the flock had grown to 32.
Noting the physical differences between tundras and trumpeters can be very tough. However, their calls differ substantially, and David confirmed that their blaring trumpet-like calls all matched the bird tapes for trumpeters, so trumpeters they are!
Once identified, the next question is where these trumpeters will go for the winter, if they leave at all. Trumpeters that nest today in Wisconsin are linked mostly to those originally brought here fifteen to twenty years ago as eggs from Alaskan nests in an effort to re-establish trumpeters in the state. So their DNA is saying to them one thing – “look for the Pacific Ocean” perhaps – while the physical reality in Wisconsin is telling them something quite different. Being thus displaced, Wisconsin trumpeters migrate an array of directions and distances, still pioneering and establishing new routes. Much of the population either remains on their breeding areas or makes relatively short (<100 miles) migrations to locations where water remains ice-free and they often receive supplemental feeding. Still, more than 50% of the Wisconsin and Iowa breeding flocks depart their breeding areas by the first or second week of October, migrating rather long distances to areas in the lower Midwest and South. The bottom line is that trumpeter swans may now be seen wintering almost anywhere in the continental United States.
Deer Intelligence – Learning to Avoid Hunters
Annually during the deer hunt, mutters of “there aren’t enough deer out there” are heard throughout the Northwoods. And depending on the year and the site, that can be true. But what’s also true is that deer are intelligent, they’re capable of learning, and they will alter their behavior in response to danger. Deer learn very quickly that hunters pose a threat to them, and they respond by reducing their movements during the day, by retreating to areas within their home range where there’s heavy cover, and by being expert at remaining still until a hunter passes. Thus, not seeing a deer doesn’t necessarily mean that there were no deer in an area – it may simply mean the deer in the area did a great job of avoiding hunters.
One study undertaken from 1999 to 2002 monitored six radio-collared deer for their positions and activity throughout the day during the hunt. They found that by the second day of the hunt the deer’s activity decreased by half. The deer also became more active at dawn and dusk by the second day of the hunt, clearly reacting to the presence of hunters.
As for locations, by day two, the deer hunkered down into swampy thickets and sat out the remainder of the season. One doe, radio-collared in the winter of 2000, was monitored for four years for her reactions towards hunters. In each of the four deer seasons, she retreated to the same 40-yard swath of tag alder thicket, and in two of those years she had fawns right by her side. She was finally shot a few years later, but only because the successful hunter walked through the same alder thicket and the doe finally jumped from her bed when he was less than five yards away.
This study isn’t a news flash by any means – most deer hunters know that deer will hunker down and that they change their habits until the hunt is over. I believe it’s simply important to give the deer credit for being masters at avoiding predation, and to tip our hats to them when they outsmart us.
Sightings
On 11/9, Pat Schwai spotted her first redpoll of the season, a male.
Christa Conner in Minocqua sent me a photo of “a mystery white bird” that she was able to photograph while hiking the Bearskin Trail this late summer/early fall. Rather remarkably, she had photographed a great egret, a species that is highly uncommon in the Northwoods. In Wisconsin, great egrets nest along the Mississippi River and occasionally as far north as central Wisconsin. Once in a while, they wander up our way for reasons unknown – I've only seen two over our 27 years living here.
This particular egret allowed Christa to come up right under the tree it was perched in so she could get some wonderful photos.
Summer Tanager in Arbor Vitae
Arlene Smith in Arbor Vitae gave me a call on 11/17 and described a bird at her feeders that had so many colors it was hard to picture in my mind. Eventually, I remembered that years ago we had a juvenile summer tanager show up at our feeders in Manitowish, and we were astonished at its colorful plumage. Figuring that the bird had to be a summer tanager, and given that summer tanagers belong well south of us, Mary and I hopped in our car and drove down to Arlene’s to photograph it. And it was wonderfully cooperative, hanging around her feeders for the 20 minutes we were there. Our photographs, taken through a screen and window, don’t do justice to the beauty of this bird, but they give you a good sense of it.
The juvenile summer tanager is dramatically different from either the adult female or male, being something of a randomly colorful cross between the two. The adult male summer tanager is arguably one of North America's most striking neotropical migrants with its distinctive rosy red plumage, while the female is more greenish. Summer tanagers are found across the southern United States from California to Florida, but usually only as far north as 40°N.
They’re noted for their consumption of bees and wasps on both their breeding and wintering ranges. They capture the adult bees and wasps in flight by sallying out, then carrying the prey back to their perch and beating it it repeatedly against the perch until it dies. They then remove the stinger by wiping the prey on a branch prior to consuming it.
Eastern populations of summer tanagers favor open deciduous forests particularly near gaps and edges. No breeding pairs were recorded as of 2000 in “The Atlas of the Breeding Birds of Wisconsin,” but they’re being seen more frequently every spring in southern Wisconsin, so no doubt Wisconsin has a nesting pair or two by now.
Summer tanagers winter in Central America and northern South America, so this juvenile needed to reset his compass and get out of Dodge before our snowstorm arrived on Saturday 11/19. And apparently it did. It came to Arlene’s feeder the morning of 11/17, and left that afternoon. What it was doing here in the first place will, of course, always be a mystery.
Summer tanagers typically begin arriving at their wintering sites in Central and South America by late September. They appear in Honduras by September 27, Guatemala by September 28, Costa Rica and Panama by the first week of October, and Ecuador by mid-October. The tanagers fly across the Gulf of Mexico, and must put on 55% of their average lean body weight in fat to fuel the crossing.
Ice-up
Pete Johnson reported that 39-acre San Domingo Lake in Mercer iced-up on 11/18, as did a number of other small lakes and marshes in the Lakeland area. Larger and deeper lakes have yet to ice-up as of this writing on 11/20.
First Snow
On the opening day of the deer hunt (11/19), the snow started in the afternoon and left that evening after dropping about 5 inches on us in the Manitowish area. We had missed the earlier snowstorm that hit Rhinelander and south a week or so earlier, so this was our first landscape-transforming event of the winter season.
I don’t know of any day in the year that quite matches the first snow for utterly changing the way the world looks. Nor do I know of another day that has the ecological impact on plants and animals that the first snow has, though the first hard autumn freeze may be close in impact. Most ground-foraging birds and animals just had the difficulty it takes to find food upped by a factor of ten, and it surely hits home for them now, if it hadn’t before, that the long road to spring has truly arrived. Every Northwoods winter has the capacity to be an Armageddon for individuals of a species, and the culling of nature’s weak has begun.
Celestial Events
On 11/26, look in the southwest for Venus about three degrees south of the crescent moon. November 30 marks the day when, on average, our high temperature drops to 32 degrees F. The long freeze now begins, and it won’t be until early March that the average high comes back up to 32.
December 6th marks the first day of the earliest sunsets of the year. From 12/6 until 12/15, the sun will set at 4:14 p.m. and then will begin to gradually set later. Our latest sunrises won’t begin to occur until 12/27. The winter solstice, as a result, occurs in between these dates on 12/21.
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