A Northwoods Almanac
for June 26 – July 9, 2015
Green Herons
Joe Mastalski sent a beautiful
photo on 6/20 of a green heron eating a dragonfly! I appreciate the photo
because green herons are not commonly seen in the Northwoods, in part because
they are far more secretive then their cousin, the great blue heron. They’re
much smaller and stockier than great blues and don’t seem to tolerate people
quite so readily.
Like a great blue heron, their most
common feeding technique is to stand in a crouched posture, body horizontal,
head and neck retracted, looking into the water. But, much different from a
great blue, they may also dive from perches headfirst into deep water, becoming
submerged. While perched, another feeding variant is for a green heron to wait
patiently until prey emerges, then throw its body toward the prey but keep its
hold on the branch, even hanging upside down on occasion to catch fish beneath
its perch. Green herons are also known to stir up their prey, by raking the
sediments.
But far more amazingly, they are
among the few tool-using birds, fabricating various baits that they drop into
the water to entice fish. These birds have been recorded as using bread, maize,
popcorn, fish pellets, feathers, twigs, leaves, berries, flies and plastic to
bait fish, clearly examples of tool use. Some birds were even observed to dig
up earthworms and then use them for bait.
Green herons are primarily fish
eaters, consuming anything they can catch and handle. But they’re also
extremely opportunistic with a highly varied diet, including earthworms,
leeches, spiders, crayfish, crabs, snails, frogs, toads, tadpoles, salamanders,
lizards, snakes, rodents, and adult and larval insects such as dragonflies,
damselflies, water bugs, diving beetles, grasshoppers, crickets, and katydids.
They’ve also been observed apparently eating vegetable matter, such as acorns,
but how often and how much is unclear.
Hail Damage to Trees
Back in May I received several
phone calls from homeowners who were concerned that conifer trees on their
property were yellowing and appeared to be dying. I was unsure of the cause and
asked that they contact the forestry department at the DNR for an answer. It turns out that hail damage from a storm on
9/4/2014 is the culprit, according to Linda Williams, a forest health
specialist for the DNR. Linda has written an in-depth summary of the storm’s
effects (see http://dnr.wi.gov/topic/ForestHealth/documents/2015/ForestHealthNE-May15.pdf),
but here is a quick overview:
“Most of the damage occurred last
year on September 4, 2014, when a storm dumped large hail on many areas around
the Northwoods . . . Hail damage to a twig is sort of like hitting your arm
with a hammer, many times . . . The damaged conifers remained green all winter,
frozen in time, but are showing symptoms of damage this spring as branches
suddenly die from multiple hail wounds.
“What can homeowners do? Trees
that have some dead branches can be pruned to remove the dead branches if there
are no longer any live buds on those branches. Then just wait for the trees to
grow callus over the hail wounds. This could take several years,
so be patient. Be aware that additional branch mortality or
whole tree mortality could occur if the tree is too badly damaged and insects
or diseases attack the tree.”
New England Hiking
Callie and
I spent nine days hiking in early June in Vermont’s Green Mountains, New
Hampshire’s White Mountains, and New York’s Adirondacks. We had dropped Mary
off in Montreal, Quebec, for an intensive Jacquard weaving class, but since
that skill is way over our heads, we decided to sample some of the myriad
hiking opportunities in northern New England instead.
If I had to
sum up the experience in two words, I would say “ruggedly beautiful.”
Folks in New England don’t seem to believe in trail
switchbacks, rightfully assuming the fastest way between two points is a
straight line, but forgetting that if the line is straight up, it will cause
lots of pain. I don’t know that I’ve ever hiked steeper, rockier and muddier
trails than we found in Vermont – we spent a lot of time gasping – but the
rewards in beauty were worth it.
One
pleasure was our ability to drink directly from the mountain streams there,
given that no giardia-carrying beaver in its right mind would have climbed
these mountain trails and tried to dam the streams (we made sure the streams
weren’t flowing from any ponds on top of the mountains).
Another
pleasure was observing the changes in vegetation and birdlife as we climbed. As
the trees grew more stunted near the top of mountains, we heard again and again
the song of blackpoll warblers, a bird we only rarely see in migration here in
Wisconsin. The blackpoll warbler occupies an extensive breeding range across
the northern coniferous forests of Alaska and Canada, in the transition zone
between taiga and tundra, and in the subalpine forests of eastern North
America. What’s remarkable about the blackpoll is that it undertakes the
longest migration of any North American warbler, with some individuals
traveling over 5,000 miles from Alaska to Brazil. Part of the fall migratory
route is over the Atlantic Ocean from the northeastern United States to Puerto
Rico, the Lesser Antilles, or northern South America. This route averages 1,800
miles over water, necessitating a potentially nonstop flight of up to 88 hours,
and requiring the blackpolls to nearly double their body mass for the necessary
fuel to make the flight.
The forest
composition also changed as we climbed. We usually began in sugar maple-beech
deciduous forests, which gradually morphed into spruce-fir forests, which
gradually declined in size and number. We never hiked a mountain that went
above the treeline – those required an elevation gain of 3,000 feet or more to
summit, and we flatlander Wisconsinites were well aware of not being in shape
for that. But we did reach the rock tops of several mountains where the trees
were lucky to reach 10 feet tall, and here the blackpolls were common, as were
dark-eyed juncos and white-throated sparrows.
We also
found some beautiful old-growth forests in the Adirondacks, one of which had
the best stand of old-growth white pines I’ve ever seen, all arranged along a
gorgeous tumbling brook.
The
similarities in flora and fauna between New England and Wisconsin are
extensive, and we felt quite at home (except for the mountains!). I should add
that our hikes were all nearly bugless, a fact I’m still trying to understand, but
which we were very thankful for.
Seven Swans
A-swimming
Sarah Krembs sent several delightful photos of a
trumpeter swan pair swimming with their seven cygnets on Powell Marsh. She
noted, “Seven cygnets swimming . . . isn't there a song that goes like that?
Those crazy swans hatched out SEVEN cygnets!!! (Last year they had four.)
“I first saw the babies on the evening of June 10th
. . . They must have only been a day or two old when I took the pictures
(on the 11th). On the 12th, the whole family ended up back by the
nest after spending time foraging. The adult sat on the nest and let the little
ones crowd around her. But, as the little ones were making their way up the
fairly steep sides of the nest, two of them fell down and rolled back down the
side. Have you ever seen fluffy little swan babies rolling down a nest?!! It is
ADORABLE. When they came to a stop, each cygnet tried again, and made it to the
top. I bet they were tuckered out.”
The breeding phenology for trumpeter swans is
lengthy. The female and male may share the brooding of the eggs, though the
female incubates far more than the male. They incubate the eggs for 32-37 days,
but the female doesn’t brood them with a brood patch on her chest like most
birds; rather she keeps them warm with both her feet. If she leaves the nest to
feed, she covers the eggs with down or nesting material.
Once hatched, the young are precocial and capable of
feeding themselves on aquatic vegetation and invertebrates found on the water
surface. The cygnets will take about 100 days to fledge, and sometimes as long
as 122 days.
Both adults defend their territory against other
swans as well as other waterfowl, mammals, and humans. In late May, I watched
the Powell Marsh pair aggressively chase away two other swans that had landed a
hundred yards or more from their nest. Last year, I saw one of the adults
repeatedly attack a pair of geese until the geese finally left the area.
Trumpeters are the largest native North American waterfowl, sporting a
seven-foot-wide wingspan and weighing 30 pounds or more, so when one
aggressively flies at an intruder, I suspect it’s a frightening sight to
behold.
Though trumpeters remain a “species of special
concern” in Wisconsin, by 2013, 220 breeding pairs were observed in 27
counties, and those pairs produced a record number of 349 cygnets.
Boom-Boom Means No
Zoom-Zoom of Birds
As July 4th
nears, and the desire in some humans to create loud explosions seems to reach a
peak, I’m compelled to remind folks that firecrackers scare wildlife. And not
just in your yard where you set off the devices, but in your neighbor’s yards
as well. May I humbly suggest that out of courtesy and regard for both humans
and wildlife, if you wish to go boom-boom, do so at a ball field or some other
large open public area, but not in the woods, over a lake, or near other
people’s homes, many of whom may have worked hard all spring to attract
wildlife.
Celestial Events
On 6/28,
look for Saturn about two degrees south of the waxing gibbous moon. On 6/30,
look after sunset for Venus and Jupiter next to each other low in the
northwest. The full moon occurs on July 1, the first of two full moons in July,
and Venus will again be just below Jupiter.
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