A Northwoods Almanac for June 7 – 20, 2024
Constructing an Oriole Nest
Baltimore orioles construct elegant hanging nests which are often very hard to find. But Bev Engstrom, a wonderful photographer in Rhinelander, not only found one, she was able to watch and photograph its construction from beginning to end, a process that took 7 days.
This particular nest was built high in an aspen tree. Nests are commonly built near the tip of outer branches of a tree high off the ground. In Ontario, the heights of 400 nests ranged from 4 to 100 feet, though 200 of these were found 18 to 35 feet off the ground.
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| 5/10/24, photo by Bev Engstrom |
The female does all the weaving of the nest utilizing hair, twine or string, wool, synthetic fibers (a nest made of cellophane and one made from fishing line have been described!), and various types of plant fibers including grasses, milkweed stems, and grapevine bark. Once the shell is completed, she commonly lines the nest with cottonwood or willow cotton, milkweed seed plumes, or feathers. Females have been observed flying for more than ¼ mile in search of appropriate construction materials.
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| 5/11/24, photo by Bev Engstrom |
Although nest construction can take up to 15 days, most nests are completed within about 1 week, depending in large part upon the weather – hard rains slow the process down.
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| 5/12/24, photo by Bev Engstrom |
Writes a researcher who has studied orioles for 40 years, “It’s absolutely fascinating to sit and watch them weave. You see the female poking one end of the string through, and then pulling her head back to weave it out, just like when you crochet or knit a bag. They can spend half an hour doing that, then go away to get another long piece of grass and do more.”
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| 5/13/24, photo by Bev Engstrom |
Why construct such a difficult nest? The most obvious benefit is that the deep cups and narrow two-to-three-inch entranceways provide better protection from predators and brood parasites like brown cowbirds.
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| 5/14/24, photo by Bev Engstrom |
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| 5/15/24, photo by Bev Engstrom |
Now, the completed nest:
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| 5/16/24, photo by Bev Engstrom |
Loon Killed by Blunt Force Trauma
I received this email from Judith Bloom on 5/27: “I had a call Saturday from lake neighbors who live 6 houses from me. They had netted a dead loon that they spotted 100 feet from their dock. Because it was banded and also because they know I monitor the loons on our lake, they contacted me. I was able to confirm that in fact this male loon was hatched on Horsehead Lake in 2016 and banded as a juvenile by Walter Piper and had held a territory on Lake Tomahawk for three years. Ironically, it was one of the pair that I had not yet located this season, and it was found not in its own territory.
“Through Linda Grenzer (she and her husband Kevin rescue a lot of injured, sick or deceased birds and waterfowl and work closely with REGI) I was in touch with Marge Gibson to see if she wanted to determine cause of death on this loon. She did. So, my husband and I picked up the loon from our neighbors dock (not touching the bird as instructed in case of avian flu) and drove to REGI [Raptor Education Group Inc.] in Antigo. There, very sadly, Marge confirmed that the loon in fact had a broken neck as a result of blunt force trauma. (Conclusion was that it was hit by a boat or jet ski.) You can see the obvious full fracture in the x-ray. It was a gorgeous, healthy weight (4.5 kilos) adult male in the prime of its life and just getting started to reproduce. It was a privilege to be there at REGI and witness Marge’s respect for this loon, her instruction to REGI’s interns and her calm demeanor in the face of sadness. John and I felt like we were in attendance at a funeral.
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| the banded loon at REGI |
“I was in touch with Walter, of course, to let him know about one of the birds in his study but also to see if he wanted the loon, hopefully for mounting for educational purposes. He does want it and will retrieve from REGI where it is currently in the freezer. Its feathers were gorgeous. The only noticeable “damage” were the dents from the hit to the neck and strafing along the top of its head.
“Tomahawk Lake has heavy boat traffic with HUGE boats where the driver cannot even see over the bow. And in my experience of 17 years of monitoring the loons on this lake, many boat drivers are not paying the slightest attention and have no interest in the wildlife on this lake. I’ve witnessed the deliberate driving of jet skis right through families of Canada Geese and harassment of loons. It makes my blood boil.”
My blood boils as well. As long as our lakes are viewed as recreational playgrounds and not as ecosystems, this immoral stupidity will only increase.
Great Lakes Ice Cover – Record Low
This year’s average ice cover for the entire Great Lakes was 4.3%, a record low since records began in 1973. Maximum ice cover reached 16% on January 22, the fourth lowest annual maximum on record. Lake Superior’s seasonal average was a record low at 2.6%.
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Indigo Bunting – To Be Blue Or Not To Be Blue
The brilliant blue of indigo buntings is universally raved about by observers – they truly are stunningly beautiful. But what is fascinating about their color is it’s all an illusion. Like all other blue birds, indigo buntings actually lack blue pigment. Their blue color comes instead from microscopic structures in the feathers that refract and reflect blue light, much like the airborne particles that cause the sky to look blue.
So, the blue of the male indigo bunting is literally a trick of the light, the brilliant azure caused by the diffraction of light around the structure of the bird’s feathers. This process scatters all but the blue light, and the resulting color shifts from black to blue to turquoise as the angle of reflected light changes.
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| photo by Bev Engstrom |
Notable Sightings – Trumpeter Swan Chicks
We’ve been walking out on Powell Marsh quite regularly and have been watching the nesting of a pair of trumpeter swans. On 5/29, we saw the pair with four tiny cygnets bobbing around them.
This pair, or perhaps a different pair (they’re not banded, so we don’t know), was unsuccessful last year, the female continually trying to incubate eggs well into July until she finally gave up. The incubation period is usually around 5 weeks, and since trumpeters return rather early in the spring, often before the ice is off the lakes, they’re early nesters, sometimes even a week or two before the ice melts.
According to the literature, when the young hatch, the adult female will brood them for a day or two, and then occasionally at night or in bad weather for several weeks. The chicks only weigh about a half pound at hatching.
The adults then lead the young to feeding areas where they will frequently tread the substrates to stir up invertebrates and vegetation for the chicks to eat. The young are precocial and capable of feeding themselves.
They’ll be nearly full-grown and ready to fledge after 3 to 4 months. And by nearly full-grown, I mean they’ll be 20 pounds, with big males sometimes reaching up to 35 pounds once they achieve full adulthood.
Notable Sightings – Cotton-grass
In the plant world, many species of wildflowers have come into bloom, but notable are the variety of species of cotton-grasses (Eriophorum sp.) in boggy areas. The tufted, cottony seed-heads may be so numerous that they appear like a cotton-field or a snow storm out in the sphagnum.
Cotton-grasses often grow into tussocks – round, bunchy clumps like pot-bound plants without the pots – that bear many stems of the plant. Individual tussocks can apparently survive for over a century! Who knew there was old-growth in the sphagnum?
photo by John Bates
Yellow Flag Iris – Kill It!
A yellow flag iris bloomed next to our house last week, a surprise to us since we never planted it, nor is it present in the wetlands below our house. While beautiful, yellow irises are highly invasive. Their thick rhizomes spread extensively and form dense, sometimes impenetrable mats that crowd out native species. The result: Reduced habitat for wildlife and fish, and reduced bird nesting and rearing sites.
The rhizomes can float, survive prolonged dry conditions, and fragments can form new plants. The plant also produces many seeds that float well away from the parent plant and rapidly germinate.
All parts of this plant contains large amounts of glycosides that are toxic to native animals.
When digging this plant out, which is the only way to effectively remove it, protect your skin as resin in the leaves and rhizomes can cause skin irritation. All parts of the plant should be dug out, particularly the rhizomes, and disposed of in a landfill or by burning.
Bottom line: Beauty can be a beast. Kill this plant without guilt.
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| photo by John Bates in Manitowish |
Iron County Bird Count
I participate in several bird counts every spring, one of which is a count specific for Iron County. Last year we were able to confirm 124 species, and so far this spring, we’ve found 136 species. We’re still counting, so I expect this number to increase by a few more species.
Why bother counting birds? Well, it’s the only way we’ll know if species are increasing or decreasing. We can’t manage wildlife if we don’t know their populations over time.
Celestial Events
For planet-watching in June, look late in the month after dusk for brilliant Venus low in the northwest. Look before dawn for Mars in the east, Jupiter later in the month in the east-northeast, and Saturn high in the southeast.
We’re getting close to summer solstice, so days are growing longer now by less than a minute.
The year’s earliest sunrises occur at 5:08 a.m. from June 10 to 20. This is 3 hours and 32 minutes earlier than our latest sunrises at the end of December.
Thought for the Week
“Life is a process of becoming, a combination of states we have to go through. Where people fail is that they wish to elect a state and remain in it. This is a kind of death.” – Anaïs Nin
Please share your outdoor sightings and thoughts: e-mail me at johnbates2828@gmail.com, call 715-476-2828, snail-mail at 4245N State Highway 47, Mercer, WI, or see my blog at www.manitowishriver.blogspot.com
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