A Northwoods Almanac for May 8-21, 2026
Sightings - First-of-Year (FOY) and Others
4/19: We heard our FOY leopard frogs. Their call is likened to snoring, but I think of it more as the rumbling sound my stomach makes when its feeling a bit too acidy, or if I haven’t eaten in a long while. This was very early for them to be singing - they’re usually an early May event.
4/20: We found our FOY trailing arbutus in flower in the Frog Lake and Pines SNA.
4/23: We had our FOY pine warbler, a normal sighting for this time of the year, but then a male Baltimore oriole briefly appeared at our feeder. That’s super early for orioles, but he hasn’t been seen since then. So, I think this one rode the south winds of one of our many storms we had during that time and then likely regretted his decision.
4/19: We heard our FOY toads chorusing in the wetlands below our home. We also observed our FOY swamp sparrows, yellow-bellied sapsuckers, and ruby-crowned kinglets.
4/22: We saw our FOY mourning cloak butterfly flittering about.
4/29: Our FOY dandelions appeared.
4/26: On a hike in Powell Marsh, we saw our FOY tree swallows, sedge wrens, and green-winged teals. That evening, we heard our FOY Wilson’s snipe winnowing over the wetlands below our house.
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| photo by Bev Engstrom |
4/27: A pine warbler briefly visited one of our sunflower seed feeders, a very odd behavior for any warbler given that most warblers are almost entirely insectivorous. However, pine warblers are the only wood-warbler known to regularly consume seeds (often pine seeds or seeds at bird feeders) in any significant amount. Remarkably, they undergo seasonal physiological changes in their digestive system to allow for digestion of seeds.
4/28: We saw our FOY palm warbler. However, most interesting of all, we got to see the exceedingly brief mating of a pair of merlins. When I say brief, I mean brief. It was just a two second mounting of the female by the male accompanied by some high-pitched chittering, and then the male departed. He should have least bought her dinner.
Hibernating Butterfly?
Mourning cloaks are one of our very few butterfly species that hibernate over winter. They’ve just spent six months nearly frozen in tree cavities, beneath loose tree bark, in wood piles, or in unheated buildings. But the cold is not a direct hazard to mourning cloaks – rather, it is the formation of ice crystals in their body tissue that can quickly be lethal. To keep from freezing, mourning cloaks reduce the amount of water in their blood by as much as 30 percent and then thicken it with a sugar solution of sorbitol, outdoing any antifreeze we humans put in our cars. Using electrical conductivity, biologists in Alaska found that mourning cloaks do not freeze until the temperature reaches -220°F.
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| photo by Mary Burns |
Once they emerge, they are short on fat and need to eat, so they often seek out running tree sap or rotten fruit. As the days become longer and warmer, they’ll mate and lay eggs for the next generation, living only a few weeks. Still, mourning cloaks win the award for greatest longevity among butterflies, living 10 or 11 months from last summer till now.
Butterflies need body temperatures close to ours to fly. All of our spring-active butterflies have dark-colored bodies and wings to aid in solar heating their bodies. Watch for mourning cloaks basking, opening their wings and angling their bodies toward the sun, to increase their body temperature prior to flight.
The mourning cloak is found throughout most of North America and Europe and in a broad band across central Asia. So, they don’t just announce spring in Wisconsin, but around much of the world.
World’s Oldest Loons Return Once Again to Seney
I write every year about these two loons, and as long as they live, I will continue to highlight their remarkable lives.
On April 25, a female loon known as “Fe,” who was first color-marked as a breeding loon in 1990, was seen on one of the pools in the Seney National Wildlife Refuge in the U. P. She will thus turn at least 40 this summer given that loons seldom mate until they are at least 4 years old, and often not until they are 6. Fe was seen with an unbanded male, who was likely her mate from 2025, as they initiated a circling round of bill dipping and jerk diving, aspects of courtship involved in forming, or re-forming, a pair bond for the season.
Nearby on another pool, Fe’s former partner of 25 years, “ABJ,” was scouting for potential nest sites with his current companion, “Aye-Aye,” with whom he bred unsuccessfully last year. Although ABJ, who will turn 39 this June, hatched a record 32 chicks with Fe, since their split in April 2022 he has failed to produce other young, and she remains the only mate with whom he has ever sired young.
Wow - this proves loons live as long as 40 years!
Winter Severity Index
We evaluate the severity of winter by a host of personal measures; from how often we had to shovel, how hard it was to shovel, the condition of the roads all winter, whether we were able to do the winter activity(ies) we love, if we ran out of wood, how much LP cost, if the lakes iced up early or late, how long the winter actually lasted as felt by our individual cabin fever index, et al. It’s a subjective tally based on a mix of objective experiences.
As a means of more objectively evaluating the severity of winter, the Wisconsin DNR uses the “Winter Severity Index” (WSI), which measures how winter weather impacts the survival of one of our most valued species, white-tailed deer. The values are obtained by adding one point for each day the temperature is colder than 0 degrees Fahrenheit and one point for each day the snow is 18 inches or deeper.
The data are recorded from Dec. 1 to April 30. At the end of the season, if the points total less than 50, it's considered a mild winter; 50 to 79 is seen as moderate; 80 to 99 is severe; more than 100 is very severe.
The 2013-14 winter was the most severe in state history, at 143 points. But recent years have brought more wildlife-friendly winters across the northern portion of the state, including WSI values of 55 in 2021-22, 69 in 2022-23 (though it was much higher in a few of the far northern counties like Iron, Ashland, and Bayfield), 10 in 2023-24, and 32 in 2024-25.
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This winter, one that represented something more “normal” for northern Wisconsin, the WSI for the southern part of our area was mostly in the moderate range via statistics from Dec.1 through the end of March. However, northern portions of Vilas and Iron County led the state with the highest severity scores from 88 to 99.
Go just a little ways south into Oneida County, and the score drops quickly to around 43, and into Lincoln County, it hits 35. The rest of the state, despite a blizzard here and there, is even lower in the mild range.
These generally mild conditions over the past decade and more have played a large role in allowing the statewide deer herd to increase. The most current estimate released by the DNR is a state record of 1.89 million deer, and very likely the largest the state has ever seen prior to records being kept. Check the attached chart: Compared to 2011, the deer population has grown 79% (there’s more data on the DNR's Deer Metrics page.)
The increase isn’t all about weather, of course. It’s also about political decisions like ending the “Earn-a-Buck” regulations and early antlerless-only gun seasons in 2011.
It’s important to also note that the WSI is very general - it isn’t a “be all and end all” tool. It doesn’t, for instance, take into account the “TDER” factors: timing, duration, extremes, and repeatability of snow and cold. It’s vital to understand when the snow and cold occurred, how long they occurred, how extreme they were, and how often they happened.
As with all things in nature, there’s complexity!
April is traditionally the transitional period of time when many animals are on the brink of starvation, and spring can’t come soon enough. Now, “green-up” has begun, and with plants burgeoning and insects hatching, the threat of starvation has receded to mostly a fever dream.
What About China?
One common objection to the U.S. taking the lead in climate action is: “But what about China? China is doing nothing!”
Well . . . that turns out to not be true.
* Last year, China installed a full half of all the world's new wind and solar energy.
* Over the past two years, China installed more new solar power each year than the U.S. has installed in total across its entire history.
* China is the world’s largest producer and consumer of electric vehicles (EVs), controlling over 70% of global production and dominating the battery supply chain. China produces nearly two-thirds of the world's EVs. In 2025, over 50% of new car sales in China were electric (including battery electric and plug-in hybrids).
* As of late 2025, China has the world's largest EV charging network, exceeding 19 million total charging facilities (including public and private).
Still, China is currently the world’s largest annual polluter, responsible for over 30% of global greenhouse gas emissions. China emits significantly more than double the CO2 of the US and has been the top emitter since 2006, though its per capita emissions are much lower than the U.S. China's population is around 1.42 billion in 2026, over four times larger than that of the United States, which is approximately 347 million. Of note, however, is that China’s population is decreasing.
So, China is the world’s largest producer of emissions, which are the main cause of climate change, but it’s also the global leader in the production of green technologies from wind and solar power to electric vehicles.
Meanwhile, the U.S. is attempting to increase its use of fossil fuels while blocking new wind and solar projects, and our CO2 emissions are ticking up.
Climate change is a global problem, and progress in one place helps everyone - no country can fix climate change on its own. We’re all in this together, because we have to be.
Celestial Events
For planet watching in May, look after dusk for brilliant Venus low in the WNW and Jupiter low in the W. Before dawn, look for Saturn rising in the East and Mars extremely low in the ESE.
The new moon occurs on 5/16.
On 5/18, look after dusk in the West for Venus 3° below the waxing sliver moon.
On 5/20, look after dusk in the West for Jupiter to have switched places with Venus and is now about 3° below the crescent moon.
Thought for the Week
Annie Dillard: “There is no shortage of good days. It is good lives that are hard to come by. A life of good days lived in the senses is not enough. The life of sensation is the life of greed; it requires more and more. The life of the spirit requires less and less; time is ample and its passage sweet . . . How we spend our days is, of course, how we spend our lives.”
