A Northwoods Almanac for April 24 - May 7, 2026
Maple Sap to Syrup Chart
Taps have been pulled, and the maple syrup season has come to a close for 2026. I don’t know how the season went overall across the state, but at least in our area the maple sugar content in the sap appears to have been down. That’s important, because the lower the sugar content in the sap, the more sap it takes to create a gallon of syrup.
In my last column, I wrote about Bob and Terry Simeone in Land O’ Lakes who have been making maple syrup for 39 years. Over that time, they’ve learned how crucial it is to have a high sugar percentage of sugar in the sap. To illustrate this, Bob provided me the following chart showing how many gallons of sap it takes to make a gallon of syrup according to the sugar content:
1% sugar 86 gallons
1.5% sugar 58 gallons
2% sugar 43 gallons
2.5% sugar 36 gallons
3% sugar 29 gallons
3.5% sugar 25 gallons
4% sugar 21 gallons
Bob and Terry pull their taps once the sugar content goes below 2%, because it takes so much more sap, and time to boil the sap, to get the desired syrup.
This year, the first run of sap in Bob and Terry’s maple stand was just above 2%, and by April 5, the content was down to 1.5%, so they pulled their taps. In a good year, the sugar content will be above 3% in the first run, and remain relatively high until the weather warms to 60°, the magic number when the trees start to metabolize, or “wake-up” if you will, and the taste changes to something much less desirable.
Interestingly, the sugar content is largely determined by the weather from the previous spring and summer. The warmer the temperatures during the previous growing season, the less sugar content there is the next year. Cloudier and cold summer weather can also lead to a lower sugar content.
Current-year conditions matter, too. If there's too little snow, trees may struggle to absorb enough water during the early spring, negatively impacting sap production.
More than anything else, however, climate change is the largest looming factor. In order for maple sugar sap to flow, temperatures need to freeze at night and thaw during the day, but these freeze-thaw conditions are changing. In a study done in Vermont, the annual number of unfrozen days has increased by about four days per decade since the 1970s, which has pushed the sugaring season earlier than it historically was. The University of Vermont’s Proctor Maple Research Center found that the average sugaring season in Vermont now begins 8 days earlier than it did 50 years ago. The first boil of the year for many sugarmakers used to be in March, but is now in February or even January. This also means that the sugaring season ends earlier than it once did.
Bob says this is true for them as well in northern Wisconsin. Their last boil used to be in mid-April, and now they rarely make it into April at all.
This year though was more of a “normal” winter, and the sap run went into the second week of April.
There’s lots of variables in why a good or bad year occurs, and maple syrup producers still debate how it all works, so Bob rightfully warns me to be wary of exclaiming any “truths.”
Still, in simplest terms, it boils down to this: no freeze, no sap, no syrup. By 2100, the region of maximum sap flow is predicted to shift northward by about 250 miles due to warming temperatures caused by climate change.
Sightings (FOYs - First of Years)
4/8: John Randolph reported seeing osprey on both of the Hwy. 47 nests north of McNaughton, a relatively early return for osprey given that they must have open water in order to fish and most of our local lakes were not open by this date.
4/9: Bev Engstrom in Rhinelander reported the first tree swallows.
4/10: Bev also reported the first yellow-rumped warblers appearing in our area.
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| photo by Bev Engstrom |
4/11: Anne Small in St. Germain reported seeing the first hermit thrushes.
4/12: Mary and I saw our first shorebirds of the year - a pair of greater yellowlegs at Powell Marsh. Paul Strong in Hazelhurst reported seeing yellow-bellied sapsuckers at his suet feeder.
4/14: Spring peepers began their tumult in the ephemeral ponds near our home in Manitowish, as did wood frogs and chorus frogs. Earlier in the day, we saw our FOY northern flickers and yellow-rumped warblers along the Manitowish River.
4/15: We heard our FOY Eastern phoebe in Manitowish, and saw a northern shrike on Powell Marsh. Northern shrikes nest in the boreal forests of northern Canada, so this individual will be soon be on his or her way.
4/16: A FOY brown-headed cowbird appeared at our feeders in Manitowish. Given their reputation as brood parasites - they lay their eggs in the nest of many different species - it’s an occasion, along with the appearance of European starlings, that we don’t celebrate.
Ice-Off
Woody Hagge reported that the ice went off 39-acre Foster Lake in Hazelhurst on 4/15, one day earlier than the 54-year average. The earliest date was March 20, 2012. The latest was May 7, 1996.
We checked 42-acre Frog Lake, which is a half mile from our house, and the water was ice-free on April 16.
We hit 73° on 4/16, so that early warmth and accompanying rain has led to a relatively quick melting of lake ice.
Wind Pollination of Tree Flowers
The flowers of many wind-pollinated shrubs and trees are seldom noticed. They’re not showy, and they don’t need to be, because they aren’t trying to lure insects into conveying their pollen to a female flower. They use the wind.
Many of these species are in flower right now. Maples, oaks, alders, birches, hazelnuts, and aspens are all examples of flowering plants that have evolved to flower before leaf-out so that spring winds can distribute their pollen. These species are the introverts of the plant world - they don’t produce quantities of nectar, don’t revel in producing large petals, and don’t care much at all about brilliant coloration.
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| Aspen male catkins |
In the vast majority of these plants, female and male flowers are either on different plants or on different parts of the same plant, with the male flowers usually grouped in hanging or “grape-like” structures called catkins. Take a look at the long, hanging catkins of tag alders and hazelnuts which have their pollen easily shaken by air currents, or by your flicking them. Once in the air, the light weight pollen can reach distant female flowers.
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| Tag alder catkins |
This quiet and unassuming approach saves a lot of energy by not bothering to produce special rewards like nectar to attract pollinators. However, wind-pollination works best in places that are drier, because pollen won’t travel well if it rains all the time, or in places where forests are more sparsely inhabited, which offers space for the wind to more freely blow.
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| Northern red oak flowers |
Homegrown National Parks
“Homegrown National Park” is a unique initiative aimed at restoring and protecting America's biodiversity by encouraging citizens to plant native species on their own properties. Spearheaded by entomologist and conservationist Doug Tallamy. The initiative emphasizes the critical role that native plants play in supporting local ecosystems. By replacing traditional lawns or non-native plants with native vegetation, individuals can contribute to the regeneration of habitats for local wildlife, including birds, insects, and pollinators.
The project calls on all of us to transform our yards, gardens, and even urban spaces into mini wildlife sanctuaries. Native plants are better suited to local soil, climate, and wildlife than non-native species, which can sometimes disrupt ecosystems by outcompeting indigenous plants. Native plants also provide vital food and shelter for a variety of species, especially insects, which are the foundation of many food chains. By fostering these natural habitats, participants in “Homegrown National Park” can help restore some of the biodiversity that has been lost due to urbanization, agriculture, and climate change.
It’s getting close to planting season. Think native.
See https://homegrownnationalpark.org.
Online Bird Migration Tools
Weather surveillance radar (WSR) is an excellent tool for determining where birds are flying, how many birds are aloft, and in what direction, speed, and altitudinal strata they are moving. If you want to know when and from where birds are moving on any given night, use the website www.birdcast.org.
World Record Holder for Non-Stop Migration
Migration is on, and while some birds only travel relatively short distances, a 4-month-old bar-tailed godwit, a small shorebird named B6, made history in October 2022, when it left the mudflats of Alaska and flew nonstop across the Pacific Ocean, landing on the shores of Tasmania, Australia 8,425 miles later. It didn’t stop, didn’t sleep, didn’t eat. It just endured 11 days of continuous wing-flapping flight making it the longest nonstop migration ever recorded by any animal on Earth.
How do researchers know it never stopped and never ate? Godwits can’t swim and have no way to take off from the ocean surface. They also don’t feed while in flight, and the route it took never touched land.
B6 averaged 765 miles every day, burned through more than half its own body weight in fat, and did it all on its very first migration, with no GPS to guide it over the ocean.
One writer summed it up this way: “A bird the size of your fist crossing the world's largest ocean alone, guided by forces we are still trying to understand - this is not just a nature story. It is a reminder that the most astonishing things on Earth are often the ones we overlook.”
March Climate Data
The average U.S. temperature for March was 50.85°F, or 9.35°F above the 20th-century average, ranking as the warmest March in the 132-year record. Over half the continental U.S. area, 1,432 counties, observed their single warmest March day on record (1950–present).
Relative to rainfall, the U.S. precipitation average for March was 1.83 inches., or 0.68 inches below average, ranking eighth driest on record. The January to March period was the driest on record for the continental U.S. - less than 70% of average. This broke the previous record set in 1910.
Meanwhile in the U.P. of Michigan, Yoopers have experienced near record snowfall. The record was set in 1978-79 of 390.4 inches in the Keweenaw - Delaware, MI to be exact. They have a chance of breaking that record yet this April in three locations: Herman, Calumet, or Keweenaw County. Herman was at 365 inches as of 4/12..
Celestial Events
The first full moon of May (the Ojibwe “Flower Moon”) occurs on May 1. The full “blue moon” will occur on May 31.
May 5 marks the midway point between spring equinox and summer solstice.
Thought for the Week
“A river - with its attendant cascades, eddies, boils, and whirlpools - is the most expressive aspect of a natural landscape, for nothing else moves so far, so broadly, so unceasingly, so demonstrably, and nothing else is so susceptible to personification and so much at the heart of our notions about life and death. Across generations and around the globe, humans, we double-footed jugs of seventy percent water, have seen rivers as both our source and the way out of this world.”- William Least Heat-Moon
