“As the days lengthen, the cold strengthens,” seemed to be an appropriate saying to explain the majority of February 2016. With a small handful of snowstorms and at least one, Arctic outbreak (albeit short-lived), our temperatures throughout New England seemed to moderate nicely AND keep the second warmest Winter on record from topping ALL the record books. Hence, the El Nino winter we are experiencing.
No doubt, as the Earth’s overall temperature continues to warm (progressively and ultimately over time), large swings in temperature will be more prevalent, as will massive storms. This past November-February is no exception. With temperatures around 30 degrees one day, to negative 10 degrees the next morning, and then back into 50 degrees once again the following day.
The question now remains, “When will Winter end and Spring really begin?” This is all relative and beyond what is considered astronomical Winter or Spring in the northern hemisphere—this refers to the position, or angle, that the sun is in the sky AND the amount of daylight we receive. Around December 21 (Winter Solstice) the sun is at the lowest point in the sky and we receive just under 9 hours of daylight. Conversely, on March 21 (Spring Equinox) the sun is a bit higher in the sky (above the Hemlocks in the front at Moose Hill) and we receive around 12 hours of daylight…AND darkness, hence “equinox.”
But…As another old, VT weather saying goes, “the first day of Spring is one thing, the first Spring day, yet another” (Ludlam, David; The Vermont Weather Book). Each year is different, obviously. What we can be certain of, though, is that the sun has increased its “elevation” in the sky significantly since early February, thus yielding warmer day time highs and lows—low 40 degrees during the day and down to about 20 degrees at night, on average—AND longer days. Over the past month we have gained close to 70 more minutes in our day, i.e. from 10 hours to 11 or so. If you have been out and about on these days, I’m sure you noticed how the 25-32 degree temperatures felt a bit moderated by the sun’s warmth. A very different feel than 25-32 degrees in December!
Because we have little or no snow on the ground (in most locations), as we progress through the month of March there will continue to be more absorption of incoming solar radiation (insolation), the soil will warm more quickly, retain that heat each day, AND cause the “events” of Spring to happen much more quickly: sap flow in Sugar Maples, spring ephemerals blooming, grass/herbaceous plants greening up, more birds singing, frogs chorusing, chipmunks active, and more.
Consider each season in “stages” with a progression of these events—early Spring usually includes snow melt, wood frogs chorusing, and birds singing (latter parts of March); mid Spring includes spring ephemerals/grass greening up and more birds singing (April); late Spring includes bud break, leafing out, black flies, caterpillars, and Neotropical migrants (May-early June)…this is the concept of meteorological seasons and what is usually observed during a 3-month period, including progressions up/down in average, daily temperatures. Spring is not a season to rush, so enjoy every minute of it!! Before you know it, we’ll be in the heat of Summer!
Yes, I have rambled enough. In keeping with the “stages” of Spring and the hows/whys (as mentioned above), here are some signs of Spring that I’ve seen at Moose Hill:
- Maple Sugaring: classic shot here of a Sugar Maples all geared up at Moose Hill. Sap flow is slowing down here after some very active runs in late Winter (February). With those increasing global temperatures yielding such a warm Winter in New England, I often wonder how much longer we’ll be able to go about this practice. No doubt, the insect leaf feeders are way ahead of the curve, acclimating (and even adapting) faster than our Sugar Maples to these warmer temps.
- Chipmunks active: I’ve seen these little woodland sprites over the last few weeks at Moose Hill, especially near the stone walls just past Wood Thrush Way on the Billings Loop AND “chipmunk alley”. Thanks to a great mast crop in the late Summer-early Autumn (acorns on the ground from late August-October) AND the lack of Winter snow, chipmunk populations are doing better than they have in years.
- Crocuses blooming: a commonly planted spring ephemeral and often the first flower to blossom in our area; check these out on the very south side of the Camp Barn!
- Daffodil leaves: these tend to be some of the first, planted spring ephemerals to pop out of the ground, occasionally in parts of February. With slightly warmer than average February (as mentioned above), they were up 6” in my neighborhood. they are able to withstand temperatures down in the teens; now those are some tough leaves!
- Snow drops blooming: aha! The first Spring ephemerals to both leaf out AND flower! We saw some with the kids this past week on that little “curve” of trail when leaving the Billings Yard and entering the open field (on the right), with the line of bird boxes.
- Vernal Pools and running water: In any case, many vernal pools are full to capacity at the moment (due to the copious amount of rain this Winter) and still have portions that are frozen, especially around the edges.
On a side note: remember that frozen water (in the form of snow, ice, etc.) is imperative in the continued formation of these pools; a good slug of rain won’t necessarily fill up them up AND with the increasing elevation of the sun by late March-early April, increasing ambient air temperatures, evaporation will also occur at a higher rate, causing many vernal pools to shrink in area/volume; bring on the rain!!
Back to early March, though…. it won’t be long before….
- The return of Wood Frogs and Yellow Spotted Salamanders!! These amazing little amphibians are STILL sleeping, believe it or not. I kept thinking that they might be active over the past few weeks, as both temperatures and humidity levels seemed just right, but after observing a number of vernal pools, I was incorrect in my assumption. So what is it that “wakes them up” from their slumbers beneath leaves and the soil?? Well, maybe I should rephrase my question: “What are the ‘environmental queues’ that these amphibians respond to?” During my Animal Behavior courses at the University of Vermont, we discussed this at great length, and my professor introduced the word, zeitgeber, a Germanic word referring to ‘environmental queues’. Some of these queues may be proximate, and others ultimate. Without getting into a large discussion ourselves, you can probably figure out what these mean. Here are some examples, though: Spring Peepers (tiny chorus frogs that frequent our forests and wetlands) respond to short bursts of warmth and humidity much better than other amphibians, hence, proximate environmental queues; whereas Wood Frogs and Yellow Spotted Salamanders tune in to the slowly increasing angle/warmth of the sun OVER TIME, hence, ultimate environmental queues. This, should therefore help to answer a part of our question – perhaps a more detailed conversation in a future posting in regards to these species.
- Red-winged Blackbirds and Grackles!! These lads are back from their sojourn in the southern U.S. and are singing/defending breeding territories in full force around these parts. Such a wonderful sign of early Spring!! Are they responding to proximate or ultimate environmental queues?? Birds are trickier to pinpoint in this regard, so both answers would be appropriate here, as early- to mid-March is usually the time that Red-winged Blackbirds return to shower us with their “conglareeeee” song early in the morning within our wetlands. They have been frequenting the feeders at Moose Hill, a wee earlier than usual this year, but great to see!!
Michael Acciavatti…Instep Nonstop
Nature Detective Notes by Michael Acciavatti. Michael is our full-time teacher naturalist who often heads out on the trails to stretch his legs and observe what is happening. His enthusiasm and knowledge make for wonderful updates about the nature of Moose Hill. We hope that you will be inspired to head out on our trails as well and enjoy the changes that each season, or better yet, each month bring to Moose Hill. We look forward to seeing you here!