That early fall nor’easter we had recently brought up the question: How did critters survive days of wind and rain?
Consider some of the creatures we frequently encounter in our neighborhoods: the birds in our trees and at our feeders, the squirrels and chipmunks in our backyards, the earthworms underfoot, and the bees on our flowers. When a nor’easter arrives, different species take different approaches to riding out the storm.
Some birds, including chickadees and nuthatches and owls, roost in cavities and probably waited out the worst of the storm in holes in trees. Cardinals, sparrows, hawks and blackbirds fluffed out their feathers to trap air to stay warm, hunkered down in vegetation or a tree away from the wind, and conserved their energy. Small birds, especially, have limited energy reserves, so they may have foraged when conditions let up a bit.
Gray squirrels (Sciurus carolinensis) would adopt a similar strategy, huddling in their nests, called dreys, built of leafy branches in the fork of a tree. An inner layer of moss and pine needles insulated them from wind and rain. If they were able to find a tree cavity, they waited out the storm in the cavity, but if not, the drey had to suffice.
Chipmunks, however, would retreat to their underground tunnels, which can be 30 feet long and contain a sleeping chamber, food-storage rooms, spare rooms and escape tunnels at varying depths. Heavy rain can flood portions of their burrows, but there is usually a dry chamber. Like humans, chipmunks hunkered down with a pantry of food nearby. Unlike humans, they probably weren’t making French toast or streaming “The Pitt.”
You might have heard that earthworms (Lumbricus terrestris) come to the surface during a rainstormrainstorm, so they don’t drown. A person can drown when water enters the lungs, but an earthworm can’t, because it doesn’t have lungs. Instead, oxygen from the air or water dissolves into the slimy mucus covering a worm’s skin. Once the oxygen dissolves, it passes into the worm’s bloodstream.
So, an earthworm needs to stay damp. If its mucus covering dries out, it cannot acquire oxygen. For this reason, worms spend most of their time underground, away from sun, heat and dry air. Lab studies have found that some worms can live for many weeks submerged in water. A submerged nightcrawler, for example, can survive on average 137 days without food as long as it is in oxygen-rich water. Of course, keeping oxygen levels high in a laboratory is easy. In the real world, microorganisms decompose organic matter in stagnant water, which consumes dissolved oxygen. In oxygen-poor water, these same worms died within 36 hours.
The soil where nightcrawlers live can become oxygen-poor quickly. Too much water displaces air pores in the soil. Air contains more oxygen than water, so it is easier for worms to get oxygen from air than from water. To rid their habitat of excess water, nightcrawlers dig vertical tunnels. During heavy rains, nightcrawlers add substantially more vertical tunnels, which helps water flow deeper into the ground, preventing waterlogged soil. In one experiment, nightcrawlers made 2.4 times as many vertical tunnels during intense rain as during a normal rainfall. Nightcrawlers also sometime block the entrances to their tunnels, preventing rain from getting into them.
Some nightcrawlers, however, take advantage of rainstorms. It is a good time to travel across the surface of the soil, especially at night, to locate mates or start new burrows.
Credit: © Claire O’Neill
Bees, or at least the mated queens of many bumble bee species, have already dug into the ground one to six inches where they enter diapause (dormancy) and overwinter in a small chamber. They stayed put during the heavy rain. Studies have shown that common eastern bumblebee queens (Bombus impatiens) can remain submerged for a week and still survive to emerge in the spring to start a new colony. However, overwintering queens reduce the likelihood of being flooded by selecting well-drained overwintering sites.
Most bumblebees we see flying about in October in our area are common eastern bumblebees. Hardy males do not return to their nests at all but spend their days on flowers, sleeping there at night and foraging during the day. If you had peered into flowers during this storm, you might have seen drenched bumblebees clinging tightly to a flower, leaf or stem, sheltering as best they could from the rain and wind. Once the storm was over, the somewhat bedraggled bees reemerged. After a period of drying out and warming up, they went back to work as if nothing had happened.
The next time a nor’easter keeps you indoors, consider what is happening just outside your rattling windows. A chickadee may be tucked into a tree cavity while a chipmunk noshes underground. A nightcrawler may be digging new tunnels while a bedraggled bumblebee clings to a flower. These creatures have been weathering New England storms for thousands of years—all without umbrellas, weather apps, radiators, or French toast.
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