Even in mid-February, there are signs of spring. Tracks of animals that hole up during the cold winter months and emerge when the nights are warmer are starting to be seen.
Raccoons often seek shelter in dens for months at a time during the winter (they don’t technically hibernate, but experience torpor). When night temperatures rise above freezing they abandon their hollow tree cavities, often following streams or visiting wetlands. Although they occasionally may forage for aquatic prey such as fish or crayfish, Raccoons in New England eat very little during the winter. Rather, they utilize the fat they store in the fall, which is often more than 40% of their body weight. By the time spring arrives, they may have lost half of their fall weight.
If you find tracks this time of year that lead to or away from a den they may well be those of a male Raccoon who has emerged to seek out a mate.
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North American River Otters are not territorial in the classic sense of marking territorial boundaries. Instead they mark prime resource areas within their territory. Often, the site is near their den or a productive food area. They visit these sites repeatedly to urinate, defecate and roll around on the ground – so much so that the surrounding vegetation is often dead or dying and is referred to as a “brown-out.”
If an otter has been eating fish, its scat is often just a pile of fish scales. However, if it has been dining on crayfish and it is fresh, the scat can be tubular. No matter what form otter scat takes, a tell-tale sign (in addition to fish scales and/or crayfish exoskeletons) is the presence of clear, white or yellow mucus (scat-jellies). It is not always deposited, but occasionally you do find it. The origin of this mucus is not known – most likely it’s from the otter’s intestinal tract or its anal glands. Research shows that the presence of mucous deposits in some otter species indicates reduced prey availability or reproductive state. (Photo: Tubular otter scat is circled in red. Mucus is on right side of photo. Thanks to David Putnam and Natalie Starr for yesterday’s and today’s photo op.)
Reasons why Mystery Photo was not
Black Bear: Scat consists primarily of crayfish remains.
Beaver: Beavers defecate only in water, and individual pellets consist of tiny woody fragments resembling sawdust.
Raccoon: Raccoons have latrines where multiple scat is deposited, similar to otters. However, only otters deposit mucus.
Winter’s coming and in the Northeast, Striped Skunks are preparing for the cold months ahead. Before they usurp the abandoned quarters of a Muskrat or Red or Gray Fox (or bunk with a willing Opossum or Raccoon), they spend a great deal of time foraging and putting on life-sustaining fat. Even though a state of torpor slows their metabolism down during the coldest months, skunks must bulk up in the fall, as they lose up to 65 percent of their body weight over the winter. Thus, they meander far and wide looking for food this time of year. In addition, this year’s young are still dispersing. For these reasons, you may have encountered the smell of skunk or the sad sight of striped roadkills in your travels lately.
Female Snapping Turtles spend a lot of time and effort finding suitable sandy soil in which to dig their nest and lay their eggs. Some turtles have been found laying their eggs as far as a mile from the nearest water source. Once she has laid her eggs and covered them with soil, the female snapper returns to her pond, leaving her eggs to hatch on their own, and the hatchlings to fend for themselves.
It is estimated that as many as 80 to 90 percent of all turtle nests are destroyed by predators, weather conditions and accidental disturbances. Most of the damage is done by predators – skunks, raccoons, foxes, crows, among others. Most nests are discovered by smell, and most are raided at night. The fluid that coats the eggs, that is lost by the mother during egg laying or is lost through breaks in the eggs, produces a smell that is easily detected by predators. While a majority of nest raids happen within the first 48 hours of the eggs being laid, studies have shown that predation occurs over the entire incubation period (June – September). The pictured Snapping Turtle nest was dug up and the eggs consumed 10 days after they were laid.
If you are aware of a spot where a turtle dug a nest and laid eggs, you can try to protect the nest from predators by placing either a bottomless wire cage or an oven rack over the nest site, and putting a heavy rock on top. The tiny hatchlings will be able to escape through the openings but hopefully, if the rock is heavy enough, raccoons and skunks will become discouraged and give up trying to reach the nest.
The next Naturally Curious post will be on 7/5/17.
Yesterday’s mystery tracks were those of a raccoon that was following a partially-open stream, emerging from the water only when it was necessary to cross ice in order to get to the next patch of open water. Temperatures have been on the mild side recently, so raccoons have been active. During very cold periods raccoons become lethargic and tend to seek shelter in hollow trees or other retreats where they may remain for up to a month or so. When the temperature at night rises above 32°F., they become active, but little or no food is consumed. Instead, they live off body fat (up to 30% of their weight) they accumulated in the fall. In addition to recent warm weather coaxing Raccoons to become active, February is the peak of their mating season.
(Muskrat, Otter and Beaver were the three other 5-toed, water-loving mammals that received the most “votes,” all viable guesses. The Raccoon’s front and hind feet are more dissimilar from each other than those of Muskrats or Otters are, and a Beaver’s hind feet are webbed and considerably larger than a Raccoon’s.)
The low water levels in our ponds this fall do have one benefit – visitors leave obvious signs in the exposed muddy banks. It is fairly astounding how much nocturnal and crepuscular wildlife regularly visits these spots and remains undetected by humans under normal conditions.
Most raccoons in the Northeast are born in April or early May and spend the next seven weeks inside a tree cavity (brush piles and underground burrows are known but not prevalent denning sites) living off their mother’s milk. Four to six weeks go by before the young are able to stand upright, but soon thereafter they are climbing and hanging out of the cavity entrance. The young raccoons are in the process of being weaned when they leave their den at the age of seven weeks. For the next month or so the mother raccoon and her offspring forage together; by the age of five months the young are doing a lot of foraging on their own. Often the family remains together into the late fall or even winter. During cold winter weather, they typically will den together, and the following spring when the new litter arrives, the one-year-old raccoons disperse. (Thanks to Andrea Ambros for photo op.)