An online resource based on the award-winning nature guide

Rodents

Eastern Gray Squirrels Swimming

e-gray squirrel swimming by Erin 2_H6A2563 copy (002)Imagine coming upon a stick floating in a large pond only to discover the “stick” had a head and tail and was making a beeline for the shore.  The fact that an Eastern Gray Squirrel (Sciurus carolinensis) had paddled half a mile to get from one shore to the opposite shore of a pond shouldn’t have come as such a surprise, as this rodent has a long history of migratory swimming behavior, but it’s such an incongruous and unexpected event that it made my companion and me initially question our eyesight and then laugh out loud.

Historical reports suggest there have been many massive Eastern Gray Squirrel migrations in the United States, beginning in 1749 in Pennsylvania.   Records show the state paid three cents for each squirrel killed; over 640,000 squirrels were turned in for bounty.  One migration from Wisconsin in 1842 lasted four weeks and involved a half billion squirrels. Because of the numerous squirrel migrations, John James Audubon was erroneously convinced that the squirrels on the move were a separate species from the Eastern Gray Squirrel and gave them the scientific name Sciurus migratorius. (This proved to be inaccurate.)

During the 1800’s, thousands of squirrels would periodically move en masse across roads, fields and forests, and swim across lakes and rivers (including the Mississippi and Connecticut Rivers) in an effort to disperse. The consensus is that these mass movements were a response to local food conditions. They occurred mostly during the month of September following a year in which there was a large production of food (acorns).

The most recent mass migration of Eastern Gray Squirrels in eastern U.S. occurred in 1968, when a bumper crop of acorns in 1967 was followed with a corresponding bumper crop of young squirrels in 1968. By fall, as the first litter of the year left the nest, there was a severe shortage of food. As a result, massive numbers of acorn-eating squirrels dispersed in search of food.

One Eastern Gray Squirrel swimming across a New Hampshire pond does not a migration make, but it might not be a bad idea to keep an eye out for excessive numbers of paddling squirrels and/or road-killed rodents come September. (Photo by Erin Donahue)

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Red and White Baneberry Fruits Maturing

8-16-18 red and white baneberry-1While the flowers of Red (Actaea rubra) and White Baneberry (Actaea pachypoda) are quite similar (the flower head of Red Baneberry is more globular than the elongated head of White Baneberry), their respective fruits, the color of which gave them their common names, quickly distinguish these two species from each other.

White Baneberry produces white fruits commonly called “Doll’s eyes” due to the persistent remains of the flower’s stigma, which leaves a black dot on each fruit.  Red Baneberry’s shiny red berries also have these black dots, though they are not as apparent. All parts of both species are poisonous, with the berries being the most toxic part of the plant.

Seed dispersal is carried out by animals that have enough tolerance to feed on the berries. These animals include various mice, squirrels, chipmunks and voles, as well as a wide variety of birds and White-tailed Deer.

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Beavers Eating & Grooming

7-11-18 beavers 049A5253

This photograph conveys the essence of a beaver’s summer – eating and grooming… more eating, more grooming. During the summer months, beavers feed on non-woody vegetation (grasses, ferns, aquatic plants, etc.) 90% or more of the time. (During March/April and October/November, their diet switches to 60%-90% tree bark, and during the winter, bark from trees stored under water composes 100% of their diet.)

When beavers are not eating, much of their time during the warmer months is spent grooming, both themselves as well as each other.  Combing debris out of their coat (with the help of a split nail on both hind feet) and applying oily material from their anal glands to waterproof their fur consume much of their waking hours, both at night as well as at both ends of the day. (Castoreum, produced in castor sacs, differs from anal gland secretion, and is used primarily to mark territory.) (Thanks to Roger and Eleanor Shepard, and Sara and Warren Demont for photo op.)

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Happy Groundhog Day !

2-2-18 woodchuck IMG_2381The Woodchuck, or Groundhog, is one lucky creature, considering past practices. The observation of “Groundhog Day” originated in the mid-1800’s, and by the late 1800’s and early 1900’s the celebration consisted of feasting on this rodent. A formalized hunt took place and participants then dined on Groundhog (which purportedly tastes like a cross between chicken and pork) and drank Groundhog punch. Since then, the Groundhog has evolved into a forecaster of weather, rather than a meal.

While New England Woodchucks are curled up in their hibernacula,  Punxsutawney Phil is busy seeing if he can see his shadow today (in which case we’re in for six more weeks of winter) or whether cloudy skies will prevent that from happening and spring is right around the corner. I’d bet on the former.

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What Goes On Beneath Our Feet In Winter

Alfred's mouse2 2018-01-16 20.39.08 (003)It’s fairly unusual to see Deer or White-footed Mice, especially in the winter – they are nocturnal and they spend much of their time in the airspace under the snow next to the ground known as the subnivean layer. (A blanket of snow traps the earth’s heat, which melts the bottom of the snow, creating this layer of space.) Here both Deer Mice and White-footed Mice travel extensively, protected from both the cold (it stays within a degree or two of 32 F. regardless of outside temperature) and the eyes of predators. On cold winter days, groups including both species of mice keep warm by huddling in a common nest. (Photo of White-footed/Deer Mouse – extremely difficult to tell the difference by sight – by Alfred Balch.)

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Porcupine Trails

1-12-18 mystery photo 049A2042Porcupines are forced to exert a lot of effort if they are in need of food and the snow is deep. Unlike many rodents that are light enough to travel on top of the snow, Porcupines must plow their way through it. Their weight, short legs, and bare footpads make traveling in snow challenging, to say the least.

If the snow is deep, the winter ranges of Porcupines are considerably smaller (18 acres in one research study) than their summer ranges (160 acres in same study).  Because of the energy needed to travel through the snow, Porcupines usually feed just a short distance from their winter dens, more often than not within 200 feet. Their feeding trails from rocky or hollow tree dens to their woody food sources (often Eastern Hemlock-note bits of branches on snow in photo, American Beech and Sugar Maple), are very distinctive. They are used every night when Porcupines leave their dens to feed and again several hours later when they return.  These trails become well marked with urine, and less frequently with scat and quills. (Photo insert: Porcupine rock den entrance)

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Beavers Breaking Ice

11-13-17 beaver and ice IMG_4410

We’re right on the verge of when beavers will no longer be able to smell fresh air, see the sun and obtain fresh bark. Until the temperature drops to around 16 degrees F. they continue to break through the thin ice covering their pond. Once the temperature remains in the teens or lower for several days, they no longer try to break through the ice and are sealed under it until spring, unless there’s a mid-winter thaw.

Once beavers are confined by the ice, their activities outside the lodge are minimal. Beavers leave their lodge in winter primarily for three reasons: 1) to swim out to their winter food supply pile and retrieve a branch which they bring back into the lodge to eat, 2) to defecate in the water, and 3) to mate in January or February. Other than these excursions, they spend most of their days in the dark, enduring life in a lodge that has a temperature of about 34 degrees F. (Thanks to Kay and Peter Shumway for photo op.)