An online resource based on the award-winning nature guide

January

Ruffed Grouse Make Do With Shallow Soft Snow Depth

snow cave 143There are about five or six inches of new powdery snow on top of an icy crust in parts of central Vermont now, with more to come soon. It is common knowledge that ten inches of snow are necessary for Ruffed Grouse to dive into and burrow under the snow in order to make an insulating nocturnal snow roost. With only five inches of snow, a grouse still seeks shelter, but somehow it knows not to dive into the snow from the air. Rather, it lands on the surface of the snow, and then walks along making a groove in the snow as it goes, until it decides to rest for the night.

Several such resting spots were apparent today at the base of trees — slight depressions fully exposed. The grouse that made the snow roost in this photograph shuffled through the snow and then scrunched down without breaking the surface of the snow where it settled for the night, so that it had an inch or two of snow over its body – hiding it from predators, if not providing much insulation. In the morning, after defecating, it departed, not bursting out of a snow bank as it would if there were a lot of snow, but instead lifting off in plain view, leaving faint wing prints on the surface of the snow.

Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.


Mourning Dove Diet

1-28-15  mourning dove IMG_0746Seeds, including cultivated grains, grasses, weeds and berries, make up 99 percent of a Mourning Dove’s diet. Because they can find enough food to sustain themselves, Mourning Doves are permanent residents, remaining year round, even in northern New England.

These birds feed on the ground and in the open, consuming 12 to 20 percent of their body weight per day, or 71 calories on average. Mourning Doves swallow the seeds and store them in an enlargement of the esophagus called a crop. Once their crop is filled (the record is 17,200 bluegrass seeds in a single crop), they can then fly to a protected area where they can safely digest their food.

Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.


Meadow Vole Tracks

1-27-15  vole tracks 130Meadow voles and mice (white-footed and deer) leave most of the tiny tracks one sees on the surface of the snow. In deep snow, meadow voles tend to remain beneath the surface in tunnels, but occasionally do travel on top of the snow. Typically, a white-footed or deer mouse leaves a leaping, four-print pattern, often with a tail drag mark running between the sets of prints. A leaping meadow vole may or may not leave a tail mark and usually has paired prints. However, voles leave a variety of tracks patterns, depending on the speed at which they are traveling and the depth of the snow, so they can be confusing.

Although one might think that three different animals made the tracks in this photograph, every tunnel, track and hole was made by a meadow vole. The trail in the lower left was made by a trotting vole, the tunnel on the right was exposed because the layer of crust just under the new snow prevented the vole from going any deeper, and at the top, the vole was quickly bounding into the safety of its deeper tunnel.

Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.


Common Redpolls Appearing

1-26-15 common redpoll male 077The birds most commonly associated with winter irruptions are the winter finches — Pine Grosbeak, Red Crossbill, White-winged Crossbill, Purple Finch, Pine Siskin, Common Redpoll, and Evening Grosbeak. Their food supply, or lack thereof, in the Canadian boreal forests where they normally overwinter, determines whether or not they will be seen as far south as the U. S. Key trees affecting finch movements in the boreal forest are spruces, birches and mountain-ashes.

Common Redpolls feed primarily on the catkins (seed-containing fruit) produced by birch and alder trees. When catkin production is low further north, as it is this winter, Common Redpolls leave these areas and irrupt into areas where food is more plentiful. (Photo: male Common Redpoll)

Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.


Great Horned Owls Courting

1-22-15  great horned owl IMG_5973The intense hooting of Great Horned Owls begins in late December or early January, about a month before actual mating takes place. Males call during most seasons of the year, but the period when the males are hooting vigorously lasts for a month or six weeks. During the mating season the deep, rich tones of the males are occasionally interspersed with the higher and huskier notes of the females. The answering calls of the females are heard for only a week or two, toward the end of the six-week period.

Eventually, when a male and female approach each other, they do a sort of courtship “dance.” The male cocks his tail, swells his white bib (see photo), and with much bobbing and jerking utters a series of deep sonorous calls that elicit calling responses by the female. He cautiously approaches the female, continuing much tail-bobbing and posturing. The owls nod, bow, and spread their wings as well as shake their heads. Courting pairs have been observed engaging in high-pitched giggling, screaming, and bill-snapping. Mutual bill rubbing and preening also occurs. Copulation concludes the courtship ritual, with both owls hooting at a rate of 4 or 5 hoots per second throughout copulation, which lasts 4 – 7 seconds. (Photo: Great Horned Owl, in captivity)

Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.


Fisher Scat

1-21-15  fisher scat-crayfish 012For seekers of animal signs, tracking a fisher is a most rewarding endeavor. Fishers are constantly marking their territory – rolling on and breaking limbs of conifer saplings as well as urinating and defecating on or near saplings or on prominent, elevated stumps or rocks.

More than other members of the weasel family, Fishers can control the amount of scat they deposit, so that there can be a minuscule amount, or a full-size scat (2” – 7” long). Perhaps because of their predilection for marking with their scat frequently, they often use this medium sparingly.

The color of Fisher scat is usually dark brown or black, but once in a great while one happens upon fisher scat that is bright orange – a sure sign that the fisher has lived up to its aquatic name and has dined on crayfish in the recent past. Fishers primarily prey on snowshoe hares, porcupines, ground-nesting birds and smaller rodents. However, they do frequent streams that remain open in the winter, where they hunt for crayfish and, very rarely, fish.

Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.


A Bobcat’s White-tailed Deer Cache

1-21-15  bobcat2 cache by Otto Wurzburg 009 (3)Rabbits and hares comprise much of a Bobcat’s diet, but when prey is scarce or hard to capture, adult male or sometimes large adult female Bobcats will attack bedded, weak or injured adult White-tailed Deer. Bobcats often cache prey (such as a deer) that is too large to eat in one feeding, returning to feed on it for an extended period of time. They scrape up leaves, bark, twigs, soil. snow – whatever is available – and cover their prey. When feeding on a deer, Bobcats bite away the hair to avoid eating it, and this discarded hair is frequently mixed with the debris that the cat drags over the kill to cover it (see main photo – taken the day after the deer was cached), or is left windblown around the carcass. A characteristic sign of Bobcat feeding is the amount of hair strewn around the carcass and the lack of broken long bones (Bobcats don’t have the strength to break them with their teeth).

Typically a Bobcat rests near its cache to protect it, but it doesn’t take long for other animals to detect and take advantage of an easy meal. Within three days of this deer being cached, Coyotes and Common Ravens had discovered it, and both they and the Bobcat had eaten enough of it to expose the deer’s rib cage (see insert).

Other predators that occasionally cache and cover their kills include Mountain Lions, Black Bears and Fishers. Large caches found in the winter in the Northeast are likely to belong to a Bobcat or Fisher (Fishers typically cache and feed on deer that they find as carrion).

(Cache discovered by Lynn & Otto Wurzburg, who observed the Bobcat leaving after caching the deer; photograph by Lynn Wurzburg)

Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.


Follow

Get every new post delivered to your Inbox.

Join 3,226 other followers