An online resource based on the award-winning nature guide

Animal Diets

Red Squirrel Gardens in the Woods

6-4-13 sugar maple seedlingsi 036Red and Gray Squirrels remain active year round, and thus, need to have access to food throughout the year. In order for this to happen, seeds and nuts must be stored in the warmer months for consumption during the winter and early spring, when food is much harder to find. While Gray Squirrels tend to bury nuts and seeds individually for this purpose, Red Squirrels often cache numerous seeds (mostly conifers and maples) in one spot, dispersing these caches throughout the woods. During the winter Red Squirrels use their memory (and sometimes their sense of smell) to locate these buried treasures. Inevitably some are overlooked and in many of these cases, the seeds germinate. Finding little patches of multiple seedlings, such as this miniature stand of young Sugar Maples, is a good indication that at least one Red Squirrel overwintered in the vicinity.


Jack-in-the-Pulpit Corm: A Black Bear Delicacy

5-23-13 jack-in-the-pulpit corm 069When black bears first emerge from hibernation, they survive mainly on emerging green vegetation in wetlands. As the season progresses, there are more and more food options to choose from, including a favorite – the corm, or underground bulb-like storage structure, of Jack-in-the-Pulpit. Even though they are large, somewhat lumbering creatures, black bears dig up and remove these corms as if they had a tiny tool designed just for this purpose. They barely disturb the earth, leaving only very small holes as evidence of their presence. A friend of mine witnessed this just outside his window one spring day, and could not believe the delicacy with which the bear extracted these morsels of food from the ground. Apparently the calcium oxalate crystals in Jack-in-the-Pulpit that cause the burning sensation in human mouths doesn’t affect bears, at least not enough to protect the plant.


Muskrat Division of Labor

5-6-13 muskrat carrying grassi 093Although muskrats are primarily nocturnal, you occasionally see them in the daytime, especially in the spring and fall. They often reside in ponds or marshes, where they live in the pond bank or build their own house out of mud, cattails and other available plant material. Muskrats are herbivores, favoring cattail roots, arrowhead, bur reed, pickerelweed and other aquatic vegetation. The pictured muskrat is not feeding, however — more often than not muskrats eat their food where they find it, especially during the warmer months. It is doing its share of parental care — this is the time of year when the first of several litters of muskrats are born. While the mother nurses her four or so young, the father spends time gathering bedding material for his offspring. The muskrat in this photograph spent a morning cutting and gathering several mouthfuls of grasses growing by the side of the pond. When he couldn’t fit one more blade of grass in his mouth he would scurry down the bank and disappear into a burrow which most likely led to a chamber where his young are being raised. Like their beaver cousins, muskrats tend to keep a tidy house and forage for fresh bedding for their young with some regularity.


Black Bear Hibernation Ends

3-20-13 black bear track IMG_7204Recent discovery of black bear tracks and scat confirm that hibernation has come to an end, at least for some bears. During the winter black bears lose an average of 23% of their body weight. Because there is a scarcity of food when they emerge from their dens, black bears continue to subsist off the fat that they put on last fall, and thus continue to lose weight. The diet of black bears is high in carbohydrates and low in proteins and fats. When hibernation is over, they head for any available succulents and protein-rich food, including bird feeders.


New Children’s Book by Mary Holland

FerdinandFoxCover PhotoDo you know a 3 – 8 year old who loves animals and would enjoy getting close-up views of the antics of a red fox kit during the first summer of his life? My second children’s book, Ferdinand Fox’s First Summer, has just been published by Sylvan Dell in both hardback and paperback. I have been lucky enough to have had the opportunity to observe and photograph young red foxes as they interact with each other and with their parents. This book consists of a selection of these photographs, accompanied by text and an educational component at the end of the book. Look for Ferdinand Fox’s First Summer in your local bookstore. If they don’t carry it, you would be doing me a huge favor by asking them to. Thank you so much. My next children’s book is on Beavers and will be coming out in the spring of 2014. (I am still looking for a publisher for Naturally Curious Kids!)


Coyotes and Beavers

3-12-13 coyote & beaver lodge2 IMG_6223A study of coyote prey (through stomach contents) in the Adirondack Mountains of New York revealed that beavers were second only to white-tailed deer. This photograph shows that, possibly for the last time this winter, a coyote recently took advantage of a still-frozen-but-fast-thawing pond by walking across it in an attempt to reach an active beaver lodge. Once there the coyote attempted to dig into it in order to reach the inhabitants. A hard, two-to three-foot-thick wall of frozen mud, logs and sticks kept the beavers well protected, as it was designed to.


Shrew Defense Mechanism

3-8-13 coyote digging up shrewIMG_5320Coyote tracks led to a hole dug in the snow, with the body of a shrew lying on top of the snow next to the hole. Apparently a coyote had succeeded in catching the prey it had heard, but upon smelling this tiny insectivore, the coyote decided it wasn’t that hungry. In addition to having poisonous saliva that immobilizes small prey, shrews possess two glands on their sides that emit an unpleasant odor, detectable even by human noses. Although this odor did discourage the coyote from eating the shrew, it wasn’t enough to save its life.


More Otter Sign

3-1-13 crayfish IMG_3205It’s often a lot easier to find signs of otters than otters themselves. Recently I discovered two dead crayfish on the shore of a mostly iced-over pond that I knew was inhabited by otters. Nearby otter scat confirmed that these crayfish were probably left by satiated otters. The most important prey item in a majority of otter scat analysis studies is fish, followed closely by crayfish. Otters will take advantage of other prey, such as frogs, salamanders, ducks, muskrats, an occasional young beaver, mice, snakes, insects and even turtles when readily obtainable, but fish and crayfish are first and second choices.


Snowshoe Hare Urine

2-28-13 hare urine IMG_4070Snowshoe hare scat is very distinctive – round, brown, pea-size fibrous pellets. Equally, if not more, distinct is their urine, which sometimes is orange, red or pinkish, depending on their diet. Often mistaken for blood, snowshoe hare urine has this color because of chemical compounds called porphyrins which are present in the chlorophyll molecules of green plants that hares consume. These compounds have such vibrant pigments that they were originally extracted from plants and used as dye for clothing. If you’re interested in seeing this colorful phenomenon, now is the time to do so, for it’s obviously a lot easier to find when there is snow on the ground!


Porcupines Tapping Out

porcupine tap IMG_3494At least one porcupine got a jump on humans this sugaring season. A porcupine eats outer tree bark in order to access the phloem (layer of inner bark cells that transport nutrients) and cambium (produces phloem and xylem cells) layers of a tree, its primary winter diet. In eating these layers, the porcupine unintentionally cuts into the xylem, or sapwood, where water and dissolved minerals (sap) are transported between the roots and crown of the tree. Unintentionally, porcupines tap the trees whose phloem and cambium they eat. In this case, the weather had warmed up enough to cause pressure in the tree, which in turn caused the sugar maple’s sap to flow just as a hungry porcupine happened along. Soon thereafter, the temperature dropped, causing the sap to freeze, forming icicles. While they looked good enough to sample, one whiff of them told me that sap was not their sole ingredient! (They were located beneath the porcupine’s den in a hollow tree, from which urine flows freely.)


Fisher Hunting Strategy

2-20-13 fisher hunting technique IMG_2988I have never heard of this particular fisher hunting technique, nor have I seen or read about it before, but there’s no denying that a fisher made these marks in the snow and that they tell the story of how it captured a mouse or vole. It’s likely that the fisher could hear or smell that the rodent tunnel in the subnivean layer was occupied. It looks as though the fisher methodically scraped snow towards the center of the circle, going completely around the tree in an attempt to trap and/or expose the mouse or vole within the circle. It succeeded in opening up the rodent tunnel (the hole is in the dead center of the photograph), and if the tiny droplets of blood on the snow near the hole are any indication, was successful in capturing its prey.


North American River Otters

2-11-13 river otters otters2 IMG_1386River otters are the most aquatic members of the weasel family. They eat the whole gamut of aquatic prey, including fish, frogs, crayfish, salamanders and turtles – not to mention snakes, small birds, mammals, earthworms and insects. It would not be an exaggeration to say that this threesome consumed a minimum of 15 fish and crayfish within half an hour. Look for signs of their sliding in the snow, both down slopes as well as on level ground.


Ruffed Grouse Roosts and Scat

1-30-13 grouse beds & scat IMG_2420A trail of ruffed grouse tracks in the snow led me to the spot where two grouse had bedded down for the night behind a fallen tree. With snow too shallow to burrow into, this was as protected a location as they could find. More often than not, a grouse defecates in its night roosting site before leaving in the morning. Grouse scat comes in two forms, one a dry, fibrous cylindrical pellet with a white-wash of uric acid at one end, and the other a softer, darker brown plop. The vast majority of a grouse’s diet (buds, twigs, leaves, catkins) goes directly through its digestive system and forms the dry, courser scat. Finer (and more nutritious) material such as the cambium layer of woody plants enters the caeca, two specialized pouches, before passing through the large intestine. The caeca contain bacteria which break down cellulose and produce the more digested, and therefore more liquefied, scat. Sometimes the two kinds of scat are deposited separately and sometimes, as in the bed on the right in the photograph, together. (Thanks to Dr. Alcott Smith who clarified grouse digestion for me.)


Fisher Scat

1-23-13 fisher scat2 IMG_0098Typical fisher scat is anywhere from ¼” to ¾” in diameter, very dark and often quite twisted. It’s not unusual to find just a small amount of scat deposited, as fishers can control the amount of scat they use to mark territory. This scat is a bit atypical, in that it is segmented and not twisted, and there is an ample amount. A close look reveals the dark, stiff hairs and quills of a porcupine, likely the fisher’s most recent meal. Look for fisher scat on raised surfaces such as stumps or at the base of old trees, where fishers occasionally make latrines.


White-tailed Deer Population Estimation

12-14-12 deer scat IMG_6670White-tailed deer are known to eat over 600 species of plants in North America. They consume, on average, about 5 to 8 pounds of food for every 100 pounds of body weight, per day. As a result, a deer, on average, defecates about 13 times a day. A crude but somewhat accurate way to estimate how many white-tailed deer are in your area is to count the number of scat piles you find in a square mile within 24 hours, and divide this number by 13. A little snow on the ground would make this particular method of population estimation a lot easier!


White-tailed Deer Diet & Digestion

11-30-12 deer eating IMG_6035A white-tailed deer’s diet consists of a wide variety of herbaceous and woody plants, the ratio of one to the other being determined by the season. Fungi, fruits and herbaceous plants form much of the summer diet. Dried leaves and grasses, acorns, beechnuts and woody browse are important autumn and early winter food. After snowfall, the winter diet consists mostly of woody browse (twigs, leaves, shoots and buds) from many different trees (maples, birches and cedars among them). Come spring, deer eat buds, twigs and emerging leaves. Deer are ruminants (as are cattle, goats, sheep and moose). They have a four-chambered stomach, which is necessary in order to digest the cellulose in the vegetation they consume. Food goes first to the rumen, the first of the four chambers, which contains bacteria and other microorganisms that help digest the cellulose. Food is circulated from the rumen back to the deer’s mouth by the second chamber, or reticulum, and the deer ruminates (“chews its cud”). The third chamber, or omasum, functions as a pump, sending the food to the final chamber, the abomasum, where the digestion process is completed.


A Great Christmas Present!

If you’re looking for a present for someone that will be used year round, year after year, Naturally Curious may just fit the bill.  A relative, a friend, your child’s school teacher – it’s the gift that keeps on giving to both young and old!

One reader wrote, “This is a unique book as far as I know. I have several naturalists’ books covering Vermont and the Northeast, and have seen nothing of this breadth, covered to this depth. So much interesting information about birds, amphibians, mammals, insects, plants. This would be useful to those in the mid-Atlantic, New York, and even wider geographic regions. The author gives a month-by-month look at what’s going on in the natural world, and so much of the information would simply be moved forward or back a month in other regions, but would still be relevant because of the wide overlap of species. Very readable. Couldn’t put it down. I consider myself pretty knowledgeable about the natural world, but there was much that was new to me in this book. I would have loved to have this to use as a text when I was teaching. Suitable for a wide range of ages.”

In a recent email to me a parent wrote, “Naturally Curious is our five year old’s unqualified f-a-v-o-r-I-t-e  book. He spends hours regularly returning to it to study it’s vivid pictures and have us read to him about all the different creatures. It is a ‘must have’ for any family with children living in New England…or for anyone that simply shares a love of the outdoors.”

I am a firm believer in fostering a love of nature in young children – the younger the better — but I admit that when I wrote Naturally Curious, I was writing it with adults in mind. It delights me no end to know that children don’t even need a grown-up middleman to enjoy it!


Avian Digestion

This slideshow requires JavaScript.

What happens to food after a bird swallows it? It may be stored in their crop, a pouch which is actually an enlarged part of its esophagus that some species of birds (and bees, fish and earthworms) have, or it may go directly to their stomach.  Birds have a two-chambered stomach.  The first chamber, the proventriculus, secretes acids that help break down food, including bones. A shrike’s well-developed first stomach chamber can digest an entire mouse in only three hours!  From the proventriculus the food goes into the second chamber, which is referred to as the gizzard, before entering the intestines.  The gizzard is a muscular organ which grinds up tough food, sometimes with the help of grit that some birds ingest.  The gizzard grinds the gravel and stones against the nuts and seeds, a process which smashes the food.  Wild turkeys can actually pulverize walnuts in their gizzards!  In some species, the gizzard remains small and insignificant during the summer when their diet consists of soft food such as flesh, insects, or fruit, but it grows more powerful during the winter when seeds are their main food.


Red Squirrel Sign

If you find a mushroom hanging in an unlikely spot, such as from tree branches or tucked into the bark of a tree where it didn’t grow, it’s likely that you have happened upon the work of a red squirrel (Tamiasciurus hudsonicus).  Red squirrels are known for their habit of snipping mushrooms and hanging them from branches and rough bark in order to dry them before collecting them and caching them for dining on later in the winter.   Unlike beavers, which share their stored cache of winter food with family members, red squirrels keep their cached fungi all to themselves.


Common Juniper

Common Juniper (Juniperus communis) is one of the few evergreen shrubs in New England and has one of the largest ranges of any woody plant.  You often find it in old pastures and meadows, where its sharp needles protect it from most herbivores.   It is a member of the Pine family, and even though its fruits look like berries, structurally they are cones (with fleshy scales).  Whereas most of the cone-bearing members of the Pine family disperse their seeds in the wind, Common Juniper uses birds and mammals to do this deed.  Cedar waxwings, evening grosbeaks and purple finches consume quantities of juniper fruit, and many other songbirds are frequent visitors.  White-footed mice and white-tailed deer occasionally eat the fruit as well.  While not aiding the dispersal of seeds, humans do use the fruit to flavor gin.


Eastern Chipmunks Gathering Food

By the end of this month or the beginning of November, most Eastern Chipmunks will have gathered and stored their winter food supply underground in a special chamber which they will visit every two or three weeks throughout the winter, grabbing a bite to eat.  Up to half a bushel of nuts and seeds can be stored here, which means many trips from the food source to the larder.  In order to minimize the number of trips, chipmunks  cram their cheek pouches as full as possible.  The contents that researchers have found in one chipmunk’s two pouches include the following (each entry represents the contents of one chipmunk’s pouches):   31 kernels of corn, 13 prune pits, 70 sunflower seeds, 32 beechnuts, 6 acorns.


Northern Watersnake

Northern Watersnakes can be found in rivers, ponds and bogs throughout New England, except for northern Vermont, New Hampshire and Maine.  They spend time foraging both day and night for fish (61% of diet), frogs and toads (21%), salamanders (12%) as well as insects and crayfish at the water’s edge.  (Snake jaws can separate at both the front and back, allowing them to eat impossibly large prey , such as the  catfish in Chris Crowley’s photograph.) They also spend a great deal of time basking on rocks and overhanging branches.  Northern Watersnakes can be formidable looking – they can grow over four feet long – but while they can be aggressive if threatened, they are not poisonous.  Watersnakes give birth to up to 70 (typically 20-40) live young between August and early October.


Great Egret & Post-breeding Dispersal

Although Great Egrets (Ardea alba) do breed sporadically as far north as Vermont, seeing one in northern New England is always noteworthy. The likelihood of a sighting increases as summer progresses, due in large part to the phenomenon of post-breeding dispersal. After young Great Egrets have fledged, individuals wander well outside their typical breeding range, as far north as southern Canada. The northward dispersal of juvenile birds peaks in August and September. (This Great Egret is about to dine on a crayfish.)


Black Bear Signs & Hyperphagia

Black bears are omnivores as well as opportunists.  They will eat almost anything that they can find, but the majority of their diet consists of  grasses, roots, berries, nuts and insects (particularly the larvae).  In the fall, prior to going into hibernation, black bears enter a stage called “hyperphagia,” which literally means “excessive eating.”  They forage practically non-stop — up to 20 hours a day, building up fat reserves for hibernation, increasing their body weight by 35% in some cases.  Their daily food intake goes from 8,000 to 15-20,000 calories (that’s roughly equivalent to 70 McDonald’s cheeseburgers).  Signs of their foraging for grubs and beetles, such as the excavated base of the snag in the photograph, can be found with relative ease at this time of year, if you live where there are black bears.  If you do share their territory with them, be forewarned that they have excellent memories, especially for food sources.  Be sure not to leave food scraps or pet food outside (my compost bin was destroyed last year but I have no solution for that particular problem), and if you really don’t want any ursine visitors, it’s best to not start feeding birds until most black bears have entered hibernation – late December would be safe most years.


Follow

Get every new post delivered to your Inbox.

Join 1,572 other followers