A new book describes how Maine’s flora and fauna adapt to our changing seasons. Here’s the story of how three creatures — barred
By Mary Holland
Excerpted from Naturally Curious: A Photographic Field Guide and Month-by-Month Journey through the Fields, Woods, and Marshes of New England, Trafalagar Square Books, N. Pomfret, Vermont; 496 pages, $39.95.
The belly feathers on some barred owls are pink. This coloration may be due to eating many crayfish.
The larger great horned owl is one of the biggest predatory threats to the barred owl.
Because the barred owl’s range has extended north and westward it is now breeding and competing with the less aggressive, endangered spotted owl in the western United States.
The plumage of male and female barred owls is similar; as in all owls, the female is larger in size than the male.
Although considered non-migratory, when prey is scarce, barred owls may leave their territory to seek food elsewhere.
Young barred owls are able to climb trees using their beaks and talons.
As the forests were cleared in eastern North America, the red fox population increased in abundance and range.
In summer red foxes tend to be more active at night; in winter, when they feed heavily on voles, they become more diurnal.
Red foxes can hear the low-frequency noises of small mammals, such as their digging, gnawing, and scurrying through leaves, even through two feet of snow.
A fox tends to mark skulls and bones, the more durable parts of prey, with scat, not urine.
The red fox scatters its caches, remembering where these secret food reserves are and usually eats them within hours or days.
Red foxes are the only North American Canid species to have a white-tipped tail.
Young hares spend the day hiding in separate spots, congregating once a day to nurse from their mother for five to ten minutes.
Snowshoe hares and cottontail rabbits rarely dig and generally do not use the burrows of other animals.
Snowshoe hare and cottontail rabbit tracks are very similar but they can easily be told from one another by measuring the width of the hind foot. Depending on the geographic area, if it is less than one-and-one-half inches wide, it’s likely to be a New England or Eastern cottontail rabbit; if it is greater than one-and-one-half inches wide, it is most likely a snowshoe hare.
Raucous Courtship You wake in the middle of the night to maniacal laughter outside your window. Raucous caterwauling, one voice on top of the other, breaks the silence of the woods. After listening to this jumble of cackles, hoots, caws, and gurgles, you know it can be none other than a pair of barred owls in the passionate throes of courtship.
Barred owls can be heard every month of the year in New England but are most vocal during the months of February and March when they engage in courtship behavior prior to mating and laying eggs.
As part of this ritual, the male and female often perform a dueling duet, asking each other, “Who cooks for you? Who cooks for you-all?” It is relatively easy to distinguish the lower-pitched male from the higher-pitched female when they call back and forth in this manner. The barred owl has a broad repertoire of calls in addition to the caterwauling and “Who cooks for you?” standard. Single hoots as well as a series of ascending hoots are also given by both males and females. There is a resurgence of vocalizations in late summer and fall, but it pales in comparison to the intense conversations that take place this time of year.
Bringing Death by Night If it weren’t for these calls, it would be very easy to overlook the presence of barred owls in our mature woods, for their nocturnal habits and sound-muffling feathers make them very hard to detect.
The only audible hint of their presence, other than their calls, is the cacophony of sound when other birds—such as ravens, crows, blue jays, and songbirds—gather to harass or “mob” an owl while it perches on a limb. Making a terrible racket and repeatedly diving at the owl, these birds recognize that although birds of prey may be a threat to an individual bird, there is safety in numbers.
At this time of year, if the barred owl isn’t courting it is usually hunting for prey. The peak of its nocturnal hunting activity occurs just after sunset. Using its acute vision and hearing, the barred owl locates and consumes small mammals, such as mice, voles, squirrels, and rabbits, which comprise up to 75 percent of its diet. Birds up to the size of a grouse, amphibians, reptiles, fish, and invertebrates make up the rest, depending on the season. In addition, predators such as owls are known to occasionally eat other smaller predators. As improbable as it may seem, a dead barred owl was found in New England with the remains of a long-eared owl inside its stomach, and inside the long-eared owl’s stomach were the remains of a screech owl.
Barred owls usually hunt by surveying the forest floor for signs of life while perched on a branch. When prey is spotted, the owl drops down and captures it on the ground with its sharp nails (talons). Barred owls have also been known to perch on a limb over open water and dive down to capture fish. Other hunting techniques that have been observed include wading into shallow water to capture crayfish and running on the ground to chase an amphibian.
A Great Big Bite Regardless of where or how they find food, barred owls swallow small prey whole, head-first. Between eight and twelve hours after a meal the owl regurgitates the indigestible parts of the prey it has eaten in the form of an odorless, compact “pellet.” The larger the bird, the larger the pellet—barred owl pellets are approximately three inches in length and one inch in diameter. Within the pellet, fur is packed around most of the sharp objects, such as bones, nails and teeth, so as to facilitate their passage through the owl’s esophagus or gullet while the pellet is being coughed up. By examining a pellet’s contents you can determine the nature of the owl’s diet, often right down to the species of rodent it last ate.
If you’re lucky, you may catch a glimpse of a barred owl gliding silently and gracefully among the branches of your woodland trees. However, these owls are definitely heard more often than they are seen. Being quite territorial and thought to mate for life (which can be as long as eighteen years in the wild), barred owls tend to remain in the same area for a long time. Step outside in the middle of a February night, or sleep with your windows open—and know that what sounds like a bunch of raucous monkeys is more likely just two infatuated feathered friends.
A Catlike Canine If your nose has been telling you for the past month or so that your woods are riddled with skunks, you may be in for a pleasant surprise. During January and February, when red foxes are breeding, their urine (particularly the males’) develops a very strong musky odor that greatly resembles skunk spray. For various purposes, all manner of vegetation as well as rocks, logs, and other prominent spots are marked.
The strength of the odor of a fox’s urine during these months is indicative of the important role urine plays in red fox courtship. Information as detailed as the marker’s sex, age, dominance status, and breeding status is conveyed via scent posts scattered throughout the fox’s territory as well as along its borders. It’s no wonder a skunk-like odor pervades the winter woods of New England in February.
Like Dog, Like Cat As we all realize from observing domestic dogs and cats, members of both the dog family, Canidae (dogs, foxes, coyotes, wolves), as well as members of the cat family, Felidae (domestic cats, bobcats, Canadian lynx, eastern mountain lions), mark with urine (as do other mammals). There are other behaviors, however, that the dog and cat family usually don’t share. The hunting strategies of the dog family generally include endurance and distance running, whereas cats are built for stealth and bursts of speed. Canids approach prey openly, outpace it during a long chase, and finally pull it down, while felines stalk a prey closely and make surprise attacks.
Anyone who has had the good fortune to witness a red fox stalking and then pouncing on its prey can testify as to the similarity between its hunting traits and those of members of the cat family. In addition, the red fox possesses many of the physical adaptations that enable cats to hunt in this fashion: a good sense of balance so it can remain motionless for periods of time; retractable claws for capturing prey (red fox nails are semi-retractable, unlike coyotes and wolves, which don’t retract at all); sharp dagger-like canines for dispatching prey; a vertical-slit pupil and green reflective layer in the eye, enhancing both night and day vision; and long, stiff whiskers whose sensitivity may be of assistance during nocturnal hunting.
Directed by Diet Although it is thought that cats and dogs evolved from a common ancestral group, they have diverged into two quite separate families. The red fox has the prerequisite morphological characteristics (elongated skull, smooth tongue, four well-developed toes, semi-rigid elongated legs, forty-two teeth) as well as behavioral traits (caching food, scavenging behavior, well-developed pair bond, and use of burrows for dens) that are typical of Canidae. There are, however, traits that the red fox, as well as other fox species, share with the cat family, often making them seem more catlike than doglike. The $64,000 question is “Why?” The answer may lie in the fox diet.
A red fox can maintain itself on about a pound of meat a day in the winter. During the summer and early fall much of its diet consists of fruit and berries, supplemented with insects and small rodents. For the remainder of the year a fox’s diet is almost exclusively small mammals, with the occasional bird. Small rodents can very quickly escape down tunnels or under logs, or when alerted, can remain motionless, making detection very difficult. Great cunning and stealth is needed in order to surprise and catch them. Perhaps the answer to why the red fox possesses qualities that make it a “catlike canine” is very simple and straightforward: In order to capture similar prey, foxes and cats have evolved similar features and behaviors.
Tracking the Highly Hunted If your objective in life is to see a snowshoe hare, there are several steps you could take to maximize your chances of success. The first would be to determine when the hare population last peaked. Snowshoe hares undergo cyclic population fluctuations, with peaks every ten to eleven years. Once you identify when the next peak year is most likely to occur, consider where and what time of day or night to look.
Head for dense woods, for snowshoe hares are a forest species, and rarely stray far from wooded areas. Search between dusk and dawn, for this is when they are most active. Planning the hunt for winter is advantageous as their packed trails are far more obvious in the snow than on the bare ground. Lastly, notice where you see collections of their small, round droppings during the day. Unlike deer, who drop all their pellets at once, snowshoe hares drop them one at a time, so when you come upon a cluster of several pellets, you know the hare has spent a considerable amount of time in that spot—most likely because it found something edible, such as raspberry or blackberry canes—and it might well return.
Fine Dining The pressure for snowshoe hares to adapt has been high, for not only is every predator of any significant size, including bobcats, fishers, Canadian lynx, foxes, coyotes, and great horned owls, wise enough to look for them in the right places at the right time, but hares are at the top of most predators’ “fine dining” list.
Being able to avoid detection by the sharp eyes of a goshawk, outrun a fisher, or simply multiply so fast that predation rates can’t keep up with productivity rates, have all proven to be effective survival techniques.
The Varying Hare’s Varying Hair Most are aware that the color of the fur of a snowshoe hare varies with the season—this is why for many years they were called “varying hares.” Brown summer hairs are shed and replaced by white (only at the tips) hairs over a period of seventy to nienty days beginning in October and ending in December. The reverse process takes place in the spring, turning the hare brown by the time snow has usually disappeared. Not only does the white coat camouflage the hare in the snow, but it also provides 27 percent more insulation than the brown hair. Because white is actually the absence of pigment, the cells in white hairs (as opposed to brown) are filled with air, not pigment, and thus provide additional thermal insulation.
Go Fast Speed and agility traveling over snow have a tremendous effect on the life span of a snowshoe hare. Not only are its hind feet large and covered with dense fur, especially in the winter, but the toes can be spread as wide as four-and-one-half inches to further increase the surface area, allowing the hare to remain on top of the snow instead of wallowing in it as many of their smaller-footed predators do. In addition, due partially to the fusion of bones in their long hind legs that gives them greater thrust, hares are able to bound up to twelve feet in a single leap, and they’ve been clocked running thirty-one miles-per-hour on ice.
Make Many Even if these adaptations were to fail them, snowshoe hares have numbers on their side. Most hares reproduce at one year of age, and females breed again soon after they give birth to their litter of one to six young. (An extra advantage that hares have over many other prey animals, such as cottontail rabbits, mice, and voles, is that their young are precocial —born fully furred, with eyes open, able to walk, and even hop.)
Gestation is a mere thirty-seven days, allowing three or four litters per summer. Given an average of three young per litter, and three litters per year, one pair of hares, in two years, produces an average of ninety-nine offspring (their young, plus their young’s offspring). Although scientists estimate that only 15 percent of hares live long enough to reproduce (due mainly to predation), this is more than enough to maintain the species.
Snowshoe hares engage in unusual behavior during courtship. A game that resembles leapfrog takes place, with one hare jumping up in the air while the other dashes under it, and then the roles are reversed. This continues for several minutes, with the airborne hare urinating on the hare directly beneath it. This behavior may have several functions. According to scientists, it is felt that the female can detect pheromones in her mate’s urine that informs her of his reproductive efficiency—a handy thing to know if you want to pass on your genes. In cottontail rabbits the “jump” is thought to help soothe the female, who is initially aggressive to a courting male. They jump each other until she calms enough for him to approach. It’s very possible that this is true for snowshoe hares, as well.
Waste Not Waste There are also more subtle behaviors, which at first glance might not seem particularly advantageous but actually are, such as the hare’s habit of reingesting its feces. This behavior is referred to as coprophagy, and it guarantees that the hare extracts as much nutrition as possible from the food it has eaten.
One way to better break down cellulose is to lengthen the digestive tract to allow greater absorption of nutrition, and this can be done behaviorally as well as physiologically. Eating one’s own scat effectively doubles the length of the digestive tract.
The first time around, the hare’s soft, jelly-like pellets are eaten directly from the anus (which is why we rarely find them). It is the recycled pellets that we commonly come across on top of the snow. This practice also allows hares to eat quantities of food rapidly while exposed to the threat of predation, and then to retire to relative safety beneath a protective conifer branch or the middle of a thicket to re-ingest the food.
Most behaviors, regardless of how odd or insignificant they may appear to us, usually play a vital part in the survival of the species exhibiting them—especially a species that is sought after by many predators. From cradle to courtship, the snowshoe hare exemplifies this.