HARE-RAISING ENCOUNTERS by Mark O’Donoghue and Susan Stuart

The following article was printed in

Natural History Magazine, February, 1993,

reprinted December 1996, Small Pack Option Magazine,

and then reprinted, with permission in,

Better Beagling Magazine, August 2017 issue and

The Rabbit Hunter Magazine, July 2017.
It is now reprinted here for your reading pleasure with permission from
 Mr. Charles Harris at Natural History Magazine.

On the Allegheny

from Joe Ewing, High HareMan of the

Big Woods Hare Hunters of the Allegheny.

Mr. & Mrs. J. Taylor

USO Sponsoring Member Since 2011

Hi Joe

While browsing through my notes, I found this interesting study and thought you could use it in your columns.

Those red squirrels are a menace and I use Ramis to solve my problems.

Enjoyed the chase.

Keep in touch.

Jim

Proud to Support our Troops

A while back I received this note from Big Woods Hare Hunters of the Allegheny charter member Jim Taylor of DuBois, PA.  A true sportsman, master hare and rabbit hunter, Mr. Taylor has mentored many hare hunters, including this reporter.

The article he relayed to me was one I sent to him back in 1997.  The twenty-year-old article which Jim saved all these years was a photocopy of a December 1996 Small Pack Option Magazine article which was reprinted from a February 1993 edition of Natural History Magazine. 

At the suggestion of Mr. Taylor, and by popular demand, I wish to share “HARE-RAISING ENCOUNTERS” with the readers of Better Beagling Magazine.  Some old-timers may recall reading the report.  I will be adding pictures from my archives and I hope everyone enjoys the story.

With permission from Mr. Charles Harris at Natural History Magazine, the Big Woods Hare Hunters of the Allegheny are proud to present…

HARE-RAISING ENCOUNTERS

                           by Mark O’Donoghue and Susan Stuart

From Natural History, February 1993, copyright © Natural History Magazine, Inc., 1993

The week-old snowshoe hare huddled motionless under the low branches of a small spruce.  All day, the baby hare, or leveret, had hidden in the same spot, its soft, molted brown fur rendering it almost invisible – but not completely.  Death came suddenly from the trees above.  In an instant – twice the size of the leveret – was upon it.  Despite its shrill screams and attempts to flee, the young hare was soon overpowered.  Responding to its cries, its mother rushed to the site, stomping her feet and clicking her teeth, but she arrived too late.  The squirrel scampered up a nearby spruce tree with its prize and stashed the carcass in the crook of two branches for later consumption.

Squirrels killing hares?  Squirrels have certainly been seen raiding bird nests, but we knew of no researchers who had noted squirrel predation of hares.

Our study of the ecology of juvenile snowshoe hares began in 1989, in Canada's Yukon Territory.  Our work was part of the Kluane Boreal Forest Ecosystem Project, a cooperative research effort of three Canadian universities, whose aim is to examine the structure of the vertebrate community in the coniferous forests of the north.  Our 125-square-mile study area was typical of boreal habitats found across a broad band of Canada, Alaska and Eurasia.  Spruce forest, broken occasionally by small natural clearings and aspen stands, dominated the landscape.  A patchy and often dense understory of willows and bog birch provided ideal cover for the hares.  Throughout the northern part of their range in Canada and Alaska, snowshoe hare demographics undergo dramatic fluctuations at fairly regular intervals.  These fluctuations are often referred to as the ten-year cycle because the hare populations reach very high densities (one to four hares per acre) every eight to eleven years, almost simultaneously across North America. Then, over the next few years, hare populations plummet.  They fall as low as about one hare per 200 acres and stay at that level for several years, after which the cycle begins again.

This cycle is central to the functioning of the boreal community.  As hare numbers rise and fall, so do the numbers of their predators, although predator numbers generally don't begin to decline until a year or so after the collapse of the hare population.  Other boreal herbivore populations, such as grouse and squirrels, may also be affected by changes both in predator numbers and in the amount of food available after hare browsing.

A Pennsylvania Boreal Forest.

Researchers vary in their explanations of why the hare cycle occurs - some support a predator-prey cycle, others cite a hare-vegetation interaction.  All major studies, however, have noted the same demographic changes in hare populations over the course of the cycle.  Whether in the Yukon, in Alberta, or in Minnesota, the survival rate of juveniles is the single most important factor responsible for increases or decreases in the hare population.  However, the rate of juvenile survival measured in previous studies was always of hares older than one month.  Younger hares were difficult to find in the field and did not enter the live-traps set by biologists.  The purpose of our research was to determine the survival rates of hares from birth through their first days and weeks and to investigate their ecology.

When we started research, our challenge was to locate some leverets.  Young hares are well camouflaged, and, unlike rabbits, which give birth in relatively conspicuous nests or burrows, hares are born in well concealed depressions, often under logs or shrubs.  To be certain of having animals to study, we placed pregnant female hares in individual pens for a few days before they were ready to give birth.  As soon as the hares were born, we removed the pens so that the mothers and young could move about freely.  We ear-tagged 850 babies in order to identify them.  And, to follow the young hares’ movements more closely, we glued tiny radio transmitters, weighing approximately one-twentieth of an ounce, to the fur between the shoulder blades of 254 of the 850 hares.  We followed the leverets around every day, noting as they grew how they fared during their first weeks of life.

Snowshoe hares are very prolific.  During the two summers of our study (which took place during the periods of high hare numbers), most of the females produced three litters, each with one to nine young.  A female averaged about twelve young per season.  Females usually mated again on the same day on which they gave birth, so the litters were spaced apart only by the snowshoes hare’s thirty-six-day gestation period.

We were able to watch the births of one litter quite closely.  Sitting up on her hind legs, the doe gave birth to six young, cleaned them, and fed them their first meal, all in about fifteen minutes.  She then moved away and did not associate with her litter again during the rest of the time that they were together in the pen, about ninety minutes.

Unlike rabbits, hares are born well developed.  They weigh approximately two ounces, are fully furred, and open their eyes within an hour of birth.  They also gain coordination quickly and are soon mobile enough to crawl into a huddle with their siblings.  Even before they were a day old, they can hop fast enough to make capturing them quite a challenge.

Most litters stayed together at the birth site for three to seven days.  The amount of maternal attention the young hares received during this period varied.  Although seldom coming close to their litters, some mothers stayed within 50 to 100 feet of their young for the entire day and vigorously chased away red squirrels, ground squirrels, and birds that wandered too near.  Other females stayed completely away from their litters during the daytime.

The red dot indicates Kluane Lake in Canada's Yukon Territory.

When the baby hares first ventured out from their birth sites, they generally moved ten to twenty feet away and hid under shrubs, leaves and logs.  Occasionally we found one or more hiding together, but most of the leverets remained alone in these concealed spots, even on the first day away from their siblings.

With the help of a colleague, Carita Bergman, we kept a round-the-clock watch at the birth sites of several mother hares to determine how and when their young were fed after their litters had broken up.  From these observations, and from following the radio tagged animals, we learned that in their first couple of weeks the leverets remained in the same hiding places, often more than 200 feet away from their birth sites and littermates, for more than a week.  During their first few weeks, we observed juveniles nursing once each day, shortly after twilight, which – in the long Yukon summer days – was usually between midnight and 1 a.m.

In two of the nursing sessions we observed, the mother hare hopped through the area in which her young were hidden, about 120 feet from their birth site and 90 feet from each other and made high chirping noise.  Then she appeared to leave the area.  The leverets moved from their hiding places and regrouped at the birth site, where their mother joined them 30 minutes later.  On four other occasion, the individual leverets gathered at their birth sites with no apparent solicitation from their mother.  Each time, when the mother arrived at the birth site, she nursed her young for only about ten minutes before leaving again.  By morning, each leveret was back to its original hiding place.  Orrin Rongstad and John Tester, both of the University of Minnesota, found similar nursing patterns, as did French and Dutch researchers studying European hares.  The European researchers also analyzed hare milk and found it to be extremely rich and concentrated, which is essential for animals that nurse their young so briefly and infrequently.

Once the leverets left the birth site, they seldom returned except to nurse.  On one occasion, a litter of three, seven day old leverets regrouped at their sheltered “nest” on a rainy day, four days after leaving it.  On another, a radio tagged leveret left its birth site at three days of age and was found during the next few days with the newborn litter of another female about 200 feet away.  The young hare was healthy and gained weight during this time, so apparently, it was not rejected by its “foster” mother.  While many mammals will only care for their own offspring, leporids (hares and rabbits) may be an exception.  Researchers studying European hares and swamp rabbits have also noted cases of females accepting strange young.

As the young hares grew older, they gradually ranged farther from their birth sites.  By the age of twenty days, their home ranges approached those of their mothers in size (four to six acres).  They also began to move more during the daytime.  Hares younger than two weeks old could easily be approached while they remained motionless in their hiding places, but older leverets fled as soon as we got within ten to twenty feet of them.  Judging from their droppings, the leverets has begun to feed on grass and other herbaceous plants when ten to fourteen days old, but they continued nursing for another week or two.  After this age, most leverets were weaned, and their mothers had another litter on the way.  Juveniles from the last litter of the season sometimes nursed until they were forty days old, however.

The first juvenile hares began leaving their natal ranges when they were about five weeks old.  Those that we could follow usually moved at least a quarter-mile away from their mothers’ home range.  Only 4 of the 850 leverets that we ear-tagged when they were newborns settled as adults near their birth sites.

Soon after we started following the radio-tagged juveniles, we began to get some puzzling results.  Many of the leverets we tagged were killed before they were ten days old, and we found almost half the carcasses (80 of the 170 that died) in trees or in red squirrel middens.  Another tenth (18) of the leveret carcasses ended up, mostly eaten, in arctic ground squirrel borrows.

Red squirrels were abundant on our study area.  They constructed large underground middens around the bases of spruce trees where they stored their winter supply of spruce cones.  The trees standing in the middens so typically served as sites for the squirrels’ nests (irregular spheres of grass in lower branches) and additional storage of mushrooms and other items they gathered.  Ground squirrels were also common, especially in small clearings, and their extensive borrow systems dotted the floor of the forest.

At first, we concluded that these baby hares must have died of other causes and had been scavenged by squirrels.  We knew that both red and ground squirrels sometimes fed on carrion to supplement their mostly vegetarian diet.  As our research progressed, however, we began to suspect that at least some of the carcasses must represent perdition by the squirrels themselves.  For one thing, the number of stashed hares just kept mounting, beyond what seemed reasonable if the squirrels were simply scavenging.  For another, we couldn’t think what predator would kill so many baby hares and then leave them around.  Coyotes and lynx generally leave little behind when feeding on such small prey.  Two other potential mammalian predators – weasels and martens – were scarce on our study site.  And birds of prey, such as hawks and owls typically either eat their prey at the spot where they made the kill, or carry it off to their nests or special feeding trees.

Several observations bolstered our suspicions.  During the course of our study, other biologists working in the area twice observed ground squirrels attacking and killing young hares.  We also saw one red squirrel carrying a live, wounded levered, and three others running away from freshly killed leverets.  Just to be sure, however, we tested the scavenging efficiency of squirrels by placing carcasses of predator-killed leverets on our study sites.  The squirrels only scavenged about one quarter of them at the same time (early June) that we were finding evidence of squirrel for more than 85 percent of juvenile moralities.  These findings, coupled with our observations of mother hares chasing squirrels from their litters, gave us strong evidence that both red squirrels and ground squirrels were indeed predators of snowshoe hares.

Over the course of the two summers of our study, we calculated that only about one-third of the baby hares survived the first two weeks of life.  In the end, we concluded that of those that died, about three-quarters were killed by small mammalian predators, most likely red and ground squirrels.  By contrast, only 5 percent of the radio-tagged leverets were killed by great-horned owls, northern goshawks, and re-tailed hawks – animals generally thought of as significant predators of small mammals.  We have evidence from other research being conducted in the area that young hares sometimes wind up being gulped down by coyotes and lynx and eaten by northern harriers and northern hawk owls.  Even gray jays – robin sized birds known as scavengers – have been seen killing baby hares.

A gray jay.

By the time they are two weeks old, the leverets are too big and too fast for the smaller, opportunistic predators to catch.  Until then, however, the best bet for a litter of young hares seems to be to lie low and to split up as soon as possible, so that if a predator does strike, it won’t be able to feast on an entire litter.  Similarly, the less often they nurse, the less likely they are to be discovered.

The behavior of young hares and their mothers makes a great deal of sense when considered as a defense against predators. The answers we have found, however, have left us with many new questions.  Do squirrels prey extensively on leverets only when they are abundant?  Does this predation have a significant effect on the hare cycle, or would most of the leverets been killed later by other predators anyway? To answer these and other questions, we will need to return to the boreal woods at different points in the hare cycle and see how the leverets fare then.  But we are sure that for baby snowshoe hares, the forest will always be full of danger.

The Kluane Boreal Forest Ecosystem Project operated from 1986 to 1996 in the southwestern Yukon.  Comprehensive research information on snowshoe hare and many other animals may be read by googling the Kluane Boreal Forest Ecosystem Project on the internet.