November morning light dappled the snowy ground as wildlife photographer Bill Marchel crept through an oak forest near Brainerd. A few hundred yards ahead, he spied his subjects: five white-tailed deer picking through leaf litter for acorns. Marchel slipped closer and then settled near a large tree with his camera and tripod. Suddenly, the small herd startled in the frosty woods. But it wasn't his presence that alerted the deer. A silent, spotted form had materialized from the undergrowth to the photographer's right: A bobcat had entered the scene.
The graceful feline moved closer to the deer. Its subtly spotted coat and black-streaked face fur were fluffed against the chill; its ears and eyes were focused with a careful intensity. When the whitetails scattered, Marchel quickly captured a few images as the stealthy wildcat with its odd, curt tail looked back his way and then melted into the woods.
Rarely tipping the scales past 25 pounds, an adult lynx might weigh less than a bobcat does, but the lynx usually appears larger due to its thicker fur, much longer legs, and larger, furrier feet.
A bobcat's ear tufts are much shorter than those of a lynx. Both species have short "bobbed" tails. A lynx's tail has a black tip all the way around. A bobcat's tail has black bands but is typically black only on the top of the tip.
Mountain lions, also known as cougars, are rare in Minnesota. They are thought to be primarily transients that do not breed within the state. Nonetheless, many sightings are reported each year, and some are verified. Many of these sightings turn out to be bobcats or even house cats.
The adult bobcat has a light brown, reddish brown, or gray coat, often with white and black markings. The mountain lion has a plain tawny coat. The adult mountain lion weighs between 80 and 160 pounds. With a tail up to a third of its body length, an adult male mountain lion is about 7 or 8 feet long from nose to tail tip. The bobcat averages about 3 feet long.
Although Marchel spends many hours afield each fall and often finds the rounded tracks of this Minnesota predator, this was the first time he had photographed a bobcat in the wild.
The bobcat's covertness and natural camouflage make it a species seldom seen by people. Yet the bobcat (Lynx rufus) is Minnesota's most abundant wild feline. Of the state's three native species of wildcats, the bobcat vastly outnumbers the rare Canada lynx and the mountain lion, which make the evening news whenever they are spotted.
From the 1970s up to about 2000, bobcat population numbers were fairly low and stable, according to John Erb, furbearer biologist for the Department of Natural Resources. But starting around 2000, the bobcat population increased rapidly. It grew for about eight years and now appears to be stabilized at about 5,200 in spring and 8,200 in fall. (That's well above the levels observed from 1977 to 1997—about 1,700 in spring and 2,300 in fall.) Erb and other wildlife managers hope to better understand the causes and potential implications of this bobcat resurgence.
Elusive and Stealthy.
The bobcat's middling size can be deceiving: It can appear large when out in the open or tiny when viewed in cover. An adult is roughly 3 feet long including its short, "bobbed" 4- to 7-inch tail. Adult males, or toms, can weigh more than 30 pounds and occasionally over 40. Adult females usually weigh 20 to 25 pounds.
Bobcats rely on secrecy and surprise to capture prey. Although they do venture out in daylight, they are much bolder between sunset and sunrise. Their large eyes, adapted for seeing in twilight and darkness, are one of their top tools for finding food and evading danger. They pursue small mammals, such as cottontail rabbits, snowshoe hares, squirrels, and mice, and occasionally large ones, such as deer. Bobcats stalk songbirds, pheasants, ruffed grouse, and wild turkeys.
Bobcats are agile but not built for endurance. Because they tire quickly, they rely on close ambush as their primary method of attack. They can thrive where prey is abundant and lots of small trees and brush allow them to employ their patient hunting strategy. With plentiful prey, bobcats respond with proportionate reproduction. A litter might have up to six kittens, rather than the more common two or three.
During the breeding season in late winter, a solitary male bobcat travels far and wide, summoning females with loud yowls. After breeding, the male moves on and leaves the female to rear the young. Born in spring, the kittens begin hunting with their mother in early autumn. By early winter, many of the young disperse to find their own territories, but some family groups stay together until spring.
Bobcats in Minnesota prefer forests with diverse prey, dense cover, and habitat edges suitable for stalking and ambushing, according to Erb. Dense cover also provides places favorable for kitten rearing.
The core of bobcat range in Minnesota is roughly a large oval with one end near Hinckley and the other in the state's northwestern corner near Warroad. Bobcats can also be found in the northeastern Arrowhead, though their population density has historically been low in this region. With deep snow and less diverse and abundant prey, conditions there are better suited to lynx.
In many parts of the country, bobcats inhabit grasslands, desert, and other open spaces. However, they are unlikely to thrive in landscapes dominated by agriculture. Places with a mix of agriculture, woodlands, and grasslands can support low to moderate densities of bobcats. In recent years bobcats have turned up in southeastern Minnesota.
Prized in the wild-fur industry, bobcats are pursued by Minnesota hunters and trappers. During the 2012–2013 season, trappers took 1,681 bobcats, and hunters harvested 194. This harvest is a major factor in bobcat mortality. The DNR requires registration of all harvested bobcats and collects data such as age and sex. The DNR uses this data, along with other information, to help estimate population size and set the harvest quota to ensure a sustainable population.
Two annual track surveys—one in fall using scent stations and one in winter—also provide bobcat population trend information. These track counts are compared with a computer model that estimates population size. The model includes harvest numbers and data such as litter size, pregnancy rates, and mortality rates. If track counts and model trends match up, DNR biologists know their estimates are on the right track.
Erb suspects multiple reasons for the recent bobcat population explosion, although he stresses the need for more research to winnow out the causes. One possible factor is the changing climate. Minnesota is at the northern extent of bobcat distribution in North America. Bobcats are less efficient deep-snow predators than are Canada lynx, which have thicker fur, longer legs, and oversized paws.
"Milder winters might be aiding survival rates, particularly for younger animals," Erb says. "Female bobcats might also be coming through winter in better condition, so they might be having better reproductive output and survival of kittens."
Forest management could also be playing a role. Erb says disturbed and younger forests often provide dense cover and abundant edge habitat, which bobcats and some of their prey prefer. He believes this habitat has expanded due to increased logging that began in the mid-1980s, accelerated in the early 1990s, and continued until recent years. He points to a similar pattern of young forests, plentiful deer, and booming bobcat populations in the 1940s and '50s, following turn-of-the-century logging, fires, and other forest disturbances.
Another factor that could be affecting bobcat populations is the increase in deer and turkey populations. Bobcats prey on deer, particularly fawns, and scavenge on dead deer, especially during winter. As prey generalists, bobcats can do well where deer and turkey are scarce. But Erb believes the long-term growth in deer and turkey populations has helped fuel the bobcat increase.
"Our deer population was quite high during much of the '90s and early 2000s, when bobcats rapidly increased. Even with recent deer declines in some areas, deer density is higher now than during the 1970s and '80s," Erb says. "This means a wider prey base for bobcats, including more deer and in some areas more turkeys, in addition to the many smaller prey species they have always been preying on."
University of Minnesota researcher Paul Kapfer recently conducted a study of bobcat populations in Minnesota and concluded that in addition to winter weather, deer density was an important predictor of bobcat distribution. Erb cautions that this might have to do with similar habitat needs rather than direct dependence. However, he says bobcats are efficient summer predators of fawns and capable of preying on adult deer.
"When you consider the size comparison between a 30-pound bobcat and an adult doe, taking down a deer is pretty impressive," Kapfer says. "But it is actually not that uncommon for felids in general to take down prey quite a bit larger than themselves. A mountain lion that weighs 80 to 160 pounds can take down a bull elk that weighs 600 pounds."
More to Discover.
While the biologists don't believe bobcats alone have much impact on the deer population, Erb has evidence the growing bobcat population might be affecting another furbearer—the fisher. A study Erb is conducting has shown fisher populations have declined in the core bobcat range.
"This notable fisher decline is not apparent in the northeastern part of our fisher range or along the southern and western periphery of fisher range," Erb says. "There, fishers appear to either be stable or, in some areas, increasing."
But in the core bobcat area—which largely overlaps the core fisher area—fisher numbers are down. The two species undoubtedly compete for some prey, and Erb has documented many fishers killed by bobcats.
"This mortality is a double-whammy because the fishers that have been killed tended to be adult females, and it is occurring during the fisher denning season," Erb says. "When the adult is killed, her whole litter dies."
The study is ongoing, and Erb says he still has many things to learn. "The fisher population declines aren't simply related to bobcats," he says. "I think there are other factors, including overharvest and some forest management issues. But I do believe the increasing bobcat population is certainly a part of what we are seeing."
Though their numbers have increased, bobcats are native to Minnesota and not out of control. Minnesota forests may have only one bobcat per 6 or 7 square miles. The bobcat's need for large areas probably keeps the bobcat population from reaching higher densities. Regulated fur harvest is likely the dominant source of mortality for bobcats, according to Erb. Beyond that, vehicle collisions and disease kill some bobcats. Erb also suspects that many kittens die of starvation when food is scarce or winter harsh.
There is still a lot biologists don't know about these secretive cats. "That's why it is important to just educate people that we do have them in this state and that we probably have quite a few more now than we did for a long time," Erb says. "Eventually, we hope to get a bobcat study going, so we can better answer some questions about the habitat, prey, and weather factors influencing distribution, survival, and reproduction."
For fans like Marchel and Kapfer, the bobcat expansion news is bright. Yet that doesn't mean spotting a bobcat is easy. "It's a lot like love," Kapfer says. "When you finally stop looking, then you just might find one."