June Nature Almanac: Bobcats Emerge from the Shadows
By Stephen Jones and Ruth Carol Cushman
June 2021
During our first few decades living in Boulder, we hardly ever saw a bobcat. Now friends and neighbors seem to report encounters with these mostly nocturnal felines almost daily.
During the past year Dan Murphy and Barbara Abrahams, who live below the National Center for Atmospheric Research’s Mesa Lab, have watched a mother and her kittens sleeping under a bush, crossing their front yard, and climbing their neighbor's maple tree. Other South Boulder residents have photographed bobcats visiting water features in their backyards, sometimes in broad daylight.
This female and her kitten were visiting a water feature in a South Boulder backyard in broad daylight. Photo by George Oetzel.
In late March, birders at Sawhill Ponds watched a bobcat climb up a dead tree and begin munching on the contents (presumably young) of a Great Horned Owl nest. On April 10 local media posted a video showing a five-year-old girl seated on a tricycle in her Castle Rock backyard and staring into the eyes of an adult bobcat who had stopped a few feet away while chasing a cottontail rabbit.
When local wildlife officials began installing motion-activated cameras in culverts under State Highway 93 south of Boulder a few years ago, they were astonished to get more photos of bobcats than of coyotes.
So are bobcats undergoing a population explosion or just a change in behavior? A 2011 survey of bobcat population studies in 48 U. S. states, seven Canadian provinces, and Mexico reported increased numbers in all those locations except Florida. The total U.S. bobcat population had risen to between 2.3 million and 3.6 million individuals.
This increase in numbers seems remarkable in light of the continuing persecution of bobcats. Trappers kill as many as 50,000 a year in the United States, with most of the pelts being shipped to Asia where they're converted into exotic apparel. Tens of thousands of bobcats are killed each year by automobiles. In California, a study determined that the primary cause of bobcat mortality was feline scabies resulting from the consumption of poisoned rats.
As habitat generalists attracted to shrubby areas rich with cottontails and other prey, bobcats may be learning--as have red foxes, raccoons, and ravens--that urban areas are relatively safe places to live and hunt. They may be shifting toward more daylight activity as shrub growth and other protective cover increase. Add to the mix the easy availability of motion-activated wildlife cameras, and we have the appearance at least, of a population explosion.
Dan Murphy photographed these two bobcats stalking a fox squirrel his South Boulder neighbor's backyard. The squirrel escaped without much effort.
Bobcats range from southern Canada to northern Mexico, occupying just about every type of habitat except cultivated farmland. Their range in Canada appears to be expanding northward as winter temperatures warm.
In June Boulder County bobcat moms will be escorting their kittens out of the den and into concealing shrubbery in ravines, riparian woodlands, and suburban backyards. Colorado bobcats typically mate most actively in winter and give birth toward the end of spring, though females may breed during any month of the year. Kittens nurse for about 60 days and remain with their moms for up to 10 months.
While bobcats pose little threat to humans, they can appear pretty ferocious. Adults can ambush and kill grouse, porcupines, and even deer. Night-stalkers by nature, they're secretive and single-minded--not unlike that aloof companion purring complacently on your lap.
Other June Events
Our recent wet and cool spring (including a daily record low temperature of 10°F on April 20) has delayed the budding of deciduous trees. Some cottonwoods may not complete leafing out until early June.
Bald Eagle chicks begin hopping around on branches adjacent to their nest.
Mariposa lilies, Rocky Mountain iris, sugar bowls, and orange arnica add splashes of color to foothills meadows. Try the Greenbrier, Skunk Canyon, or Goshawk trails just after sunrise for spectacular floral displays.
Recently-arrived monarch butterflies lay eggs on milkweed plants within the South Boulder Creek and Boulder Tallgrass Prairie state natural areas and at Sawhill Ponds.
Stephen Jones and Ruth Carol Cushman are authors of Wild Boulder County and the North American Prairie.