Dennis Cavallo, a longtime friend and volunteer of Placer Land Trust, has been spending a lot of his time at our Swainson’s Grassland Preserve in Lincoln lately.
And there’s only one reason we know of why he’d put up with this kind of heat—baby burrowing owls!!
For the last few years western burrowing owls have been a “Species of Special Concern” in California. Their breeding populations have continued to drop across the nation from habitat loss and the rise of natural predators. Burrowing owls don’t build nests high in the canopies, instead they do just what their name suggests, they dwell underground. Western burrowing owls live and nest in the unoccupied or abandoned burrows of other ground diggers such as ground squirrels, prairie dogs, or skunks.
Populations can only grow as large as their food source and habitat, and there are plenty of both at Swainson’s, as indicated by the plethora of owl pellets containing the remains of voles, mice and insects.
Placer Land Trust has installed 6 artificial nests over the years. Four made of clay sewer pipes, partially submerged in the ground and two enclosed burrows that are entirely underground. Swainson’s is the only known place in the county with successfully breeding burrowing owls, and this year we have 3 active nests. That means babies!! We’ve been trying to keep an eye on them and as far as we can tell about 14 owlets have survived so far.
Burrowing owls are not nocturnal like most nighttime loving owls. California’s burrowing owls are diurnal, meaning that most of their activities, like hunting, mating and nesting, take place during the daylight hours. It takes about 1 month for the female to lay and hatch her eggs. During the incubation period the female does not leave the nest, which means her male partner is responsible for the important task of bringing her food day and night. Interestingly, it is difficult to visually determine the gender in many owls’ species but because the burrowing owl males spend more time outside hunting during the day they get a distinct “sun bleached” look that helps us to tell them apart from their darker hued female partners.
About a month behind the more southern counties, Placer County sees the appearances of baby owlets around the first week of July. About two weeks after they hatch, the owlets begin to venture outside only to hurry back in to the safety of the burrow. At 3 weeks the baby owls begin to flap their wings and test their running feet around the nest. At about a month old the owls will start to take short flights around the burrows floating from one nest to another. At about 2 to 3 months old the owls will leave the safety of their nests and disperse themselves throughout the area, never leaving more than a few miles from where they were hatched. As residents to the area, burrowing owls don’t migrate like many other owls and will continue to live and reproduce in the same area as long as the habitat will allow it.
“I’ve always been fascinated with owls, and about five or six years ago I was asked if I’d be interested in monitoring Swainson’s Grassland Preserve. My wife and I have always been interested in the conservation of the planet and preserving species for future generations. I think we’re doing a good job at that and I hope that whoever takes over after me, that that next person will have the same aspirations to preserve the owls for the next generation as I do. I believe if we can preserve this one species, it will inspire us and others to continue to preserve more.” – Dennis Cavallo
For more information on Swainson’s Grassland Preserve please visit:
www.placerlandtrust.org/project/swainsons-grassland-preserve/
