Burrowing Owl BiologyBurrowing Owl Statistics: Nests | Migration Distance | Productivity | Demography
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Appearance
Common name: Western Burrowing Owl
Scientific name: Athene cunicularia which means little digger. This is a slightly misleading name, as the burrowing owl very seldom digs its own burrow but prefers to use the vacated burrows of small mammals like prairie dogs and ground squirrels as is the case at Mission College.
The burrowing owl is a small ground-dwelling raptor native to the United States. It is
found west of the Mississippi and also in southern Canada and northern Mexico.
It is endangered in Canada, Mexico, and the US in the states of Minnesota and Iowa. The burrowing owl is designated as a "Species of Special Concern" in 6 other states including California.
The burrowing owl is approximately 9 inches tall and weighs up to 6 ounces.
They have a rounded head, lack ear tufts, but are easily distinguishable by their white eyebrows, bright yellow irises and long stilt-like legs. Their plumage is a mottled brown and white coloring. The female is slightly smaller than the male and a little darker in coloring.
Burrowing owls have a symbiotic relationship with ground squirrels. They take over vacated squirrel burrows and live in the same colonies as the ground squirrels but not in the same burrow. The ground squirrels gain an extra pair of eyes to watch for predators from this relationship. The birds normally have satellite burrows near the main burrow which are used to escape predators.
Special Traits
- Unlike most owls, the burrowing owls are active both day and night, especially during dawn and dusk.
- Out of 171 species of owls worldwide, the burrowing owl is the only one that lives in burrows.
topDiet
Burrowing owls are opportunistic feeders whose diet includes:
- small rodents such as mice, voles and shrews.
- reptiles such as frogs and lizards. The Environmental Awareness Association (EAA), a Mission College student club, has seen remains of frogs outside of a few of the burrows at Mission College, most likely from feeding at the Calabasas Creek.
- insects, especially Jerusalem crickets and earwigs, which comprise the vast majority of their diet.
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| Photo by Ray Bersabe |
Breeding
The breeding season for burrowing owls starts in February when pairs will bond together and search for an appropriate burrow. Egg laying begins in March and a female can lay as many as 6 - 12 eggs although the success rate for survival is much lower. Both parents feed the young and by September the young will have fledged.
Courtship at Mission College
EAA observed a pair on campus during February 2000, during a courtship display. They had chosen to set up home at an artificial mound consisting of 6 burrows. The male and female were located at the entrance to 2 separate burrows when the male flew over to a nearby post on a fence. The female immediately flew to the adjacent post whereby both birds began preening themselves while facing each other. Then the male returned to his original location at the entrance to his burrow and the female returned to hers. Then the male flew to a third burrow carrying something in its beak. It faced the entrance to the burrow, opened its wings fully, bobbed up and down and then entered the burrow. The female immediately followed suit and both birds remained inside for approximately 6 minutes. Then both birds returned to their original burrows.
topHabitat Preference
The burrowing owls usually choose their homes in a flat grassy area. Burrowing owls, being only 9 inches tall, do not like vegetation in close proximity to their burrows to be taller than 6 inches. They will forsake their burrows if the vegetation gets too tall.
Since there is a major lack of large flat areas, there are ways to accommodate these creatures right in your back yard. These furry looking birds also love native vegetation. Native plants and flowers encourage local insects liked by the owls. A list of preferable plants has been compiled which not only the owls prefer but the indigenous wildlife also can take advantage of.
EAA is taking up an experimental project at Mission College. The purpose of the experiment is to plant as many native plants and flowers from the list, and see which species work the best at Mission College. EAA hopes to accumulate a list to share for easier planting, maintaining and better surviving native plant garden.
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| Photo by Ray Bersabe |
Building an Artificial Burrow
The photo to the left is an opening of an artificial burrow at Mission College. The rest of the burrow is buried underneath the soil.
Although burrowing owls live in the burrows of small mammals, they will readily live in artificial burrows. EAA constructed a mound containing 6 artificial burrows in a circular pattern in November 2000. By February 2001 a pair of owls had set up home in these burrows. First, EAA choose a location with good drainage and limited interference from road and pedestrian traffic with few or no trees in close proximity. A pair of owls has already moved in and made the burrows EAA built their new home.
The parts list for one burrow includes a 12 - 14 inch long irrigation control valve box, two four foot lengths of four inch diameter terra cotta pipes, a 45 degree angle terra cotta piece and two gaskets to connect the angle piece to each of the pipes.
EAA cut out a "U" shaped hole at the top of the valve box and then turned it upside down so that the open part was face down on the ground. EAA then placed one of the pipes into the" U" shaped hole, placed a gasket at the other end of the pipe, and connected the angle piece to the gasket. At this stage EAA put soil at an angle of 25 degrees to enable the final piece of pipe and gasket to lay at a 25 degree angle to the ground. EAA then constructed 5 other similar burrows in a circular pattern and covered the entire area with soil to a height of about 5 feet.