The Florida Burrowing Owl Project

The Florida Burrowing Owl Project includes a statewide population survey of the Florida Burrowing Owl, Athene cunicularia floridana, and on-going conservation efforts.

The Burrowing Owl is a small owl, measuring approximately nine inches in length with a wingspread reaching 22 inches. The owl weighs an average of 135 to 150 grams (less than a "Quarter Pounder" with all its toppings and wrappings). The Burrowing Owl is the only North American owl species in which males are larger than females. This sexual size dimorphism is not as pronounced in the Florida subspecies. The owl has a round head and lacks ear tufts. Adult plumage is brown with white bars and stripes on the back and beige with brown bars and stripes on the front. White feathers along the brow, under the eyes and across the throat give these owls the appearance of having eye brows, a mustache and a collar. During the breeding season, males appear to be lighter in color than females. Females spend long periods incubating eggs in the burrow and retain a dark feather coat. The lighter feather coat in males may be due to sunbleaching while guarding the burrow entrance. Burrowing Owls have bright yellow irises; chocolate, olive and straw-colored irises have also been observed. The Burrowing Owl's bill is yellow or greenish-yellow. These owls have long unfeathered legs.

We Can Accomplish Great Things
By Putting Our Heads Together

The Project is looking for help in locating Burrowing Owl colonies and seeking volunteers to participate in the statewide population survey. Volunteers will be making history! In 1987, Florida was estimated to have between 3,000 and 10,000 pairs of breeding adults. However, a statewide population survey of the Florida Burrowing Owl has never been conducted, despite its listing as a species of special concern in 1979. This will be the first statewide population survey of the Burrowing Owl in Florida and will serve as a baseline for future studies in the state.

About The Florida Burrowing Owl Project

The Florida Burrowing Owl Project is being coordinated by Ms. Pamela J. Bowen as her masters thesis research at the University of Central Florida in Orlando. Pam is a member of the Florida Audubon Society, the Florida Ornithological Society, the Raptor Research Foundation, the Florida Chapter of the Wildlife Federation and the Florida Academy of Sciences. She has been an active volunteer with Florida Audubon's Center for Birds of Prey since 1993. She has also conducted research on urban and rural Bald Eagle nest productivity for Audubon's EAGLEWATCH program, a volunteer-based nest monitoring program.

The project is committed to the following objectives:

* Locating and documenting as many accessible active Burrowing Owl sites as possible.
* Accurately counting all Burrowing Owls observed at each site during the 1999 breeding season.
* Compiling the data to provide a demographic overview of Florida's total Burrowing Owl population.

The statewide population survey will be conducted during the Burrowing Owl breeding season, when Burrowing Owls are more diurnal and any migratory owls would be back on their territories. Surveying will begin in the Florida Keys in April and will conclude at the Georgia border in late July.

How You Can Help

Helping with The Florida Burrowing Owl Project is simple. If you know of a Burrowing Owl site in Florida, send Pam an e-mail at This e-mail address is being protected from spam bots, you need JavaScript enabled to view it with information about the site(s) including the county, nearest city or town, and location. For urban owls, include the street address or the address of the closest house. For rural owls, directions to the site are helpful; use landmarks like power poles (try to get a pole number), the number of fence posts from a gate or mileage from a known intersection to describe the location.

For those who want to be more actively involved (or want to "make history" by taking part in the first statewide survey), volunteering will provide opportunities to survey Burrowing Owls in a specific area of the state (like your own county) and/or to monitor a known Burrowing Owl site (close to home). If you are interested in volunteering for the project and want to know more about volunteer opportunities, contact Pam via e-mail at This e-mail address is being protected from spam bots, you need JavaScript enabled to view it .

Training

Rather than having volunteers attend a formal training class, monthly newsletters are mailed to volunteers to provide them with training information related to Burrowing Owls and the statewide population survey. Using the newsletter as a training tool, volunteers can read and enjoy the information at their leisure. The newsletter also provides volunteers with a vehicle to share information from around the state about unique Burrowing Owl observations. Submit items of interest to This e-mail address is being protected from spam bots, you need JavaScript enabled to view it .

The following articles from The Florida Burrowing Owl Project Newsletter will give you more information about the project and about the Burrowing Owl in Florida.

Surveying Techniques: How to Find Burrowing Owls
From The Florida Burrowing Owl Project Newsletter, Volume 1, Issue 2

Many obstacles exist in counting these tiny owls...not only do they roost and take refuge underground, but they may be more nocturnal during certain periods of the year. This section provides tips on how to find Burrowing Owls.

When to Look for Burrowing Owls:
Although Burrowing Owls may be diurnal during the breeding season, they may be most active and most visible during the morning or late afternoon. The best time to look for Burrowing Owls is from 6:00 to 10:00 in the morning and 3:00 to 7:00 in the late afternoon (3:00 can be a little early).

Where to Look for Burrowing Owls:
Burrowing Owls can be found in very open habitats with short grass and few trees. The best place to look for Burrowing Owls is in natural grasslands, pastures, ball fields, school yards, parks, cemeteries, airport verges, neighborhood lawns, and cleared vacant lots. Another good place to look for them is where you know they have occurred in the past.

Territory Fidelity and Knowing Where to Start:
Burrowing Owls, like Bald Eagles, exhibit strong territory fidelity. They will remain on the same territory as long as the habitat meets their biological and reproductive needs. Burrowing Owls should continue to occur on historic sites provided there have been no changes in the habitat. Based on this, historic and current data on known Burrowing Owl locations will be used as starting points for the survey. Location data has been gathered from Florida Game and Fresh Water Fish Commission records, Breeding Bird Atlas data, Florida Natural Areas Inventory records and numerous other sources such as the 1998 Christmas Bird Count. Over 1,000 historic and currently known Burrowing Owl sites are expected to be included in The Florida Burrowing Owl Project's statewide population survey.

Using the Landscape:
Sometimes Burrowing Owls will place there burrow entrance next to a fence line or a post. Check fence lines for these little owls. It is thought that they do this in order to keep avian predators, like Red-tailed Hawks, from swooping down on them. These owls will also use fence posts as a perch to watch for terrestrial predators or just to roost.

Looking for Signs of Burrowing Owls:
Look for a burrow entrance. In a natural grassland or pasture, the burrow entrance may have a great deal of sand in front of it (like a Gopher Tortoise burrow). Burrowing Owls will use abandoned tortoise burrows. A burrow dug by a tortoise has a tunnel shaped like the shell of the tortoise. A burrow dug by a Burrowing Owl has a more circular tunnel (about 5" tall and 3.5" wide). An active Burrowing Owl burrow will have bits of undigested bugs or small bones littering the entrance. Feathers from preening or molting may also be evident. The entrance mounds of burrows with eggs in them will be decorated with shiny or unique objects. In an urban setting, where property owners are aware of the owls, look for patches of unmowed lawn, signs or stakes identifying the burrow or even T-perches installed just for the owls. Not all burrows have a sandy entrance. Some burrows may be dug into the side of a hill or berm; others are dug straight down like a golf hole.

Listening for Burrowing Owls:
During the breeding season, male Burrowing Owls will respond to a tape of the male primary call. Listen for that call: "Coo-cooooo". Burrowing Owls have the greatest number of calls among North America's owls with a total of 13 different calls. Also listen for their alarm call: "Twut-twut" when mildly disturbed or a rapid repeated "Cack-cack" when danger is near. Burrowing Owls do not always call when threatened: their cryptic coloration and silence may do a fine job concealing them.

Surprising Things that Burrowing Owls May Do:
Don't forget that there are some things Burrowing Owls may do that might surprise you:

* Burrowing Owls may use culverts or drain pipes for roosting or as a burrow.
* They may also perch up high to watch for predators. Burrowing Owls have been seen perching in trees and on power lines. (One Burrowing Owl was even observed flying out of a thicket of trees while Pam was setting up her scope to watch a burrow in a pasture.)
* Burrowing Owls have also been recorded breeding or roosting in unusual places. One FGFWFC biologist documented a pair of Burrowing Owls that bred in the dormer of a house. Our Punta Gorda volunteers have seen one pair that roost, and according to the property owner also bred, under the eaves of a house. While reviewing FGFWFC permits, one permit included photographs of an owl using the eaves of a house.

Persistence Pays Off:
The longer you observe Burrowing Owls at a site and the more often you visit that site, the more accurate your sightings will be. Frequent visits to a site and long observation periods can reveal a great deal. On Pam's first trip to Sorrento to see owls, she saw one owl. On her second trip, she saw three owls. On later trips, she saw eight owls.

The Natural History of Burrowing Owls in Florida
From The Florida Burrowing Owl Project Newsletter, Volume 1, Issue 1

The Burrowing Owl was first described by Molina, a Jesuit priest in Chile, in 1782. He gave the species the name Strix cunicularia, placing it in the same genus as the Barred Owl. In 1842 the genus was changed and the species renamed Speotyto cunicularia. "Speo" means "cave" and "tyto" is after the Barn Owl (another owl with long unfeathered legs). In 1983, the American Ornithologist's Union renamed the species Athene cunicularia, placing it in the same genus as the Greek goddess Athene's Little Owl in Europe.

Barred Owl Barn Owl Burrowing Owl

Species Status:
The Florida Burrowing Owl, Athene cunicularia floridana, is a "species of special concern" established by the Bureau of Nongame Wildlife, Florida Game and Fresh Water Fish Commission. It was assigned this designation in 1979 and is protected under the Commission's rules, Chapter 39 of the Florida Administrative Code. It is also protected under the Migratory Bird Treaty Act. On a national level, Burrowing Owls in several western states have experienced declines and, on an international level, the species is listed as endangered in Canada.

Historically, the Florida Burrowing Owl is thought to have been nomadic, following natural disturbances such as fires and floods. These owls were originally described as being found in Florida's Central Prairie Region. During this century, the Florida Burrowing Owl has made extensive use of man-made disturbances. These disturbances have resulted from large scale clearing of forested areas (for pastures and development) and have ultimately resulted in a breeding range expansion. Today nesting pairs and colonies can be found in urban and agricultural environments, as well as natural grassland environments. Burrowing Owls occur on airport verges, golf courses, college campuses and other artificially derived habitats.

Reliance on artificial habitats has made the Florida Burrowing Owl vulnerable. Man-made habitats may only provide a "temporary" home for these owls and extensive development may pose a threat to the species. One study conducted in Cape Coral, Florida revealed a lower population density of Burrowing Owls in the most heavily developed sections of the study site. Burrows in these sections had relatively lower productivity and lower success rates. In an urban environment, the Burrowing Owl is subject to increased mortality resulting from vehicle collisions, predation by domestic animals and human harassment. These threats, coupled with limited knowledge of Florida's total Burrowing Owl population, substantiate the need for the designation of "species of special concern".

Distribution in Florida:
The Florida Burrowing Owl was originally associated with natural grassland habitats in the Central Prairie Region of the state. With extensive land clearing, these owls have undergone a northern and southern breeding range expansion. In 1954, Florida Burrowing Owls were observed in the Keys. Today, they can be found breeding at Eglin Air Force Base in the Panhandle. The Florida Burrowing Owl is considered to be nonmigratory. However, banding data suggests there may be short seasonal north-south movements associated with these owls in the northern portion of their range. The degree of movement is difficult to determine; low winter survey counts may also reflect changes in behavior.

Food Items:
These owls prey on insects and small vertebrates. Beetles, grasshoppers and crickets are important food items. Other items include crabs, crayfish, frogs, toads, lizards, brown anoles, snakes, rodents and various species of birds. Foraging for prey involves low short flights and, occasionally, momentary hovering. These owls have been seen foraging on road-killed animals and on small migratory birds that have hit windows. Burrowing Owls may be diurnal, crepuscular or nocturnal, depending on the time of year, and may be seen foraging during the day, near dusk and dawn, or during the night.

Nesting:
Florida Burrowing Owls have been described as nesting in loose colonies with burrows located 20 to 30 yards apart. Although they will use a Gopher Tortoise burrow, Florida Burrowing Owls can dig their own burrow in two days. The burrow entrance is approximately 5.0 inches high and 3.5 inches wide. The tunnel is four to eight feet in length and may make several turns before rising at an angle into the nest cavity. The nest cavity is 12 to 18 inches in diameter and may be six inches to three feet below the ground. Urban Burrowing Owls line their burrow with grass, palm fronds, dog and cat feces and other materials. Burrowing Owls in agricultural environments line their burrows with dry horse or cow manure. The entrance of burrows that have eggs may be decorated with shells, shredded paper, tin foil, or other decorative objects.

Incubation:
Breeding generally occurs between February and July when a clutch of two to six eggs is produced. However, egg-laying may occur as early as October and as late as May. The eggs are incubated by the female for 28 to 30 days. The production of two broods in one year was observed in five pairs of Owls in one Cape Coral study. However, this behavior was rare and only occurred in one percent of the nests observed.

Young:
The altricial young (eyes closed, unable to leave the nest, totally dependent on the parents) are brooded and fed by the female. Males usually do not feed the young but present the female with food for the young. Young owls emerge from the burrow at approximately two weeks of age. They are able to take short flights at four weeks of age and can fly well at six weeks of age. Fledging generally occurs 45 days after hatching. Florida Burrowing Owls fledge fewer young than the western migratory subspecies. During 1987 and 1988, nests in Cape Coral fledged 1.7 and 2.0 young, respectively, per active pair. In comparison, the western subspecies fledged 3.1 to 4.9 young per pair.

Survival Rates and Threats:
If they survive, young owls are capable of breeding at one-year of age. Based on one study at Cape Coral, the survival rate for fledglings attaining one-year of age is 19%. The survival rate for experienced adult males is 68% and adult females have a survival rate of 59%. One natural threat to this subspecies is exposure to the elements, such as hail or heavy rains, which has caused death and/or flooding of burrows. Avian predation by Cooper's Hawks, Peregrine Falcons, Merlins, Great Horned Owls, Red-tailed Hawks and American Crows also represents a natural threat to survival. Predation by other vertebrates such as skunks, opossums, raccoons, weasels, coyotes and snakes has also been observed. Human-associated threats include vehicle collisions, predation by domestic animals, human harassment and direct exposure to pesticides. Indirect effects may also be experienced from pesticides due to the loss of prey bases.

A Special Way You Can Help
Florida's Burrowing Owls and Birds of Prey

Florida Audubon's Center for Birds of Prey, Maitland, Florida, is dedicated to rescuing, rehabilitating and releasing injured birds of prey. The Center receives 500 to 600 injured, ill and orphaned owls, eagles, hawks, falcons and osprey every year. Approximately 46% of these birds can be returned to the wild after receiving care at the Center. But the costs of feeding, treating and rehabilitating these birds are high. The Center is a non-profit organization and is totally dependent on public donations. If you want to help Florida's Burrowing Owls and other birds of prey, adopt a Burrowing Owl, eagle, hawk or falcon at the Center for Birds of Prey.

Bobby, the adorable Burrowing Owl on our first page, was attacked by dogs and lost the use of both wings. He is a permanent resident at the Center for Birds of Prey and has been a "big" supporter of the Florida Burrowing Owl Project. If you want to learn more about adopting Bobby, or any of the other birds at the Center, visit the Adopt-a-Bird website at http://www.adoptabird.org.