Monday, September 16, 2019

The Florida Burrowing Owl

 

 

(Speotyto cuniclara floridana)

This familiar Marco Island resident is named from the Greek words speo
meaning cave and tyto meaning owl and, cuniclara derived from the Latin word cuniclarius meaning little miner. As the name suggests, the Florida Burrowing Owl digs caves or burrows and is the only owl species that nests underground.

The Burrowing Owl, found from Canada to South America, is prevalent in the western states with an isolated population in Florida. Though migratory in the west, burrowing owls are year round residents in Florida, most commonly observed during the nesting and hatching season between the months of February and July.

Historically, these owls inhabited treeless grasslands and pastures of central and south Florida. The inland owl population has decreased because of disappearing natural habitat. This has caused the owls to be more innovative in their selection of habitat. Now coastal south Florida areas enjoy the scattered population in partially developed areas such as Broward and Dade counties, the City of Cape Coral, and Marco Island.Habitats include golf courses, playgrounds, cultivated lands such as farms, airport fields, or as we see here on Marco, cleared and mowed lots without trees. They do tend to favor well-drained dry, level open terrain with vegetation at low height. This helps improve their ability to see predators and detect prey and makes Marco Island’s undeveloped, regularly mowed lots the owls’ preferred habitat.

Averaging only nine inches in height on distinctly long legs with a wingspan between 20-24 inches, this owl is one of the smallest owl species. Though it lacks ear tufts and has no facial disc, there is no question it is an owl. Their bright yellow irises with expressive white eyebrows do catch one’s attention immediately. The dorsal plumage of both the male and female is dark to sandy brown, with scattered white bars and spots that blend perfectly with the open sandy habitat the owls prefer. A dark brown collar around the neck, white abdomen, and white chin are common characteristics. The young resemble the adults in size and facial features but have rust colored, downy plumage on their throats and bellies.

Due to similar size and markings, the male and female are difficult to tell
apart. However, during nesting season, the male has been observed to be paler or bleached by the sun, from the amount of time he is sentinel to the nesting female within the burrow. The female appears darker as she is mainly below ground and her plumage becomes stained from the nest’s contents.

The preferred diet of the owls is larger insects, small amphibians and
reptiles, and occasionally small birds and mammals. They are not strictly nocturnal like all other owls, but hunt both day and night by walking, running, and hopping after prey on the ground. Prey is caught with talons and transferred to the bill to carry and feed each other and the young. Indigestible food parts, mainly consisting of bone and fur, are regurgitated as pellets in and around the burrow entrance.

These ‘little miners’ efficiently excavate a 5 to 12-foot burrow in less than two days using their long, almost featherless legs to accomplish this task. The entire burrow structure consists of three parts: an entrance mound of the excavated soils; a curved tunnel that can be six inches in height, eight inches wide, and five to twelve feet in length; an enlarged nest chamber at the end of the tunnel. Only one entrance per burrow is the norm, but commonly observed on Marco Island, the male may dig a satellite (nearby) burrow during the nesting season that could be an anti-predatory strategy, (i.e. if a predator locates the active nest, a back-up nest is nearby for the chicks’ and female’s safety.) Typical for birds of prey, the

 

 

same burrow or general location will be used year after year by the same pair of breeding adults.

Courting behavior begins with both male and female adults displaying unique flight patterns, preening each other and rubbing bills. During the courting, the pair will ‘decorate’ the burrow mound with miscellaneous shiny objects and animal feces. This behavior is thought to camouflage the location and scent of the burrow from predators. Once the burrow is decorated, it is considered to be ‘active’ or having a nest, eggs, or flightless young present. With courtship successful, eggs are laid and the young are then brooded in the burrow chamber. Clutch sizes average between five to eight small, round, white eggs that are incubated for 28-30 days. The female solely provides incubation while the male sits above ground guarding the nest and hunting food. During the nesting season, driving down the streets of Marco Island, such as Lamplighter or Goldenrod, you can count the round heads of owls standing watch. The adult breeding pairs will mate for life, although if one dies, another partner will be quickly taken.

The young hatch in intervals a few days apart. At 10 days to three weeks of age the chicks emerge from the burrow. They are the approximate size of the adult, but fuzzy and copper-colored. Usually awkward and clumsy, they are not yet afraid of much. The owl parents hunt and feed the chicks until they are able to do so themselves. At about 42 days, the young can fly and hunt on their own: they are fledged. Once the young are fledged, the burrow is considered inactive or not containing a nest, eggs or flightless young. Only one or two chicks reach maturity per nest; the rest fall victim to a variety of
predators: snakes, opossum, raccoons, osprey, dogs, and cats, or suffer from lack of food, urban development pressure, and flooding of burrows during heavy rains. The survivors are ready to breed in one year’s time. Burrowing owls do not have the hooting call we commonly associate with owls; rather they have a two-note call described as “coo-coooo”. Both male sand females when defending the burrow will use a series of clucks, chatters, and screams. You will experience these calls if you ever stand too close to an active nest.

Protected federally by the Migratory Bird Treaty Act and listed by the state of Florida as a “species of special concern”, and also by the City of Macro Island Protected Species Ordinance, the city actively monitors and works with state and federal authorities to ensure protection of this listed species. The “species of special concern” description means the burrowing owls, the nesting burrow, their eggs and flightless young are all protected by law from harassment and/or disturbance.

The City currently has approximate 89 properties with burrows posted.
Posting an approximately 20-30 square foot diameter, the burrow areas are marked with orange flagging tape and a sign warning “Do Not Disturb”. Posting the sites does help reduce disturbance or accidental destruction by lot mowers and other large equipment activity along the roadsides. Construction fencing is used as a barrier if extensive construction is taking place in the vicinity.

Longtime residents and newcomers alike have inquired why the City makes such a concerted effort to identify and protect these birds. Considering the fact that there seem to be so many here in Marco Island, why are these owls listed as protected species? One of the main threats to the owl’s survival is destruction of habitat. Due to agricultural and residential development, once thriving populations of burrowing owls in other parts of the Florida have suffered severe decline and total extermination. Without protective measures, Marco Island’s owl population, a significant portion of the

Nancie Richie

Nancie Richie

overall Florida population, may face the same fate.

Some people wrongly believe that a property cannot be developed if
burrowing owls are present: that is not the case at all. If the burrow is
outside the building footprint and can be roped off or surrounded by a silt fence creating a protection zone of about six to ten feet, the property can be developed at any time. If maintaining that required protection zone through construction is not possible, the developer can request a permit from the Florida Fish and Wildlife Conservation Commission (FWC) to destroy the nest. This needs to be done prior to receiving a City of Marco Island building permit and copied to the City. FWC will issue a permit if the nest is observed to be inactive. There is no fee for this permit. Collapsing any burrow without the FWC is both a State and City violation. Please contact FFWCC for the
permit application at the following address:

State of Florida Fish and Wildlife Conservation Commission
Division of Wildlife, Bureau of Wildlife Diversity Conservation
620 South Meridian Street
Tallahassee, FL 32399-1600
Phone: (850) 410-0656 ext. # 17310

The idea behind this permitting is to prevent active nests (containing nest, eggs or flightless young) from being destroyed. The nesting season is February 15 through July 10, and if the burrow is observed to be active, a permit will be on hold status until the young are fledged and carefully monitored to ensure the young owls are flying freely or have left the site. On Marco Island, approximately 50% of the adult owl population is observed year round, so if there is an owl present at the burrow outside nesting season, the burrow is considered inactive. It is important to note that on Marco Island the nesting season starts earlier, mid to late January.

What Can You Do?
Strongly urged is constructing a “starter burrow” for the owl(s) to relocate when the original burrow is destroyed. It is easily done by simply clearing away about one to two feet of sod, dig an indentation that looks like a beginning of a tunnel or burrow and placing a t-perch next to indentation. To date, this has been successful at 4 out of 5 locations tried on the island. If more residents are interested in the opportunity to play an important (and rewarding!) role in the fate of this Species of Special Concern, it might be the answer to maintaining a healthy, productive, bug-eating owl population for the Marco Island ecosystem. Free t-perches can be picked up at City Hall.

For more information on burrowing owls, permitting procedures, and/or starter burrows, please call Nancy Richie, Environmental Specialist, City of Macro Island, at (239) 389-5003. If destruction or harassment of burrowing owls and/or their burrows is observed, please report to the City of Marco Island (239) 389-5000 and FFWCC Wildlife Alert 1-800-282-8002.

Nancy Richie and her husband Michael, have lived on Marco Island since 1992; they have two daughters, Madeleine and Camille. With a Bachelor of Science degree in Marine Biology from Texas A&M University at Galveston, she was the microbiology analyst for an environmental laboratory, Enviropact, and then a hazardous waste inspector for the Collier County Pollution Control Department before becoming the City’s Environmental Specialist in May 1999. In 2005 she received the Guy Bradley Award from the Collier County Audubon Society for her stewardship of Marco Island’s environment.  A few of her duties at the City include: vegetation trimming permitting, beach vendor permitting, protected species monitoring, water quality monitoring, staff representative for the Beach Advisory Committee, and a liaison with federal, state, county and local environmental agencies and groups.

Nancy is a member of St. Marks Church, Friends of Tigertail Beach, the
Audubon Society, and Marco Island Historical Society. We are pleased to share her expertise with our readers.

Leave a Reply

Your email address will not be published. Required fields are marked *