by Judy Biss | Mar 17, 2017
Beaver lodge, Calhoun County Florida. Photo by Judy Biss
Even though the “work” beavers do can sometimes cause frustration to land owners, they are truly amazing creatures. A number of questions have come into the Extension Office lately about managing beavers, so it is a good time to discuss a little about the history and biology of these unique animals, as well as the management options available for land owners.
Beavers in the American Landscape
Hundreds of millions of beaver once occupied the North American continent until the 1900s, when the majority had been trapped out in the eastern United States for the fur trade (Baker, B.W., and E.P. Hill. 2003. Beaver (Castor canadensis)). “Growing public concern over declines in beaver and other wildlife populations eventually led to regulations that controlled harvest through seasons and methods of take, initiating a continent-wide recovery of beaver populations.” (Baker, B.W., and E.P. Hill. 2003. Beaver (Castor canadensis)). In its current range, the beaver “thrives throughout the Florida Panhandle and upper peninsula in streams, rivers, swamps or lakes that have an ample supply of trees.” (Florida Fish and Wildlife Conservation Commission, Aquatic Mammals, Beaver: Castor canadensis).
Adaptations
Beavers are the largest rodent in North America. In Florida, they commonly weigh between 30 – 50 pounds. Beavers are considered an aquatic mammal, having adaptations such as a streamlined shape, insulating fur, ears and nostrils that close while underwater, clear membranes that cover their eyes while underwater, large webbed feet, and a broad flat rudder-like tail that aid in swimming. They can remain underwater for 15 minutes at a time! Their tree-cutting, bark-peeling front teeth grow continuously, and as a result, are continuously sharpened as they grind against the lower teeth. (Baker, B.W., and E.P. Hill. 2003. Beaver (Castor canadensis), Florida Fish and Wildlife Conservation Commission, Aquatic Mammals, Beaver: Castor canadensis).
Habitat and Behaviors
Beavers typically mate for life and live in family groups consisting of the adult male and female, and one or two generations of young kits before they are old enough to disperse on their own. They are primarily nocturnal, being active from dusk to dawn. Beavers eat not only tree bark, leaves, stems, buds, and fruits, but herbaceous plants as well. Their diet is broad and can consist of aquatic plants, such as cattails and water lilies, shrubs, willow, grasses, acorns, tree sap, and sometimes even cultivated row crops. (Baker, B.W., and E.P. Hill. 2003. Beaver (Castor canadensis)).
Top of beaver dam in Calhoun County FL. Water level difference is nearly 3 feet. Photo by Judy Biss
Dam and Lodge Construction
The sound of moving water triggers beavers to build, repair, or maintain their dams. (Baker, B.W., and E.P. Hill. 2003. Beaver (Castor canadensis)). The two main structures they build are the water-slowing dam and their living quarters or lodge. The lodge is separate from the dam and is oftentimes located in the stream or pond bank. “The ponds created by dams also provide beavers with deep water where they can find protection from predators — entrances to dens or lodges are usually underwater. Some beavers in Florida do not build the massive stick lodges associated with northern colonies. Instead, they are more likely to live in deep dens in stream banks…” Florida Fish and Wildlife Conservation Commission, Aquatic Mammals, Beaver: Castor canadensis).
Pear tree felled by beaver in Calhoun County FL. Photo by Judy Biss
Impacts
Beavers are called “nature’s engineers” for good reason. Their tree cutting and building behaviors certainly alter surrounding landscapes. Outside of any connection to human civilization, their activities tend to increase diversity and habitat options for both plants and animals. Many scientists have examined the intricate biological and ecological effects beavers have on surrounding landscapes. Their activities in our backyard, however, do not always result in positive outcomes. Often, beavers are triggered to build dams in running water through road culverts causing significant impacts to road drainage, and surrounding flood management. Their construction of dams along creeks can flood farm fields and woodlands. Their feeding and tree cutting can kill desired trees in nearby timberland and orchards.
Management Options for Land Owners
The Florida Fish and Wildlife Conservation Commission (FWC) publication, “Living with Beavers” provides excellent advice, along with a summary of the regulations regarding this native wildlife species. As per this document, “The beaver is a native species with a year-round hunting and trapping season in Florida.” Beaver hunting and trapping regulations can be found on the FWC Furbearer Hunting and Trapping website. A beaver can be taken as a nuisance animal, if it causes or is about to cause property damage, presents a threat to public safety, or causes an annoyance in, under, or upon a building, per Florida Rule 68A-9.010.” Other recommendations from this FWC publication are:
- “Beaver dam removal provides immediate relief from flooding and can be the simplest and cheapest way of dealing with a beaver problem. However, beavers often quickly rebuild a dam as soon as it is damaged. “
- “When removing a dam is infeasible or unsuccessful, installing a water level control structure through the dam can allow for the control of water flow without removing the dam. This technique also reduces the likelihood of the beaver continuously blocking water flow. For technical assistance, contact a wildlife assistance biologist at a regional FWC office near you.”
- “If a beaver dam is blocking a culvert or similar structure, installing a barrier several feet away from the culvert can be the most effective solution. This prevents the beavers from accessing the culvert to dam it. Please contact a wildlife assistance biologist at a regional FWC office near you for technical assistance.”
- “Protect valuable trees and vegetation from beaver damage by installing a fence around them or wrapping tree trunks loosely with 3-5 feet of hardware cloth or multiple wraps of chicken wire. This prevents the beavers from chewing on the trees and other plants.”
- “Lethal control should be considered a last resort.”
FWC also points the reader to this publication from Clemson University Cooperative Extension Service, Department of Aquaculture, Fisheries and Wildlife, “The Clemson Beaver Pond Leveler.” This publication provides diagrams and a list of materials needed to construct a device which is designed to “minimize the probability that current flow can be detected by beavers, therefore minimizing dam construction.”
All questions regarding beaver management should be directed to your local FWC Regional Office. Land owners can also request a list of Nuisance Wildlife Trappers available in their area:
FWC Northwest Region Office
3911 Highway 2321
Panama City, FL 32409-1659
(850) 265-3676
Links to the references used for this article:
by hollyober | Mar 17, 2017
Bluebirds are very energetic birds. If you enjoy watching wildlife in your yard, now is a fantastic time to put up a few bluebird houses. You might gain hours of entertainment watching all the hard work these small birds put into gathering materials to build nests and gather food to feed their chicks.
In the Panhandle, bluebirds begin in March to create their first nests of the year. They carefully weave a basket of pine needles and twigs, and line it with fine grasses. Photo by Holly Ober.
March is when bluebird nest-building begins in the Panhandle. Believe it or not, these enterprising birds are likely to continue building nest after nest from now through July or even August!
The reason we can observe bluebirds more closely than many other birds is because they prefer to nest in cavities situated in open, sunny locations. These birds readily use nest boxes because natural cavities in clearings are quite scarce.
If you’re considering putting up a nest box to attract bluebirds, be aware that these birds are rather fussy when it comes to selecting nest boxes. They prefer structures that are approximately 4”x4”x9” or 5”x5”x9”. These structures could be rectangular, cylindrical, or wedge-shaped. It’s best if the entrance hole is 1.5” in diameter, and located about 5” above the floor of the box. Each house should be mounted on a pole 4-8’ above the ground.
We have been conducting an experiment the past few years to determine which of three common nest box designs local bluebirds prefer. The three types of houses we tested were:
- traditional wooden rectangular house (4”x4”x9”)
- Gilbertson (cylindrical houses made of a PVC tube with a wooden floor and roof)
- Peterson (wedge-shaped houses made of wood and covered in metal, with a sloping floor and roof).
We tested bluebird preferences for 3 types of houses: the traditional rectangular wooden house (left), the Gilbertson (cylindrical house of PVC, center), and Peterson (wooden wedge-shaped, right).
We put up 18 houses during the summer of 2013 and have been keeping track of the number of nest attempts, eggs laid, and chicks fledged ever since. The ambitious birds using these 18 houses have fledged 124 chicks during the past three years! The standard rectangular wooden houses have performed best, with bluebirds laying an average of 8.3 eggs per house per year, and fledging 4.3 chicks per house per year. The other two house types performed similarly, with bluebirds laying an average of 4.3 eggs per house per year in each. An average of 2.4 chicks fledged from each of the Gilbertson houses each year, whereas 1.8 chicks fledged from each of the Peterson houses each year.
Regardless of which type of house you choose to put up for bluebirds, be sure to place the houses at least 100 yards apart. These birds are very territorial and will not allow other bluebirds to nest nearby.
by Sheila Dunning | Feb 28, 2017
Cuban Anole. Photo credit: Dr. Steve A. Johnson, University of Florida
The brown anole, a lizard native to Cuba and the Bahamas, first appeared in the Florida Keys in 1887. Since then it has moved northward becoming established in nearly every county in Florida. By hitching a ride on boats and cars, as well as, hanging out in landscape plants being shipped throughout the state, the Cuban anole (Anole sagrei) has become one of the most abundant reptiles in Florida. However, the native Carolina green anole (Anole carolinensis) has been impacted.
While both anole species are capable of thriving on the ground or in the trees, the invasive brown anole has altered the behavior of the native green anole by forcing them to remain arboreal. Anoles eat a wide variety of insects, spiders and other invertebrates. Cuban brown anoles feed on juvenile green anoles and their eggs, reducing their population even more. Brown anoles are brown to grayish in color. While they can adjust to various shades of light or dark, brown anoles cannot turn green. The native Carolina anole can camouflage itself by altering its skin color from light green to dark brown, including many hues in-between, but have no distinctive markings on their backs. Male brown anoles often have bands of yellowish spots, whereas females and juveniles have a light vertebral stripe with dark, scalloped edges. An additional identification feature is the dewlap of the male Cuban anole. Male anoles extend the skin of their lower jaw (the dewlap), displaying a bright orange to red color, in order to attract females or warn other males. Cuban brown anoles have a white line down the middle of the dewlap.
Egg surface of Native anole (left) vs Cuban anole (right). Photo credit: Todd Campbell
If the Cuban brown anole and Carolina green anole are placed side by side, the one with the shorter snout is the brown anole. Throughout the warm months, female anoles lay single, round eggs in moist soil or rotten wood at roughly 14 day intervals. The eggs of brown anoles have longitudinal grooves, whereas green anoles have raised bumps. Once identified, control measures can be taken. Brown anole eggs can be destroyed by freezing or boiling. Adult brown anoles can be located and captured by performing night time hunts with lights. Being diurnal, cold blooded creatures, Cuban anoles tend to congregate together under shrubs and along structures. Once collected the invasive Cuban brown anoles can be humanly euthanized by rubbing lidocaine on their skin and placing them in the freezer.
by Rick O'Connor | Jan 27, 2017
After Hurricane Ivan devastated the Pensacola area in 2004, my son was working to repair docks in local waterways. One day, after working on a project in Bayou Texar (near Pensacola Bay), he came by our house and said that he had seen a bald eagle fly over. My wife and I both responded with amazement but at the same time were thinking… “Yea right”. A few days later, we were sitting on the back porch (we live near Bayou Texar) and glancing up we saw a huge bird flying over… you guessed it… a bald eagle. We both looked at each other and just shook our heads saying “did you just see?… yep, that was a bald eagle”. It was totally cool!
An adult and juvenile bald eagle on nest in Montana.
Photo: Molly O’Connor
In the 1970’s I worked for a local chemical plant on Escambia Bay that had a bird sanctuary on the property. Occasionally a bald eagle would appear during the winter months but it was not annually, and it was a real treat to see it. However, since Ivan sightings in the panhandle have become quite common. Folks are seeing them over Pensacola Bay, Perdido Bay, Garcon area of Santa Rosa County, Gulf Breeze peninsula, almost everywhere! I actually saw three flying together over Big Sabine on Pensacola Beach recently. They are actually now nesting in the area.
These are large birds, 30-40” long with a 7-8 feet wing span, and hard to misidentify – everyone knows a bald eagle. However, the juveniles do not have the distinct white head and tail or the brilliant yellow beak. Rather they are dark brown with possible white spots on their wings, and the beak is darker. The mature color change occurs in 5-6 years. Their diet is mostly fish but they will take small birds and mammals. They are also scavengers, including road-kill, and will “pirate” captured food from other birds. Observations support that ospreys and bald eagles do not really get along.
Bald eagles tend to migrate between their breeding grounds in Canada and those of the Gulf Coast. The migrants are typically non-breeding individuals. Breeding ones tend to remain in their breeding areas year round. As of 2014, Florida has the highest densities of southern breeding populations in the lower 48 states, about 1500 nests. Most return to Florida in the fall for nest building. Their nests are typically in forested areas near waterways. They prefer the tallest trees. The nests are quite large; the record in Florida was 9.5 feet in diameter. They typically lay one clutch of 1-3 eggs but may lay a second clutch if the first is unsuccessful. The young remain in the nests until they can fly – usually April or May. Wintertime is a good time to view these animals in our area.
Their numbers plummeted for a variety of reasons, including the introduction of DDT, and they were placed on the U.S. Fish and Wildlife Endangered Species list. DDT was banned in 1972 and listing them on the ESL protected from them from poaching; they have since recovered. Today they are no longer on the Endangered Species list and were removed from the Florida Fish and Wildlife Conservation Commissions (FWC) imperiled species list. However, they are still protected federally by the Bald / Golden Eagle Protection Act and the Migratory Bird Protection Act; they are also protected in Florida by state law.
Potential viewing locations can be found on FWC’s bald eagles nest location site. https://public.myfwc.com/FWRI/EagleNests/nestlocator.aspx
This site provides known locations between 2012 and 2014. Recent surveys were conducted between 2015 and 2016 in several panhandle counties but those locations have not been posted yet. For those in the Pensacola area, there are four permanently injured bald eagles at the Wildlife Sanctuary of Northwest Florida. The public is welcome to visit the sanctuary Wednesday through Saturday from 12:00 – 3:30PM (self-guided).
105 North S Street, Pensacola FL 32505
http://www.pensacolawildlife.com/
For more information:
http://myfwc.com/wildlifehabitats/managed/bald-eagle/information/
http://myfwc.com/wildlifehabitats/profiles/birds/raptors-and-vultures/bald-eagle/
http://myfwc.com/wildlifehabitats/managed/bald-eagle/faqs/
by Carrie Stevenson | Jan 8, 2017
Arbor Day has a 145-year history, started in Nebraska by a nature-loving newspaper editor who recognized the many valuable services trees provide. We humans often form emotional attachments to trees, planting them at the beginning of a marriage, birth of a child, or death of a loved one, and trees have tremendous symbolic value within cultures and religions worldwide. So it only makes sense that trees have their own holiday. The first Arbor Day was such a big success that his idea quickly spread nationwide–particularly with children planting trees on school grounds. In addition to their aesthetic beauty and valuable shade in the hot summers, trees provide countless benefits: wood and paper products, nut and fruit production, wildlife habitat, stormwater uptake, soil stabilization, carbon dioxide intake, and oxygen production. If you’re curious of the actual dollar value of a tree, the handy online calculator at TreeBenefits.com can give you an approximate lifetime value of a tree in your own backyard.
Arbor Day events in the western Panhandle.
While national Arbor Day is held the last Friday in April, Arbor Day in Florida is always the third Friday of January. Due to our geographical location further south than most of the country, our primary planting season is during our relatively mild winters. Trees have the opportunity during cooler months to establish roots without the high demands of the warm growing season in spring and summer.
To commemorate Arbor Day, many local communities will host tree giveaways,plantings, and public ceremonies. In the western Panhandle, the Florida Forest Service, UF/IFAS Extension, and local municipalities have partnered for several events, listed here.
For more information on local Arbor Day events and tree giveaways in your area, contact your local Extension Office or County Forester!
by hollyober | Dec 16, 2016
Christmas trees can provide benefits to wildlife long after they have served as holiday decoration indoors. Credits: IFAS photo database.
Americans purchased approximately 30 million live Christmas trees last year. If you plan to have a live tree this winter, and you’re wondering what you could do with your tree once it has finished its role as holiday decoration in your home, read below. Rather than simply dragging your tree to the curb for the waste disposal truck to pick up, you could prolong the life of your holiday tree by repurposing it to benefit wildlife.
YOUR TREE COULD PROVIDE FOOD FOR WILDLIFE
Many of the needles may have dropped from your Christmas tree as it dried out while indoors, but the branches should still be intact. This means your tree could be used as a frame to present food for wildlife. After removing your indoor decorations, consider propping the tree up in your yard (perhaps using the same stand you used indoors), and adorning the branches with food enjoyed by wildlife visitors. Some low-budget options include mesh bags filled with bird seed (black oil sunflower seed, safflower seed, and thistle (nyjer) are favorites of many common backyard birds), pine cones smeared with peanut butter, home-made suet cakes, and strings of fruit such as apple slices, orange slices, or grapes. If you choose this option, beware that you may attract not only birds, but mammals such as squirrels, raccoons, opossums, and others.
If you’d like to watch your wildlife visitors, be sure to attach the food items with string so that the animals must eat the food at the site of the tree rather than carrying it away to eat or store elsewhere out of view. Consider using a biodegradable string (i.e., cotton) to secure the food items to your tree so you can eventually compost the tree without worrying about needing to remove the string.
YOUR TREE COULD PROVIDE SHELTER FOR WILDLIFE
If you’re tired of seeing your holiday tree in its upright position, consider taking it outdoors, laying it down, and heaping other vegetative debris loosely on top to form a ‘brush pile’. Brush piles are mounds of woody vegetation created specifically to provide shelter for wildlife.
The lower portions of a brush pile can offer cool, shaded conditions that allow small mammals such as rabbits to hide from the weather and from predators. Meanwhile, the upper portions can serve as perch sites for songbirds. The entire pile may be used as resting sites for amphibians and reptiles. In yards with few understory trees or shrubs, and at times of year when many trees and shrubs have limited foliage, these brush piles can provide much-appreciated cover for many kinds of wildlife.
YOUR TREE COULD PROVIDE SHELTER FOR FISH
Your retired Christmas tree could be used to make long-lasting habitat improvements for fish. In artificial ponds with little submerged vegetation, the addition of one or more Christmas trees could upgrade the quality of refuge and feeding areas for fish. Small fishes may hide among purposely submerged Christmas trees for protection, and larger fishes may follow them. If you’ve got an artificial pond on your property, consider adding discarded trees to create a place where fish can hide and find food, and also to concentrate fish for angling. Simply secure a cinder block to your holiday tree using heavy wire or thin cable and place it far enough from shore that water covers the top of the tree by a couple of feet. When constantly submerged, Christmas trees can persist for many years underwater.
Not only can your tree offer enjoyment to you when decorated with lights and ornaments indoors, but it can also allow you to provide post-holiday gifts to the wildlife and fish on your property.
