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Titel: NAPLES DAILY NEWS ; Forgotten gopher tortoise preserves threaten animal's popul.
Bericht door: schildpaddennetcrew op 13 Juni 2008, 12:21:25
NAPLES DAILY NEWS (Florida) 16 October 05 Forgotten gopher tortoise preserves threaten animal's population (Kate Spinner)
If there's a subdivision, an apartment complex or a condominium building standing on dry scrubby land in Southwest Florida, chances are there's a gopher tortoise preserve there, too.
Boxy little land turtles, often heard rustling through underbrush before they're seen, gopher tortoises are abundant here.
Wildlife biologists estimate there are 750,000 to 1 million of the burrowing reptiles in Florida, but the long-term fate of the species is a concern because suitable habitat is swiftly giving way to concrete and asphalt.
To keep urban growth from killing off the tortoises, state laws require developers to take certain measures before building on tortoise territory. In other parts of the state, developers can get permits to fill in tortoise burrows, as long as they chip in money to buy habitat elsewhere. But in Lee County, entombing gopher tortoises in their burrows is illegal.
Instead, developers must move the critters to a preserve somewhere on the developed property or to another spot.
As a result, hundreds of gopher tortoises eke out their lives on islands of sandy woodlands behind housing developments and shopping centers. They're surviving on those small plots, but most policymakers expect their stay to be short-lived.
The small preserves, many of which are less than 10 acres, are difficult for county workers to inspect, complicated to manage and often forgotten when the property changes hands.
When The Gardens, a former apartment complex on Matheson Avenue, turned condo 10 months ago, the new homeowners' association members were shocked to find out the fenced land skirting their property was a tortoise preserve.
Joe Lawler, secretary of the homeowners' board, said the land had been continuously mowed with a lawnmower and ignored by residents who did not know gopher tortoises lived there.
"I didn't think that was right, because lawnmowers have no concern over what they run over," Lawler said.
The homeowners' association immediately told landscapers to carefully mow the 2-to 3-acre preserve with a weed trimmer instead. Meanwhile, Lawler started looking into how to manage the preserve.
"Why turn something into preservation if no one's going to keep track of it?" Lawler said.
Forgotten preserves are a problem countywide, said Kim Trebatoski, a Lee County environmental planner. Once a small preserve is in place, it's up to the property owner to manage it and make sure the next property owner knows it's there. After the preserves are created, county officials don't inspect them unless complaints are made.
For the most part, the small preserves are just a humane way to deal with a relatively rare species.
"These populations within developments allow tortoises to live out their lives," Trebatoski said.
"It's not enough to be a long-term situation, because there's not enough contiguous land."
For gopher tortoise populations to survive for generations, they need a minimum of 25 acres.
Most of the preserves in large planned communities, such as Bonita Bay and Pelican Landing, are 25 acres or more, said Jim Beever, a biologist with the Florida Fish and Wildlife Conserva tion Commission. Such preserves, he said, require more stringent permitting, monitoring and reporting. Still, they can fall through the cracks because staff is limited.
"It would be good if there were more people to do the monitoring," Beever said. He and one other biologist are responsible for checking up on preserves in 12 counties.
Joan Berish, a research biologist for the Florida Fish and Wildlife Conservation Commission, said small pockets of gopher tortoise habitat can help keep the animals from dying out if they're managed well. Under the right conditions, a gopher tortoise can live for 60 years.
"With intensive management and with some oversight and some forethought, these little populations can hang on and perhaps serve as ambassadors for their species," Berish said. She is part of an action team that is researching how to manage the tortoises more effectively.
As Florida becomes more residential and less wild, Berish's task becomes harder. Over the past 100 years, somewhere between 60 and 80 percent of the gopher tortoise population has shrunk because of urbanization and loss of habitat, she said.
In the days before widespread development, Florida's pine uplands burned periodically.
Fire clears underbrush, returns nutrients to the soil, pops pine seeds from their cones and makes way for saplings to sprout. Fires also makes room for adult pines to branch out. The sparse tree cover lets sunlight dapple the soil and prompts low-growing grasses to flourish.
Gopher tortoises love to chomp on native grasses and they like to dig their burrows in areas where the sun beats down. The warmth is good for the tortoises' eggs.
While it's difficult to obtain a permit to do a prescribed burn, there are ways to manage the land to mimic fire. Taking out weeds to keep the undergrowth and shrubbery under control is one approach. Pulling out exotic plants such as Brazilian pepper and melaleuca is also important.
An example of a tiny preserve that hasn't been forgotten or neglected is behind the Art League in Bonita Springs. Behind the league's building on Old 41, a little more than 4 acres of woodlands are dedicated to gopher tortoises. Though Art League Director Susan Bridges said the preserve is not heavily managed, the sandy ground is dotted with saw palmettos and native grasses and strewn with pine needles. Scattered clusters of cabbage palms grow hunched beneath a thin canopy of slash pine limbs and the occasional golf ball, almost camouflaged against the sand, drives home the message that the habitat is definitely urban.
About 12 different tortoises have been spotted there, Bridges said, and they've got some room to roam, plenty of open areas to dig burrows and lots of low-growing plants to chew on.
Berish said the prognosis for the long-term survival of small tortoise populations is not good, but she said it is important to retain them and take care of them.
She said research has shown small populations can be consolidated successfully on much larger parcels where tortoises have disappeared.
But moving tortoises should be left to the biologists. It is illegal to transport gopher tortoises from one locale to another without a permit. Without a biologist's oversight, introducing tortoises to new areas could spread a deadly and highly contagious respiratory illness throughout an otherwise healthy populaton.
Two healthy populations that are threatened by development or so isolated that reproduction is impossible might be combined together on a large tract of land that needs tortoises.
"If we're going to retain the regional resource, we're going to have to get more creative, and that will sometimes involve these smaller tortoise populations," Berish said.
Dry uplands with gopher tortoises are starkly different than similar lands without tortoises, Berish said.
The tortoises enrich the soil by tilling it, they create a foothold for plants and their holes serve as refuges for a slew of other threatened creatures, including gopher frogs, gopher mice, indigo snakes and a host of unique bugs.
"This little helmet-looking, shelled critter is an animal that increases biodiversity," Berish said. "They're landlords of sorts ... they have a profound ecological importance."
http://www.naplesnews.com/npdn/news/article/0,2071,NPDN_14940_4162621,00.html