Florida law that limits light pollution from the state's 12 million coastal residents has done wonders protecting the habitat of some marine animals, like the majestic yet threatened sea turtle.

But there's at least one terrestrial critter that would prefer even darker shores along parts of Florida's peninsula: the endangered and elusive beach mouse.

A new University of Florida study has found that light restrictions enacted to encourage continued nesting of turtles have done little to protect dune dwelling rodents from predation. Rules requiring long-wavelength fixtures at seaside hotels and homes, which translate to less costal light in heavily populated areas, are still too bright for the beach's protected mice, the research concluded.

Lyn Branch, a biology professor at UF's department of wildlife ecology and conservation, said the beach mouse is likely just one of many beach creatures suffering in the shadows of human development.

"Light pollution worldwide has increased dramatically," and much of that increase can be linked to development near the coast, said Branch, one of three researchers whose study appeared in the journal Conservation Biology last month.

"We would expect a large number of species to be affected. Not only mice, but amphibians that feed at night, fish, all sorts of species," the professor said.

Branch said numerous studies have documented the impacts of light on marine animal behavior, most notably sea turtles. Sea birds, for example, have been found to become disoriented during night flight near stationary light sources.

But unlike UF's study, no beach light research had ever focused solely on a coastal creature.

The quest to change that trend was initiated by the U.S. Fish and Wildlife Service.

"Beach mice are nocturnal, and we knew we had requirements for lighting for sea turtles," said Lorna Patrick, a biologist with the federal agency's Panama City field office.

"In implementing the sea turtle lighting, we were wondering how that affected beach mice. We knew the university was doing work out there, and we thought it was a good opportunity to do additional work."

The task of unraveling the mouse mystery was handed to Brittany Bird, a former university graduate student now working for the Wildlife Habitat Council in Detroit.

To test how the turtle-friendly lights impact beach mouse foraging habits, Bird and colleagues focused their attention on the Santa Rosa subspecies, the only one of eight varieties living in the coastal dunes of Florida and Alabama that isn't threatened or endangered.

With partially FWS funding, the team erected a series of 10-foot poles along a portion of sand on Santa Rosa Island in the Panhandle. At the top of the poles they fastened long-wavelength lights to illuminate large patches of coastal real estate.

They then placed trays of millet around each set of lights, and did the same along darkened stretches of coastline.

By collecting and weighing the millet that remained in the trays each morning, the team was able to determine that the mice greatly preferred foraging in dark areas over well lit ones.

Bird said the reasons behind the dining preference are obvious.

"Increased lighting makes the mice more visible, and that can only increase their vulnerability to predators," the former UF student said.

Of course, light wasn't the only threat affecting the protected rodent's eating habits, Bird said.

"Beach mice are particularly vulnerable to predation by domestic cats, because they evolved in a cat-free environment and haven't evolved ways to recognize and avoid them."

Hungry felines aside, Patrick of the Fish and Wildlife Service said UF's findings should serve as an important reminder to the state's coastal residents.

"We can do both. We can live on the beach but we can also protect endangered species," Patrick said. "It's a fairly simple concept, that you should just put light where you need it.

"You don't need to light up the whole beach."

Greg Bruno can be reached at 374-5026.