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Extinction Countdown

Extinction Countdown

News and research about endangered species from around the world

Motored Down: Record number of manatee, Florida panther deaths in 2009

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2009 was the deadliest year on record for Florida panthers (Felis concolor coryi) and manatees (Trichechus manatus), two endangered species that most often lose their lives when their habitats collide with that of humans.

panther roadkillA record high 17 panthers were struck by vehicles and killed in Florida last year, two deaths above the previous high set in 2007. The deaths are terrible news for a species that numbers maybe 100 individuals and which is already heavily inbred.

The 16th vehicle-related death, which occurred on December 29, was particularly tragic as the panther came from a relatively pure bloodline. Unlike most other Florida panthers, the female cat did not have a kink in its tail, a birth defect caused by inbreeding. The 17th death was even worse: a three- to four-month-old kitten was killed on New Year's Eve. Another recent vehicle fatality is still being investigated, because whoever killed the panther also removed its head after its death.

Just a few weeks ago, the Florida Fish and Wildlife Conservation Commission (FWC) put out a press release asking motorists to slow down in panther zones. (Fines for speeding in a panther zone start at $200.)

All told, 24 panthers died in Florida in 2009. Three were killed by other panthers (which are very possessive of their territories), one was illegally shot, and two died from uncertain causes—one additional death is still under investigation.

The panther is Florida's state animal, but little has been done to truly protect it in the face of Florida's booming human population growth. Several environmental groups recently announced plans to file a lawsuit to try to protect critical panther habitats.

Although the Florida panther is a long way from safety or recovery, it isn't all bad news: The animals are breeding, and despite the deaths the number of panthers has been relatively constant for the last few years. "We must remember there's reproduction going on, some of which we don't document," David Onorato of the FWC recently told The New York Times.

2009 deadly for manatees, too

As for the manatee (technically, the West Indian manatee), in 2009 at least 429 of the marine mammals died in Florida, the highest number on record. The previous high was 417 deaths in 2006. (Manatee death-counts have been collected since 1974, when these marine mammals became one of the first species protected under the federal Endangered Species Act.)

manateesAccording to data gathered by the FWC, at least 97 of those deaths—or 22 percent—were caused when watercraft collided with manatees. Boat-related accidents have long been the leading cause of manatee injuries and mortality, and numerous laws and regulations are in place in Florida to try to minimize their occurrence.

Humans, however, didn't cause all of the manatee fatalities in 2009. Fifty-six manatees died during unusually cold weather, more than twice the number of cold-related deaths in 2008. Manatees also experienced a very high infant-mortality rate this past year, with 114 known perinatal deaths. When used to describe manatees, the term "perinatal" refers to the length of the animal rather than the exact age, and these deaths encompass stillborn manatees, birth defects, other natural causes, and other young animals that were too decomposed by the time their bodies were located to find a definitive cause for their deaths, according to Katie Tripp, director of science and conservation for the Maitland, Fla.–based Save the Manatee Club.

Despite the threats they face, manatee populations have grown to an estimated 3,800 animals, about 500 more than the previous high set in 2001. But the FWC warns against assuming that the higher number of deaths is just because the manatee population has increased. "The situation is not that simple," reads an FWC statement. "Both the carcass totals and the annual counts from statewide aerial surveys are considered minimum numbers only, and they cannot be used to calculate long-term population trends."

And even with the recent growth, the manatee population still isn't large enough, and last year's deaths don't help. According to a recent stock assessment by the U.S. Fish and Wildlife Service (FWS), the current watercraft-caused death rate is seven times the sustainable level for the population to stay healthy. "Boating in Florida has really exploded in recent years, with over a million registered boats," says Miyoko Sakashita, an attorney with the Center for Biological Diversity, which sued the FWS to assess manatee populations and threats.

"We've seen that you can put a lot of watercraft and manatee in the same water and as long as you have compliance with regulations, there isn't a problem," Tripp says. "We just want people to watch out for manatees."

In addition, a lot of new waterfront household and commercial development has been approved in Florida, and that "infringes upon habitat and creates more opportunities for conflict. The way that they're permitting these new developments is suspect, and there isn't a lot of compliance with current regulations," Sakashita says.

As Florida's human population continues to grow, the amount of space left for the panther and the manatee to thrive continues to shrink. And, for now, so do these two species' populations, along with their chances for survival.

Images: Florida panther killed by a motorist earlier this year. Photo courtesy of Florida Fish and Wildlife Conservation Commission. Manatees, courtesy of the U.S. Geological Survey

The views expressed are those of the author and are not necessarily those of Scientific American.

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