To gauge the populations chance of survival, the researchers drew on data gathered by Wooten and other scientists who had spent several years in the 1980s and 1990s using live traps to collect and count mice at the sites. They analyzed the data with computer models using a method known as population viability analysis.
Their results are not promising. For one thing, the scientists estimates of actual numbers of remaining mice are quite low. At only one of the four sites did estimates top 1,000 mice during the six or more years when the populations were sampled, while low numbers for the years reached 50 mice or fewer for all the sites. Large population fluctuations are typical of small mammals, but the pattern is dangerous for beach mice because their already low numbers mean a dip in the population can prove a fatal blow, the scientists said.
I think if you take a particular population, almost any of them has a high probability of extinction within 100 years thats probably a normal function of their biology, Wooten said. Its just that now, with so few populations, that fluctuation poses a threat to the species.
The problem is that hurricanes have the potential to wipe out mouse populations -- thanks to coastal development, Oli said.
On undisturbed lands, beach mice live on dunes, but retreat to nearby scrub dune habitat when a hurricane destroys their burrows or temporarily eliminates seeds such as s
Contact: Madan Oli
University of Florida