Unnaturally frequent wildfires may wipe out reptiles and
amphibians that live in complex shrub lands, shrinking the
biological diversity of burned areas, a study in San Diego County
The study, released this week to the media and published in the
Journal of Herpetology, looked at 55 plots of land that burned
during the 2003 wildfires, which torched nearly 380,000 acres in
San Diego County.
U.S. Geological Survey researchers looked at 38 types of
lizards, snakes and salamanders, comparing their populations before
the fires to their numbers afterward. These animals serve as
indicators of a "healthy, diverse system," and as food sources for
birds and larger reptiles said Carlton Rochester, the lead author
of the study and a biologist with the survey.
Researchers published the first two years of results in the
article, showing that more-frequent blazes exceed the animals'
abilities to rebound from a wildfire.
"As we get those fires coming more frequently, these shrub lands
don't have time to recover," Rochester said. "As the fires impact
the vegetation, the animals that live in those areas are
While a handful of species appeared to thrive in the hot, dry
grasslands that replaced the burned chaparral and coastal sage
scrub, others diminished after the blazes, or even disappeared.
Whiptail lizards and side-blotched lizards prefer open, sunny
habitat, which allows them "to get their body temperatures up and
run around like crazy," Rochester said.
Two species of whiptails and the common side-blotched lizard
more than tripled in chaparral areas after the fire, and also
increased in coastal sage scrub habitat, the study showed. However,
Rochester said, animals like these are "generalists" that don't
require specific habitat to survive. Other animals that need more
specialized conditions fared poorly after the fires, he said.
"Some species need moist habitats, and need the leaf litter that
collects under shrubs," he said. "When that burns off, the soil
holds less moisture.The sun is beating directly on the soil,
temperatures get higher .... Salamanders don't do well with that
and retreat underground."
The study found that the garden slender salamander disappeared
from chaparral habitat that burned in the fires, and dwindled in
coastal sage scrub areas. The salamander species Ensatina vanished
from both habitat types after the fire, results showed. Several
species of frogs and toads also disappeared or diminished, the
"For some species, we don't know what happened," Rochester said.
"The yellow-bellied racer (snake) disappeared after the fire. We
don't know what change accounts for that."
Rochester said the findings could provide an argument for
protecting sensitive ecological areas during wildfires. However,
fire authorities said they're limited in how they can tackle fires
in such areas, and often lack the personnel to address
environmental concerns during wildfires.
"The environmental issues are a factor, but only after lives and
property," said Sid Morel, fire marshal for the North County Fire
Protection District, which serves Fallbrook, Bonsall and
"There's very specific things we are able to do or not able to
do (in sensitive areas), such as using bulldozers to make fire
breaks, or using fire retardant from airplanes," said Gary Lane,
division chief of operations for the district. "And for us to
commit resources where no human life or property is there, I don’t
know that we would ever have the resources to make that
Rochester said, however, that San Diego County's wide range of
reptiles and amphibians are threatened by human changes to the fire
cycle, and deserve consideration in fire-fighting efforts.
"There's already talk that humans are causing mass extinctions,
and these animals that have been here for millions of years could
get wiped out by us," he said.
Call staff writer Deborah Sullivan Brennan at 760-740-5420.