ADVANCES
22 Scientific American, March 2020PHILIP DALTONGetty ImagesANIMAL BEHAVIORBurn
Benefits
Bat species proliferate
in forests thinned by fireBats are nature’s pest patrol. Every night
the winged mammals venture forth from
their caves and roosts to chow down on mil-
lions of insects, including some that plague
farmers. But habitat loss and climate change,
as well as infectious diseases such as white-
nose syndrome, are hampering bats’
ability to do their job. A new study adds
another item to the list: wildfires. But not
too many—too few.
In California’s Sierra Nevada ecosys-
tem, bats have adapted to occasional blaz-
es. But a century of fire-suppression poli-
cies has kept some areas unburned for
unusually long periods, resulting in denser
forests with thicker undergrowth. “We
wanted to see how these shifts in how fires
are burning might be influencing bat biodi-versity,” says University of California,
Berkeley, ecologist Zack Steel, who con-
ducted the research while a graduate stu-
dent at the University of California, Davis.
Steel and his colleagues deployed an
array of microphones to count bats by
recording their distinctive echolocation
chirps and squeaks over four years at
six sites in the Sierra Nevada. Three of the
areas had recently endured fires, and three
remained unburned.
Seventeen bat species call these forests
home. The study revealed that eight of
them tended to frequent the unburned
patches, whereas 11 used the burned areas
(some species visited both). “We expected
to see one group of species benefiting from
fire—the more open-habitat-adapted spe-
cies—and another group, the more clutter-adapted species, being negatively affected
by fire, preferring the unburned areas,” Steel
says. “But even some of those species were
occurring more often in burned areas.”
What is ideal, the researchers write, is
a combination of unburned areas and ones
burned at different levels of severity—which
they refer to as pyrodiversity. The results
were published last December in the jour-
nal Scientific Reports.
“When there’s lots of variation in habi-
tat after a fire, many species benefit in dif-
ferent ways,” says University of Connecti-
cut biologist Andrew Stillman, who was
not involved in the study. “On the whole,
the community becomes more diverse,
and that’s a good thing for the landscape.”
Extinguishing wildfires early leads to
some species losing out on food and
resources. “Fire is a natural part of the eco-
system, and many animals require the dis-
turbance from fire to create the types of hab-
itat that they need,” Stillman adds. “It dem-
onstrates another negative consequence of
keeping wildfire away from fire-adapted for-
ests in California.” — Jason G. GoldmanMexican free-tailed batsADVANCES
PHILIP DALTONGetty ImagesANIMAL BEHAVIORBurn
Benefits
Bat species proliferate
in forests thinned by fireBats are nature’s pest patrol. Every night
the winged mammals venture forth from
their caves and roosts to chow down on mil-
lions of insects, including some that plague
farmers. But habitat loss and climate change,
as well as infectious diseases such as white-
nose syndrome, are hampering bats’
ability to do their job. A new study adds
another item to the list: wildfires. But not
too many—too few.
In California’s Sierra Nevada ecosys-
tem, bats have adapted to occasional blaz-
es. But a century of fire-suppression poli-
cies has kept some areas unburned for
unusually long periods, resulting in denser
forests with thicker undergrowth. “We
wanted to see how these shifts in how fires
are burning might be influencing bat biodi-versity,” says University of California,
Berkeley, ecologist Zack Steel, who con-
ducted the research while a graduate stu-
dent at the University of California, Davis.
Steel and his colleagues deployed an
array of microphones to count bats by
recording their distinctive echolocation
chirps and squeaks over four years at
six sites in the Sierra Nevada. Three of the
areas had recently endured fires, and three
remained unburned.
Seventeen bat species call these forests
home. The study revealed that eight of
them tended to frequent the unburned
patches, whereas 11 used the burned areas
(some species visited both). “We expected
to see one group of species benefiting from
fire—the more open-habitat-adapted spe-
cies—and another group, the more clutter-adapted species, being negatively affected
by fire, preferring the unburned areas,” Steel
says. “But even some of those species were
occurring more often in burned areas.”
What is ideal, the researchers write, is
a combination of unburned areas and ones
burned at different levels of severity—which
they refer to as pyrodiversity. The results
were published last December in the jour-
nal Scientific Reports.
“When there’s lots of variation in habi-
tat after a fire, many species benefit in dif-
ferent ways,” says University of Connecti-
cut biologist Andrew Stillman, who was
not involved in the study. “On the whole,
the community becomes more diverse,
and that’s a good thing for the landscape.”
Extinguishing wildfires early leads to
some species losing out on food and
resources. “Fire is a natural part of the eco-
system, and many animals require the dis-
turbance from fire to create the types of hab-
itat that they need,” Stillman adds. “It dem-
onstrates another negative consequence of
keeping wildfire away from fire-adapted for-
ests in California.” — Jason G. GoldmanMexican free-tailed batssad0320Adva3p.indd 22 1/22/20 4:52 PM
Scientific American is a registered trademark of Springer Nature America, Inc. Google Play and the Google Play logo are trademarks of Google LLC. Apple, the Apple logo, iPhone, and iPad
are trademarks of Apple Inc., registered in the U.S. and other countries and regions. App Store is a service mark of Apple Inc.halfHorizTemplate.indd 2Untitled-5 1 1/23/20 11:15 AM1/23/20 11:45 AM
© 2020 Scientific American