50 YEARS AGO
UPDATE: Two years after
the American peregrine falcon
(Falco peregrinus anatum) was
declared endangered, the
United States banned DDT in
1972. The pesticide lingered in
the environment, however, and
by 1975, North America’s population of peregrine falcons hit
a low of 324 nesting pairs. State
and federal agencies worked
with conservation groups to
breed the species in captivity,
with some 6,000 birds released
into the wild since 1974. The
species was removed from the
U.S. endangered species list in
Excerpt from the
February 22, 1969
issue of Science News
THE SCIENCE LIFE
Termites help rainforests withstand a drought
Fierce and swift, steel blue
in color and called the
world’s most perfect flying machine, the peregrine
falcon is heading toward
extinction in North America.
The reason: DDT. Perilously
high levels of the pesticide
and related chemicals have
been found in the eggs, fat
and tissues of the birds….
[The falcons] are not picking up the DDT directly, but
get it by eating other birds
which, in their southern
migrations, ingest DDT-contaminated insects.
With tea bags and toilet paper rolls, tropical
ecologist Kate Parr and colleagues showed
how termites help tropical rainforests
resist drought. Forests with more termites
have more leaf litter decomposition, soil
moisture and seedling survival during a
drought than forests with fewer termites.
Termites play an important role in
tropical ecosystems, but “nobody knows
exactly how important,” says Parr, of the
University of Liverpool in England. To
isolate the effects of termites from other
soil critters, the researchers exploited
termites’ cellulose diet.
In 2014, Parr’s team buried insecticide-
soaked rolls of toilet paper and tea bags
in four forest plots, each with an area of
about five Olympic swimming pools, in the
Maliau Basin Conservation Area of north-
ern Borneo. Toilet rolls are like cotton
candy for termites — “this really amazing,
easy-to-digest food,” Parr says. The tea
bags were used in case some termites
“were fussy and didn’t eat the toilet paper.”
Termites died after eating the poisoned
baits, while the 14 other most commonly
found invertebrates, including ants and
beetles, were unaffected. Few of the other
critters nosh on hard-to-digest cellulose.
For nearly three years, the team
destroyed any termite mounds that
appeared, while replenishing the poisoned
baits every six months. The researchers
went through about 3,500 rolls, including
some without poison so the team could
check how much termites were chomping.
This helped in gauging an area’s termite
activity — a proxy for termite numbers.
Termite activity fell by 45 percent in
treated plots, compared with four
The project, described in the Jan. 11
Science, was part of a larger effort led by
the University of Liverpool and the Natural
History Museum in London to examine
how ants and termites affect both decom-
position and consumption in rainforests.
When drought hit a year into the study,
Parr’s team worried the insect-activity
research would be compromised. Instead,
the halt in rain offered a “wonderful
opportunity,” Parr says.
During the drought, termite numbers
doubled and leaf litter decomposed faster
in untreated plots than in treated plots.
Untreated plots also had more soil mois-
ture and nutrient mixing, as well as better
seedling survival rates. These effects were
not observed during nondrought periods.
The researchers aren’t sure why termites
kicked into high gear during drought, but
the insects might have benefited from
easier tunneling in drier soil or from fewer
predators. — Yao-Hua La w
Toilet paper rolls were sliced in half and dunked in
liquid insecticide, offering an attractive meal for
cellulose-munching termites. Thousands of
poisoned rolls reduced termite populations in
forest plots, without harming other animals.
termites, such as the
here, improve leaf
moisture and seedling
survival during rainforest drought, a new