TV Program Description
Original PBS Broadcast Date: February 24, 2009
Once every 48 years, forests of the bamboo known as
Melocanna baccifera go into exuberant flower in parts
of northeast India. And then, like clockwork, the event is
invariably followed by a plague of black rats that spring from
nowhere to spread destruction and famine in their wake. For
the first time on film, NOVA and National Geographic capture
this massive rat population explosion in the kind of vivid
detail not possible in 1959, when the last invasion occurred.
Shot in the Indian state of Mizoram, where the massive
onslaught occurred on schedule in 2008, this NOVA/National
Geographic Televison special shows hordes of rats emerging
from the forest right at harvest season, consuming entire
crops and leaving subsistence farmers facing starvation. The
chance to document and study this remarkable rat outbreak
won't occur again for another half-century. (By contrast,
oak-tree masting, the best-studied mass seeding in the world,
occurs every few years—see
Population Explosion.)
In the film, the world's foremost rat biologist, Ken Aplin of
the Australian National Wildlife Collection (and National
Geographic research grantee) arrives before the onset of the
attack to try to understand the cause of the colossal
infestation, which is steeped in local lore. According to
tradition, the regular 48-year cycle of bamboo flowering,
seeding, and death, called Mautam, spawns armies of
rats, which come out of trees and underground burrows to
indulge in the abundance of food. (Noted ecologist
Dan Janzen explains
why this happens, and what's in the relationship for all
involved—plants, animals, and people.)
Aplin, who has been studying rats for 10 years, has been
bitten countless times but has no fear of the rodents, just
sheer enthusiasm. In the film, he is literally up to his
elbows in rats, reaching into burrows to pull out litters of
rat pups while looking for clues as to how the invasion is
progressing. "A lot of people are disgusted by rats," Aplin
tells NOVA, "but I love rats. They're so successful!"
Once the invasion starts to wane as both natural and
human-produced foods begin running out, the now-starving rats
begin killing their own infants in order to survive. (See
Killer Instinct
for a look at possible reasons why animals commit infanticide,
which is surprisingly widespread in nature.)
Also featured in the program is James Lalsiamliana, a
biologist with the Mizoram Agriculture Department, who teams
up with Aplin to solve the rodent mystery. At one point they
inspect a pile of 30,000 rat tails collected in a
government-sponsored bounty program designed to reduce the
invaders' numbers. The impressive mound of tails is a small
fraction of the over 1.5 million rat tails collected in the
region. But this substantial culling appears to have had
little effect on the burgeoning rat population.
So prolific are the creatures that local people regard the
bamboo seeds on which they feed as a powerful
aphrodisiac—a theory tested by Mizoram residents in many
home kitchens, where they concoct delicacies with the seeds.
NOVA also shows how some of the local Mizo people eat the rats
themselves for food. (So does
Jeremy Zipple, the
coproducer who doesn't shy away from the full experience of
living among the Mizo people during the film shoot—see
The Producer's Story.)
"Rat Attack" sheds light on the amazing biology of the black
rat (Rattus rattus) and its relationship with the life
cycle of the Melocanna bamboo, which has a remarkable
biology of its own. Given the long interval between rat
plagues, Aplin says this is his last chance to work out what
really happens during Mautam, to work out the details
of the connection between bamboo flowering and rat outbreaks.
And, ultimately, to help local people better cope with the
next attack—due in 2056.
Program Transcript
Program Credits
