Biology Reference
In-Depth Information
rare aggregation of multihued birds dazzled us—as did the swarms of brightly colored but-
terflies fluttering along the shoreline as we returned to the boat.
A cold front, known locally as a
friaje
, had moved upriver with us, and we spent the next
two days in a chilly rain forest—who would imagine 10°C (50°F) in the Peruvian Amazon?
The Madre de Dios region seemed caught in a collective shiver, and at night the temperat-
ure dropped precipitously. The effects of the friaje were most evident in the absence of local
nocturnal wildlife seen or heard. We spent one night in a blind above a mineral lick usually
frequented by salt-seeking tapirs. None appeared. Bats were scarce along the trails they typic-
ally used to commute between their roosts and their feeding areas. The silence was also con-
spicuous. Quiet were the lead vocalists, the kinkajous—rain forest relatives of raccoons—the
night monkeys, and the amphibians and insects that provide the background chorus.
That the cold weather disrupted the normal rhythms of the forest dwellers could explain
what we saw late the next afternoon. We were heading back to camp when our sharp-eyed
boatman pointed to a sandy stretch along the Tambopata floodplain. He slowed the boat and
whispered, “
Mira!
Jaguar!”
Reclining on the beach was a large male jaguar. He was magnificent and quite unperturbed
by the close approach of the boat. The driver turned the prow upstream, and we sat and
watched the stationary cat. Ten minutes went by, then twenty. Perhaps the sandbank held the
warmth of the sun's rays in the approaching dusk, and after a frigid week in the forest the
jaguar was content to rest and warm his bones. We were so enraptured by our sighting that
we ignored a smaller boat idling nearby until we noticed the three men in the craft eyeing
the same splendid cat. Tucked below the gunwale was a barely concealed rifle. To foil the
hunters, we waited until it grew too dark for them to see the outline of the jaguar. With no
chance for a kill, the men headed back downriver. We disembarked and walked toward the
jaguar, urging it back into the forest for its own protection. In their years in Peru, George and
Sue had never seen such a calm jaguar, much less have to save one from other humans.
That evening, the unforgettable encounter with both predator and poacher was at the center
of our conversations. “George, if the poachers had arrived before we did, there would have
been one less jaguar hunting along the floodplain of the Tambopata. But take it to the ex-
treme. What if protection broke down completely and hunters shot every last jaguar in these
parts? How would this ecosystem be different?”
George didn't hesitate. “You remember John Terborgh's studies in Venezuela at Lago
Guri, don't you?” George was referring to one of conservation biology's leading field men,
a hero to us. Terborgh's innovative natural experiment in Venezuela involved censusing the
inhabitants of islands created by dam impoundments in once continuous forest. Some of the
human-made islands were too small to support even a single jaguar or other felid. Terborgh
showed that when such top predators are lost in a system, the forest changes rapidly because
there is a swift increase in the numbers of sloths, monkeys, deer, and peccaries that eat plant
