Biology Reference
In-Depth Information
ingested transmitters for the Reinert-Cundall method. First, I'd gently coax a pitviper
into a plastic tube, in which it was exposed to the same vaporizing anesthetic used on
people. Then Dave snipped a small incision, behind the stomach and forward of the gon-
ads, through which he inserted a lipstick-size radio. Finally, the radio's ten-inch antenna
was threaded forward under the skin, and a few sutures closed the wound. We located
telemetered animals by using a handheld receiver and directional antenna to play hot
and cold with the signal, despite interference from the rugged terrain and a tiny rain-
forest frog whose piercing call sounded exactly like the transmitter signal's tink-tink-
Manuel Santana, a Salvadoran wildlife biologist, rounded out our team of snake mon-
itors. For weeks we daily checked a pregnant terciopelo basking on a tree-fall, once
witnessing her drinking rain droplets off her own scales. Another big female shed her
skin while crawling rectilinearly over wet leaves, transforming within minutes from dull
and mud-smudged to lustrous velvet. Terciopelos were sometimes diurnally active, but
the larger bushmaster, as Manuel, Dave, and I discovered by keeping both species un-
der round-the-clock surveillance, is truly a creature of habit. As night fell and patterns
on the forest floor became indiscernible, up went the chiseled head in an alert ambush
posture that was maintained until shortly before dawn; just as a filmy gray light settled
on the understory, down that head went into a resting coil—night after night, day after
day, for up to sixty-seven days at a site. My strongest memories are of phenomenal cam-
ouflage. One morning I saw an experienced local woodsman walk by a big bushmaster
coiled in plain view at trailside, and another day, after a group of us had talked and
taken photographs around a six-foot terciopelo for several minutes, someone remarked,
“What about the other snake?” And there he was, a smaller male, completely in the
open, lying against her.
La Selva never yielded the sustained observations of individual pitvipers that I
craved, but since Dave proved an enthusiastic collaborator, we commenced long-term
joint research on black-tailed rattlesnakes in 1985. We suspected that the easygoing,
three- to four-foot-long rattler species and its fairly open habitat were well suited for
behavioral studies, and Dave's home in Arizona's Chiricahua Mountains could serve as
our base. Our two-mile-long field site was drained by Silver Creek and bordered on the
north by the slanted, knobby crest of Limestone Mountain; to the south rose Silver Peak
and the main range of the Chiricahuas. Massive stumps testified to historically forested
slopes, now clothed in pinyon-juniper woodland and low thickets of white-thorn acacia,
agaves, and several kinds of cacti. Sycamores and cottonwoods formed shady galleries
along the stream. White-throated woodrats, rock squirrels, cliff chipmunks, and desert
cottontails provided prey for blacktails, and we recorded coyotes, bobcats, black bears,
mountain lions, ringtails, coatis, and gray foxes as potential predators at the site. 28
Dave and I watched the Silver Creek Canyon blacktails for fifteen years. He drove
down from Tucson at least monthly to monitor telemetered snakes, and I'd join him for
several weeks during the summer monsoon season. We'd get out shortly after dawn,
walking the rocky slopes and locating animals before they took shelter from the mid-
day heat, each of us carrying telemetry gear, capture equipment in case new snakes
were found, and plenty of water. Our daily routine was to walk toward the sun, so as not
to cast shadows and disturb the snakes, moving low and slowly to within a few yards
for observations and photographs. The blacktails often seemed aware of us but typic-
Search WWH ::

Custom Search