Biology Reference
In-Depth Information
in earlier diet studies, Auliya recorded bats, tarsiers, and a binturong, the largest civet.
One eighteen-foot retic contained a long-tailed macaque and her clinging infant, and a
twenty-two-footer beside a stream was digesting a barking deer. 22
Gabriella Fredriksson scored another fascinating glimpse of big snake natural his-
tory when a 130-pound Borneo retic ate the fifty-one-pound radio-collared sun bear she
was tracking. Having confirmed that her study animal was active one afternoon, the
Dutch conservation biologist located its telemetry signal the next morning in a thicket
a third of a mile away, emanating from the bulging twenty-three-foot serpent. Upon be-
ing poked with a stick the python retreated to a stream, remained there four days, then
moved four hundred feet and took refuge in an enormous hollow log. Twenty-six days
later the python returned to the stream; it was captured a week later and kept captive
until it defecated bear bones, after which the transmitter was surgically removed. 23
Knowledge of the heaviest living snake species also accumulated slowly, through
both random encounters and, more recently, targeted field research. Green anacondas
inhabit savannas and rainforest in the Orinoco and Amazon drainages. Dark spots punc-
tuate the murky tan to dull green skin, such that these huge boas are shockingly ob-
scure in their watery lairs. The head is smaller and more rounded than in pythons, its
outline disrupted by black-bordered orange stripes, and the eyes and nostrils are elev-
ated for lurking beneath the water surface. Green anacondas reach twenty feet in the
llanos of northern South America and likely much longer in Amazonia—one report of a
thirty-seven-footer feels reliable, especially given the recent discovery in Colombia of
a sixty-million-year-old, forty-two-foot fossil relative! 24 And the big gals are undeniably
massive. Male green anacondas usually reach less than ten feet in length, but a twenty-
foot female in prime condition might exceed three hundred pounds, a thirty-foot snake
twice as much. The fossil behemoth, aptly named Titanoboa, would have weighed in at
well over a ton.
Green anacondas like lagoons, swamps, and streams, often basking nearby or hiding
in waterside holes and vegetation. Females deliver twenty to eighty two-foot-long
neonates and devour the birthing debris and stillborn young, thereby recouping energy
and eliminating odors that attract predators. Observations and dissections have re-
vealed an unusually broad diet of fishes, frogs, caiman, turtles, lizards, anteaters, capy-
baras and other rodents, peccaries, deer, foxes, dogs, cattle, diverse birds, and the oc-
casional human. Anecdotes further hint at a rich array of interactions with other anim-
als. A green anaconda in Surinam snatched up a wattled jacana as the sharp-eyed bird
waded over vegetation, 25 and an Internet film clip shows an enormous Brazilian indi-
vidual disgorging a capybara, its jaws astonishingly far apart on the carcass. 26 Black-
chested moustached tamarins in Peru often crossed a lake inlet on fallen trees, until an
anaconda struck from the depths and ate one of the shaggy little critters. 27 For days
the survivors avoided that route, and perhaps their descendants still chirp nervously
around water.
One of my academic younger brothers, Jesús Rivas, obtained a Ph.D. with Gordon
Burghardt studying green anacondas on the seasonally flooded Venezuelan llanos. For
seven years he conducted visual surveys, probed barefoot for submerged snakes, and
followed dozens with radiotelemetry, obtaining data on hundreds of individuals with a
passionate, swashbuckling flair that plays well in wildlife documentaries. Spectacled
caiman, capybara, and white-tailed deer were often eaten, and although herpetolo-
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