Graduate School - Tracks and Shadows: Field Biology as Art - page 55

mimicry while examining coralsnake stomach contents there, he asked, “What if there
doesn't have to be any learning? Maybe they can be models even if their enemies die.”
I'd studied those strange spotted Pliocercus while in the army and seen the likewise
patterned Tuxtla coralsnakes, so Bill and I collaborated on a theoretical paper about
innate recognition of venomous serpents. We imagined a population of predators that
genetically vary in tendencies to attack red and black patterns, with those more likely
to avoid coralsnakes being favored, while their offspring, with no previous experience,
avoid harmless snakes resembling the deadly models. Neither of us had ever had a
manuscript rejected, but American Naturalist and Evolution turned down that one for
lack of supporting data. Our essay was finally published in The Biologist, 16 and later
studies confirmed Jay's idea that predators innately avoid coralsnake patterns, as well
as the central tenets of Wallace's coralsnake mimicry hypothesis. 17
My pleasure proctoring biology labs was inspired by Bill's quiet passion and rigorous
professionalism. He complained about “not much liking this teaching business,” re-
ferred to writing exams as “a dreadful task,” and spoke of having “survived” the chaos
of course registration, but he also mesmerized undergraduates in the natural history
class by imitating a heron, his crooked right arm jabbing at imaginary prey. One day he
passed around a live glass frog, so named because its green bones and beating heart
are visible through the translucent belly skin, and deadpanned, “This one doesn't have
many secrets.” On a field trip he brushed aside concerns about a threatening storm
with “We'll get these kids wet and exhausted hunting salamanders. They'll love it!” He
stretched us grad students, too, into more critical ways of thinking. We read Darwin's
On the Origin of Species for a seminar course, 18 and years later I realized Bill's reti-
cence encouraged shier members of our group to speak out, a lesson that would restrain
my own commentaries as a professor at Berkeley.
Bill's colleague Tom Kennerly, who'd studied gophers with Frank Blair at Austin, also
excelled at field teaching. His attention to trapping and preparing mammal specimens
would have made M.V.Z.'s Grinnell proud, and on class trips he gestured at roadside
habitats from a weaving van as if they were all that mattered. To better appreciate “pi-
oneer organisms,” at a local cemetery we inspected twenty-five tombstones in each of
four age categories. Polished new ones were barren, but on those only a few years old
we encountered lichens, the symbiosis of rock- and bark-dissolving fungi with photosyn-
thetic algae or bacteria. Still older markers had lichen growth as well as moss on their
most favorable corners, and nineteenth-century gravestones, their tops and sides con-
verted to soil, hosted flowering plants within lush coverings of more primitive organ-
isms. Tom had cleverly shown us a century of ecological succession in an afternoon.
For a thesis “defense,” the student presents research and answers questions; then
the professors, if satisfied, formally approve the document. Mine commenced with a
routine summary of results and implications, beginning with an ethogram of twenty-
eight coralsnake behaviors and the experiments on cues controlling headfirst ingestion.
Museum diet samples showed that the feeding biology of one species was fairly constant
from Florida to Texas, despite size-related, seasonal, and geographic variation. Finally,
I'd studied nearly half of the other species as well as their close Asian relatives, and
with few exceptions—one Amazonian species ate fish, another velvet worms—a diet of
snakes and other elongate vertebrates typified the group.