Biologists Follow the Path Less Traveled (cont'd)
is a fine art to handling tiger sharks. Lethal at either
end, they can kill or maim with a crunch of their jaws
or a flip of their tail. Yet when Mike Heithaus lies
awake at night, it isn't the hazards of handling the
sharks that steal his sleep.
marine biologist, Heithaus has learned that a little
care goes a long way. Tiger sharks can be dangerous.
But their preference in meat leans toward sea turtles
and other marine life, not man. The big danger is that
a shark, which may weigh half
a ton and run 18 feet long, will thrash while in tow
alongside his outboard.
does keep Heithaus awake are the mysterious journeys
of the creatures of Shark Bay, a pristine stretch off
Australia's western coast. Sharks are the major player
in that aquatic ecosystem, but sea snakes, manatee-like
dugongs, green and loggerhead turtles, and dolphins
also cruise the waters.
a doctoral student at Canada's Simon Frazer University,
Heithaus' research challenges are in part demographic:
he wants to know where sea life congregates and in what
numbers. But it isn't enough just to count the creatures.
A simple census won't solve the deeper mystery of what
drives the sea life to come and go--a complex formula
that includes food supplies and the weather. It's like
asking why people cluster in New York, but not in rural
Ohio. There may be hundreds of reasons.
has a working theory. He figures sea life operates
much as we do. "Animal behavior models borrow incredibly
from economics," he says. "People make decisions almost
exactly the way that animals do. For years people
have done economic models of how to maximize money-making
ability. In animals that often translates into finding
also the risk factor, where sea life again acts like
humans. "Often the animals that go into high-risk
habitats are close to starving," says Heithaus. "If
you've got no money and can barely put food on the
table, you're a lot more likely to go out and do something
simple enough. But in Shark Bay, as elsewhere, the
devil is in the details. "The central goal of my work
is to find out why animals are distributed the way
they are," he says. Since Shark Bay is a system in
which the main characters come and go, the question
isn't easily answered. Sometimes, for instance, the
sharks are there, sometimes they aren't. Where they
go, no one knows. "For all we know, some are swimming
to Indonesia or over to Africa," says Heithaus. Nor
does anyone know how sharks find their way back. One
theory holds that they are able to navigate by sensing
slight changes in the Earth's magnetic field, much
as we find our way by recognizing landmarks.
started out asking why the dolphins are where they
are," says Heithaus. "To do that you have to look
at both food supplies and predators, such as the tiger
sharks. But the sharks don't often eat dolphins. So
why are the tiger sharks there?"
answer nature's deeper questions, Heithaus has mounted
the aquamarine equivalent of a long police stake-out--one
that will last for years.
He is aided by the latest high-tech gadgets, including
seaworthy camcorders called Crittercams that are clamped
on the dorsal fins of sharks. The camcorders were
developed by the National Geographical Society, which
featured Heithaus' Shark Bay research on its "Explorer"
television show this spring.
was the starting point for the training that is helping
Heithaus unravel the life of Shark Bay, particularly
Professor Roger Laushman and other mentors in the
biology department. Four years of swimming under coach
Dick Michaels taught teamwork and endurance, with
practices at 7:30 a.m. and 4:30 p.m.--classes and
weight-training were sandwiched in-between.
gives you the discipline to work to exhaustion and
then keep working," says Heithaus, who won multiple
All-American honors. And although he doesn't remember
when exactly he decided upon his life work, he predicts
that it was well before he could walk. "All my life
I have been around the water, be it swimming competitively,
poking around a local stream or fishing on the ocean,
and I have never considered doing anything else. My
mother has said she thinks that it all started when
I caught a fish in my diaper when I was about 1 year
best part of his job, he says, is working with fascinating
animals in such an amazing place. "I get to wake up,
roll out of bed, walk to the beach, and decide whether
I'm going to spend the day watching dolphins, catching
tiger sharks, or jumping off the boat to catch turtles.
I can't believe I get paid to do this! Of course,
there is also a lot of satisfaction in figuring out
how things work--it's a lot like finally finishing
a huge puzzle."
he says, usually ask about the adventure surrounding
his work. "People have sometimes described what I
do as an extreme sport." Indeed, dangers abound. A
300-pound loggerhead turtle can snip off a finger
with ease. The sea snake, usually quite docile, is
among the most lethal creatures on earth if it bites.
And sharks are sharks. Though they usually are calm
when Heithaus and his crew fit them with camcorders,
he finds it never hurts to play it safe with creatures
that can tear your arm off.
Heithaus isn't in it for an adrenaline high. He wants
to find out how things work, a tall order in a field
where the answer to one question may open a can of worms.
"Really, what makes science work is curiosity and caution,"
he says. "Every time you get an answer, dozens of other
questions crop up."
everyone has come across one of those curious volumes
of bird paintings--each portrait so studied, so detailed,
so carefully posed that it would seem that the feathered
subjects willingly sat through a series of portrait
sessions. If you pause for a moment, you might wonder
who paints them. How do they get the birds to sit
still? Or you might ask why anybody bothers. After
all, a photograph should do just as well.
answers, we turned to Kristin Williams. She has been
at it for 18 years, often perched on catwalks just
under the glass dome of the National Aviary in Pittsburgh,
where she's been dubbed the "spider woman" for her
nimble work 30 feet above the ground. She says the
pay is often low and the work can be hazardous and
endlessly frustrating, thanks to the birds, who don't
sit still unless they have been stuffed or preserved
in a jar of alcohol.
been pecked, dive-bombed and attacked," says Williams.
"I've been approached by curious hummingbirds eager
to sample the cadmium red on my palette. I've had
paint tubes punctured and water containers upset.
Pencils and paint brushes have a way of vanishing.
Occasionally, the paintings themselves become the
objects of bird assaults. One painting was torn from
my grasp by an aggressive curassow and flung into
a fountain. One particularly annoying bird named Igor
ran across my wet palette and then across my painting,
leaving behind a trail of multicolored footprints."
are the things that happen on a good day. At least
she has a live bird to paint. But more often than
not, she must turn to the strange world of specimens,
stuffed birds found in the collections of natural
history museums, or dead birds floating in a jar of
preservative. Then her job gets really challenging.
The colors are often misleadingly dark in the pickled
birds, and the stuffed birds may have been misshapen
during the preservation process. For example, the
tail may have been pushed in, which could lead an
illustrator to think that the tail is shorter than
it really is.
Williams uses both, hoping the stuffed sample will
get the colors right, while the pickled birds will
be properly proportioned. She also uses photographs,
videotaped segments from televised nature programs,
or videos she has taken herself. But why bother to
paint anything? Why not rely on photos if you need
photographs are usually not as accurate as professional
portraits. Wildlife photographers operate on a catch-as-catch-can
basis, snapping pictures of birds in the wild.
photographers only capture the birds at odd angles
or in poor lighting before the bird disappears into
the brush, not to be seen again. "You're the slave
of the moment with photographs," says Williams.
bird watchers had to rely solely on photos to identify
birds, they might make the wrong identification. A
carefully posed painting can get everything right--the
colors, the proportions, and the facial and body features.
A painting can emphasize small features that are crucial
to identification, such as subtle markings that might
not show up in a photo. And that's the point. Without
accurate pictures, there would be no accurate bird
counts. Without accurate bird counts, scientists can't
determine whether a species is thriving or vanishing
from the earth. In other words, those curious books
of bird portraits underpin much of the science of
entered her profession with a degree in biology and
scant wildlife art training. That's to be expected.
"My field is so odd," she says. "It's not like people
go to school in ornithological illustration." But
she was at loose ends after leaving Oberlin. She had
no idea what to do with her biology degree. With time
on her hands, she volunteered at the National Aviary,
a facility that had a first-rate collection of live
birds but a second-rate system to help visitors identify
what they were seeing. Williams began creating 5-by-8-inch
portrait identification labels, a task that soon turned
into a paying job that stretched over ten years as
the aviary found funds to pay her. The aviary work
led to work on two portrait anthologies--birds of
the West Indies, and birds of Missouri, the latter
venture still under way. Her next project will deal
with birds of the Midwest.
not an easy way to make a living. In the tradition of
artists through the ages, Williams lives from job to
job, from commission to commission. But as the years
pass, she has compiled a body of work that will help
scientists determine whether our planet's bird life
is flourishing or going the way of the dodo. And that
serves the same purpose as canaries in a coal mine.
If the birds perish, the rest of us won't be far behind.
MCINNIS is a freelance science writer. His articles
have appeared in The New York Times, Popular Science,
New Scientist, and other publications.