The Stockton Record
November 12, 1998

MANTECAN INVENTIVE BY NATURE
Gadgeteer's creations key to wildlife studies

The Miniature Optical Lair Explorer, otherwise known as the MOLE, can creep
underground like a tiny tank and videotape burrowing owls, kit foxes or
badgers while they sleep.

The postage-stamp-sized camera on the tip of the TreeTop can squeeze into a
space only 1.2 inches wide--perfect for getting into the cavities
woodpeckers dig out of trees.

These are the inventions of longtime Manteca resident John Christensen, who
after a dozen years in the Navy and 15 years as an engineer for Lawrence
Livermore National Laboratory has propelled himself toward a custom-built
career tinkering with toys to invent research equipment for wildlife
biologists.

"I love the environment, and I love working with these researchers,"
Christensen said.  "What I tell people is, 'How would you like your
children or grandchildren to have to live in a planet that's paved over,
with no breathable air?' "

Christensen and his wife Ann founded Christensen Designs in 1989 and [began
marketing environmental monitoring inventions in 1994].

One of them is the MOLE [descendent Theseus Tethered Exploration Device
(TED)], a battery-powered, 5-inch-long video robot that resembles a tank
whose turret houses a near-infrared video camera.  [The MOLE was partially
constructed with parts from a toy store, and Theseus is machined from
Delryn.]  Both devices are hooked up to a cable and guided by a
remote-control device deep into the dens of burrowing animals.

The freelancer has marketed camera-mounted poles that can reach high enough
to view red-cockaded woodpecker colonies, and a head-mounted television
monitor that allows researchers hands-free operation as they guide probes
into animals' underground homes.

He built a PicoCam, a miniature video camera designed for wildlife
surveillance.

The 1.5-inch-wide, waterproof cube weighs less than 2 ounces and can
capture images of the most minute details.

The mounting system consists of an assortment of simple, rugged mounting
tools allowing the camera to be mounted in virtually any location.

Karen Brown an environmental specialist with the Department of Water
Resources, has worked with Christensen's Peeper design (which is similar to
the MOLE, but smaller) for about five years.

She said she needed up to five days to study movement, tracks or droppings
near burrows, which can easily collapse, before she started using the
device.

Brown learned of the Peeper while she was monitoring about 300 burrows
along the California Aqueduct in the lower San Joaquin Valley.

The invention, she said, cut her filed time by two-thirds.  And she
accomplished her mission: to confirm there were no kit foxes inhabiting the
burrows, so maintenance on the embankments could go forward.

"He's pretty much the only one doing this on this scale," Brown said.  "I
know people who have invented one product, but to have somebody actually
doing it and (who) is willing to customize their product to fit your needs,
it's great."

Christensen, 52, is working on designs he hopes will be available for 1999.
One of them is a vocalization system for dolphins.

He said the project is being driven by a researcher in Hawaii who needs a
system that can record the large range of pitches made by dolphins that are
not audible to the human ear.

The only system currently available, Christensen said, automatically
translates the pitches to make them audible to humans.  But the researcher
wants the sounds recorded without any changes to avoid losing messages in
the translation.

Christensen also wants to manufacture binocular night-vision equipment and
expand the field of view to include peripheral vision.

The only night-vision equipment now available is monocular, he said.

Developing objects to help study birds is another project.  Christensen is
working as a contractor for the Lawrence Livermore Lab to fit a camera at
the apex of a nesting box the lab plans to place on tope of a power pole at
its Site 300, near the Altamont Pass.  Christensen said a pair of mating
golden eagles keeps perching on the wires, risking electrocution.  The
laboratory wants to give them a new home--and study them if they choose to
nest.

"We don't know if it will work.  It's just a hope," he said.

The Christensens won't say how much money they're making on the inventions,
but some devices featured in their company's catalog range from $1,950 to
$6,750.  Christensen says he doesn't want to become a large-scale
manufacturer.

"I don't want to be Hewlett-Packard.  If I find a market of 100, that's a
big deal," he said.

Written by staff reporter Roxanne Stites
Copyright The Stockton Record 1998

[Brackets indicate where corrections to the original article were made.]

Submitted 12/1/98