Return of the species



1. Wolves. Endangered?
2. Wolves on the rebound
3. History of extermination
4. Midwestern wolves

5. Causes of extinction
6. Trumpeter swan sings
Wisdom of reintroductions
8. Helping the plants
9. Moving the plants

10. Genetics movement
11.House flies!











Giant white birds with black feathers at wing tips and black faces, legs hanging beneath them.
Whooping cranes swooping over a marsh.
Fish & Wildlife Service

  If you lead a horse to water,
will it know how to drink?

A tall white crane with a red beak struts in front of Armstrong, who holds a yellow plastic brush ready for protection.
Long ago, this whooping crane "imprinted" on human handlers, so he will not enter breeding condition unless a human engages in this mating dance. George Archibald, director of the International Crane Foundation, is a master of this peculiar dance. This being Wisconsin, his protection against the big bird is a -- dairy pail brush.
© David Tenenbaum

You can't generally take a captive-bred animal to the wilderness and tell it to get lost. Here are some ways that biologists teach wild animals to be wild. There's much more here.

The International Crane Foundation (Baraboo, Wis.) has raised all 15 species of cranes in captivity, using a technique that avoids human contact. Crane chicks "imprint" on whoever cares for them in their first days of life, and they seek that species for a mate. If Siberian cranes and whooping cranes which are destined for reintroduction to the wild imprint on a human, that's a major problem. See our major 2009 update on whooping crane reintroductions.

California condor
The huge California condor, a vulture with a nine-foot wingspan, benefited from a long, expensive recovery effort that started releasing captive-bred birds in 1992 As of 1999, 49 birds were alive in the wild, of a total population of 161.

The bird went extinct in the wild in 1987, largely due to habitat loss and poisoning from lead shot in the carrion it eats. Lead shot was banned from waterfowl ammo in 1991 (although not from ammo used for deer hunting). To face other problems, the birds got some remedial education:

Condors often perch their 20-pound bodies on electric towers, and a clumsy takeoff can lead to a deadly crash with a power line. To teach the condors to find more suitable perches, biologists ran a small current through phony towers in the rearing area; the giant scavengers soon associated electric towers with a nasty jolt.

To teach the birds to fear people, humans acted like loud, drunken undergraduates, and sometimes briefly captured the birds.

"Return of the Condor" (see bibliography) says the birds were reared --- with mixed success -- using the "anti-imprinting" technique first used with cranes.

The wolves introduced to Yellowstone underwent a little "re-education" of their own. After being captured in Canada and shipped to the Yellowstone area, they are placed in large pens for a couple of months. The goal? To break the animals' homing instinct, which would otherwise cause them to truck on back to Canada.

The wisdom of reintroductions
Species reintroductions are not a perfect solution to a vanishing speciesSpecies reintroductions may be impressive, but they are hardly a perfect answer to the problem of vanishing species. For one thing, large, attractive animals attract the big restoration money; reptiles, invertebrates or plants get far less attention.

Since each reintroduction takes so much work, the technique will never become a universal tool for reviving damaged ecosystems. Instead, ecologists say, preserving and restoring habitat is more appropriate for broad-scale preservation of species.
The dispute over how to preserve species often relies on lingo "in situ" versus "ex situ" conservation. To decode the Latin, "in situ" means saving species in their existing locations, while "ex situ" conservation occurs in seed banks, zoos and botanical gardens. Both techniques have their uses, but in the last analysis, most scientists favor conserving habitat rather than individual species.

Peter Bryant, a biology professor at University of California, Irvine, said habitat restoration is an elementary step in sustaining endangered plants and animals. "Most endangered species are in trouble because their habitat has been fragmented, destroyed or degraded, so the first requirement is to get some patches back in decent shape."

Three wolves, two gray, one black, romping. Black wolf is nipping the back of one gray wolf, which is lunging toward the third wolf.
Wolves playing in ankle-deep snow. Look mom! No mittens!
Courtesy The Searching Wolf

The Nature Conservancy is a major advocate of habitat preservation. "My personal view, and that of the Nature Conservancy, is that in situ conservation is what we should be striving for," says Bruce Stein, a scientist who worked at the Conservancy and now works for Association for Biodiversity Information. "Ex situ has a role, but it can lead people to become complacent. ... The goal of any ex situ conservation program has to be getting a population re-established in the wild."

Similarly, professor of conservation biology Donald Waller, at the University of Wisconsin-Madison, says he's a "bit more cynical" about reintroduction programs. He suggests that there's little biological justification for spending so much money to save lovable, showy critters like wolves while shortchanging the promiscuous Stephens' kangaroo rat or Florida's four-petal pawpaw.

Not so easy
Another factor is the simple difficulty of replicating nature, Waller adds. "A lot of plants -- like animals -- are fussy about habitat and culture conditions." Plants may parasitize other plants, require that a certain fungus grow on their roots, or be pollinated by a rare bat or moth. These conditions aren't always known, and even if they are, they are difficult to reproduce in captivity and after the plant is reintroduced in the wild.

Often, the argument over preserving individuals or ecosystems is moot. If a species is extinct in the wild, there's little choice but to work with what's left in captivity. Finally, restored habitats may attract species thought to be locally extinct, turning ecological restoration into a method for reintroducing species.

Animals aren't the only organisms that need help. What about plants?

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