Conscious Choice: Endangered Species Update

August 2000

Endangered Species Update

by Janine Kostecki

Today, in a country large enough for an endless variety of habitats and creatures perfectly adapted to fill them, 961 animals and plants found throughout the United States are officially listed as endangered. Many others are considered threatened or are candidates for the endangered species list. Conservationists blame around 85 percent of these tragedies completely or partially on habitat destruction and degradation. An animal that has spent eons evolving a niche in a particular environment can’t always pack up and move into a suburban subdivision.

One endangered species, the Kirtland’s warbler, is practically a poster child for songbirds in trouble. It is a tail-bobbing, insectivorous wood warbler with a black mask, yellow breast, and a streaked blue-gray back. Kirtland’s will nest in only jack pine stands of at least eighty acres, which are found only in northern Michigan’s lower peninsula. The pines in which they choose to nest must be young, because older pines lose the lower branches that shelter the warblers’ ground nests.

Forest fires keep stands young, burst open cones to release their seeds, and clear ground vegetation that would otherwise complete with the young trees. But fires have been suppressed for their adverse effects on human settlements, and anyway, much of Kirtland’s forests have been logged. Logging (together with livestock, farm fields with waste grain, and suburban lawns with bird feeders) has created open woodlands favorable to the brown-headed cowbird, a parasitical bird that lays its eggs in smaller birds’ nests. Young cowbirds usually out-compete the parents’ own chicks, leading to the death of the chicks whose nest they’ve co-opted. Cowbird parasitism has taken a heavy toll on Kirtland’s warblers and other songbirds.

There is hope, however. The Endangered Species Act authorizes the Fish and Wildlife Service and the United States Forest Service to acquire and manage Kirtland’s habitat. These agencies and the Michigan Department of Natural Resources have done so, and are doing controlled burns and judicious logging with replanting. They are also excluding people from nesting sites (except on special tours), and trapping and removing cowbirds.

Endangered and extremely rare, the piping plover may sometimes be seen in Illinois during its migration to the southeastern Atlantic coast and Gulf of Mexico. The piping plover is a small, washed-out looking shorebird that probes beach sand for insects and small crustaceans. This bird ranges the northern coasts of the Great Lakes, where it is endangered. It is also found along the northern Atlantic coast and on river and lake shores in the northern Great Plains, where it is merely threatened. But different populations of the same species are not equivalent. Each may have special genetic adaptations to its particular region.

The piping plover needs nearly bare stretches of beach on which to nest; it spaces its nests 200 feet apart. But in the Great Lakes region, what’s left of the plover’s nesting habitat often is used recreationally. People frequently, albeit unintentionally, crush nests or scare adults into abandoning their young. Also, manipulation of water levels can either dry out inland plover nests (allowing overgrowth of shoreline vegetation) or flood them out.

Beaches near human settlements also generate yummy garbage, which tips the balance of nature in favor of nest raiders such as rats, raccoons, and gulls. These animals, free from the predators that eat them, harass or eat eggs and young, and, in the case of gulls, take over the nesting spots of less aggressive birds.

Governmental recovery efforts focus on protecting the plover’s habitat from development and recreational destruction, and on educating people to cooperate. Some private landowners in Michigan have agreed not to develop nesting habitats for the piping plover, and certain areas are regularly closed to people during nesting season. The Environmental Defense Fund is suing the Army Corps of Engineers to try to correct shoreline problems. And biologists are also monitoring population trends and studying piping plovers to learn additional ways to protect them.

Similarly beach-dependent is the sea turtle. Most species of sea turtle are threatened or endangered; one that is a focal point for American conservationists is the hawksbill sea turtle. The hawksbill is a smallish turtle with an upper jaw shaped like — you guessed it — a hawk’s bill. Its shell, unfortunately, is the coveted "tortoise shell."

Hawksbills range throughout the warmer oceans and seas. In the United States, they can nest on the shores of Texas, Florida, and some Hawaiian islands. They have also been seen, rarely, as far north as Massachusetts. They have been endangered throughout their range since 1970.

Sea turtles nest on beaches, and any human disturbance can be fatal. Tire ruts or beachfront fortifications can be impassable to hatchlings or mother turtles, and even a quiet nighttime human presence can scare away a female about to lay a clutch. Adding, removing, raking, or compacting sand can be fatal to nests, and light from a nearby development can draw nestlings toward it, thus toward traffic and people.

When surviving hawksbills make it to the sea, they risk getting entangled in nets, colliding with boat propellers, eating floating garbage, or meeting up with oil spills and destruction of their coral reefs. But the single greatest threat to hawksbills, according to the National Marine Fisheries Service, is being killed for their shells, which sell at over $200 per kilogram (or just over two pounds).

Much of hawksbill protection rests on adherence to CITES, the Convention on Trade in Endangered Species treaty, as amended. But not all countries have ratified CITES (which, in any case, has loopholes), and any treaty can be ignored. Other protections include preservation of nesting and ocean habitats, control of nest-raiding animals accidentally introduced in Hawaii, enforcement of anti-poaching and egg-taking laws, and laws requiring turtle-excluding devices to be installed in shrimp nets. Atlantic hawksbill populations are increasing somewhat, and the National Marine Fisheries Service has made progress in implementing recovery programs for Pacific Populations.

People don’t usually think of Illinois as rattlesnake territory, but we do have two species. One is the eastern massasauga rattlesnake, northeastern Illinois’ only poisonous snake. It can be hard to work up sympathy for a deadly animal, but it might help to learn that there has been only one known fatality from this snake, according to Joel Greenberg, author of Natural History of the Chicago Region. An Indiana child happened to be bitten during the Great Depression. The doctor who was called decided that the family could not afford the serum and never administered it, making this case more like death by managed care than death by massasauga rattler.

The massasauga’s small, stocky body is a chocolate-blotched gray to light brown. It gives birth to live young, has chemoreceptors, a heat-sensitive pit, and a working rattle. Most of us will never see this laid back, very private snake; it is a candidate for the endangered species list and flagged as threatened or of concern everywhere in its range, from southern Ontario and the northeastern and upper midwestern United States as far southwest as Missouri.

Massasaugas live in wetlands and travel to nearby dry areas, including savannas, but development and the resulting habitat fragmentation is making this impossible — these snakes literally cannot cross the road. Though massasaugas are not yet protected by the Endangered Species Act, the Fish and Wildlife Service is working to learn more about them and to persuade private landowners to protect their habitat. The agency also is trying to teach people not to murder them just for being snakes.

Also beneficial but hated and feared, many species of bats are endangered, mostly because of habitat destruction and contamination or reduced populations of their food, which is flying insects. Bats generally roost and breed in caves (some will use shelters), but they do not find just any cave acceptable. Temperature, humidity, proximity to feeding areas, and absence of predators must all be near perfect, and bats won’t tolerate much deviation. Vandalism or disturbance of their caves can cost bats dearly. If disturbed, even by someone walking into a cave, bats awakened from hibernation may use up part of their fat reserves attempting to mate, or mother bats may drop their young (never to retrieve them ). After repeated intrustions, a colony might eventually abandon an otherwise acceptable cave.

Bat protection focuses mainly on protecting caves. Many cave entrances have already been purchased by the Fish and Wildlife Service and gated. Conservationists are also educating recreational cave users not to disturb bats. These efforts are reversing population declines for the gray bat, which is the largest eastern U.S. bat and is found in the southeastern United States and parts of Illinois, Kansas, and Oklahoma. The Virginia big-eared bat of Virginia, West Virginia, Kentucky, and North Carolina, is doing better. The Ozark big-eared bat has disappeared from Missouri, but it is doing well in Arkansas and has a wildlife refuge in Oklahoma.

The Indiana bat, however, is not faring well. It ranges further north than the other eastern U.S. bats here, needs riverside forests for feeding, and hibernates in large colonies rather than migrating. Many of their hibernating caves have disappeared, and large colonies of hibernating bats are vulnerable to cave tampering. The Fish and Wildlife Service calls the Indiana bat "nearly extinct," though it has not given up on the animal. The agency has gated some of the bat’s caves, and it may find a reprieve in the fact that this bat will use other shelters such as trees and bridges.

Also cave-dependent is the Illinois cave amphipod, a pale, almost ghostly, delicate blue-gray crustacean less than an inch long. The amphipod feeds on bacteria and decaying matter in dark, cold cave waters, and is very sensitive to light, disturbance, or pollution — so sensitive that it is like the canary in the coal mine. Its decline can alert scientists to water contamination problems. Unfortunately, all three of its caves (down from six) are close to the growing St. Louis area, and the ground waters that feed the cave streams are being polluted by pesticides as well as human and animal sewage. Protection under the Endangered Species Act and the Illinois near-equivalent allows the agencies to preserve the integrity of the amphipod’s habitat and prohibits direct harm to the creature itself. Parts of one cave are protected as a nature preserve, but the other two caves are still open to the public.

Some insects also are endangered. One is the Karner blue butterfly, which is about the size of an Illinois cave amphipod and a lot more colorful. The male is mostly blue, with black and white edges. The females, which are not always blue, have orange-crescent edges. The Karner has been extirpated from many states and from Ontario, Canada (where naturalists are working to reintroduce it). Today, it is found mostly in small, isolated populations in New Hampshire, New York, Indiana, Michigan, Wisconsin, and Minnesota. Karner caterpillars will feed on only wild lupine, an oak savanna and pine barren plant that depends on burning to clear the woody plants that would otherwise shade it.

Saving Karners is a no-brainer. It means saving wild lupines. Fires are usually suppressed on the few savannas and barrens that haven’t been developed, but some land managers are now doing controlled burns and using other clearing methods. The Fish and Wildlife Service, as well as state and local governments, private individuals and institutions, and conservation groups such as The Nature Conservancy are active in preserving and managing rare wild lupine habitat, and in making sure that land set aside for other purposes is managed for Karners as well. Already, savannas have been preserved in many different northeastern and upper midwestern states.

Much of the protection for endangered species in the United States is through anti-pollution laws, habitat preservation, and the Endangered Species Act, which prohibits killing or otherwise harming, possessing, or trading in listed species, and authorizes the United States Fish and Wildlife Service to acquire and manage habitat and to carry out recovery plans for individual species. But the Endangered Species Act is just a law. It doesn’t execute or fund itself. Even the Fish and Wildlife Service admits that there are many, many more United States species of animals and plants actually in danger of becoming extinct than are officially listed under the Endangered Species Act.

Getting a species listed is slow, mired in politics and bureaucracy, and often comes too little and too late. In order to get notice, and possible protection, a population’s numbers may have to drop perilously low. And getting listed may not do any good. Many designated species are still declining, partly because an increasing number of listed species are chasing a much more slowly growing amount of money allotted for their rescue. Much of that money tends to be spent on a few "sexy" high-visibility creatures.

In any case, the Endangered Species Act cannot alter global factors, force people to live sustainably, get politicians to ignore their personal bottom lines, or effectively compel private landowners to put endangered species over personal profits (although the Fish and Wildlife Service and some non-profit groups are trying to sweeten the pot with incentives for individuals who preserve or restore habitat).

Perhaps there are enough of us who will fight against living in a world without wildlife, and for whom even one extinction more is too many. Chaos theory teaches that, over time, small alterations multiply into huge change; that the flapping of a butterfly’s wings at one end of the world can significantly affect the weather at the other. What if that butterfly never again flapped its wings because it had become extinct? This planet and its ecology are so complex and bound in interrelationships that we might never know the answer. It’s clear, however, that we’re taking a risk: if we don’t stop pulling threads out of the web of life — and soon — we may find ourselves falling through it.

Resources

The Condor’s Shadow: the Loss and Recovery of Wildlife in America, by David S. Wilcove, New York: W.H. Freeman and Company, 1999

United States Fish and Wildlife Service

National Marine Fisheries Service, Office of Protected Resources

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