Cape Vulture

Description and biology

The Cape vulture, also called the Cape griffon, is an Old World vulture that belongs to the same family as hawks and eagles. It has a long, bare neck and a specially shaped tongue that allows it to feed inside the carcasses (dead bodies) of sheep, cattle, pigs, goats, and horses. The bird roosts (rests or sleeps) with other vultures in colonies on cliffs.

Unlike most birds of prey, the Cape vulture does not use thermals (rising warm air currents) to fly. Instead, it uses the swift air currents that exist around its roosting sites. The vulture used to eat the carcasses of large migratory mammals. Now, it must depend on dead livestock for food.

Cape vultures begin to build their nests in early March. The nests are made of grass with a rim of feathers and sticks. They are usually built on south–facing cliffs that have ledges. Once constructed, the nests are often used for several years.

A female Cape vulture lays a clutch (eggs produced at one time) of only one egg between April and July. Once the chick hatches, it is fed the meat and, sometimes, bones from animal carcasses. Both eggs and newborn chicks face several natural threats. Clouds that settle on south–facing cliffs can often cause them to freeze to death. They also are preyed upon by black eagles and white–necked ravens.

Habitat and current distribution

The Cape vulture is found only in the southern African countries of South Africa, Lesotho, Swaziland, Botswana, Namibia, Zimbabwe, and Mozambique. It breeds primarily in two areas. An estimated 2,300 breeding pairs are found in Transvaal (northeastern province in South Africa) and in eastern Botswana.

Another group of about 950 breeding pairs are located in the Transkei (self–governing republic in South Africa), Natal (eastern province in South Africa) and Lesotho.

Because Cape vultures generally live and forage for food away from their breeding areas, their range extends almost over all of southern Africa. Biologists (people who study living organisms) have estimated that about 12,000 Cape vultures currently exist. The birds prefer to inhabit open spaces. They forage over grassland, desert, and other areas with sparse vegetation.

History and conservation measures

In the nineteenth century, the Cape vulture was seen in high numbers in southern Africa. It began to decline in the early twentieth century, though, when a disease wiped out many cattle in the region, robbing the bird of its food source. A drop in the number of cattle due to disease and other factors between the years 1950 and 1971 again hurt the Cape vulture population.

Today, the main threat facing the Cape vulture is not food quantity but food quality. Cape vulture chicks require calcium in their diets to prevent osteodystrophy (pronounced os–tee–o–DIS–trow–fee), a disease that causes their bones to become weak and deformed. When large mammals kill and feed upon animals, they often crush their bones in the process.

Vultures then feed on the remaining carcass, and the chicks are fed meat that has bone flakes (calcium) mixed in it. Since the number of large mammals in southern Africa has declined, however, vulture chicks have suffered because they have not been able to eat enough meat mixed with bone flakes.

Cape vultures are also threatened by humans who disturb their breeding grounds and who poison them. Many farmers and ranchers in the bird’s range believe it attacks sheep and then transmits to other animals any disease the sheep might carry. To prevent this, these farmers and ranchers often put out poisoned carcasses for the vultures to feed on, and the birds die as a result.

The belief that Cape vultures normally attack sheep and spread disease is a mistaken one. Conservation groups in southern Africa have tried to stop farmers and ranchers from leaving poisoned carcasses for the birds.

Conservationists (people protecting the natural world) have also set up areas where carcasses with crushed bones have been put out for the vultures. This practice has helped reduce the number of vulture chicks suffering from osteodystrophy. The Cape vulture has full legal protection throughout its range.

Kirtland’s Warbler

Description and biology

The Kirtland’s warbler is a songbird that grows to an average length of 6 inches (15 centimeters). It has a blue–gray head and upper body with black streaks on its back. Its underside is pale yellow speckled with darker streaks. Males have a black spot on their cheeks while females have a gray one.

Both sexes have incomplete white rings around their eyes. The Kirtland’s warbler has a habit of bobbing its tail as it moves along the ground. The bird has been seen feeding on moths, caterpillars, ants, and numerous other insects.

The Kirtland’s warbler nests and breeds in a very specific habitat. It rejects areas that have dense underbrush or forests that are dominated by deciduous (shedding) trees. It chooses only areas at least 80 acres (32 hectares) in size with large stands of young jack pine on relatively level ground. These areas develop naturally only as a result of intense forest fires.

The warbler moves into the area 9 to 13 years after a fire has swept through and the new jack pines are about 5 feet (1.5 meters) tall. After 6 to 12 years, when the pines have reached 12 to 18 feet (3.6 to 5.5 meters) in height, the warbler abandons the area for a new one.

The warbler builds a nest of grass, bark, and fibers on the ground beneath a jack pine. A female Kirtland’s warbler lays 3 to 5 brown–speckled white eggs between mid–May and mid–July. She then incubates (sits on or broods) them for 10 to 14 days until they hatch.

Habitat and current distribution

The Kirtland’s warbler breeds only in a few counties in the area of north–central Michigan’s lower peninsula where extensive stands of young jack pine are found. Beginning in late September, the bird migrates to the Bahamas and the Turks and Caicos Islands located at the southeast end of the Bahamas. Its winter habitat consists mainly of pine woods. The warbler returns to its summer habitat in early May.

During the summer, a few Kirtland’s warblers may range to Wisconsin, Minnesota, and even Ontario or Quebec, Canada. However, they do not nest in these areas. Biologists (people who study living organisms) estimate that over 1,400 Kirtland’s warblers currently exist in the world.

History and conservation measures

The Kirtland’s warbler was first discovered in the Bahamas in 1841, but its nesting grounds in Michigan were not discovered until 1903. These were found near the Au Sable River at the border of Oscoda and Crawford Counties. Roughly 90 percent of the warbler’s current nesting grounds are found within a three–county vicinity of these original grounds.

Because of its finicky nesting habits, the Kirtland’s warbler probably never existed in great numbers. At the beginning of the twentieth century, extensive logging in Michigan reduced the bird’s already meager habitat. Then, officials who oversaw the way forests were managed in the state limited the number of forest fires.

As a result, forests grew and developed beyond the specific needs of the warbler. In the 1950s and 1960s, 15,000 acres (6,000 hectares) of suitable warbler nesting habitat existed. Today, only 30 percent, or 4,500 acres (1,800 hectares), exists.

The Kirtland’s warbler has also been threatened by the brown–headed cowbird. This bird normally inhabits farmland and meadowland. As forests have been cleared in Michigan, it has expanded its range into that of the Kirtland’s warbler.

The brown–headed cowbird likes to lay its eggs in the nests of other birds, including the warbler. This behavior is called parasitism (pronounced pair–a–si–TIZ–um). When the cowbird nestlings hatch, they are raised by the new parents.

The parents’ own nestlings often cannot compete with the cowbird nestlings for food, and they starve to death. From the 1930s to the 1970s, as many as 60 percent of warbler nests were believed to be parasitized by the cowbird.

The Kirtland’s warbler made a comeback in the 1990s. Conservationists and public land managers have worked to maintain and develop suitable nesting habitat for the bird in Michigan. They have also tried to control the brown–headed cowbird population within the range of the Kirtland’s warbler.

Ivory-billed Woodpecker

Description and biology

The ivory–billed woodpecker is the largest North American woodpecker. It measures from 18 to 20 inches (46 to 51 centimeters) long. The color of the plumage (covering of feathers) on its body is a shiny blue–black.

Broad white markings appear on its wings and neck. Its strong, straight, heavy bill is pure white. Males of the species have a bright red crest (projecting tuft on top of its head); females have a black one. The bird has short legs and feet that end in large, curved claws.

The ivory–billed woodpecker uses its bill to strip bark from dead or dying trees in search of wood–boring beetle larvae and other insects. Male–female pairs occupy a large territory of up to 4,000 acres (1,600 hectares).

Breeding season lasts from March to June. The woodpecker creates a nest by boring out a hole high up in a tree. The female ivory–billed woodpecker then lays a clutch (eggs produced at one time) of 3 to 5 glossy white eggs in the unlined hole.

Both parents incubate (sit on or brood) the eggs for about 20 days. The nestlings fledge (develop flying feathers) about 35 days after hatching.

Habitat and current distribution

Many biologists (people who study living organisms) consider the ivory–billed woodpecker to be extinct, or almost extinct. Up until the early 1990s, they believed that a few of the woodpeckers still survived in eastern Cuba.

There had been unconfirmed sightings of the bird along the Gulf Coast of North America from the 1950s through the 1970s. These “sightings” led biologists to believe at the time that the bird might still survive in remote forests in Louisiana, South Carolina, Mississippi, Georgia, or Florida.

In the 1990s, biologists had lost hope that the bird existed anywhere, but in April 1999, a student saw what many believe was a couple of ivory–billed woodpeckers on the Pearl River in Louisiana. There were other credible, but unconfirmed, sightings after that.

In the United States, the woodpecker inhabits hardwood swamp forests and, on occasion, pine forests. In Cuba, it occupies mixed pine and hardwood forests.

History and conservation measures

The ivory–billed woodpecker was always considered rare throughout its range in the United States. At the end of the nineteenth century, the logging and clearing of virgin swamp forests in the southern United States decimated the remaining population of these woodpeckers. Hunters and trappers also quickened the bird’s decline. By 1941, the ivory–billed woodpecker population was estimated at 24 birds in five scattered areas.

Just seven years later, the last identified population disappeared. Over the next 30 years, reports were made that the bird had been sighted. However, none of these were ever confirmed. No reports had been made in the 20 years leading up to 1999.

In Cuba, the ivory–billed woodpecker was thought to have existed over much of the island. By 1956, due to the clearing of its natural habitat, the bird’s Cuban population numbered only about 12. These birds disappeared shortly afterward, and the woodpecker was believed to have become extinct on the island.

In 1986, however, Cuban biologists working in eastern Cuba found three woodpeckers in a hilly pine forest called Ojito de Agua. Hopes were raised that the birds could make a comeback, but expeditions to find these birds in 1991 and 1993 proved futile.

In 1996, the ivory–billed woodpecker was declared extinct by the International Union for the Conservation of Nature and Natural Resources (IUCN). In 1999, with several new sightings of the bird in southeastern Louisiana, a flurry of research and then extensive searches were conducted in the Pearl River area in 2000 and 2001.

In 2002, Cornell University’s Lab of Ornithology (study of birds) in cooperation with Zeiss Sports Optics and the Louisiana Department of Wildlife and Fisheries used high–tech recording equipment to record the sounds at twelve different positions within the remote forest area for a period of three months.

The project turned up no indication of the ivory–billed woodpecker’s presence. The IUCN changed the bird’s status to critically endangered, in the hope that there are a few remaining birds in the wild.

Red-cockaded Woodpecker

Description and biology

The red–cockaded woodpecker is so–named because the male of the species has tiny red patches or “cockades” on the sides of his head (a cockade is an ornament worn on a hat as a badge). Female red–cockaded woodpeckers lack these patches.

An average red–cockaded woodpecker measures 7 inches (18 centimeters) long and has a wingspan of 15 inches (38 centimeters). The plumage (covering of feathers) on the bird’s upperparts is black with white stripes.

Its chest and belly are white with black–flecked sides. The bird has a black crown and prominent black bands that start at its bill and run down both sides of its neck. On each cheek, between the band and the bird’s crown, is a large white patch.

The red–cockaded woodpecker feeds on insects (ants, beetles, caterpillars, roaches, and spiders) both on and below tree bark. It also eats fruits, berries, and seeds. The bird nests in groups called clans.

These clans consist of a male–female pair, their fledglings (young that have just developed flying feathers), and their young male offspring from previous years called “helpers.” Clans forage or feed over territories of approximately 200 acres (40 to 80 hectares).

This bird is the only woodpecker that bores out a nesting hole with its sharp, chisellike bill in live, mature pine trees (other woodpeckers create holes in dead or dying trees).

A female red–cockaded woodpecker lays a clutch of two to five white eggs in the nesting hole in April or May. The helpers assist their parents in incubating (sitting on or brooding) the eggs for about ten days. They then assist in raising the nestlings.

Habitat and current distribution

The red–cockaded woodpecker is found in the southeastern United States from Texas and from Oklahoma east to the southern Atlantic Coast. The largest concentrations of birds are located in Florida and South Carolina. Biologists (people who study living organisms) estimate the total red–cockaded woodpecker population to be between 10,000 and 14,000 birds.

These woodpeckers prefer to inhabit old–growth pine forests, mainly those with long–needled pines averaging 80 to 120 years old. These types of forests usually have very little underbrush.

History and conservation measures

The red–cockaded woodpecker was once abundant throughout a range that stretched as far north as Missouri, Kentucky, and Virginia. At the beginning of the twentieth century, however, the bird’s population began to decline and its range began to shrink.

The main reason was habitat loss. Mature pine forests were rapidly cleared to create farmland or cut down to supply the increased demand for timber. If new trees were planted in these areas, they were not the long–needled pines favored by the red–cockaded woodpecker, but faster–growing hardwood trees. Over the last 100 years, 90 percent of the bird’s habitat in the southeast has been cleared.

Most of the remaining forested pine areas suitable for the woodpeckers are on federal lands and are, therefore, protected. In other areas, foresters and wildlife specialists are trying to increase the amount of red–cockaded woodpecker habitat by burning underbrush and small trees, leaving only old pines standing.

In 1993, the Georgia–Pacific Company (a timber company) signed an agreement with the U.S. Fish and Wildlife Service to help protect the woodpecker on thousands of acres of company land.

Two more timber companies, Hancock Timber Resource Group and Champion International Corporation, have since signed similar agreements to protect the red–cockaded woodpecker on their lands.

Illinois Cave Amphipod

Description and biology

The Illinois cave amphipod is a small freshwater crustacean. It is light blue–gray in color, with small eyes and one long and one shorter antenna. A male Illinois cave amphipod is usually about .8 inch (20 millimeters) long and a female about .5 to .6 inches (12 to 16 millimeters) long.

Illinois cave amphipods live in utter darkness in cave streams. They need very cold water and avoid light. They cannot leave their caves, so they will eat any kind of food matter they can find by means of their keen sense of touch, including dead animals, plants, and bacteria.

Illinois cave amphipods are extremely sensitive to pollutants that are introduced into their water supply. The species is an excellent indicator of the quality of the water in the cave systems it inhabits and the groundwater from the surrounding area.

Because they live underground and away from humans, little is known about the behavior of this species.

Habitat and current distribution

The Illinois cave amphipod lives in karst regions (areas composed of limestone that feature sinkholes, underground streams, and caverns). It is known to occur only in Monroe and St. Clair counties in southwestern Illinois.

History and conservation measures

The Illinois cave amphipod is endemic (native to and occurring only in a particular region) to several cave systems in Monroe and St. Clair counties in southern Illinois.

The species was once known to occur in six cave systems, all within a 10–mile radius of Waterloo, Illinois. In 1995, the species was found in only three of these systems, all in Monroe County. This reduction in its range signals a decline in the population of the species.

Groundwater contamination, usually from pesticides used by farmers, is the principal threat to the species. Contamination from human and animal wastes from sewers and septic systems and livestock feedlots in the area also pose a grave danger. The poor water quality, if not corrected, will probably cause the extinction of the species.

Sinkholes in the karst region inhabited by the amphipods are sometimes used to dump trash and other pollutants. Because there is no natural filter in a sinkhole to stop the pollutants from reaching the underground waters, the risk of contamination is very high.

When amphipods are damaged or killed by the contamination of the streams and groundwater, there is good reason to believe that humans who use the same water sources will be affected as well.

The small range of the Illinois cave amphipod is very close to St. Louis, Missouri, and so the habitat may face further harm from the urban (city; densely populated) environment.

The Illinois Department of Natural Resources owns the entrances to two of the three caves known to be Illinois cave amphipod habitats. The entrances to the third cave are privately owned, but have been designated as nature reserves.

There are several recovery plans in progress, which include pursuing a better scientific understanding of the species and its habitat needs. The Illinois cave amphipod is currently protected by the Illinois State Endangered Species Protection Act, which prohibits harming or killing it.

Hell Creek Cave Crayfish

Description and biology

The Hell Creek Cave crayfish is colorless. It has small eyes that lack any pigment (color) and a spined rostrum (snout). An average adult measures 2.6 inches (6.6 centimeters) long. Like other crayfish, it feeds on both plants and animals, including algae, snails, insects, worms, and mussels.

Although appearing similar to lobsters (their salt water cousins), crayfish have a different life cycle. They do not pass through any larval stages, but go directly from an egg to a miniature adult form.

Hell Creek Cave crayfish reproduce very slowly. Biologists (people specializing in the study of living organisms) believe they lay eggs once every five years, on average.

As in other crayfish species, the female Hell Creek Cave crayfish shelters her fertilized eggs by carrying them attached to her abdomen. After the eggs hatch, the young crayfish cling to that spot on the mother’s body for several weeks before letting go.

Crayfish are preyed on by bass, sunfish, raccoons, otters, herons, and kingfishers.

Habitat and current distribution

The Hell Creek Cave crayfish is found only in a deep pool in Hell Creek Cave, which is located in the Ozark Mountains in Stone County, Arkansas. Surveys conducted in the mid–1980s recorded less than 50 crayfish at this site and the population has remained near that figure into the 2000s.

Hell Creek Cave is mostly wet and muddy throughout the year. Many of its passages are flooded during the rainy seasons and after storms. A narrow, shallow stream leads to the pool inhabited by the crayfish. The pool is approximately 150 feet (46 meters) away from the cave entrance.

History and conservation measures

There are about 330 known species of crayfish, which are also known as crawfish or crawdads. Although nearly half of those species are endangered or imperiled, only four species have been placed on the U.S. Endangered Species List. The Hell Creek Cave crayfish is one of those four.

This species of crayfish faces a number of threats. A surface stream supplies water to the cave’s pool. This stream can easily become polluted with wastes from nearly industries. Once polluted, the stream will in turn contaminate the pool, destroying the crayfishs’ fragile habitat.

Biologists believe the Hell Creek Cave crayfish reproduces so slowly because it does not get enough nourishment. The cave has a shortage of organic matter for the crayfish to use as energy.

In the past, most of this organic matter came from the guano (feces) of gray bats (Myotis grisescens). However, the gray bat is now an endangered species. It has disappeared from Hell Creek Cave as well as from many other caves.

Finally, the Hell Creek Cave crayfish is threatened by human collectors who venture into the cave to capture specimens. The removal of any adult crayfish, especially reproducing females, can have a dramatic effect on the future population of the species.

A tract of land that includes the entrance to Hell Creek Cave has recently been placed under protection. This act should limit the number of humans entering the cave and disturbing its ecosystem (an ecological system including all of its living things and their environment).

Conservationists (people protecting the natural world) hope it will also allow gray bats to return to the cave, which will greatly benefit the Hell Creek Cave crayfish.

Nashville Crayfish

Description and biology

The Nashville crayfish, also called the Shoup’s crayfish, measures about 2 inches (5 centimeters) long. It has thickened ridges on its rostrum (snout), four pair of walking legs, and two long–fingered chelae (pronounced KEY–lee; claws or pincers).

It consumes plants and animals, including algae, insects, worms, fish eggs, snails, and mussels. Raccoons, fish, and reptiles are among the main predators of this crayfish.

Biologists (people who study living organisms) know very little about the reproductive habits of the Nashville crayfish. Mating can take place from late summer to early spring. Egg laying seems to occur in early spring.

Like females of other crayfish species, the female Nashville crayfish shelters her fertilized eggs by carrying them attached to her abdomen. Upon hatching, the young crayfish are fully formed, miniature versions of the adults. They cling to the mother’s abdomen for several weeks after hatching before venturing out on their own.

Habitat and current distribution

This crayfish is found only in Mill and Sevenmile Creeks, tributaries of the Cumberland River near Nashville, Tennessee. In its streambed habitat, the Nashville crayfish requires adequate cover. Those crayfish in Mill Creek have been found typically in pool areas under flat slabs of limestone and other rocks.

Biologists do not know how many Nashville crayfish currently exist, although they believe the number is quite low.

History and conservation measures

Biologists have classified about 330 species of crayfish, which are also called crawfish or crawdads. Tennessee alone has more than 70 distinct species. Of the total number of crayfish species known, almost half are endangered or imperiled.

Only four crayfish species in the country have been granted federal protection by being placed on the U.S. Endangered Species List. The Nashville crayfish is one of those four listed.

In the past, the Nashville crayfish was found in three additional areas in Tennessee: Big Creek in Giles County, South Harpeth River in Davidson County, and Richland Creek in Davidson County. Biologists are unsure exactly why the crayfish disappeared from these locations, but they do know it cannot tolerate pollution and increased silt (mineral particles).

This is the threat currently facing the Nashville crayfish in its Mill Creek habitat. A constant barrage of pollutants has been flowing into the creek. Industries have built warehouses right up to the edge of the creek’s banks.

Nearby roads and parking lots drain into the creek. Upstream from the crayfish’s habitat, pesticides and fertilizers sprayed on farmland run off into the creek.

To ensure the survival of the Nashville crayfish, conservation efforts must focus on protecting Mill Creek from further contamination.