Black Rhinos Released Into the Wild

Conservationists hope the recent release of endangered black rhinos into the wild will put the species on the path to recovery. (Photo credit: Gary M. Stolz/US FWS)

Conservationists hope the recent release of endangered black rhinos into the wild will put the species on the path to recovery. (Photo credit: Gary M. Stolz/US FWS)

Captive-bred black rhinos were released this week into their natural habitat in Kenya. The release of black rhinos into the wild was hailed by conservationists as a victory in the effort to return black rhinoceros populations to normal. During the nineteenth century, black rhinos were widespread across the continent of Africa. Although black rhinos are typically solitary animals, European explorers recounted seeing dozens of black rhinos over the span of just one day. Unfortunately, black rhino populations quickly plummeted across eastern, western, and central Africa due to rampant poaching by settlers.

The main reason behind the poaching of black rhinos is the desire for the rhinos’ horn. In the 1960s and 1970s, poaching reached an all-time high due to high demand for rhinoceros horns in the Middle Eastern and Asian markets. In the Middle East, rhino horns are made into daggers carried by Yemeni men as a status symbol. In Asia, rhino horns are used in the creation of traditional medicines touted as a cure for fever. As a result of these demands, black rhino populations decline significantly. In the 1970s, the black rhino population in Kenya was estimated to be 20,000 animals. Since that time, the rhino population has declined to only about 500 animals. Clearly, unless conservation biologists intervened, black rhinos were on the very brink of extinction. In order to protect the black rhinos from extinction, the remaining animals were confined to wildlife sanctuaries.

Members of the Kenyan Wildlife Service and members from the Zoological Society of London are working in collaboration in the effort to return black rhinos to the wild. A primary part of the recovery effort is to make the wild a safe place for the rhinos. The prevention of poaching is key to the black rhinos’ survival in their natural habitat. Anti-poaching efforts, such as increasing the penalties for poaching and an increase in anti-poaching patrols, were instituted. Another important aspect of the black rhinos’ recovery program was the development of a breeding program. As a part of the breeding program, researchers worked to maintain individual populations at an optimal size and moved rhinos of reproductive age from one population to another to help bolster healthy populations.

Introducing healthy black rhinos back into the wild is the first step in returning black rhino populations back to normal levels. A combination of vigilant anti-poaching patrols, education programs, and the maintenance of a healthy breeding population will be necessary to ensure the long-term success of black rhinos in the wild.

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North American Freshwater Fish Imperiled

The endangered holiday darter, native to the southeastern United States, is just one of the many species of imperiled freshwater fish found in North America. (Photo Credit: Noel Burkhead/USGS.

The endangered holiday darter, native to the southeastern United States, is just one of the many species of imperiled freshwater fish found in North America. (Photo Credit: Noel Burkhead/USGS.

A study conducted by scientists from the U.S. Geological Survey in collaboration with researchers from Canada and Mexico has found that nearly 40 percent of fish found in North American streams, rivers, and lakes are in danger of extinction. The study, published in the journal Fisheries, a publication of the American Fisheries Society, is an update to a report on the same topic published in 1989.

In the previous study, 364 species were listed as imperiled. In the 2008 study, a total of 700 species are listed. This change is an increase of 92 percent. Among these 700 species of fish, 230 are listed as “vulnerable,” 190 are listed as “threatened,” 280 are listed as “endangered,” and 61 species are presumed to be extinct.

According to the report, the groups of fish that are the most at risk include salmon and trout endemic to the Pacific Coast and western North American mountain regions; minnows, suckers, and catfish across North America; and pupfish, livebearers, and godeids native to Mexico and the southwestern United States. The areas with the most vulnerable populations of freshwater fish include the southeastern United States, mid-Pacific Coast, lower Rio Grande, and inland basins of Mexico.

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Huge Population of Gorillas Discovered in the Congo Republic

A previously-unknown population of endangered western lowland gorillas was recently discovered in the northern forests of the Congo Republic. Scientists from the Wildlife Conservation Society, working alongside local researchers, found the population of gorillas living across two tracts of land covering 18,000 miles. The researchers discovery of over 125,000 gorillas is quite significant as the population is two times the previously-known worldwide population estimate of western lowland gorillas.

In 2007, western lowland gorillas were classified as critically endangered by the World Conservation Union. In recent years, the western lowland gorilla population has been decimated by disease, led by the Ebola virus. The exploitation of natural resources, including an increased international desire for tropical hardwoods, has severely impacted the gorillas forested habitat. The presence of logging roads makes it easier for poachers and subsistence hunters to reach populations of the reclusive gorillas.

The newly-discovered population of gorillas was found in an area of the Congo Republic referred to as the green abyss. This swampy area is difficult to traverse and therefore has remained relatively free of development up to now. Unfortunately, the Congolese government has begun selling logging rights to the northern forests. However, there is hope for the future. One of the study areas has been designated as a national park. The area, a region called Ntokou-Pikounda, is believed to be home to 73,000 gorillas. In another positive development, some logging companies are working in collaboration with conservation groups and the Congolese government to produce sustainably-harvested lumber. Minimizing the amount of roads that criss-cross through the gorillas habitat will protect them from poachers and other intruders.

The northern population of western lowland gorillas is thought to be safe for the time being. Scientists hope that implementing an alliance between conservation groups, industry, and the Congolese government early on will help protect the newly-found populations from exploitation and prevent the same problems faced by other populations of gorillas.

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Black-Footed Ferret Recovery Faces Major Set-Backs

Black-footed ferrets, in the best of times, are elusive creatures. In addition to maintaining low populations and leading quiet lives, ferrets are most active at night, making studying them that much more difficult. Though native to the Great Plains, an area much traveled by pioneers and explorers during America’s early years, the existence of black-footed ferrets wasn’t officially recognized by naturalists until 1851.

Fast-forward 100 years to the 1950s, and still not much was known about black-footed ferrets, although it was thought that small populations existed throughout the Great Plains. In 1964, scientists began a study of the only-known population of black-footed ferrets living in southwestern South Dakota. By 1967, the black-footed ferret was listed as an endangered species. In 1974, the population disappeared. It was thought at that time that black-footed ferrets had become extinct.

In 1984, a small population of 130 black-footed ferrets was discovered in northwestern Wyoming. Soon after its discovery, the population was devastated by an outbreak of sylvatic (bubonic) plague and canine distemper. As a drastic measure, researchers took the remaining 18 black-footed ferrets into captivity. In 1987, a captive-breeding program was begun to increase the population of black-footed ferrets. Four years later, in 1991, the first black-footed ferrets were released back into the wild. Since their reintroduction into Wyoming, black-footed ferrets have also been released in Montana, South Dakota, and Arizona.

One of the most successful reintroduction sites is located in South Dakota, in an area just south of Badlands National Park. At one point in time, over half of the U.S. population of black-footed ferrets could be found at this site. That all changed earlier this year when the ferret population there, numbering 300 animals, was decimated by an outbreak of bubonic plague. It is believed that one-third of the population died. Black-footed ferrets are particularly sensitive to the plague and die fairly quickly after becoming infected. The plague is not a new problem for black-footed ferrets (or the colonies of prairie dogs that the black-footed ferrets depend on as their main food source). However, this year’s outbreak has been particularly harsh as the plague thrives in wet conditions. This past spring was particularly rainy, leading to an explosive outbreak of plague within black-footed ferret and prairie dog colonies.

Population loss due to the plague is not the only problem facing black-footed ferret recovery efforts. As mentioned above, prairie dogs are the main food source for black-footed ferrets. Just like ferrets, prairie dogs are also susceptible to outbreaks of the bubonic plague, which is spread throughout the colony by infected fleas. When prairie dog populations decrease due to the plague, so do black-footed ferret populations. However, a greater problem exists for prairie dogs than just the plague. Prairie dogs are considered to be pest species by many ranchers in the Great Plains region. Ranchers complain that prairie dogs denude rangeland of the grasses their cattle need to eat. Some scientists counter-argue that prairie dogs actually help increase the digestibility and protein content of rangeland grasses by acting as natural fertilizers. Regardless, the U.S. Forest Service still maintains an active population control program by poisoning prairie dog populations at the request of ranchers. The U.S. Forest Service is currently considering an expansion of the prairie-dog poisoning program onto land that would be suitable for the reintroduction of black-footed ferrets. An expansion of the prairie-dog control program would mean the loss of prairie dog populations that could feed black-footed ferret populations.

In the mean time, scientists are working to prevent the spread of bubonic plague within colonies of black-footed ferrets and prairie dogs. One effective method has been to dust prairie dog burrows with insecticide that kills the fleas that spread the plague. (In addition to eating prairie dogs, black-footed ferrets also live in abandoned prairie dog burrows.) Another successful method involves inoculating black-footed ferrets with a vaccine that protects the animals from becoming infected with the plague. Scientists hope that these two methods put together will successfully prevent a cataclysmic population crash among black-footed ferrets and keep the animals on the path to recovery.

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