There are plenty of species left to cover – I’m looking forward to the next volume already. And I keep daydreaming about camels. Least concern is the lowest level of conservation. A species of least concern is one that has a widespread and abundant population. Human beings are a species of least concern, along with most domestic animals, such as dogs and cats. Many wild animals, such as pigeons and houseflies, are also classified as least concern. Hexham Book Festival is a Not For Profit CIC and delivers an annual festival that takes place in and around Hexham each year. But you could make your own choice from quite a lot of mammals, some birds, an amphibian, a fish, an echinoderm, a mollusc and that plant. The spread includes well-known and not-so-well-known species and a smattering of marine species as well as terrestrial and aquatic ones.

Population restriction is a combination of population and area of occupancy. A species is vulnerable if it is restricted to less than 1,000 mature individuals or an area of occupancy of less than 20 square kilometers (8 square miles).There are currently 41,415 listed endangered species, and over 16,000 of them are threatened with extinction. The snaggletooth shark ( Hemipristis elongatus) is found in the tropical, coastal waters of the Indian and Pacific Oceans. Its area of occupancy is enormous, from southeast Africa to the Philippines, and from China to Australia. The Tahiti reed-warbler ( Acrocephalus caffer) is a songbird found on the Pacific island of Tahiti. It is an endangered species because it has a very small population. The bird is only found on a single island, meaning both its extent of occurrence and area of occupancy are very small.

The Siberian sturgeon ( Acipenser baerii) is a large fish found in rivers and lakes throughout the Siberian region of Russia. The Siberian sturgeon is a benthic species. Benthic species live at the bottom of a body of water. An endangered species is a type of organism that is threatened by extinction. Species become endangered for two main reasons: loss of habitat and loss of genetic variation. Ebony ( Diospyros crassiflora) is a tree native to the rain forests of central Africa, including Congo, Cameroon, and Gabon. Ebony is an endangered species because many biologists calculate its probability of extinction in the wild is at least 20 percent within five generations.

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Species that are not threatened by extinction are placed within the first two categories—least concern and near-threatened. Those that are most threatened are placed within the next three categories, known as the threatened categories—vulnerable, endangered, and critically endangered. Those species that are extinct in some form are placed within the last two categories—extinct in the wild and extinct. A species is classified as endangered when its population has declined at least 70 percent and the cause of the decline is known. A species is also classified as endangered when its population has declined at least 50 percent and the cause of the decline is not known. Probability of extinction in the wild is at least 50 percent within 10 years or three generations, whichever is longer.

The Tahiti reed-warbler is also endangered because of human activity. The tropical weed Miconia is a non-native species that has taken over much of Tahiti’s native vegetation. The reed-warbler lives almost exclusively in Tahiti’s bamboo forests. The bird nests in bamboo and feeds on flowers and insects that live there. As development and invasive species such as Miconia destroy the bamboo forests, the population of Tahiti reed-warblers continues to shrink.

A species is extinct when there is no reasonable doubt that the last remaining individual of that species has died. Development can also endanger species indirectly. Some species, such as fig trees of the rain forest, may provide habitat for other species. As trees are destroyed, species that depend on that tree habitat may also become endangered. Tree crowns provide habitat in the canopy, or top layer, of a rainforest. Plants such as vines, fungi such as mushrooms, and insects such as butterflies live in the rain forest canopy. So do hundreds of species of tropical birds and mammals such as monkeys. As trees are cut down, this habitat is lost. Species have less room to live and reproduce. The definitions of the three threatened categories (vulnerable, endangered, and critically endangered) are based on five criteria: population reduction rate, geographic range, population size, population restrictions, and probability of extinction. The Bolivian chinchilla rat ( Abrocoma boliviensis) is a rodent found in a small section of the Santa Cruz region of Bolivia. It is critically endangered because its extent of occurrence is less than 100 square kilometers (39 square miles).