Doves - Threats and Conservation

Threats and Conservation

While many species of pigeons and doves have benefited from human activities and have increased their ranges, many other species have declined in numbers and some have become threatened or even succumbed to extinction. Amongst the 10 species to have become extinct since 1600 (the conventional date for estimating modern extinctions) are two of the most famous extinct species, the Dodo and the Passenger Pigeon.

The Passenger Pigeon was exceptional for a number of reasons.It is the only pigeon species to have gone extinct in modern times that was not an island species. It was once the most numerous species of bird on Earth. Its former numbers are difficult to estimate, but one ornithologist, Alexander Wilson, estimated one flock he observed contained over two billion birds. The decline of the species was abrupt; in 1871, a breeding colony was estimated to contain over a hundred million birds, yet the last individual in the species was dead by 1914. Although habitat loss was a contributing factor, the species is thought to have been massively overhunted, being used as food for slaves and, later, the poor, in the United States throughout the 19th century.

The Dodo, and its extinction, was more typical of the extinctions of pigeons in the past. Like many species that colonize remote islands with few predators, it lost much of its predator avoidance behaviour, along with its ability to fly. The arrival of people, along with a suite of other introduced species, such as rats, pigs, and cats, quickly spelled the end for this species and all the other island forms that have become extinct.

Around 59 species of pigeons and doves are threatened with extinction today, about 19% of all species. Most of these are tropical and live on islands. All of the species are threatened by introduced predators, habitat loss, and hunting, or a combination of these factors. In some cases, they may be extinct in the wild, as is the Socorro Dove of Socorro Island, Mexico, which was driven to extinction by habitat loss and introduced feral cats. In some areas, a lack of knowledge means the true status of a species is unknown; the Negros Fruit Dove has not been seen since 1953, and may or may not be extinct, and the Polynesian Ground Dove is classified as critically endangered, as whether it survives or not on remote islands in the far west of the Pacific Ocean is unknown.

Various conservation techniques are employed to prevent these extinctions, including laws and regulations to control hunting pressure, the establishment of protected areas to prevent further habitat loss, the establishment of captive populations for reintroduction back into the wild (ex situ conservation), and the translocation of individuals to suitable habitats to create additional populations.