Conservation status

According to the IUCN, the family Estrildidae contains six species which are considered Near Threatened, eight which are Vulnerable, and two that have reached the status of Endangered. The reason for the decline in most of these species' numbers is multifactorial. Several species, including the green avadavat (Amandava formosa), the green-faced parrotfinch (Erythrura viridifacies), and the Timor sparrow (Padda fuscata), which are all listed as Vulnerable, have suffered from habitat loss and modification in addition to trapping for the pet trade. Early and strict laws governing the exportation of Australian fauna have nearly eliminated the threat of trapping for the pet trade on that continent. However, habitat modifications in the form of fragmentation, overgrazing by cattle, and widespread burning have affected the populations of the star finch (Neochmia ruftcauda), the diamond firetail (Stagonopleura gut-tata), and the Endangered gouldian finch in Australia. Having a range that is limited only to a small island or two means that a threat to an already decreased population can have major consequences. This has been the case for several par-rotfinches including the royal parrotfinch (Erythrura regia), considered by some ornithologists to be a subspecies of the red-headed parrotfinch (Erythrura cyaneovirens). This species has felt the impact of logging and cattle grazing in its native range of Vanuatu and Banks islands. However, the Java sparrow, another island denizen with a small population, is gradually succumbing to the combined effects of trapping for the pet trade, killing, and egg-robbing because of their effects on

The western bluebill (Spermophaga haematina) has a distinctive, colorful bill. (Photo by Doug Wechsler/VIREO. Reproduced by permission.)

rice crops, and hunting for food. Population numbers are not the only factors considered when classifying the conservation status of a species, however. Population trends play a major role as well. This is well illustrated by comparing the Anambra waxbill (Estrilda poliopareia) and the pink-billed parrotfinch (Erythrura kleinschmidti), both of which have populations fewer than 1,000 individuals. The former's population is stable and it is therefore classified as Vulnerable whereas the latter's population is declining, earning it an Endangered status.

0 0

Post a comment