Merlin (bird) - Relationship With Humans - Status and Conservation

Status and Conservation

Altogether, the Merlin is not particularly rare, and due to this and its wide range it is considered a Species of Least Concern by the IUCN. Its numbers are—except in the Asian part of its range, where the situation is less well determined—regularly censused. In about every major country it inhabits, many hundreds to many thousands are found, ranging from a "mere" 250-300 pairs in Belarus to perhaps as many as 30,000 pairs of aesalon in European Russia as determined in 1993. It is listed on CITES Appendix II and on a local level protected as other birds of prey; while some countries allow to capture Merlins, e.g. for falconry, international trade requires an export permit.

By far the most serious long-term threat to these birds is habitat destruction, especially in their breeding areas. Ground-nesting populations in moorland have a preference for tall heather, and are thus susceptible to overmanagement by burning vast tracts instead of creating a habitat mosaic containing old and new growth. Still, the Merlin is rather euryoecious and will even live in settled areas, provided they have the proper mix of low and high vegetation, as well as sufficient prey (which is usually the case) and nesting sites (which is a common limiting factor).

In North America, the species seems to have been more widespread in the past, or perhaps its range has shifted northwards: F. c. columbarius was an uncommon breeding bird in Ohio before the 20th century, but e.g. in Seneca County, as early as the 1900s even single adults were rarely seen in the breeding season. It is encountered in Ohio as a passage migrant and rarely as a winter guest, though two recent nestings have been confirmed. Changing land-use in Ohio mainly turned forest into agricultural land and thus is not very likely to have rendered the region inhospitable to the Merlin; global warming on the other hand cannot be dismissed as a reason, given that the Merlin is essentially a subarctic species that barely ranges even into temperate climes. Also, it may be that the number of Merlins wintering in the northern USA has increased during the 20th century.

Perhaps the most frequent cause of accidental death for individuals is collision with man-made objects, particularly during attacks. This may account for almost half of all premature deaths of Merlins. In the 1960s and 1970s, organochlorine pesticides were responsible for declines—particularly in Canada—due to eggshell thinning and subsequent brood failure, and compromising the immune system of adults. This has since been remedied with restrictions on the use of DDT and similar chemicals, and numbers have rebounded. Overall, Merlin stocks appear globally stable; while they may decline temporarily in places, they will usually increase again eventually, suggesting that this phenomenon is due to the fluctuations of supplementary food stocks discussed above.