Looking for Merlins

By Bruce Haak, Idaho Department of Fish and Game The merlin is the second smallest falcon in North America. Because it is cryptically colored, and easily confused in the field with the much more common American kestrel, its presence often goes undetected. Merlins (Falco columbarius) are distinguished by their chunky appearance, barred tail, and rapid, sustained flight. They do not have the facial markings and bright color patterns of the more common kestrel. Three subspecies of merlins are found in Idaho. The most common is the taiga merlin that is uniformly brown; the Richardson's merlin that is pale, almost white; and the black merlin that is quite dark. Juveniles and females have similar plumages, while adult males have a bluish tint on the back. Merlin populations across North America were greatly reduced during the DDT era. They are now increasing in number and expanding their range across the continent. During autumn and spring, merlins from as far away as Canada and Alaska pass through Idaho on their annual migration. During winter, good numbers of merlins may be found wintering at lower elevations, especially near towns, dairies and feedlots. Within the past 30 years, new populations of Richardson's merlins have been established in southern Saskatchewan and Alberta. In addition, nesting pairs of black merlins have been located in nearby western Washington, between Seattle and the Canadian border. These days, merlins are adapting to urban environments where large trees, year around water, and abundant food resources can be found. Typically, merlins occupy the abandoned stick nests of crows and magpies. When conditions are good, they can raise up to five young per year, and are noisy and aggressive when defending their territory and young. In contrast, kestrels prefer to raise their young in tree cavities, large bird boxes, and even openings in buildings. Historically, precious few merlin nests have been found in Idaho. For example, during the mid-1970s, only two nests were documented in eastern Idaho. Last year, an active nest was found in northern Idaho and others were suspected. Because the merlin is ranked as a Species of Greatest Conservation Need under Idaho's Comprehensive Wildlife Conservation Strategy, work is underway to verify active merlin nests throughout the state. Anyone who finds a merlin nest, or a territory being defended by a pair of merlins, is encouraged to report those findings to the nearest Fish and Game regional office. These days, more skilled birders are in the field than ever before. Because merlin nests are rare, help is needed to verify the presence of breeding merlins during spring and summer. With good communications between Fish and Game staff and the wildlife viewing public, and with a concerted survey effort, we should be able to increase our knowledge of Idaho's nesting merlin population. Bruce Haak is the nongame wildlife biologist in the Southwest Region.