Merlin {Falco columbarius) 



Distribution: In North America, breeding occurs from western Alaska east to Labrador and south 

 to northern Maine, New York, Minnesota, southern Wyoming and Oregon. Widespread but 

 local during the breeding season in Montana (Bergeron et al. 1992), and locally uncommon 

 or rare in western South Dakota (S.D. Omithol. Union 1991). Winters within southern 

 breeding range south through Mexico and the Gulf coast to northern South America. 



Habitat Use: Uses relatively dense coniferous forest to mixed grasslands with scattered trees for 

 nesting, depending on the race. Needs open areas for hunting. The race breeding in 

 southeastern Montana and northwestern South Dakota, richardsonii, uses grasslands and 

 shrubsteppe habitats. In Carter County, Montana patchy shrub/grassland is the preferred 

 hunting habitat (Becker and Sieg 1987), where sagebrush and grasses are interspersed; 92% 

 of prey items were birds (mostly grassland species), 5% insects, and 3% mammals (Becker 

 1985). Ponderosa pine is probably not important hunting habitat, but it is used for nesting. 

 Home ranges (13-28 km-) include both habitat types. Some populations in Canada breed in 

 urban habitat (Sodhi et al. 1993). 



Nest Sites: Does not build nests; rather it uses old corvid and hawk nests. All nest sites (48) 

 reported in Carter County, Montana (Becker 1978, Sieg and Becker 1990) were in old 

 American Crow or Black-billed Magpie nests high (10-17 m above ground) in the crowns of 

 . live ponderosa pines. Nine nest sites described from Harding County, South Dakota units of 

 the Sioux District (see Appendix 3) were in old magpie nests in ponderosa pines; nests are 

 documented from the South Cave Hills (6 nests), North Cave Hills (3 nests), and Slim Buttes 

 (2 nests) between 1979-1989. Merlins in northeastern Wyoming also use old magpie nests in 

 pines (Phillips and Beske 1 990, Phillips et al. 1 990). 



Nest Success: Usually lays 3-6 eggs. Mean clutch size in Carter County, Montana ranged from 

 4.1-4.5 in 1978-1981 for 48 clutches; 43 (90%) of the clutches produced an average of 3.6 

 fledglings/nest (Becker and Sieg 1985). Productivity in Alberta and Saskatchewan was 

 3.6-3.8 young/nest for 276 nests (Sodhi et al. 1993). 



Breeding Phenology: For Carter County, Montana, egg-laying occurs from mid-April to early 

 June, eggs hatch from late May to late June, and fledging occurs in late June through July 

 (Becker and Sieg 1985). In South Dakota, the nesting season extends from late April through 

 July (Pettingill and Whitney 1965, S.D. Omithol. Union 1991). Fledging usually occurs in 

 July in Saskatchewan (Sodhi et al. 1993). 



Status: Locally rare to common. Pulkrabuk and O'Brien (1974) estimated 52 nesting pairs in 

 Harding County, South Dakota. Becker (1978) considered the Merlin to be fairly common in 

 the Montana units of the Sioux District. However, more recent Breeding Bird Survey data 

 indicate significant declines in Montana (Dobkin 1994). While numbers have been 

 decreasing in the southern breeding range, such as Wyoming, there are significant increases 

 in Alberta (White 1994). 



Natural Heritage Program rank: G4; S4 in Montana; S3B,S3N in South Dakota. 



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