Merlin (bird) - Systematics - Subspecies

Subspecies

That the Merlin has a long-standing presence on both sides of the Atlantic is evidenced by the degree of genetic distinctness between Eurasian and North American populations. Arguably, they might be considered distinct species, with gene flow having ceased at least a million years ago, but probably more.

By and large, color variation in either group independently follows Gloger's Rule. The Pacific temperate rain forest subspecies suckleyi's males are almost uniformly black on the upperside and have heavy black blotches on the belly, whereas those of the lightest subspecies, pallidus, have little non-dilute melanin altogether, with grey upperside and reddish underside pattern.

American group

  • Falco columbarius columbariusTaiga Merlin, Tundra Merlin
Canada and northernmost USA east of Rocky Mountains, except Great Plains. Migratory, winters in S North America, Central America, the Caribbean, and N South America from the Guyanas to the northern Andes foothills. Rarely winters in the northern USA.
  • Falco columbarius richardsoniPrairie Merlin
Great Plains from Alberta to Wyoming. Resident (some winter dispersal).
  • Falco columbarius suckleyiCoastal Forest Merlin, Black Merlin
Pacific coast of North America, from S Alaska to N Washington state. Resident (some altitudinal movements).

Eurasian group

  • Falco columbarius/aesalon aesalon
Northern Eurasia from British Isles through Scandinavia to central Siberia. Population of northern Britain shows evidence of gene flow from subaesalon. British Isles population resident, rest migratory; winters in Europe and the Mediterranean region to about Iran.
  • Falco columbarius/aesalon subaesalonsmyril (Faroese), smyrill (Icelandic)
Iceland and Faroe Islands. Latter population has some gene flow with aesalon. Resident (some winter dispersal).
  • Falco columbarius/aesalon pallidus
Asian steppes between Aral Sea and Altay Mountains. Migratory, winters in S Central Asia and N South Asia.
  • Falco columbarius/aesalon insignis
Siberia between Yenisei and Kolyma Rivers. Migratory, winters in continental East Asia.
  • Falco columbarius/aesalon lymani
Mountains of eastern Kazakhstan and surrounding countries. Short-distance migrant.
  • Falco columbarius/aesalon pacificus
Russian Far East to Sakhalin. Migratory, winters in Japan, Korea and nearby.

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