MacGillivray’s Warbler

Geothlypis tolmiei
Range Map

MacGillivray’s Warblers are migratory and spend their summers in the temperate forests of the western United States, and in the boreal forests of British Columbia and western Canada. In winter, they migrate back to Mexico and Central America. In 2012, scientists renamed this bird’s genus from Oporornis to Geothlypis.

There is a shyness in their nature, often making them difficult to locate, even in habitats where they are plentiful. Dense shrubs and brush, rather than trees and forests, are their preferred habitat.

Despite the similarity in appearance to their close relatives, the Mourning Warblers, neither the summer nor the winter ranges of these birds overlap. Studies show that MacGillivray’s Warblers migrate entirely over land.

Modern science recognises two subspecies of MacGillivray’s Warblers:

  • G. t. tolmiei breeds west of the Cascade and Sierra Nevada mountains from southeastern Alaska the Yukon, south to southern California. They spend winters from southwestern Mexico to Panama.
  • G. t. monticola breeds east of the Cascade and Sierra Nevada mountain ranges from eastern British Columbia east to Saskatchewan and south through Oregon and the Rocky Mountains through Arizona, to Coahuila and Nuevo León (Mexico).

My first encounter with a MacGillivray’s Warbler occurred in 2005 during my final few days in Alaska. Most of my meetings with this species have come on Santa Rosa Mountain in southern California, but I’ve enjoyed the company of migrating birds on South Padre Island (Texas) and breeding birds in the Siskiyou Mountains of southern Oregon as well.

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