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    Author(s): Bruce G. Marcot
    Date: 1995
    Source: Gen. Tech. Rep. PNW-GTR-343. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 64 p
    Publication Series: General Technical Report (GTR)
    Station: Pacific Northwest Research Station
    PDF: View PDF  (8.0 MB)


    A review of literature on habitat associations of owls of the world revealed that about 83 species of owls among 18 genera are known or suspected to be closely associated with old forests. Old forest is defined as old-growth or undisturbed forests, typically with dense canopies. The 83 owl species include 70 tropical and 13 temperate forms. Specific habitat associations have been studied for only 12 species (7 tropical and 5 temperate), whereas about 71 species (63 tropical and 8 temperate) remain mostly unstudied. Some 26 species (31 percent of all owls known or suspected to be associated with old forests in the tropics) are entirely or mostly restricted to tropical islands. Threats to old-forest owls, particularly the island forms, include conversion of old upland forests, use of pesticides, loss of riparian gallery forests, and loss of trees with cavities for nests or roosts. Conservation of old-forest owls should include (1) studies and inventories of habitat associations, particularly for little-studied tropical and insular species; (2) protection of specific, existing temperate and tropical old-forest tracts; and (3) studies to determine if reforestation and vegetation manipulation can restore or maintain habitat conditions. An appendix describes vocalizations of all species of Strix and the related genus Ciccaba.

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    Marcot, Bruce G. 1995. Owls of old forests of the world. Gen. Tech. Rep. PNW-GTR-343. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 64 p


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    Owls, old growth, old-growth forest, late-successional forests, spotted owl, owl calls, owl conservation, tropical forests, literature review

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