geography of birds. palearctic region largest region site of origin of all birds great diversity of...
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Geography of Birds
Palearctic Region
• Largest region• Site of origin of all
birds• Great diversity of
habitats• Poor bird variety
(cold climate, sharply accentuated breeding season)
Palearctic Region
• 1026 species (55% passerines)
• 69 families• Only 1 endemic
family• Similarities with
Nearctic, Ethiopian, Oriental
Nearctic Region
• 750 species• Dominant - Parulidae
(warblers), Icteridae (blackbirds)
• 61 families (no endemic)
• Similarities with Palearctic, Neotropical
Ethiopian Region
• 1556 species (62% passerines)
• 73 families• 6 endemic families• Similarities with
Palearctic, Oriental
Oriental Region
• 961 species• 66 families• Only 1 endemic
family• Most similar to
Ethiopian, less to Palearctic, Australian
Australian Region
• 906 species• 64 families• 13 endemic
families
Neotropical Region
• 3300 species (dominated by non-passerines)
• >95 families• 31 endemic
families• Similarities with
Nearctic
Active Dispersal
• Change in distribution of species
• Driven by:• Changing
environment• Interspecific
competition• Population pressure
Active Dispersal
• Enhanced by mobility
• Irruption - rapid range expansion
• Withdrawal - loss of range
Passive Dispersal
• Strong winds, storms - “accidentals”
• Humans - House Sparrow, European Starling, Rock Dove, Ring-necked Pheasant
Monk Parakeet
• Crate of imported birds broke open in 1967 at JFK International Airport
• Now live in New York and 15 other states
Monk Parakeet
Barriers
• Mountain ranges• Oceans - Cattle
Egret• Cold temperatures• Food resources -
e.g., hummingbirds