Geography of Birds. Palearctic Region Largest region Site of origin of all birds Great diversity of habitats Poor bird variety (cold climate, sharply.

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