Palearctic region

Of the approximately 9200 species of birds, only about 290 are marine species although land only covers about 29% of the globe

Palearctic region • Largest • East-west mountain ranges • Diverse in climates and habitat although much of the region is very cold

Birds of Palearctic • 1026 species • Birds may have evolved in this region • Most birds are migrants and insectivorous • One endemic family, Prunellidae

Shared species • 12.5% with Nearctic • 15% with Ethiopian • 22% with Oriental

Palearctic and Nearctic form Holarctic region • Loons, auks, grouse found only in these two regions

Nearctic region • Also cold • North-south mountains

Birds of Nearctic • 740 species • Most birds are migrants and insectivorous • Many wood-warblers and blackbirds • No endemic families although Meleagrididae (wild turkey) is close to being endemic

Origins of Nearctic birds • Some are unknown—wrens, warblers, vireos, sparrows • Some from Palearctic by way of the Bering Strait—pigeons, owls, thrushes • Some from Neotropical region—hummingbirds, flycatchers

Neotropical region • 70% of land surface is low elevation and with abundant moisture • 32% of South America is tropical rain forest (only 9% of Africa, 4.5% of Australia) • 38% of South America is savanna

Birds of Neotropical • 3300 species • Many suboscines, as opposed to oscines • About 31 of 95 families are endemic • Some species emigrated from the Nearctic, including pigeons, jays, blackbirds, warblers

Ethiopian region • Less climatic variability than other regions • Receives only half the rainfall of the Neotropical region, hence there are more deserts, grasslands, savannas

Birds of Ethiopian region • 1556 species • Many seed-eating and ground-dwelling birds • Many weaverbirds, larks • 6 endemic or nearly endemic families

Oriental region • Smallest region • Much of it is tropical and subtropical • Much rain

Birds of the Oriental region • 960 species • Most shared species with the Ethiopian, Palearctic and Australian regions • Two endemic families

Australian region • Diverse climates although much of the region is dry • Isolated region

Birds of the Australian region • 906 species • No woodpeckers • Parrots and doves are important groups • 13 endemic families

Birds may have originated in the Holarctic • Therefore areas separated from the Holarctic by substantial barriers, e.g. Australia, sub-Saharan Africa, Madagascar, and South America tend to have more endemic taxa than areas less isolated from the Holarctic

Tropical vs. Temperate Birds • Many more studies on temperate birds • I will be presenting generalizations

Tropical vs. Temperate Environments • Less seasonality due to temperature differences • Instead, wet and dry seasons • Many tropical food resources are available year-round

Population ecology of tropical birds • Breeding seasons longer and more variable • Less synchrony within a population • Breeding seasons not always driven by food availability • Fewer available mates in tropical systems

With fewer available mates in tropics: Fewer EPCs Smaller testes Song output consistent year-round Sexes tend to be monomorphic

Because tropical birds maintain territories year-round • Territories are much larger than for temperate species • Population sizes much smaller • However, keep in mind that 1/3 of tropical birds don’t have conventional breeding territories

Other patterns: • Nest predation higher • Adult survival higher • Clutch sizes lower • More cooperative breeders • Many species are less active

Tropical vs. temperate communities • More species-rich • More fruit-eaters, nectar-eaters, ant swarm followers, large insect eaters (more guilds) • Many bigger birds in tropical areas • More species per guild • Mixed-species flocks year-round • More suboscines

Tropical community characteristics • Highest diversity within forest, not at edges • Many intra-tropical migrants that are nectar or fruit-eaters • Fruit and nectar-eating birds more colorful than insectivores

Palearctic region