1 / 25

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

starns
Download Presentation

Palearctic region

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


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

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

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

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

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

  6. Nearctic region • Also cold • North-south mountains

  7. 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

  8. 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

  9. 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

  10. 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

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

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

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

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

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

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

  17. 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

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

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

  20. 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

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

  22. 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

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

  24. 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

  25. 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

More Related