BIOL2712 Final: Island Biogeography and Metapopulations
25 Jun 2018
School
Department
Course
Professor
Island Biogeography and
Metapopulations
Biogeography
The study of the distribution of plants and animals around the world
The father of biogeography was Alfred Wallace
oRealized that different regions of the world had distinctive faunas and that
some of these were related
oAfter crossing from Bali to Lombok (14 nautical miles)
He had changed faunas
Animals are not evenly distributed
True of all animals and best studied in birds
Birds are NOT found uniformly around the world
oLooking at the avifauna, skilled birders know where they are
The world can be divided into characteristic zoogeographic regions
Each region has characteristic species and Families
Using birds as representation
find more resources at oneclass.com
find more resources at oneclass.com
The mobility of many birds, plus their proclivity to migrate
oHas allowed the movement of some groups between realms
Once a species arrives in a new area
oAdaptive radiation often generates new species
Palearctic Region
Europe, Africa north of the Sahara and almost all of Asia
Geographic barriers include:
oSahara Desert
oHimalayas
oBering Sea
Largest region
1025 species – most migratory
69 families
oOne endemic (Prunellidae)
Predominant group – Sylviidae (warblers)
Shares many species with:
oNearctic (13%)
oEthiopian (15%)
oOriental (22%)
Nearctic Region
North America and Greenland
750 species of breeding birds
oRelatively low species richness, because:
Access from Siberia through tundra and cold coniferous forest (no
access during periods of glaciation)
Tropical species from the south are faced with a climatic gradient
E.g. only 1 hummingbird and 2 tanagers in eastern deciduous
forests
Low species richness in deciduous forests because:
Continuous block (restricting opportunities for speciation)
Been compressed during glacial maxima
Many species migratory
Predominant families include:
oParulidae (new world warblers)
oEmberizidae (buntings, sparrows)
find more resources at oneclass.com
find more resources at oneclass.com
Palearctic + Nearctic = Holarctic
Families endemic to the Holarctic inc:
oDivers or loons (Gaviidae)
oWaxwings (Bombycillidae)
oAuks or alcids (Alcidae)
Relatively low species richness
oDue to cold climate and large areas of homogeneous habitat
Neotropical Region
South America (the bird continent), Central America, lowlands of Mexico and the
west Indies
70% of land mass is low, well-watered and tropical
3700 species
o1/3 of all bird species
oGreatest bird diversity of all regions
31 endemic families (twice that of any other region)
oSuggests an ancient and distinctive evolutionary history
Some endemic families have undergone extensive evolutionary radiation and
contain many species
oHummingbird
oWoodcreepers
oJacamars etc.
Other endemic families have undergone little radiation
oSeedsnipes
oOilbirds
oPlantcutters etc.
In addition, several more recent arrivals
oVultures
oPigeons
oCrows
oWrens etc
Several other groups have pantropical distributions, inc:
oCuckoos
oParrots
oTrogons
Other families are typical of the region
oTanagers
oFlycatchers
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
The study of the distribution of plants and animals around the world. The father of biogeography was alfred wallace: realized that different regions of the world had distinctive faunas and that some of these were related, after crossing from bali to lombok (14 nautical miles) True of all animals and best studied in birds. Birds are not found uniformly around the world: looking at the avifauna, skilled birders know where they are. The world can be divided into characteristic zoogeographic regions. The mobility of many birds, plus their proclivity to migrate: has allowed the movement of some groups between realms. Once a species arrives in a new area: adaptive radiation often generates new species. Europe, africa north of the sahara and almost all of asia. Geographic barriers include: sahara desert, himalayas, bering sea. Shares many species with: nearctic (13%, ethiopian (15%, oriental (22%) 750 species of breeding birds: relatively low species richness, because:
