Chapter 7 Distribution and Abundance: Most speciessmall geographical area, few wide spread Polar specieslarger range Widespread species are more abundant than species with small geographic range

Generalists: eat a variety of food Specialists: eat only a few food Chapter Opener Generalists: eat a variety of food Specialists: eat only a few food Rapport’s rule: from the polar to the equatorial latitudes, mammal geographic range sizes decreased. Siberian Tiger: 80-100 Km/night Lion in Africa: 40-50 km2

Figure 7-1 Moss, Tetraphis

Range size 1370 NA bird species Korean p: 220,000 km2 Figure 7-2 Range size 1370 NA bird species Korean p: 220,000 km2 1499 vascular plant species (British)

Range size and latitude Figure 7-3 Range size and latitude 523 species of N. American mammals South Korea: 99720 km2 Low latitude species have Smaller ranges in N. America: following Rapport’s rule

Each points is one species n=81, Minimal at 10- 20: not Figure 7-4 Each points is one species n=81, Minimal at 10- 20: not supporting Rapport’s rule Woodpeckers’ range

Not supporting Rapport’s rule Figure 7-5 38 elevation classes 614 species of trees in Himalaya in Nepal Not supporting Rapport’s rule

Shallow marine fish Need data Blue: upper critical temp. Figure 7-6 Need data Shallow marine fish Blue: upper critical temp. Red: lower critical temp. Tolerance of temp minimal at polar and trophical. Climatic variability hypothesis: temperate fish should have the widest temperature limits

Interaction of topography and temp. Figure 7-7 Interaction of topography and temp. 3839 species of native birds in America. Not supporting Rapport’s rule Tsuga canadensis in Alabama

strongly in warmer climates Figure 7-8 Lowland: <1000m 3839 bird species from Americas, Topography affects range sizes much more strongly in warmer climates About 50 % (topography and temperature) about 50 % (biotic, glaciation, etc)

Range size and abundance?????? 263 species of British moth Figure 7-9 Range size and abundance?????? 263 species of British moth More wide spread species are typically more abundant. Hanski’s rule Each dot represents one species. =Hanski’s Rule Distribution is the number of trap sites.

Range size and abundance Figure 7-10 Range size and abundance Geese and ducks of the world. More wide spread species are typically more abundant. Hanski’s rule

Ecological specialization model Local population model Skip There are three main explanations of why distribution and abundance maybe correlated Sampling model Ecological specialization model Local population model

Two closely related species in the two genera Draba and Erigeron Figure 7-11 Two closely related species in the two genera Draba and Erigeron Arrow: range of rare species, Rare species: 5 times abundant Arrow: range of rare species, Rare species: twice abundant The prediction of a strong positive relationship between distribution and abundance does not always hold

Individual species declining in abundance Figure 7-12 Individual species declining in abundance Common species rare species go in any direction

Negative relationship between abundance and distribution Figure 7-13 Negative relationship between abundance and distribution Breeding Bird SURVEY 20 years of declining abundance During the decline in abundance, geographic range has been increasing.