Spent 22 Months Collecting Fine Scale Data on the Composition & Abundance of Bat Species in Caatinga & Edaphic Cerrado Biomes of Northeastern Brazil COMMUNITY ECOLOGIST

Time Consuming Narrow Specificity Insufficient for Addressing Broad Questions Unclear Comparative Context LIMITATIONS

RANGE MAPS: Wealth of Biogeographic, Ecological, and Evolutionary Information

BAT RANGE MAPS: Hall for North America Koopman for South America Supplemented by “Others”

RANGE MAPS: Expert Opinion Metadata Problems Heterogeneous Quality

GRADIENTS OF RICHNESS AND RANGE SIZE: BATS AND MARSUPIALS IN THE NEW WORLD

LATITUDINAL GRADIENT OF SPECIES RICHNESS

CAUSES Competition Population Size Growth Rates Epiphyte Load Harshness Predation Heterogeneity Niche Width Patchiness Host Diversity Mutualism Epidemics

CAUSES Stability Productivity Heterogeneity Aridity Habitat Number Predictability Rarefaction Area Seasonality Range Size Evolutionary Speed

LIMITATIONS Qualitative PredictionsQualitative Predictions Non Mutually ExclusiveNon Mutually Exclusive Unspecified FormUnspecified Form No Expected ValuesNo Expected Values

Hemispheric Patterns

CLASSICAL APPROACH RICHNESSRICHNESS L A T I T U D E HOHO H A1 H A2 CHANCE

STOCHASTIC PROCESSES AND NULL MODELS

SIMULATION NULL MODEL SIMULATION NULL MODEL LATITUDELATITUDE RICHNESSRICHNESS

SIMULATION APPROACH Randomly generate N & S termini for a speciesRandomly generate N & S termini for a species Repeat until S = richness of species poolsRepeat until S = richness of species pools Calculate richness at each latitudeCalculate richness at each latitude Repeat 1,000 timesRepeat 1,000 times Calculate mean and variance of richness per latitudeCalculate mean and variance of richness per latitude

EFFECT OF SPECIES POOL SIZE SIMULATION RESULTS

1 q p P 0 PROBABALISTIC APPROACH

BINOMIAL NULL MODEL p + q = 1 ( p + q ) 2 = 1 p pq + q 2 = 1 2 pq S = Richness at “P”

1 0 q p P SPECIES RICHNESS GRAPHIC REPRESENTATION 2pqS Domain

NULL MODEL Predicts Form of RelationPredicts Form of Relation Quantitative PredictionsQuantitative Predictions FalsifiableFalsifiable

NEW WORLD BATS AND MARSUPIALS

Chrotopterus auritus

Neoplatymops mattogrossensis

BATS Species rich Trophically rich Abundant in tropics

BATS – ENTIRE CONTINENT

BATS – TAXON EXTENT

BATS – 95% OF EXTENT

Didelphis virginiana

Marmosa cinerea

MARSUPIALS Ancient group of mammals Moderate species richness Trophically diverse in past

MARSUPIALS – ENTIRE CONTINENT

MARSUPIALS – TAXON EXTENT

MARSUPIALS – 95% OF EXTENT

MODEL UTILITY Deviations from the model differ between bats and marsupialsDeviations from the model differ between bats and marsupials Deviations are not related to the area of latitudinal bandsDeviations are not related to the area of latitudinal bands

RANDOM SUBSETS 20 Ranges20 Ranges 20 o Latitude20 o Latitude 20 Species20 Species

RANDOM SUBSETS SPECIES RICHNESS 1 0 q p BATS 20 *** r = 0.77 MARSUPIALS 19 *** r = 0.73 P

ASSESSMENT Although stochastic mechanisms may not be the only factors affecting gradients, they play an appreciable role throughout the distribution of a biota

MODEL UTILITY Deviations from the model differ between bats and marsupialsDeviations from the model differ between bats and marsupials Deviations are not related to the area of latitudinal bandsDeviations are not related to the area of latitudinal bands

MULTIFACTORIAL Many FactorsMany Factors Species-Specific LimitsSpecies-Specific Limits Factor-Specific N and S LimitsFactor-Specific N and S Limits

EXTRAPOLATIONS Disturbance GradientsDisturbance Gradients Productivity GradientsProductivity Gradients Abiotic GradientsAbiotic Gradients

LATITUDINAL GRADIENT OF SPECIES RANGE SIZE

RAPOPORT’S RULE RAPOPORT’S RULE

METHODOLOGICAL BIASES Tropical Species Temperate Species 0o0o

SIMULATION APPROACH Randomly generate N & S termini for a speciesRandomly generate N & S termini for a species Repeat until S = richness of species poolsRepeat until S = richness of species pools Calculate correlation between latitudinal range size and mid-latitudeCalculate correlation between latitudinal range size and mid-latitude Repeat 1,000 timesRepeat 1,000 times Calculate mean and variance of correlationsCalculate mean and variance of correlations

SOUTH AMERICANORTH AMERICA LATITUDINAL RANGE MID-LATITUDE BATS

SOUTH AMERICANORTH AMERICA LATITUDINAL RANGE MID-LATITUDE MARSUPIALS

BATS FREQUENCY CORRELATION COEFFICIENT MARSUPIALS MID-LATITUDE RESULTS Less Negative Less Negative

LATITUDE RANGE SIZE MID-LATITUDE RESULTS Rapoport’s Rule Empirical Pattern Stochastic Pattern

Comparisons of Gradients of Diversity at Two Scales: Communities Versus Regional Species Pools

SCALE Regional Patterns Local Patterns

LATITUDINAL GRADIENTS OF COMMUNITY ORGANIZATION

DESIGN Geographical Constraints (50 km)Geographical Constraints (50 km) Ecological Constraints (biome)Ecological Constraints (biome) Sampling Constraints (asymptote)Sampling Constraints (asymptote) Temporally Constrained (1-5 yr)Temporally Constrained (1-5 yr)

32 Sites Temperate Subtropical Tropical Subtropical Temperate

DIVERSE HABITATS Riparian Temperate Forest (1) Desert (4) Montane Tropical Forest (6) Wet Tropical Forest (13) Dry Tropical Forest (2) Tropical Woodland-Savanna (1) Wet Semi-Tropical Forest (4) Dry Semi-Tropical Forest (1)

FAUNAL POOL - SPECIFIC DATA Number of species whose geographic range overlaps a communityNumber of species whose geographic range overlaps a community Identities of species whose range overlaps a communityIdentities of species whose range overlaps a community

COMMUNITY - SPECIFIC DATA Species identities & abundances in each communitySpecies identities & abundances in each community Indexes of diversity that are sensitive to richness (3), evenness (4), dominance (3), diversity (4)Indexes of diversity that are sensitive to richness (3), evenness (4), dominance (3), diversity (4)

BIODIVERSITY INDICIES RICHNESS Community Richness Margalef Index Menhinick Index EVENNESS Shannon Index PIE Index Camargo’s Index Shoener’s Index DIVERSITY Camargo Index Log Series Alpha Brillouin Index Shannon Index DOMINANCE Simpson’s Index Berger-Parker Index McIntosh Index

FACTOR 1 FACTOR 2 Tropical Subtropical Temperate Evenness Dominance Diversity Richness Factor Analysis CE O BP PIE SI MD SHD B CD A MAR R SHE MER

Latitudinal Gradients Richness Evenness B 1 = ; r 2 < 0.01; P = B 1 = ; r 2 = 0.37; P < 0.001

REGIONAL & LOCAL GRADIENTS Latitude Richness RegionalLocal 12O

LATITUDINAL GRADIENTS