TRAIT–RELATED RESPONSES TO

HABITAT FRAGMENTATION IN AMAZONIAN BATS

Fábio Z. Farneda, Ricardo Rocha, Adrià López-Baucells, Milou Groenenberg,

Inês Silva, Jorge M. Palmeirim, Paulo E. D. Bobrowiec, Christoph F. J. Meyer

• Functional trait: any trait affecting, directly or indirectly, performance and fitness of an individual

• Functional diversity: the value and range of functional traits of the organisms present in a given ecosystem

Functional diversity

Loss of functional diversity

Affects ecosystem functioning and process that structure assemblages

Objectives & Hypothesis

Assess which functional traits contribute most to species’ fragmentation sensitivity

Identify which bat species are most vulnerable to fragmentation based on the traits identified in

Understand how specific environmental characteristics (local vegetation structure and landscape attributes) set pathways to local loss of functional traits

We tested the general hypothesis that there is a significant relationship between species functional traits, environmental gradients, and patterns of species distribution

Biological Dynamics of Forest Fragments Project

fragment-matrix contrast

World’s largest and longest-running experimental study of habitat fragmentation

8 forest fragments (1, 10, 100 ha)

+ 9 controls in

continuous forest

Bat sampling

Phyllostomidae Mormoopidae

P. parnellii +

4,845 captures – 6 families and 59 species

26 SPECIES

...

Functional traits

Trait

1. Body mass

2. Trophic level

3. Dietary specialization

4. Vertical stratification

5. Mobility

6. Wing morphology

1. “Dispersal” (body mass + mobility + wing morphology)

2. “Population size” (body mass + trophic level)

3. “Specialization” (dietary specialization + vertical stratification)

Additional models

Species prevalence & Change in abundance

Trait correlates of fragmentation sensitivity

PGLS – Phylogenetic generalized least squares

Panamanian land-bridge islands

fragment-matrix contrast

Low and High fragment-matrix contrast

Relative wing loading, body mass, and trophic level are among the highest-ranked traits based on AICc in both studies

© 2013 madalenaboto.com

Environmental variables

Local-scale vegetation

1. Number of trees ≥ 10 cm

2. Average DBH of trees ≥ 10 cm

3. Vertical stratification in vegetation density

4. Liana density

5. Number of potential roosts

6. Number of Vismia spp. and Cecropia spp. trees

7. Tree height

Landscape-scale

8. Forest cover

Categorical

9. Habitat modification gradient

4th-corner analysis Quantifies and statistically tests the relationships between environmental variables and traits Dray et al. 2014. Ecology

Trait-environment relationships

RLQ analysis Maximizes the covariance between sites and species based on environmental variables and traits Dray et al. 2014. Ecology

Trait-environment relationships

RLQ analysis

Trait-environment relationships

Fourth-corner analysis

P-values corrected by the false discovery rate method (FDR)

Trait-environment relationships

Model 2 Links the matrices L and Q and tests the null hypothesis that the distribution of species with fixed traits is not influenced by environmental conditions

Model 4 Links the matrices L and R and tests the null hypothesis that the species composition of sites with fixed environmental conditions is not influenced by the species traits

P < 0.001

P = 0.2

Conclusions

•Body mass •Trophic level

• Body mass • Trophic level • Wing morphology • Mobility

4th-corner analysis PGLS - AICc

Assess which functional traits contribute most to species’ fragmentation sensitivity

Identify which bat species are most vulnerable to fragmentation based on the traits identified in

Conclusions

Degree of contrast

Matrix quality

Connectivity

Buffer zone Buffer zone

Understand how specific environmental characteristics (local vegetation structure and landscape attributes) set pathways to local loss of functional traits

• Continuous forest interior • Tree height • Forest cover

Acknowledgments

Gleaning animalivorous bat

© 2013 madalenaboto.com

Functional traits

Trait Description Source

1. Body mass Based on the average body mass of each species

Our capture data

2. Trophic level Animalivorous or phytophagous Literature

3. Dietary specialization

Percentage of the contribution of each food item to the total dietary records for each species

Literature

4. Vertical stratification

Proportion of captures in ground vs. canopy nets

Our capture data

5. Mobility Mean and maximum recapture distance Our capture data Literature

6. Wing morphology

Aspect ratio and relative wing loading Our capture data