Covered and Evaluation Bat Species Western Red Bat Townsend’s (Lasiurus blossevillii) Big-Eared Bat (Corynorhinus townsendii)
California Leaf-Nosed Bat (Macrotus californicus)
Western Yellow Bat (Lasiurus xanthinus) Background
• Capture surveys started in 2007 at two habitat creation sites • CVCA was added in 2009
• PVER was added in 2010
• ‘Ahakhav was reestablished in 2011 • Cibola Nature Trail was planted in 1999
• ‘Ahakhav was planted in 2001
• CVCA was planted in 2006 (Phase 1)
• PVER was planted in 2006 (Phase 1) and 2009 (Phase 4) Methods
• Each site was surveyed once per month from May‐September • Surveys started at sunset and continued for 4.5 hours (weather permitting) • Three triple high mist‐nets (over 8 meters high) were used at all sites • Net length varied from 6‐18 meters Triple highs were usually set within potential flyways where bats would be “funneled” into a smaller area where the net could cover the entire area Edges were also surveyed at PVER and CVCA ‘Ahakhav Tribal Preserve Netting Areas PVER Netting Areas CVCA Netting Areas Cibola Nature Trail Netting Areas Results ‘Ahakhav Tribal Preserve • 405 net hours of effort (# of hours x # of 6‐m nets) • 272 bats of 9 species were captured • Three MSCP species captured
California Leaf-Nosed Bat Townsend’s Big-Eared Bat Western Yellow Bat Species Diversity and Composition ‘Ahakhav Tribal Preserve
3.34 140 Myotis species
Townsend's Big‐Eared Bat 120 California Myotis
100 Yuma Myotis
Western Yellow Bat 80 3.73 Cave Myotis 4.22 60 California Leaf‐Nosed Bat
40 6.59 Arizona Myotis
Big Brown Bat 20 1.89 Pallid Bat
0 May June July August September Results Palo Verde Ecological Reserve • 405 net hours of effort (# of hours x # of 6‐m nets)
• 136 bats of 10 species were captured
• Three MSCP species captured
• One new LCR species captured
Western Red Bat Western Yellow Bat California Leaf-Nosed Bat Western Mastiff Bat Species Diversity and Composition Palo Verde Ecological Reserve 3.33
60 Western Mastiff Bat
Mexican Free‐Tailed Bat 50 California Myotis
Yuma Myotis 40 2.98 California Leaf‐Nosed Bat
30 Western Red Bat
4.37 Western Yellow Bat
20 3.22 Cave Myotis
Pallid Bat 3.78 10 Big Brown Bat
0 May June July August September Results Cibola Valley Conservation Area
• 303.75 net hours of effort
• 260 bats of 9 species were captured
• Three MSCP species captured Species Diversity and Composition Cibola Valley Conservation & Wildlife Area
120 3.41 Mexican Free‐tailed Bat
California Leaf‐nosed Bat 100 4.61 Western Red Bat
80 California Myotis
Cave Myotis 60 Western Yellow Bat
Yuma Myotis 40 5.19 3.82 2.38 Pallid Bat
20 Big Brown Bat
0 May June July August September Results Cibola NWR Nature Trail • 286.8 net hours of effort (# of hours x # of 6‐m nets)
• 70 bats of 7 species were captured
• One MSCP species captured Species Diversity and Composition Cibola NWR Nature Trail
3.31 40 Canyon Bat (Pipistrelle)
35 Cave Myotis
30 Yuma Myotis
25 California Myotis
20 August survey ended after just over an hour due to weather California Leaf‐Nosed Bat 5.67 15 Pallid Bat 3.37 10 2.94 Big Brown Bat 5 1.00
0 May June July August September Results All Sites
• 1400.55 net hours of effort (# of hours x # of 6‐m nets) • 737 bats of 13 species were captured • 35 California leaf‐nosed bats captured (all 4 sites) • 34 western yellow bats captured (3 sites) • 12 western red bats captured (2 sites) • 1 Townsend’s big‐eared bat captured (1 site) Monthly Species Diversity All Sites
7
6
5
PVER 4 CVCA CIBO 3 AKTP
2
1
0 May June July August September Species Diversity and Composition All Sites (captures per net hour)
4.52 Townsend's Big‐Eared Bat 0.8 Western Mastiff Bat
0.7 Arizona Myotis 5.06 Canyon Bat (W. Pipistrelle) 0.6 Mexican Free‐Tailed Bat California Leaf‐Nosed Bat 0.5 Western Red Bat 4.51 0.4 California Myotis Western Yellow Bat 5.00 0.3 Cave Myotis Pallid Bat 0.2 Yuma Myotis 0.1 Big Brown Bat
0 CVCA PVER CIBO AKTP Statistical Comparisons • Species diversity calculations were compared using a bootstrap procedure with Program PAST¹ version 2.05 • Nine different diversity indices were compared • Each site was compared to every other site • Only five indices produced significant results
¹ Hammer, Ø., Harper, D.A.T., and P. D. Ryan, 2001. PAST: Paleontological Statistics Software Package for Education and Data Analysis. Palaeontologia Electronica 4(1): 9pp. Diversity Indices • Simpson: Measures 'evenness' of the community from 0 to 1. 1‐dominance. • Dominance: Ranges from 0 (all taxa are equally present) to 1 (one taxa dominates the community completely). 1‐ Simpson index. • Evenness e^H/S: Evenness value based on the H value from Shannon index. • Equitability J: Shannon index divided by the logarithm of number of taxa. This measures the evenness with which individuals are divided among the taxa present. • Berger‐Parker dominance: The number of individuals in the dominant taxa relative to the total number of individuals Statistical Results
PVER vs. PVER vs. PVER vs. CVCA vs. CVCA vs. CIBO vs. Index CVCA CIBO AKTP CIBO AKTP AKTP
Dominance 0.736 0.088 0.003 0.129 0.003 0.862
Evenness 0.429 0.008 0.195 0.016 0.328 0.087
Simpson 0.736 0.088 0.003 0.129 0.003 0.862
Equitability J 0.549 0.013 0.132 0.020 0.224 0.103
Berger-Parker 0.728 0.040 0.000 0.043 0.000 0.412
Take Home Message: PVER and CVCA have a higher dominance of a single species (big brown bat) compared to CIBO and AKTP
Note: There was no significant differences between sites using the Shannon index. Why the differences? • CIBO and AKTP are older more mature sites compared to CVCA and PVER • Sample size • Differences in insect abundance/diversity • Big brown bat roosts may be closer to the younger sites • Or, big brown bats just really like CVCA and PVER better Conclusions? • Does it matter? Red and yellow bat captures are highest at PVER and CVCA • As PVER and CVCA mature, species diversity may increase (dominance may decrease) • While patch size appears to affect species richness (total number of species), it does not affect species diversity at this scale • More data! What’s next? • The same four sites will be surveyed in 2012
• Red and yellow bats may be PIT tagged to help determine site fidelity
• Your invited! Questions?