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					An Introduction
    to Bats
Creepy, blind, blood-
 sucking RODENTS of
  the night….right?
       What do YOU know
        about bats????
• Bats are flying rats
• Bats will attack you
  for no reason
• Bats will fly into
  your hair
• Bats are blind
     Actually…..              likes
   • Those are all just
       BAT MYTHS
• Bats won’t fly into your
  hair or attack you
• They aren’t blind at all
• And they aren’t even
 The Only Way
Rodents Can Fly
Common Questions
   about Bats
So, What ARE Bats???
• Class Mammalia

• Order Chiroptera (“hand-wing”)
  – Suborder Megachiroptera- flying
     • 1 Family, ~166 species

  – Suborder Microchiroptera- micro
    • 16 Families, ~759 species
Bat Stats
  • 4,200 species of mammals

      • ~1,000 species of bats

  • Of these, 88% are tropical
 Bats: Unique Small Mammals
• Long lived (some up to 30 years)
        • Possibly due to reduced metabolic activity during
          torpor (40% of the year in some species).
• Low fecundity
        • Temperate zone bats are monestrous and usually have
          1 young/yr
        • Exceptions are the red bat (twins and triplets are
          common) and the southeastern myotis (twins are
• Long period of infant dependency
        • 2 month gestation and 1 month of infant dependency
• High survivorship
        • 50-80% chance of surviving each year once adulthood
          is reached (Findley 1993).
        • Common predators of bats are owls, snakes, hawks and
          feral cats
    What do Bats Eat?
• FRUIT- “frugivory”
• FLOWERS- nectar or pollen
• CARNIVORES- birds, reptiles,
• FISH- highly specialized carnivores
• BLOOD- “sangrivory”
• INSECTS- aerial or foliage
      How do Bats Fly?

• Bats are the
  only mammals
  capable of
  TRUE powered
  Bats Actually Fly With Their Hands,
           Not Their Arms!

Illustration from BCI Educator’s Activity Book
 What is Echolocation?
• Microbats use ECHOLOCATION
  for navigation and prey capture:

       Animation from
    More About Echolocation
• 1700’s: Lazarro Spallanzani first proposed bats
  could “see” with their ears
• 1930’s: Donald R. Griffin of Harvard coined term
• Not all bats echolocate- just Microchioptera
• Most echolocation calls are between 9 to 200+kHz
• Humans can only hear up to 20 kHz
• Bat detectors allow us to hear bat calls
• Can ID bat species by their echolocation calls
Why Are Bats Important?
            • Bats are important
              pollinators of many
              plant species
              including the agave
              plant (ie. Tequila),
              the saguaro cactus
              and many
              rainforest plant
            • Bats are vital for
              the control of insect
  Economic Importance of
    Bats in Agriculture
                             • The story of Mexican free-tailed
                               bats in Central Texas
                                – Bracken Cave: ~20 million
                                  Mexican free-tailed bats
                                  (single largest aggregation of
                                  mammals in the world)
                                – Central Texas caves,
                                  including Bracken Cave, are
                                  summer maternity roosts for
                                  ~ 100 million Mexican free-
                                  tailed bats
                                – It is estimated that these bats
Photo from        eat about 2 million lbs of
                                  insects every night
Tadarida brasiliensis
Mexican Free-tailed

  Photo From BCI:
                 Bats Aloft:
      A Study of High Altitude Feeding
• Bat Biologists Knew:
   – Mexican Free-tailed bats fly as high as 10,000 ft.
   – Densest aggregations are at 600 – 3,200 ft.
• Entomologists Knew:
   – Corn earworms are one of the most destructive Ag. pests in
   – Corn earworm moths fly at same altitudes during dispersal
       • Early June: emerge from Lower Rio Grande Valley of Mexico
       • 3 days after peak emergence in Mexico, moths begin laying eggs
         on agricultural crops in Central Texas
       • 3 weeks later, next generation spreads north through the Central
            Could the free-tail bats be eating
              corn earworm moths?????
The Problem
Helicoverpa zea
Corn Earworm
    “Bats Aloft” Partners
• Dr. Gary F. McCracken, University
  of Tennessee
• Dr. Wayne Wolfe and Dr. John
  Westbrook of USDA Research
  Station in College Station, TX
• U.S. Weather Service
• Bat Conservation International
       A Problem of Timing
• Researchers needed to know if the moths were
  flying in TX at the same time the bats were
• Seemed improbable because the moths were still
  traveling to TX when the bats emerged in the
• Plus, other studies had shown that moths were
  only 30% of the bats diet - EXCEPT…..
• Bats forge 2x a night- early evening and early
• Further investigation showed that in early June,
  bats only ate 37% moths in the early evening but
  96% moths during their dawn feeding!
Doppler Radar Images

Images From: McCracken, G. F. 1996. BATS 14(3): 7-10 on
         Ok, Bats are Beneficial- but
           What About Bats and
• Bats ARE carriers of rabies
• Rabies caused by a bullet-shaped virus of the genus
  Lyssavirus. It causes a very serious viral infection of the
  Central Nervous System
• Rabies can only be transmitted through saliva or spinal
  fluid, not blood or urine
• If you are exposed, you will need post-exposure
  vaccinations ASAP (series of 5 itty-bitty shots in the arm)
• FYI- Raccoons pose the most serious risk of rabies in
  South GA. Surprisingly, otters are also a risk
        Rabies Prevention

  including bats!!!!!!

• Keep your pets vaccinated

• If you think you have been exposed, seek
  medical attention promptly
     • Histoplasmosis is caused by a ground fungus
                   Histoplasma capsulatum
•   It causes flu-like symptoms which, in rare cases,
    can be quite serious
•   Severity of disease is related to dosage of exposure
    (number of spores inhaled)
•   It is most often associated with bird droppings, but
    bat and rodent droppings also pose a risk- esp. in
    hot, humid climates
•   Keep your home and outbuildings free of fecal
Bats in Georgia:
  16 Species
Family Vespertilionidae:

     The Evening Bats
             Rafinesque’s Big-eared Bat
              Corynorhinus rafinesquii
                                 • Rare- possibly declining in
                                   numbers due to habitat loss
                                 • Roosts in abandoned
                                   buildings, hollow trees and
                                   caves in or near bottomland
                                   hardwood habitats
                                 • Will glean insects from
                                   foliage or capture them in
                                 • Easily disturbed
Photo From BCI:
                     Southeastern Myotis
                     Myotis austroriparius
                                 • Species of Concern by
                                 • Cave bat eastern US
                                 • Roosts in hollow trees,
                                   culverts, and bridges in
                                   areas w/o caves
                                 • Also associated with
                                   bottomland hardwood
                                 • Only Myotis bat to have
Photo From BCI:
                           Big Brown Bat
                           Eptesicus fuscus
                                 • One of the most common
                                   bats in urban areas and
                                   bat houses
                                 • Often roots in buildings-
                                   prefers snags in natural
                                 • Often return to
                                   maternity roost where
                                   they were born
                                 • Forage in a variety of
Photo From BCI:
                          Eastern Red Bat
                          Lasiurus borealis

                                 • Solitary, tree-roosting bat
                                 • Hangs by one foot
                                 • Will also hibernate in leaf
                                   litter on forest floor
                                 • Used to form large daytime
                                   migratory flocks in 1800’s
                                 • 2-5 young (usually 3)

Photo From BCI:
                      Hoary Bat
                   Lasiurus cinereus
                                 • Solitary, roots among foliage
                                   on forest edges
                                 • Can fly 24 miles in one night
                                   while foraging
                                 • Territorial over foraging sites
                                 • Often migrate with bird flocks
                                 • One of the most widespread
                                   bats in N. America
Photo From BCI:   • Hawaii’s only native land
                          Evening Bat
                       Nycticeius humeralis

                                 • Abundant in SE US
                                 • Forest bat- hardly
                                   ever in caves
                                 • Little is known about
                                   its migration patterns

Photo From BCI:
                         Eastern Pipistrelle
                        Pipistrellus subflavus

                                 • Common in forest edges
                                   and near agricultural
                                 • One of first bats to
                                   emerge in evening
                                 • Forage high in canopy
                                 • Will hibernate in caves
                                   and in culverts
Photo From BCI:
                    Northen Yellow Bat
                    Lasiurus intermedius
                                 • Roosts year-round in
                                   Spanish moss and
                                   palm fronds
                                 • Abundant on the
                                 • Will forage over sand
                                   dunes and beaches
                                 • Typically have 3 pups
Photo From BCI:
Family Molossidae
 The Free-tailed Bats
          Mexican Free-tailed Bat
           Tadarida brasiliensis
                                 • Another very common
                                   urban and bat house bat
                                 • One of most widely
                                   distributed mammals in
                                   Western Hemisphere
                                 • Highly gregarious
                                 • Much of the population
                                   is migratory

Photo From BCI:
     Other Bats in Georgia
•   Silver-haired bat
•   Seminole bat
•   Gray myotis
•   Small-footed myotis
•   Little brown myotis
•   Eastern long-eared myotis
•   Indiana myotis-
Bat Conservation
Threats to Bat Populations
•   Habitat destruction/fragmentation
•   Loss of historical roost sites
•   Disturbance of roost sites, esp. caves
•   Ignorance:
    – General public: negative attitudes
    – Scientific: Very little is known about
      the distribution, numbers and specific
      requirements of most bat species
      Hot Topics in Bat
•   Phylogeny and evolution
•   Functional morphology
•   Echolocation
•   Conservation Biology
    – North American Bat Conservation
      Partnership (NABCP) Strategic Plan
  Top 5 Conservation Research
        Goals (NABCP)
• Goal 1: Identify key resources- Flyways, roosts,
  drinking and foraging habitats
• Goal 2: Establish baseline populations and trends
• Goal 3: ID species requirements and limiting factors
• Goal 4: Describe, quantify, and monitor the effects of
  current land-management practices and other human
  disturbances on bats.
• Goal 5: Quantify the economic and social impacts of
  North American bats.
      Top 4 Management Goals
• Goal 1: Develop management standards and
  guidelines for bats, including them in existing
  management plans for other wildlife and associated
• Goal 2: Identify, protect, and enhance key roosting,
  feeding, and drinking resources for bats.
  Reestablish bat populations to the extent necessary.
• Goal 3: Incorporate bat conservation language into
  existing statutes for wildlife protection.
• Goal 4: Integrate strategic plans for bats into other
  existing plans and initiatives.
 Common Methods For
Studying Bat Populations
• Population Surveys: Counts
  –   Direct Roost Counts
  –   Nightly Dispersal Counts
  –   Maternity Roost Counts
  –   Ultrasonic Bat Detectors
       • Simple handheld
       • ANABAT (records for computer analysis)
• Population Surveys: Captures
  – Mist Nets
  – Harp Traps
  – Trip Lines (over water sources)
Bat Management
    Basic Habitat
 Requirements for Bats
  – Including maternity, bachelor and
    hibernation roosts
  – Caves, hollow trees, stumps, live trees,
    abandoned buildings, bridges, culverts, etc.
  – Waterways, roads, pipelines, forests, edges,
    clearings, beaches, etc.
  – Lakes, rivers, streams, bays, stock tanks,
    swimming pools, etc.
     General Practices that
         Benefit Bats
• Protection of known or potential roosts,
  including: snags, hollow trees,
  abandoned buildings, caves, bridges, etc.
• Creating artificial roosts
• Maintaining water quality (BMP’s)
• Wise use of insecticides
• Keep cats indoors!
• Leave known bat populations
                     Bat House Design
                                 Bat houses should have the
                                 following specs:
                                 – AT LEAST 2 ft. tall and 14 in.
                                   wide- bigger is better!
                                 – Have a 3-6 inch landing strip
                                   covered with plastic hardware
                                   cloth below entrances
                                 – Inner partitions (1-4+) should
                                   be ½ to 1 in. apart and
                                   covered with plastic hardware
                                   cloth or roughened manually
                                 – Ventilation slot 6 in. from
                                   bottom of house

Photo From BCI:
Bat House Construction
 and Wood Treatment
• Use plywood, cedar or a combination
• Exterior of house: Apply 3 coats of
  dark or medium colored exterior
  grade, water-based paint or stain
• Interior of house: Apply two coats
  black, exterior grade, water-based
• Caulk all seams
                          Bat House Placement
                                 • Full all day sun is
                                   best- minimum is 6
                                   hours of sun
                                   exposure a day
                                 • Place near water if
                                 • Mount house on a
                                   pole 15-20 ft. high
                                 • Make sure entrance
                                   is unobstructed
Photo From BCI:                           Photo From BCI:
Bats That Will Use Bat
  Houses In Georgia
   •   Little brown myotis
   •   Southeastern myotis
   •   Eastern pipistrelle
   •   Big brown bat
   •   Evening bat
   •   Mexican free-tailed bat
    Recommended Steps for
       Bat Management
• Conduct bat surveys
• Identify roosts- esp. maternity roosts
• Provide artificial roosts (bat boxes)
• Incorporate bat management practices into
  your overall management plan
• Work with neighboring landowners to provide
  as much habitat as possible
• Discourage human disturbance of bat roosts
• Monitor bat populations and make the data
  available to researchers
  For More Information
• Bat Conservation International
• Buzbee’s Bat House
• Bat CREW

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