15 - Chiroptera

Annotations:

• 202 genera, 1,120 species - second only to RODENTS
• specialized feeding, reproduction, behavior, morphology 
• flight allowed WIDE GEOGRAPHIC distribution 
• fill many feeding niches 
• mostly INSECTIVOROUS 
• but also carnivorous, piscivorous, nectarivorous, frugivorous, or sanguinivorous
• varied reproductive approaches: -sperm storage -delayed fertilization
• 1 or 2 young per year 
• roost in various sites 
• solitary or communal 
• mostly NOCTURNAL, except island-dwelling megabats 
• for size, very LONG-LIVED (30+ years) 

1. microchiropterans

   Annotations:

   • echolocation
   • mostly insectivorous 
   • tragus is well-developed 
   • nose or facial ornamentation
   • generally SMALL body size
   • small eyes 
   • modified cervical vertebrae 
   • head flexed DORSALLY when roosting 
   • tail and uropatagium present 
   • postorbital process usually ABSENT
   • echolocating bats, microbats 
   1. Vespertilionidae

      Annotations:

      • ~30 species
      • "Evening" or "vesper" bats
      • "plainnose" bats
      • most WIDESPREAD family worldwide 
      • some colonial, some solitary, migratory, or resident 
      • mostly INSECTIVOROUS 
   2. Molossidae

      Annotations:

      • 6 species
      • ALL insectivores
      • MOST are fast-flying ariel insectivorous
      • LARGE colonies (up to 20 million holy shit)
      • guano deposition
   3. Mormoopidae

      Annotations:

      • 1 species
      • "leaf-chinned" or "ghost-faced" bats
      • insectivorous
      • colonial
   4. Phyllostomidae

      Annotations:

      • 4 species
      • "leaf-nosed" bats
      • wide food habits 
      • insectivorous, carnivorous, nectarivorous, frugivirous, sanguinivorous
      • forelimbs for FLIGHT and in some species, CLIMBING or FOOT HANDLING
2. megachiropterans

   Annotations:

   • almost NO echolocation
   • fruit or nectar eaters 
   • NO tragus
   • NO nose or facial ornamentation
   • generally LARGE body size
   • LARGE eyes 
   • NO modification of cervical vertebrae
   • head VENTRAL when roosting
   • tail and uropatagium usually ABSENT 
   • postorbital process is WELL DEVELOPED 
   • Old World fruit bats, megabats 
   1. Pteropodidae

      Annotations:

      • flying foxes, fruit-eating bats
      • large ears, eyes 
      • flat-crowned molars for crushing fruit 
      • crepuscular or diurnal, can not fly in total darkness 
      • Ethiopian, Oriental, and Australian regions only 

Annotations:

• only VOLANT mammals
• pectoral area is MODIFIED
• fusion of last C and 1st 2 T vertebrae 
• t-shaped manubrium 
• STRONG RIBS for anchoring wings
• wing from skin (aka patagium) is stretched between ARM, WRIST, and FINGER bones
• patagium is THIN but RESISTANT TO TEARS and quick-healing 
• bones of arms and hands ELONGATE and SLENDER
• flight membranes: -plagiopatagium, chiropatagium, uropatagium (calcar may be present), and propatagium  
• modified SHOULDER LOCK in many species 
• flight muscles arranged for increased maneuverability 
• relatively SLOW but highly MANEUVERABLE
• wings provide both THRUST and LIFT
• wing profile is ASYMMETRICAL
• unequal pressures above and below wing generate LIFT

1. flight

   Annotations:

   • bats have relatively LOW wing loading (aka ratio of body weight to wing area)
   • many bats have LOW aspect ratio wings (aka ratio of wing span to wing chord)
   • downstroke is POWER stroke 
   • wing tips TWIST and provide additional thrust 
   • upstroke is RECOVERY stroke
2. sensing the environment

   Annotations:

   • nearly all bats have functional vision 
   • eyes LARGE in megabats
   • visual acuity secondary in MICROBATS
   • high-frequency acoustic orientation and audible vocalizationprimary means
   • ECHOLOCATION: the process of emitting sounds and using information from returning echoes to sense the surrounding environment 

1. Icaronycteris

   Annotations:

   • early EOCENE, ~52 million years ago 
   • claws on first two wing digits 
   • tiny remnants of claws on other hand digits 
   • long HUMERUS
   • short, broad wings 
   • could probably ECHOLOCATE 
   • bony adaptations of hyoid and ear region present 
2. 2 Main Clades

   Annotations:

   • Yinpterochiroptera
   • Yangochiroptera

Annotations:

• benefits outweight negatives
• most significant predator of nocturnal pest insects 
• pollinate ~200 economically imported plants 
• GUANO for fertilizer and gunpowder
• medical research
• population declines and range reductions 
• cave enclosures, destruction 
• loss of foraging or ROOSTING habitats (snags)
• siltation or DRAINING of riparian areas
• insecticide accumulation 
• pathogens/disease, including white-nose syndrome 
• changing perceptions of bats is KEY to conservation 

1. Negatives

   Annotations:

   • Bacterial, rickettsial, viral, and fungal diseases 
   • Rabies in <1-4% of members of the population (well below that seen in skunks, foxes, dogs, raccoons)
   • loss of LIVESTOCK to disease transmitted by vampires