Lecture 9 Flashcards
Bats are more closely related to _______ than they are to rodents
Whales, dolphins and hippos
Chiroptera
Second largest mammalian order
- 20 families
- 1500 living species
- Comprise 20% living mammals
True powered flight
Echolocation in most species
- 98% use echolocation
- Used to find prey and avoid bouncing into objects
Exploit wide array of foods
Cosmopolitan distribution
Temperate to tropical habitats
-Greatest diversity in tropical regions
Found all over the world (even most distant islands); only absent in extreme polar climates where insects can’t survive
Bat Evolution
Traced back to about 50Mya
Fossil possesses neomorph/calcar; looks like another toe in back, actualy used to connect flap of skin; acts as ankle spur to provide support
Which Evolved First: Echolocation or Flight?
FLIGHT evolved first
Features Onychonycteris finneyi shared with extant bats:
- Patagium
- Keeled sternum (projection of bone to allow for greater attachment of pectoralis muscles)
- Evidence of strong breast muscles associated with flight
Tragus
Flesh-like flap sits within the pinna to act as a secondary satellite dish and focus it into the base of the ear
2 Suborders in Chiroptera
Pteropodiformes
Vespertilioniformes
Order Chiroptera
Suborder Pteropodiformes
Family Pteropodidae
Family Craseonycteridae
Family Megadermatidae
Order Chiroptera
Suborder Vespertilioniformes
~15 families
Order Chiroptera
Suborder Pteropodiformes
Family Pteropodidae
Old World fruit bats or “flying foxes”
Largest up to 1.5kg (1.2m wingspan)
Some are small (13g and 245mm wingspan)
Non-echolocating bats
- Secondarily lost ability to echolocate
- A few species use tongue-click echolocation, different larynx-generation sounds
Tongue clicking also found in shrews (not as efficient as larynx production)
Fruit eaters, don’t need echolocation
NO tail membrane or tail
Hammerhead bats
- Males form communal leks
- -Lek: Congregation (usually males) to display to attract females
- Males have facial flaps to make honking sounds
Face with fox-like rostrum and large eyes
Ears lack tragus
Well-developed postorbital process/bar
2-clawed wing digits
-Except in Eonycteris and Dobsonia
Tail short and rudimentary
Eat fruit or nectar and pollen
Typically roose in colonies in trees
One species (Hammerhead bats) has unique mating strategy
- Males form communal leks
- Massive vocal apparatus
Echolocating bats
19 families
Tremendous variation
Nose leaf: Focuses out soundwaves being generated
Tragus: Acts as antenna
Bio-sonar: hearing so sophisticated that they can determine if what they’re hearing is a moth they want to eat
Most bats produce sound in their larynx
-Just 2 species use tongue clicks
Reflected sound provides information about objects
Brief pulses of sound
-0.25 to 100 milliseconds in duration
Frequency varies widely among species
- Mostly ultrasonic (above human hearing range)
- -14 Kilohertz to over 200KHz
- -Human audible signals produced by some bat species
- Complex calls
- -Species specific signatures (can use diagrams that measure sounds to ID species)
Mouth emitters use lips like megaphones
Face emitters:
- Horseshoe-like noses
- -Rhinolophidae, Hipposideridae
- Noseleaves
- -Nycteridae, Megadermatidae, and Phyllostomidae
Order Chiroptera
Suborder Pteropodiformes
Family Craseonycteridae
Smallest bat (tied for smallest mammal)
Adults weigh ~2g
Distr: Thailand and Myanmar
Pelvis and several lumbar vertebrae fused
Roost in caves, forage by gleaning
Highly endangered
Order Chiroptera
Suborder Pteropodiformes
Family Megadermatidae
Inhabit tropical forests and savannas, often near water
3 species are carnivorous, 2 insectivorous
Hunt partly by sight
-Uses echolocation BUT must use sight when hunting other bats, as they would hear them, too
Old World species
Prey of some species includes OTHER BATS
Order Chiroptera
Suborder Vespertilioniformes
Family Myzopodidae
Endemic to Madagascar
Very large ears, mushroom -shaped structure similar to a tragus
Thumb and sole of foot bear sucker disks
-Function by “glueing” not suction
One of 2 families with sucker-like disks at the sole of the foot; looks like a suction cup, extension of flesh tissue at wrist and ankle regions; secretes sweat-like material to “glue” to surfaces like leaves
Order Chiroptera
Suborder Vespertilioniformes
Family Noctilionidae
Bulldog/fisherman bats
Greater bulldog is a fish specialist
Mexico, West Indies, to northern Argentina
Heavy lips (resemble bulldog)
Pointed ears
Feet greatly enlarged, with sharp claws
Calcar ossified
Lesser bulldog bat primarily insectivorous
Greater bulldog bat catches fish by trawling with claws in water
Roost during the day in groups in hollow trees and rock fissures, caves, and even buildings
Order Chiroptera
Suborder Vespertilioniformes
Family Phyllostomidae
Neotropical distribution
Conspicuous nose leaf
Wide diversity in morphology and ecology
- Insectivorous, carnivorous, frugivorous, nectivorous
- -Vampyrum is large and carnivorous
- -Trachos specializes on frogs
- -Choeronycteris feeds on nectar
- -Artibeus feeds on tropical fruits
