Chiroptera (hand-wing)

Order Chiroptera The only true flying mammals Date to Eocene epoch (50 mya) worldwide 17 families 170 genera 850 species suborders Megachiroptera-flying foxes of tropics Microchiroptera-worldwide

Vertebrate Flight True flight is found in 3 vertebrate groups. Reptiles (Pterosaurs etc) Aves Mammalia Many vertebrate glider groups, including mammals, frogs, geckos, lizards, snakes, and fish.

Some Weirdness. Bats do a number of interesting morphological things. Musculature differences. Forearm specialization. Modification of the shoulder. Hind limb rotation. Tricks w/ echolocation.

Characteristics Can carry rabies Small bats eat insects Large bats eat fruit Vampire bats (3 species) feed on blood:live in Central and South America 14 Species of Bats in Idaho

Little Brown Myotis Myotis lucifugus

Little Brown Myotis Just the facts: 6-9 grams may live to 25 years favors ponds and streams for foraging forages at about 13 mph, 3-6 m above ground mate in early autumn; fertilization in spring upon rousing; 50-60 day gestation move to maternity colonies of hundreds born after 30 minute labor in late May weighing1.5 grams reaches sexual maturity at 8 mos.

notch

Silver Haired Bat Lasionycteris noctivagans Feeds on small to medium sized flying insects over small water bodies in conifer forests. Found throughout Idaho

Big Brown Bat Eptesicus fuscus

Hoary Bat Lasiurus cinereus

Vampire Bat

Megachiroptera Pteropodidae 36 genera and 154 species of tropical and subtropical Old World fruit and nectar feeding bats. Predominantly nocturnal, with body sizes ranging from 15g to 1.6Kg. They do not echolocate like micro-chiroptera, they are specialized for feeding on fruit and nectar (note teeth and palates: they do not consume pulp), and they have odd eye structures.

Basic Physical Requirements of Vertebrate Flight Need for a lifting surface each group evolved wings. Means of propulsion again, wings provide thrust. Control of stability wt. Concentrated near center of mass for metabolic efficiency decreased wt. of appendages increased appendage manageability Physiological and CNS changes.

Echolocation True echolocation occurs only in the Microchiroptera. Sound is produced in the larynx. Sound is emitted through the nose or the open mouth. Echolocation works in a similar way to sonar. Bats make calls as they fly and listen to the returning echoes to build up a sonic map of their surroundings. The bat can tell how far away something is by how long it takes the sounds to return to them. These calls are usually pitched at a frequency too high for adult humans to hear naturally. Human hearing ranges from approximately 20Hz (cycles per second) to 15 to 20 kHz (1000Hz) depending on age. In comparison, some bats can hear sounds up to 110 kHz in frequency. By emitting a series of often quite loud ultrasounds that either sweep from a high to low frequency or vary around a frequency, bats can distinguish objects and their insect prey and therefore avoid the object or catch the insect. Individual bat species echolocate within specific frequency ranges that suit their environment and prey types. This means that we can identify many bats simply by listening to their calls with bat detectors.

Bat Diversity Earliest bat fossils are from the early Eocene of North America: Icaronycteris index There are no intermediate forms - earliest bats are good bats. Underived characters include 38 teeth (compared to 44 for underived eutherian number).

Bat Diversity Icaronycteris was capable of flight and echolocation, but lacked a keeled sternum. Icaronyceris had only partial fusion of the radius and ulna, and dorsal position of the scapula. Earliest megachiroptera are from the early Oligocene of Europe and Africa Archaeopteropus and Propotto.

Bat Diversity As is often the case in biology, there has been a rather ugly controversy concerning the evolutionary history of the megachiroptera and microchiroptera. Are they diphyletic or monophyletic?