Morphology, ecology, and behavior

Transcription

1 ORDER DERMOPTERA Distribution rich fossil record, much larger geographic distribution one genus (Cynocephalus), and 2 very distinct species Current distribution: Oriental 1 Morphology, ecology, and behavior Membrane exending from forelimbs to hindlimbs Glissant: 2 1. Dermopteran skeleton kg Morphology 3

2 Pectinate Lower Incisors grooming scraping leaves [Fig ] 4 Ecology and Behavior Diet: Very long intestine and caecum May be hunted for meat and/or fur Crepuscular 5 ORDER CHIROPTERA 18 families, 178 genera, 926 species (the second largest mammalian order) Merlin Tuttle and Bat Conservation International (BCI) 6

3 Bat Morphology 1. Forelimb modified for flight [figs. 5.16, 12.1] A. Wing membrane supported by elongate metacarpals and digits Bat Morphology 1. A. B. flight membranes are highly elastic, one of the fastest-healing of vertebrate tissues 8 Bat Morphology 2. Modification of shoulder girdle and musculature for maneuverable wing A. Sternum usually keeled B. Clavicle present 9

4 Characters, cont. Uropatagium [fig. 12.2a] in most bats Calcar to support uropatgium 10 Characters, cont. 3. Hindlimbs relatively small, knee directed outward and backward A. specialized tendons 11 Bat Flight Typical bats are slow, fluttering fliers, typical birds are fast, soaring fliers. Dr. Steven Carr mun.ca/biology/scarr/2900_aerodynamics.htm 12

5 Hovering Flight in Bats Photographs showing wing movements in a nectar-feeding Bat. 13 Aspect Ratio Aspect Ratio = Wing Span 2 / Wing Area rapid flight long narrow wings and high Aspect Ratios slower, more maneuverable flight lower Aspect Ratios 14 Fig Increasing wing aspect ratios. 15

6 Bat Wing Types The Fruit-Eating Bat (Artibeus) Western Mastiff Bat (Eumops) mun.ca/biology/scarr/bat_wing_aspect_ratio.htm 16 Wing Loading 1. Body Weight/Wing Area 2. Bats have low Wing Loadings 3. The lower the Wing Loading Number the slower a bat can fly and still maintain enough lift to stay aloft. 17 Diet 18

7 CLASSIFICATION Bats are subdivided into two suborders 1. Megachiroptera 2. Microchiroptera [Table 12.1, Fig ]. 19 Suborder Megachiroptera-- "flying foxes" Family Pteropodidae--Old World fruit bats [figs ] 42 genera, 166 species 20 Pteropodidae Distribution Oriental, Ethiopian, Middle East, Australian, and the Caroline and Cook islands 21

8 Morphology Body mass: g wingspan up to 2 m. 22 Morphology mostly nocturnal only Roussettus echolocates no nose or facial ornaments pinna simple (no tragus) second digit of wing free of third, usually clawed 23 Diet frugivores and nectivores pollinators and seed dispersers teeth are specialized for a fruit diet 24

9 Behavior do not hibernate communal roosts 25 Hypsignathus monstrosus [fig ] Hammer-headed bat larynx fills most of chest cavity, 26 Hammer-headed Bat Leks [courtship arenas] 1. males establish and defend a lek 2. topis 3. typical Hypsignathus lek 4. batcon.org/batsmag/v13n1-6.html 27

10 Suborder MICROCHIROPTERA 17 families 136 genera 760 species Family Emballonuridae Family Craseonycteridae Family Rhinopomatidae Family Nycteridae Family Megadermatidae Family Rhinolophidae Family Phyllostomidae Family Mormoopidae Family Noctilionidae Family Mystacinidae Family Molossidae Family Myzopodidae Family Thyropteridae Family Furipteridae Family Natalidae Family Vespertilionidae 28 Echolocation Ultrasonic sounds produced in larynx and emitted through nose or mouth Microbats use for navigation and prey capture 29 Ultrasound human hearing: 40 Hz to 20 khz bat hearing: 20 khz to 120 khz (some bats up to 210 khz) Advantages of high frequency sound 1. Short range: 2. predators 3. discrimination 30

11 Oral emitters versus Nasal emitters 31 Sound Wars Fenton. Spring 2002, Bats Magazine 20(1) batcon.org/batsmag/v20n1-02.html 32 Bat versus cricket Sound Wars Bat versus moth Fullard 1991, Bats 9(2):7-9 spotted bats (Euderma maculatum) Fenton. Spring 2002, Bats Magazine 20(1) 33

12 More Characteristics many are heterothermic and hibernate pinna often complex, tragus or antitragus present nose or facial ornaments often present second digit of wing without claw, completely enclosed in wing membrane Fishing bats Noctilionidae 36

13 Family Phyllostomidae genera, 141 species 2. Southwestern U.S., Mexico, Neotropical 3. conspicuous nose leaf present on muzzle [fig A]. animaldiversity.ummz.umich.edu/media/anat/family _pages/chiroptera/phyllostomidae2.jpg 37 variable diets:. insects, lizards, rodents fruit eaters [fig 10-30] Nectar and Pollen feeders Bat tongue in nectivores Frog eating bat 38 Desmodontinae [fig 10-31, 10.32] Vampire bats sanguivores Diphylla is known from a single record in west Texas 39

14 Feeding behavior of Desmodus Desmodus batcon.org/batsmag/v9n1-3.html 41 Adaptations for Sanguivory highly modified teeth three pits in hairless skin surrounding nose tongue with grooves at border anticoagulant in saliva 42

15 Desmodus may consume 40% body weight per feeding livestock problem: disease transmission 43 Family Vespertilionidae 1. cosmopolitan 2. most speciose family: 35 genera, 318 species 3. tragus prominent [fig C] 4. tail extends to margin of uropatagium 5. mainly insectivorous 6. Vespertilionids known from Kleberg County 44 Vespertilionid skull morphology 45

16 Family Molossidae Free-tailed Bats Cosmopolitan 12 genera, 80 species Insectivorous Texas molossids: tail extends well beyond margin of uropatagium 46 Molossidae fastest flying of the bats A. B. C. 47 Free-tailed Bat Roosts Carlsbad Caverns Congress Avenue Bridge, Austin Bracken Cave eat up to 200 tons of insects per night. 48

17 Crasseonycteridae Crassonycteris thonglonyai Kitti s hog-nosed bat bumble-bee bat 30 mm g Perhaps, the smallest mammal 49 Reproductive Variations in Mammals A. Spontaneous Ovulation B. Induced Ovulation C. Delayed Fertilization D. Delayed Implantation E. Delayed Development 50 (C) Delayed Fertilization 51

18 Delayed Fertilization Common in hibernating, north temperate insect eating bats Copulation usually occurs before hibernation (September and October) Female stores sperm. in the spring, fertilization takes place 52 Pattern in Myotis lucifigus 1. in the spring. 2. spermatogenesis 3. copulation motile sperm stored 4. ovulation and fertilization after female emerges from hibernation. 53 Delayed Fertilization Adaptation to winter dormancy. Availability of food. spermatogenesis. Females, 54

19 (D) Delayed Implantation 55 Delayed Implantation Implantation of the fertilized blastocyst is delayed until environmental conditions are favorable (weather, food) Occurs in many eutherian orders including some bats, insectivorans, armadillos, carnivores (bears, mustelids, all pinnipeds), and artiodactyls Obligate or facultative 56 Delayed Development both micro- and macrochiropterans Blastocyst implants after fertilization, but the development is slow Why? 57

20 Delayed Development a synchronizing strategy as in delayed implantation; related to. 58 Adaptive hypothermia hibernation: prolonged and controlled profound dormancy associated with: A B C D 59 Thermoregulation true hibernators: Tachyglossus, some marsupials (Dromiciops; Burramys) ground squirrels, marmots (largest true hibernator), hedgehogs, Madagascan fat-tailed dwarf lemur (Cheirogaleus medius), some bats (e.g., Myotis lucifigus [little brown bat]) - many bats migrate duration varies for Myotis: 60

21 Arousal from Hibernation energetically expensive hibernators periodically arouse themselves. 61 Migration Some populations of Tadarida migrate more than 1600 km. 62 Bat Conservation Habitat destruction/fragmentation Loss of historical roost sites Disturbance of roost sites, esp. caves Pesticides Ignorance: General public: negative attitudes Scientific: Very little is known about the distribution, numbers and specific requirements of most bat species 63