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REPORT TEXT by Afra Hanify Auly Avecenia. GENERAL. Bats : mammals forelimbs wings can fly. (the only mammals naturally capable of true and sustained flight) do not flap their entire forelimbs (flap their spread out digits)
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GENERAL Bats : mammals forelimbs wings can fly. (the only mammals naturally capable of true and sustained flight) do not flap their entire forelimbs (flap their spread out digits) Chiroptera
about 1,100 bat species worldwide • 20% classified mammal species • 70% Insectivores • 10 % frugivores, or fruit eaters • Many tropical plants depend entirely on bats for the distribution of their seeds (perform vital ecological roles such as pollinating flowers and dispersing fruit seeds)
Echolocation • a perceptual system ultrasonic sounds are emitted to produce echoes. • By comparing outgoing pulse returning echoes brain and auditory nervous system detailed images of the bat's surroundings
allows bats to detect, localize and even classify their prey in complete darkness. At 130 decibels in intensity, bat calls are some of the most intense airborne animal sounds. • In order to distinguish returning information, bats need to be able to separate their calls from the echoes they are receiving. Within the former microbats there are two distinct approaches. 1.Low Duty Cycle Echolocation 2. High Duty Cycle Echolocation
1.Low Duty Cycle Echolocation: Separate their calls and returning echos in time. use this approach time their short calls to finish before echoes return. important because these bats contract their middle ear muscles when emitting a call in order to avoid deafening themselves. The time interval between call and echo allows them to relax these muscles so they can clearly hear the returning echo. 2. High Duty Cycle Echolocation: emit a continuous call and separate pulse and echo in frequency receive echoes back at the finely tuned frequency range by taking advantage of the Doppler shift of their motion in flight, have adapted to change their pulse emission frequency in relation to their flight speed so echoes still return in the optimal hearing range.
WINGS • The finger bones of bats are much more flexible • the cartilage in their fingers lacks calcium and other minerals nearer the tips • The cross-section of the finger bone is flattened • The skin on their wing membranes has more elasticity and so can stretch much more than other mammals. • much thinner can manoeuvre more quickly and more accurately
able to regrow, can heal quickly. • The wings is equipped with touch-sensitive receptors on small bumps called Merkel cells • These sensitive areas are different in bats as each bump has a tiny hair in the center,making it even more sensitive and allowing the bat to detect and collect information about the air flowing over its wings • Some bats like the little brown bat can use this
Reproduction • Most bats have a breeding season • have one to three litters in a season • Females generally have one offspring at a time. • Female bats nurse their youngster until it has grown nearly to adult size • Females of some species have delayed fertilization, in which sperm are stored in the reproductive tract for several months after mating.
another strategy, fertilization and implantation both occur but development of the fetus is delayed until favorable conditions prevail • All of these adaptations result in the pup being born during a time of high local production of fruit or insects • A single bat can live over 20 years
Fooding food consumed includes: • Insects • Fruits and flower nectar • Vertebrates • Blood
Hunting • Bats are nocturnal creatures. • daylight hours : grooming, sleeping, and resting • nighttime hours that they hunt • The means by which bats navigate while finding and catching their prey in the dark was unknown • until the 1790s LazzaroSpallanzani conducted a series of experiments & concluded that • bats were not using their eyes to fly through complete darkness • bats were able to catch and find their prey through the use of their ears • bats use their ears to locate and catch their prey