Bat Radar (Echolocation) and other bat matters

"Chiroptera" from Ernst Haeckel's Kunstformen der Natur, 1904.


Townsend's big-eared bat, Corynorhinus townsendii.

Wiki:

Bats are flying mammals in the order Chiroptera (pronounced /kaɪˈrɒptərə/). The forelimbs of bats are webbed and developed as wings, making them the only mammals naturally capable of true and sustained flight. By contrast, other mammals said to fly, such as flying squirrels, gliding possums and colugos, glide rather than fly, and can only glide for short distances. Bats do not flap their entire forelimbs, as birds do, but instead flap their spread out digits, which are very long and covered with a thin membrane or patagium. Chiroptera comes from two Greek words, cheir (χείρ) "hand" and pteron (πτερόν) "wing."

There are about 1,240 bat species worldwide, which represent about twenty percent of all classified mammal species.[3] About seventy percent of bats are insectivores. Most of the rest are frugivores, or fruit eaters. A few species such as the Fish-eating Bat feed from animals other than insects, with the vampire bats being the only mammalian parasite species. Bats are present throughout most of the world and perform vital ecological roles such as pollinating flowers and dispersing fruit seeds. Many tropical plant species depend entirely on bats for the distribution of their seeds.

The smallest bat is the Kitti's Hog-nosed Bat, measuring 29–34 mm (1.14–1.34 in) in length, 15 cm (5.91 in) across the wings and 2–2.6 g (0.07–0.09 oz) in mass.[4][5] It is also arguably the smallest extant species of mammal, with the Etruscan shrew being the other contender.[citation needed] The largest species of bat is the Giant Golden-crowned Flying-fox, which is 336–343 mm (13.23–13.50 in) long, has a wingspan of 1.5 m (4 ft 11 in) and weighs approximately 1.1–1.2 kg (2–3 lb).

A depiction of the ultrasound signals emitted by a bat, and the echo from a nearby object.

Wiki:

Echolocation, also called biosonar, is the biological sonar used by several animals, most notably microchiropteran bats and odontocetes (toothed whales and dolphins), but has also been demonstrated in simpler form in other groups such as shrews, one genus of megachiropteran bats (Rousettus) and two cave dwelling bird groups, the so called cave swiftlets in the genus Aerodramus (formerly Collocalia) and the unrelated Oilbird Steatornis caripensis. The term echolocation was coined by Donald Griffin, whose work with Robert Galambos was the first to conclusively demonstrate its existence in bats in 1938. However, long before that, the Italian 18th century scientist Lazzaro Spallanzani had, by means of a series of elaborate experiments concluded that bats navigated by hearing and not vision. Echolocation in odontocetes was not properly described before two decades later, by Schevill and McBride.

Echolocating animals emit calls out to the environment and listen to the echoes of those calls that return from various objects in the environment. They use these echoes to locate, range, and identify the objects. Echolocation is used for navigation and for foraging (or hunting) in various environments.

Spectrogram of Pipistrellus Bat vocalizations. Detail is shown as the pulses transition to a faster repetition rate. The bat appears to use a hybrid pulse which combines a sharp falling frequency chirp with an extended constant frequency tail. Such a waveform may offer combined benefits of range estimation as well as Doppler shift detection. Spectrogram generated with Fatpigdog's PC based Real Time FFT Spectrum Analyzer.

Sketch of the regions of the auditory cortex in a bat's brain.

Quite apart from hunting for food, you can see why such a skill would be necessary in a bat colony:

Skeleton of Geater Mouse-Eared Bat (Myotis myotis).

Scapulae, spine and ribs of Myotis lucifugus (Little Brown Bat).

Giant Golden-crowned Flying-fox, Acerodon jubatus.

Newborn common Pipistrellus pipistrellus.

Colony of Mouse-eared bats, Myotis myotis.

A colony of Great Fruit-eating bats.

Bat feeding.

A Vampire Bat feeding on a pig.

THE BAT IN POPULAR CULTURE:

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Christopher Lee as Count Dracula.

Batman made his debut in Detective Comics #27 (May 1939). Cover art by Bob Kane.

Several years ago my mom had bats living in the crawl space of her attic. Because they are a protected species, you can't just kill them, you have to find someone who will plug all their entrance holes except for one and then make that last one so that they can get out for the night but not back in. It was very freaky hearing all these bats scratching around when they would fly back into the attic at dawn, trying to get settled in for the day. Every so often one would fall down thru the walls into the basement, and oh my, did that ever cause a freak out! Thankfully, the bat-guy was able to get rid of them for her.

MANBAT!