Humans can\nnormally hear in the 20 to 20 kHz (20,000Hz) range, but we will lose the\nability to hear higher frequencies as we age. Any sound with a\nfrequency below the audible range of hearing (i.e., less than 20 Hz) is known\nas an infrasound\n<\/strong>and any sound with a frequency above the audible range of\nhearing (i.e., more than 20 000 Hz) is known as an ultrasound<\/strong>.<\/p>\n\n\n\n Bat detectors have a microphone and a speaker. Our bat detectors also have a frequency dial that allows us to set the incoming frequency to the bat species we might be looking for; during our bat walks we will change the incoming frequency during our walks looking for the different species of bats.<\/p>\n\n\n\n Bat detectors can work in a number of different ways. Our bat detectors are known as heterodyne bat detectors.<\/p>\n\n\n\n They work by filtering the ultrasonic (and therefore inaudible) bat sound with an ultrasonic signal from the detector, and producing the audible difference between the two sounds. If you set the bat detector to 50 kHz and the incoming bat call has a peak frequency of 49 kHz the detector will play the call at 1 kHz which we can hear. Bats though usually call across a range of frequencies creating audible sounds that can be characteristic of the species. To confirm our ID we can also look at the the call using computer programmes to analyse the structure of the call. <\/p>\n\n\n\n Bats detect their\nprey using echolocation. They shout out sounds and listen to the echoes; these\ngive them details of the size, shape and direction of their prey. Bats also\nhave social calls for communicating with their neighbours.\n<\/p>\n\n\n\n Typically\necholocation calls have a well-defined structure and are generally consistent;\nif not exactly species specific they can produce characteristic frequencies and\ngeneric call structures. <\/p>\n\n\n\n If you have a\nheterodyne bat detector why not wander around Pittville Park, or other parks in\nCheltenham, looking out for their flight patterns, and listening out for their\ncalls.<\/p>\n\n\n\n These produce a\nseries of loud, fast clicks that are often referred to as sounding like \u201cwet\nslaps\u201d. Their call will be the loudest around 45 kHz. We often begin our bat\nwalks with our detectors set at 45 kHz as we listen out for our most common bat\nspecies.<\/p>\n\n\n\n These sound very\nsimilar to the common pipistrelle but their calls are loudest at 55 kHz. You\nmight also hear their call at 45 kHz but when you retune the detector to 55 kHz\nit will sound louder.<\/p>\n\n\n\n These bats\nproduce the loudest calls of all the British bat species. While echolocating\nthey produce two alternating call types at different frequencies (about 19 kHz\nand 24 kHz) this produces a \u201cchip-chop-chip-chop\u201d sound. Their calls are slower\nthan the pipistrelles.<\/p>\n\n\n\n They produce a\nseries of very rapid clicks. The repetition rate is very fast and regular when\ncompared to pipistrelles. The call will sound the loudest around 45 kHz but can\nbe distinguished from the pipistrelles by tuning down below the frequencies of\nthe pipistrelles to 35 kHz where dry \u201cclicking\u201d sounds can be heard. Caution is\nneeded to identify these bats based on their calls as several related bats also\nhave similar calls.<\/p>\n","protected":false},"excerpt":{"rendered":" Updates on types of bat detectors and how they work.<\/p>\n","protected":false},"author":53,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[3],"tags":[],"class_list":["post-332","post","type-post","status-publish","format-standard","hentry","category-bats"],"blocksy_meta":{"styles_descriptor":{"styles":{"desktop":"","tablet":"","mobile":""},"google_fonts":[],"version":6}},"acf":[],"_links":{"self":[{"href":"https:\/\/sites.glos.ac.uk\/bats\/wp-json\/wp\/v2\/posts\/332","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sites.glos.ac.uk\/bats\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/sites.glos.ac.uk\/bats\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/sites.glos.ac.uk\/bats\/wp-json\/wp\/v2\/users\/53"}],"replies":[{"embeddable":true,"href":"https:\/\/sites.glos.ac.uk\/bats\/wp-json\/wp\/v2\/comments?post=332"}],"version-history":[{"count":2,"href":"https:\/\/sites.glos.ac.uk\/bats\/wp-json\/wp\/v2\/posts\/332\/revisions"}],"predecessor-version":[{"id":495,"href":"https:\/\/sites.glos.ac.uk\/bats\/wp-json\/wp\/v2\/posts\/332\/revisions\/495"}],"wp:attachment":[{"href":"https:\/\/sites.glos.ac.uk\/bats\/wp-json\/wp\/v2\/media?parent=332"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/sites.glos.ac.uk\/bats\/wp-json\/wp\/v2\/categories?post=332"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/sites.glos.ac.uk\/bats\/wp-json\/wp\/v2\/tags?post=332"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}![\"\"](\"https:\/\/sites.glos.ac.uk\/bats\/wp-content\/uploads\/sites\/159\/sites\/325\/2019\/11\/15.jpg\")
Why do bats call?<\/h2>\n\n\n\n
What echolocation calls to listen out for at Pittville Park?<\/h2>\n\n\n\n
Common pipistrelles<\/h2>\n\n\n\n
Soprano pipistrelles <\/h2>\n\n\n\n
Noctule<\/h2>\n\n\n\n
Daubenton\u2019s<\/h2>\n\n\n\n