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<h1>Durham Bat Group home page</h1>
<p>Dates and venues of bat walks and meetings, Bat calls, reports
on bat activity, and soon to be added a map of recorded sightings throughout the Durham
bat group area.</p>
<h3>Introduction: What Are Bats?</h3>
<p>Bats (Chiroptera) are mammals that have evolved to fly.
My interest is mostly in British bats (MicroChiroptera). These feed on flying insects and
avoid predators by hunting just after dusk and sometimes before dawn. (They are
'crepuscular'.) Bats are warm blooded, so prefer warm conditions, and they hibernate when
it is cold. Although their sight is quite good, they use sonar to help them navigate
around obstacles and locate their prey in the dark .<br>
<br>
<img src="images/sonar.gif" alt="sonar.gif (7299 bytes)" align="left"
border="0" hspace="5" width="220" height="158">The bat makes a loud noise, at a pitch
above our hearing range. (Long eared bats have super sensitive hearing and so can use
quieter sounds.) The reflected sound is interpreted by the bat to form a kind of picture
of its surroundings. We can transform the sound from the bat to a
lower pitch with a bat detector, so that we can hear it. </p>
<p>You can access some of the pages in this frameset by clicking on the links below.</p>
<p> </p>
<p> </p>
<p><a href="durham.htm">Durham Bat Group</a></p>
<p><a href="batsindurham.htm">Bats in Durham</a></p>
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