I stay on Paros for a couple of months each year and several friends visit me from Holland.
One of them I’ve known for years as we were both members of a youth nature study organisation’s ‘mammal workgroup’.
My friend Martijn brings a device called a “bat-detector” which makes audible to the human ear the high frequency sounds that bats emit. With this, and of course a tape recorder, we go out several nights to places we think will be hotspots for bats.
Bats are the only flying mammals. These tiny, intelligent, creatures fly and find their way in the dark searching for food. While flying, they produce sounds between 10 and 120 kHz depending on the species - some use a lower frequency band, others higher. If you clap your hands in a dark room it is possible to estimate the dimensions of the room and even the distance to a wall. This is roughly the system that bats use, but of course in a much more advanced way. Bats call several times per second, not only to ‘look’ at their surroundings but also to locate their prey - insects. This is probably the main reason why they use such a high frequency, so that the soundwaves remain focused and don’t spread out in all directions. We found it very interesting that the bats here on Paros use a slightly higher frequency than the same species in Holland - we have not found a reasonable explanation for this yet.
You can identify different principles in wingshapes, such as the thick hollow wings of birds and aeroplanes; the thin flat wings of insects and thin hollow wings that we find with bats - the same shape as used for hang-gliders. The wingshape of bats allows them to make quick turns to collect insects. On warm summer evenings one can watch their acrobatic manoeuvres near streetlights. It is not the light that attracts the bats, but the insects attracted by that light.
On Paros, we were surprised to find the Blasius horseshoe bat, which appeared at one of our expected hotspots at the old marble mine near Marathi. In and around the village of Kostos we heard Common Pipistrelle and Kulls’ Pipistrelle.
Another hotspot we had in mind was the duckpond close to the sea in Drios, as bats like to be close to fresh water. Although we did not find any particularly noteworthy species here, several different types of pipistrelles were flying around and nearby, over the promenade along the seashore, we found one Savi’s Pipistrelle.
These small, winged, hairy, peculiar faced predators with their sophisticated night vision are to me quite fascinating, for they have developed such an individual lifestyle and, besides, one can also be grateful that they do their part in catching mosquitoes!
Ed: To finish off, here’s a quote from Bat Conservation International Inc. (see www.batcon.org for more info):
“Many things people think they know about bats aren’t even true. Bats aren’t blind, they’re not rodents and they won’t get tangled in your hair. The truth is that bats are among the most gentle, beneficial and necessary animals on earth. But because of centuries of myth and superstition, they are also among the world’s least appreciated and most endanged animals.”