HermitIbis
Well-known member
You are right, I should better focus on the real bats, there are enough of them. As you said in an earlier post: "... Lakes or Rivers where you tend you hit hotspots quite frequently.." Pforzheim's rivers were a perfect starting area for me. One of my sonograms had four different bat species. Yesterday I saw three Daubenton's bats at the same time in a calm section of the Enz, in the center of the city. So we definitely have a large bat population here. :t:Don't know.. Another possible gotcha is electrical interference from an alarm system pulsing or similar.. I must admit, much of my recordings are skipped thru until the classic sine wave of a series of definite bat calls is found.
Now I believe the "Park Bats" were in fact park rats, or some other rodent. The recordings made on Saturday and Monday gave a hint: these walks of mine had overlapped only in a short segment. By narrowing down the place to a few dozens of metres, it was easy to solve the puzzle. Yes, I had paused there on Saturday, near the river, for some recording. - The closer I was to the shore today, the stronger the whistles. It became clear why some calls had "holes": it is the same phenomenon which can happen with Daubenton's calls: they fly so close to the water that the call is reflected by the surface, and the echoes eradicate parts of the original call. Similar effects could be expected in the case of "water-rats" or other shore-inhabitating rodents.