Bat migration project started at Ottenby

During this autumn, 15 August to 15 October 2009, CAnMove representatives will be monitoring the bat migration at Ottenby, southern tip of the island Öland in the Baltic Sea. This is a famous place regarding bird migration with a bird observatory estblished in 1946 and still running. That bats migrate at Ottenby has been known from the use of bat detectors, but hitherto no systematic study has been conducted. This year the bat activity will be monitored using a new bat detector, D500X, which automatically records bat sounds and save them as sound files for analysis. We use 5 units of the D500X, strategically placed around the southern tip of Öland. Only in the first week of field work several hundred of files containing bats have been recorded, although several nights have been windy with rather low bat activity. We have also tried to catch bats for ringing, but only few bats have been caught so far. The most common species recorded so far is Pipistrellus pygmaeus, follwed by P. nathusii and Nyctalus noctula. We have also recorded a few Pipistrellus pipistrellus (a more continental species), Myotis daubentoni, Eptesicus nilsonii and E. serotinus. More species may be hidden among the many files not yet analysed. We expect increasing number of P. nathusii as it is known to be migrating in large numbers along the opposite side of the Baltic (e.g. Latvia). The field work is carried out by Master Student Laura Guia, and during the first week we have also been helped by german bat expert Lothar Bach, who has itroduced us into the art of catching and identifying bats, both in the hand and from sound recordings. The project will also inlcude an attempt to track bats using radio transmitters.

Even if the knowledge about bat migration lags behind that of birds, we will hopefully learn more from this project.

The pictures show (from the top):

Lång Jan, the majestic light house on southern Öland (upper left).

The bat detector D500X (Upper right).

A D500X is being placed on the shore at sun-set by Lothar Bach and Laura Guia (center left).

A D500X being rigged for the night, using local geological attributes (center right).

Catching a bat in net (lower left).

A long-eared beuty Plecotus auritus (lower right)