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Method & Materials

Study site and time

Fieldwork for the study was conducted in Linköping, Sweden, within Tinnerö Eklandskap. The time of fieldwork was between June and July, which is the time during the bat-season when all bats are present and active, with bat movement being more limited since the young is greatly dependent on their mothers during this time (Gerell & Gerell Lundberg 2003; Claesson et al. 2004; Dietz et al. 2009).

Equipment

High frequency detector (left) and MP3-recorder (right). Photo by Lina Sjöstrand.

A high frequency detector and a WAVE/MP3-recorder was used to detect and record bat observations and the identifications sofware were Omnibat and Batsound.

A wireless weather station to collect messurements of temperature, moist and air pressure was used while Sweden's Meterological and Hydrological Institutes website was used for determining how much moonlight was visible.

Data processing

I gathered data from six full nights (from sunset to sunrise) and put all species occurrence patterns together to determine when all observed species where active.

To discover the temporal change in activity I used Webster's method (Legendre & Legendre 1998) on the summed observations for the five most frequent species for each of the six full nights.

Linear regression was performed on weather data from nine nights to determine if there was a connection between different weather factors to the frequency of bat species and the sum of bat observations. All weather-parameters were also tested against the sum of Nyctalus noctula and Myotis daubentonii, the two most frequent species in this part of the study.

References

Gerell R, Gerell Lundberg K (2003) Övervakning av fladdermöss i Skåne.Environmental Protection Agency of Scania: Malmö. (Swedish)

Dietz C,nvon Helversen O, Nill D (2009) Bats of Britain, Europe & Northwest Africa. A & C Black Publishers Ltd: London.

Claesson K, Askling J, Ignell H (2004) Fladdermöss i Östergötland Resultat från inventeringar utförda 1978 - 2004. LÄNSSTYRELSEN ÖSTERGÖTLAND Miljövårdsenheten. (Swedish)

Legendre, P. & Legendre, L. (1998) Numerical ecology. Elsevier Science Ltd: Amsterdam.


Responsible for this page: Agneta Johansson
Last updated: 05/16/13