Q1. Surveying three different locations in a 1-km square is not feasible in the remote area that I would like to record in. We ask that whenever surveyors are intending to survey squares that they can easily access on a daily basis, that they follow the standard protocol of 3 different locations per square. In other squares, we are happy for detectors to be left in one location, as close as possible to the centre of the square. Ideally in this situation detectors should be left to record for 3 days. However, where this is not possible, a shorter run of 1 or 2 days is permissible. [we recommend this knowing that where there is high bat activity, the batteries of the detector will not last for the complete three nights].
Q2. We have our own bat detector, can we use this for the survey? We are very keen for anyone who has a similar full spectrum static bat detector to use this. We are using full spectrum detectors because they give us the best chance to identify some of the more cryptic species. Unfortunately we are not able to make use records or recordings made on heterodyne, frequency, division, time-expansion or zero-crossing (e.g. Anabat) detectors. If you have an SM2Bat+ or similar full spectrum detector – you can download information on the filter and audio settings used HERE.
Q4. I have heard some species of bats are very difficult to identify from recordings, how well is this equipment able to distinguish species? This project aims to address a problem that only a few species of bats can be identified with any confidence using simple (heterodyne or frequency division) detectors. This project uses a full-spectrum detector, which produces high quality sound files, which give us the best chance of distinguishing species.
However there is one family of bats, known as Myotis bats, which are very similar acoustically. In Norfolk this includes Daubenton’s, Natterer’s, Whiskered and Brandt’s bats, with Whiskered and Brandt’s being the most difficult species pair to distinguish. Until discrimination of this family improves (see Q1), we will only assign recordings to species where there is good evidence to support this. In addition, the project is working closely with the Norfolk Barbastelle Study Group and Norfolk Woodland Myotis Study Group to ground truth identification of bats in the hand (using mist-netting), at a sample of sites where these species are recorded through the project, where there is access permission.
Q5. I have had a problem trying to reserve my 1-km square using your online map. What can I do? If you have a problem, please email us directly at firstname.lastname@example.org letting us know what 1-km square or squares you are interested in covering.