Bats and wind power – investigations required for risk assessment in Denmark and Sweden

Ingemar Ahlén, Hans J. Baagøe

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    Abstract

    Ingemar Ahlén1 & Hans J. Baagøe2
    1Department of Ecology, SLU, Box 7002 (Natur icum), SE-750 07
    Uppsala, Sweden, [email protected]
    2Natura l History Museum of Denmark, Zoological Museum,
    Universitetsparken 15, DK-2100 Copenhagen Ø, Denmark
    Bats and wind power – investigations required for risk assessment in
    Denmark and Sweden
    We experienced an urgent need among authorities and consultancies to get
    clear guidelines for planning and field investigations at suggested wind parks.
    Certain minimum conditions must be fulfilled concerning evaluation of the
    project area, timing of investigations etc. to provide data necessary for a
    meaningful risk assessment.
    We prepared “Guidelines for bat investigations prior to wind projects” for
    distribution to authorities. Recommendations were based on our research on
    bat ecology and behaviour at wind power installations and our many years of
    experience of bat occurrence and behaviour in the landscape. To avoid misunderstandings
    our guidelines are detailed and carefully argumented, but only
    the headline contents can be given here:
    Current knowledge justifies an introductory classification of project areas
    into three categories: 1. high risk sites, 2. uncertain but possible, 3. low risk
    already documented. Only category 2 needs field investigations, while 1 should
    be stopped and 3 can go on. This will speed up the planning process and minimize
    expensive field investigations to the areas in most need of risk assessments.
    Field investigations require studies on activity and species composition
    in a project area also including suitable colony habitats and hunting sites
    within a radius of at least 2 km. Methods include automatic registration,
    detector listening etc. to ensure data on species presence, number of observations
    and facts on activity and status. Investigations are obligatory for the
    following periods: A) At least two separate nights in the breeding season (late
    June – early August), B) two nights in mid-August to mid-September when
    bats migrate or disperse. C) If certain “key habitats” are suspected with mass
    occurrence of insects in spring, two additional nights of investigation are
    required in late April – May.
    We warn that it is difficult to predict bat activity at wind turbines before
    they are built. At certain weather conditions turbines may attract huge masses
    of insects and bats are able to discover such new food resources even if they
    occur far out in “non-bat areas”. This also occurs in the breeding season.
    Investigations and risk assessments should be carried out by independent
    bat specialists with high competence. All data and conclusions must be presented
    with open access.
    Post-construction surveys and stop regulation are suggested for cases with
    remaining uncertainty about risks.
    Original languageEnglish
    Title of host publicationBook of abstracts : Conference on Wind Power and Environmental Impacts Stockholm 5-7 February
    Number of pages1
    Place of PublicationStockholm
    PublisherNaturvårdsverket
    Publication dateFeb 2013
    Pages30
    ISBN (Print)978-91-620-6546-1
    Publication statusPublished - Feb 2013
    EventConference on Wind Power and Environmental Impacts - Stockholm, Sweden
    Duration: 5 Feb 20137 Feb 2013

    Conference

    ConferenceConference on Wind Power and Environmental Impacts
    Country/TerritorySweden
    CityStockholm
    Period05/02/201307/02/2013
    SeriesSweden. Naturvaardsverket. Rapport
    Volume6546
    ISSN0282-7298

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