Abstract
From 2007 inclusive, NINA has received economic support for research on wind power and birds from the Norwegian Research Council (NFR) through the RENERGI-programme. The project is named Pre- and post-construction studies of conflicts between birds and wind turbines in coastal Norway (BirdWind). BirdWind is approaching its finalisation; with 2010 as the last ordinary year where data-collecting activities takes place. In 2009 the project was significantly strengthened through a new PhD-position funded by Statkraft and NINA. The position is held for four years, and the overall aim of the work conducted by the PhD-student is to model the future white-tailed eagle (WTE) population development based on reproduction and mortality data. Weekly searches with dogs for birds killed within the wind-power plant have been carried out throughout the year; in general searches are conducted every 7 days (plus or minus one day). 25 ‘primary turbines’ are selected and searched together with one of two dogs. A full search of all turbines is performed at larger intervals. In 2009 (up to December 1) 31 specimens of at least 8 species have been recorded. The most frequent victims are willow ptarmigan and WTE with 10 and 7 carcasses, respectively. Of waders 3 common snipes have been recorded. Five carcasses were recorded of hooded crow, and single carcasses of parrot crossbill, northern wheatear, teal and mallard. Some records from earlier years have been revised as collision victims or not. Also in 2009 censuses for willow ptarmigan have been carried out in spring and autumn on Smøla and Hitra. The preliminary results do not indicate any obvious differences between the two areas, but autumn density in the wind-power plant area seems to be more stable compared to the control area. Interestingly the higher density within the wind-power plant area in autumn is evened out in spring each year, so also in spring 2009. To obtain data on habitat selection, movements, collision risks, survival of eggs, chicks and adults and general population dynamic parameters, willow ptarmigan specimen have been radio-tagged in 2008-2009. The activities regarding breeding waders and small birds (mainly passerines) have this year focused on the EIA-activities on Hitra in connection to the planned extension of the existing power plant on Hitra I; the Hitra II Wind-Power Plant. Since 2003, 50 nestlings of white-tailed eagle have been equipped with satellite transmitters. In 2009, eight WTE nestlings were tagged, six with solar-powered and two with battery-powered transmitters. One was tagged within the wind-power plant, the others in close vicinity of it. The solar-powered transmitters used in 2009 were programmed to give one position per hour during summer in order to have finer resolution of movements for risk-modelling purposes. During winter less frequent downloading is scheduled, due to low light and poor battery-charging. One of the tagged nestlings was found killed by a turbine October 7. We have continued to collect feathers from active nests and chicks also in 2009, as well as from eagles killed in collisions with wind turbines. DNA-analyses from bones of six eagles killed by electrocution on power-line pylons on Smøla will also be included. For increased efficiency in the laboratory, and to streamline the production of DNA-data, the use of an extraction robot has been implemented. All WTE nest sites on Smøla were surveyed during the summer. Territorial activity, identified by either moulted adult feathers, chicks in the nest or fresh nest material, was confirmed in 61 different territories on the main island and in the surrounding archipelago. In these territories 27 chicks from 21 different clutches were recorded. This is the second highest number of chicks recorded ever on Smøla, giving a reproductive output of 0.44 chicks/confirmed occupied territory. In order to investigate behavioural differences for the WTE related to the distance from the turbines, data on flight activity (moving flight, social behaviour and soaring) and flight height (below, in and above the rotor zone) were collected at 12 vantage points, 6 from inside the wind-power plant area and 6 from control areas close to the power-plant area. The results indicate that the WTE on Smøla does not have any behavioural responses to the wind-power plant constructions. It may, however, contribute to explain why the WTE is vulnerable to collisions with the turbines and the number of killed individuals recorded within the power-plant area. The results may also contribute to explain the high percentage of adults found killed in the wind-power plant area. The WTE has a peak activity early in the breeding period, which can be fatal to both adult individuals, and thus also to the nestlings. In 2009, all 30 dead WTEs recorded in connection to the wind-power plants on Smøla and Hitra have been examined. The eagle carcasses varied considerably with respect to what a post-mortem examination could reveal, and the condition of most carcasses did not allow for a thorough classic autopsy. All eagles were x-rayed and their damages were described. Three willow ptarmigan and one merlin recorded on Smøla were also autopsied. The precise findings and assessment will be presented later. Seven camera systems were developed and deployed during spring 2008, and have been collecting data throughout the year. For the time being several terabytes is waiting to be analysed. The reason for this is that the system has a malfunction, being triggered by other movements than those of birds. How to proceed with the data analyses will be discussed on a meeting with Statkraft in January 2010. The main focus regarding the avian radar has been the development of GIS-tools to learn more about the radar range and scanning accuracy, development of database routines to optimize radar data (including false alarms filtering and categorization of bird tracks using data-mining techniques). Experimental tests of the radar performance with respect to accuracy in detecting and following birds was done using model aircrafts and ground-truthing (identify bird species spotted by the radar by field observations). Methodological challenges of the radar system are to which extent the tracking-algorithm is able to record bird flights, the verification of recorded radar tracks to species and the characterisation of species-specific track-characteristics to enable extrapolation to the entire database. We have developed a web application, "WebTracks", which allows radar tracks to be visualized together with ground-truthed data. This gives an instant view of where the radar might have low visibility. It also visualizes where the radar loses track of the object, and splits tracks into multiple segments, where they should have been contiguous. By selecting and displaying ground-truthed data, or model-aircraft tracks, together with tracks from the radar database in the same time interval, an instantaneous overview of the radar-tracking capabilities can be obtained. It is possible to overlay both topographical maps, and clutter maps in the map window of the application. Together with colour coding of the objects height, the clutter map indicates where the object should be visible for the radar. Based on laser elevation data from the laser scanning of Smøla in 2008 a high resolution terrain model was established in March 2009. The LIDAR data was delivered in LAS-format. The LIDAR DEM-model is an important input in the modelling of theoretical land-clutter areas and areas with wind-turbine interference. These clutter and interference areas reduce the radar detection performance and have to be flagged as clutter in the database. The land-surface clutter model is nearly completed, but has to be further improved and tested before it is applied into the database as a mask to flag clutter pixels. This is an important step in order to be able to interpret the database.