Bird protection within the APG grid
For over two decades, APG has been committed to protecting animals on high and ultra-high voltage lines.
We have been working to promote biodiversity along our transmission line routes for many years. Our more than 20 years of research has focused especially on bird protection and the associated restoration of natural habitats. APG is actively involved in a wide range of bird protection projects including nesting aid programmes, bird migration studies and bird diverters.
Species conservation projects
The Red Kite is listed as least concern (LC) on the International Union for Conservation of Nature’s Red List of Threatened Species (BIRDLIFE INTERNATIONAL 2017). This assessment is based on population decline owing to poisoning and habitat degradation, especially in Germany, Spain and France, where the species is most prevalent (BIRDLIFE INTERNATIONAL 2017). For this reason, it is very important that we use telemetry data to deepen our knowledge of the ecology of this species, analyse the significance of individual causes of death in an unbiased manner, and adapt or improve conservation and management measures based on this knowledge.
APG has collaborated with the Technical Office for Biology and Dr Rainer Raab to record and assess the movement patterns of 627 individual birds of prey (including 420 Red Kites equipped with transmitters). This also made it possible to depict the habitat use and migration behaviour of the Red Kite.
The Saker Falcon is one of Austria’s rarest birds of prey. By the mid-1970s, Saker Falcons were thought to be nearly extinct in Austria. However, the population has been recovering for some years now. In 2010, a cooperative project to protect the Saker Falcon was initiated with BirdLife Austria and the Research Institute for Wildlife Ecology of the Vienna University of Veterinary Medicine. Based on past experience, the overriding credo of the project was to offer the Saker Falcon safe, sustainable and long-term breeding grounds within the APG grid.
Both nests and cliff walls are in short supply in the Saker Falcon’s current habitat. Due to its large size, the Saker Falcon requires an especially stable nest foundation. Nesting platforms attached to APG’s extremely solid high-voltage electricity pylons provide the needed stability. The platforms are made of aluminium and are also used by Hobby Falcons and Kestrel Falcons. Since 2011, more than half of all Saker Falcons in Austria have been using APG transmission line towers as breeding grounds. The 2013 season saw a total of 26 pairs of Saker Falcons, an increase of 25% compared with 2011. In the 2016 breeding season, 64 fledglings hatched, or twelve more than in 2015. The installation of nesting boxes on APG power pylons is one of the reasons for the increase in population.
Together with BirdLife, APG has launched a project to protect the Hoopoe in the Gailtal valley of Carinthia. The first 17 nesting boxes were mounted on the 220-kV Obersielach–Lienz line in April 2015 in an initiative to save the endangered bird. The Gailtal valley is one of the regions of Carinthia that are frequently used as breeding grounds for the Hoopoe. Since the Hoopoe is a cavity-nesting bird, installation of the nesting boxes supports preservation of the species by providing nesting places to supplement the birds’ natural breeding grounds, which unfortunately have become rare. BirdLife Carinthia will be monitoring the project in the coming years.
Placing nesting boxes on transmission towers is an important part of efforts to preserve the Hoopoe. Together with BirdLife Carinthia, we affixed the wooden boxes at a height of around two to three metres at the first or second crosspiece of the transmission tower footings. The nesting boxes, which are designed especially for the hoopoe, are around 40 x 25 centimetres in size and made of larchwood stained in a walnut colour. The roofs have a vapour sealing to protect against rainstorms, and the front of the box has an entry hole of approximately 5 centimetres in diameter.
The Ural Owl disappeared in Austria in the middle of the last century. APG supports the project implemented under the scientific direction of the Vienna University of Veterinary Medicine in the Vienna Woods region with the aim of reintroducing the bird of prey by providing safe breeding grounds. This is achieved by mounting nesting boxes mounted — depending on the conditions — either on trees permanently protected from timber harvesting or on electricity pylons. These measures are intended to help to resettle the Ural Owl in Austria.
Power line routes provide food-rich hunting areas for the Ural Owl, while nesting boxes on the pylons constitute safe places for the birds to raise their young. The aluminium nesting boxes are coated dark green and mounted at a height of 10 to 15 metres. They are monitored using small mirrors so as not to disturb nesting birds.
While there were still around 300 Great Bustards in Marchfeld (Lower Austria) around 1940, by 2000 only two males and four females were left. Since then, the population has recovered thanks to extensive protective measures such as bird diverters and comprehensive conservation concepts. In 2017, around 500 Great Bustards were counted. One of the factors behind this success was the EU-sponsored LIFE project aimed at saving the Great Bustard in Austria, in which APG participated from 2005 to 2010. Since then, bird warning flags, plates and balls have been attached to APG power lines in the area inhabited by these rare birds. These serve to make the lines more visible and help avoid collisions by Great Bustards and other bird species. Thanks to the success of the project, another LIFE+ project was initiated and is currently underway.
Great Bustards are social birds usually living in small, single-sex flocks. Female Great Bustards normally select breeding sites close to where they hatched themselves. Once a female has decided on a breeding site, she is likely to stick with it for the rest of her life. The nest itself is a shallow indentation in the bare ground. In Austria, most nests are located in wheat fields or fallows. The optimum habitat for the Great Bustard is open, unfragmented, low-traffic and actively managed agricultural land mixed with plenty of fallow land that has been set aside for the bustard. The Western Weinviertel, Marchfeld and Parndorfer Platte regions offer such habitats.
Nesting boxes general
Throughout Austria, all sorts of bird species have discovered power lines as supplemental habitat structures to the existing natural environment. They use them as spots for brief retreats, perches when on the lookout for prey and even for building nests. To encourage the birds to continue using the transmission line structures, we have developed a nesting box design in cooperation with property owners, local authorities, NGOs and research institutes. The objective is to mitigate the risk to domestic bird species arising from loss of their habitats and breeding grounds. More than 200 nesting boxes have been installed thus far as part of sustainable habitat management. The nesting boxes are looked after and the birds’ breeding success documented with the assistance of the Vienna University of Veterinary Medicine, BirdLife Austria, BirdLife Carinthia and the WWF.
Bird diverters general
As part of its bird protection initiative, APG has dealt with the topic of bird diverters since 1989. Comprehensive studies have been conducted to review and evaluate the effectiveness of attaching bird diverters to power lines. We work with ornithologists to identify critical line sections throughout the APG network where there is a high probability of bird collisions. Bird diverters are particularly important where power lines cross depressions in the land topography or run along rivers or streams. In these areas, APG normally affixes diverter flags at a distance of 30 to 35 metres. The bird diverters consist of separate black and white metal rods that move in the wind and are therefore easily recognisable to birds. Our extensive experience built up over the years and the data show that the birds easily recognise the diverters placed on the lines and fly above or below them. This has significantly reduced the risk of collisions in recent years.