APG, Birdlife, WWF
To encourage the birds to continue using the transmission line structures, Austrian tranmission system operator (TSO), APG, have developed a “nesting box concept” 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. Two collaborative projects target two rare and endangered birds in particular, the Saker Falcon and the Eurasian Hoopoe.
It is not uncommon for birds of diverse species to use power lines as a supplemental habitat to the existing natural environment. They use them as brief resting spots, perches when on the lookout for prey and even for building nests. To ensure that these interactions can continue and to mitigate risk of electrocutions from nesting in unsafe positions on the line, APG and partners designed and installed nesting boxes along the lines.
More than 200 nesting boxes have been installed thus far as part of sustainable route 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.
The Saker Falcon one of the rarest birds of prey in Europe. 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.
In the regions in which the Saker Falcon can currently be found, both nests and cliff walls are in short supply. 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 towers provide the needed stability. The platforms are made of aluminium and are also used by other Falcon types: Hobbys and Kestrels. 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 12 more than in 2015. The installation of nesting boxes on APG power masts are one of the reasons for the increase in population.
Together with BirdLife, APG 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. 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, APG affix 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.