Red Kites and Wind Farms—Telemetry Data from the Core Breeding Range

Abstract

Red Kites (Milvus milvus) are the second most often reported species in relation to collisions with wind turbines in Germany. Germany houses more than half of the world’s population of Red Kites and, therefore, has a high international responsibility for the protection of this species. The German Federal Ministry of the Environment, Nature Conservation and Nuclear Safety funded a field study to investigate why Red Kites and other birds of prey frequently collide with wind turbines, and which risk mitigation measures are most appropriate. The study took place in the core of the Red Kite global breeding range in Sachsen-Anhalt between 2007 and 2010. Ten breeding adult Red Kites were equipped with radio tags (seven birds) or GPS satellite transmitters (three birds). Each bird was tracked for one or two breeding and non-breeding seasons. Data on flight height and habitat preference were collected by visual observations. The collision risk was modeled in relation to the nest’s proximity to wind turbines. It was found that Red Kites spent most of their time close to their nests. Most (54%) of the fixes were located within a radius of 1000 m around nests. It is important to note that the data did not indicate displacement of Red Kites by wind farms. Red Kites frequently visited wind farms for foraging and spent about 25% of their flight time within the swept heights of rotors of the most common wind turbines present in the study sites. The probability of closely approaching a wind farm significantly decreased with the distance between wind turbines and nests. Furthermore, the collision probability model predicted a sharp decrease of collision risk with increasing distance from the nest. The results clearly indicate that implementing buffer zones around nest sites reduces collision risk.

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