tracking hybrid lesser/greater spotted eagle
Nestling hybrid spotted eagle has been equipped with a 30 g tracker in August 2015. Since then we followed its migration to West Africa and back to Lithuania. Currently, in 2018, the bird is spending the third winter in Senegal.
Interesting to note that one year earlier (in 2014), another juvenile hybrid of the same pair of lesser spotted eagle female and greater spotted eagle male chose eastern migration route. The map below (Fig. 1) shows autumn migration tracks of hybrid juvenile spotted eagles in 2014 (blue) and 2015 (red).
A geofence of 1 second was set over the waters of the Strait of Gibraltar. But the eagle decided not to cross to Africa right away and recorded fine resolution track over southern Spain instead (Fig. 2). After some hesitation and over a month in southern Spain the eagle eventually crossed the strait. KML file of the track during the day of crossing can be downloaded following this link (to dropbox).
Tracking birds at high resolution reveals threats that they are facing. We witnessed near fatal collision of this bird with a wind turbine near Puerto Real, southern Spain. On October 24 the eagle approached a wind turbine and dropped to the field nearby where it spent more than 20 hours including a night. We thought the bird was killed or at least badly injured by the turbine and were pleasantly surprised when it flew away on October 25, just minutes before the rescue party of Spanish ornithologists, organised by Teo Todorov, arrived to the location (Fig. 3). The bird was probably stunned by a pressure wave crated by rotating turbine blades, but managed to recover.
The full track of this bird could be viewed on Movebank study "Hybrid Spotted Eagle Lithuania GPS 2015" where tracking data is live fed from the transmitter.
Fig 1. Autumn migration routes of juvenile hybrid spotted eagles raised by the same pair of lesser spotted eagle female and greater spotted eagle male in different years: blue - 2014, red - 2015. The track of 2015 has been simplified by merging the adjacent positions.
Fig 2. Fragment of the hybrid spotted eagle track showing hesitant flight near Tarifa after seeing open water. This section of the track shows GPS positions logged at 1 second intervals.
