For the first time in Romania, the Milvus Group is monitoring the movement of Golden Eagles (Aquila chrysaetos) by using GPS transmitters. Three eagles were fitted with such transmitters during the last year, in the Trascău Mountains area and in the Apuseni Natural Park. One bird managed to take off the device before leaving the nest, but the other eagles have provided relevant data, about the behaviour of these birds in the first months of life.
One of the chicks from Trascău moved very little after leaving the nest. During the August 2015 – January 2016 period, it made very few and short flights, rarely more than 1.5 km, but there were even months (August and December) when didn’t not left the nest’s site. During this period it has been observed with its parents, often begging for food. A notable exception was a 110 km flight in November, during a single day, when it reached a distance of 40 km from the nesting site.
The situation changed in February, when it began to travel long distances, and in early March it has left the nesting area. Most probably, with the beginning of the nesting period, the parents simply chased him out of their territory.
After leaving the nests area in March-April, the eagle moved great distances, sometimes pausing for several days in certain regions. The bird has traveled 1700 kilometres, reaching Alba, Bihor, Bistrița Năsăud, Cluj, Maramureș, Mureș and Sălaj counties. Although it preferred the Apuseni mountain area, the bird spent relatively long periods in the hilly areas of Cluj, Sălaj, Bistrița Năsăud and Maramureș counties, but visited briefly the Transylvanian Plain, respectively the Tîrnava and Jidvei areas.
The other nestling (from the Apuseni Natural Park) made longer flights just after leavig the nest. Its behaviour did not change in the forthcoming months, moving around the nesting area relatively long distances, sometimes reaching distances of even 8 km from the nest.
Unfortunately, from November we have not received any data from this bird, this may be caused by the bird’s death or by the transmitter’s failure.
The Golden Eagle is one of the rare raptor species nesting in Romania; its population is estimated to be only 90 – 150 pairs. Due to its relative rarity and the lack of information about the species, in 2001 the Milvus Group decided to initiate a program to research and monitor as well as to protect this species.
The Golden Eagle is a large species, the second largest raptor nesting in Romania. They become mature the earliest in the fourth year of life, most of them nesting for the first time only in the fifth year. The first two – three years are spent traveling, searching for pair and suitable breeding territories. In this period of life, when eagles move much and are not linked to certain territories, their monitoring is hampered considerably and until a few years ago, very few information were available about the immature birds, their movements and habits.
The situation changed with the development of small GPS transmitters, that can be mounted on the back of the birds. These GPS transmitters according to the custom settings can provide several times a day information about the location of the birds.