Determination of the hunting area and rate of activity of the Bonelli's eagle (Hieraaetus fasciatus) in the Natural Park Sant Llorenš de Munt i l'Obac

This is the summary of the presentation conducted in the VI Encounter of students of Sant Llorenš del Munt i l'Obac (10th of November of 2005) by Elena L. Zozaya1, Albert Peris2, Vicenš Bros2, Daniel Guinart2, Rafel Bosch1, Albert Tintˇ1 and Joan Real1.

The Bonelli's eagle is one diurnal raptor whose populations have undergone an important declivity in the last decades. During the decade of the 70 in the Natural Park Sant Llorenš del Munt i l'Obac four pairs existed whereas at the present time only there is only one occupied territory.  

The objectives of the present study are to know the hunting area, to define the habitats more used and to determine the rate of activity of the pair of Bonelli'ss eagles present in the Park of Sant Llorenš del Munt i l'Obac to know their ecology and to establish conservation measures.

For it, the radiotracking of the male of the pair present in the Park has been made throughout 56 days, beginning one hour after the sunrise until the sunset, during years 2004 and 2005.

The global area of hunting used by the male has been of 115.9 Km2 (MPC). The hunting area described by the Kernel of 99% and by Kernel 90% have been of 51.4 Km2 and 10.9 Km2 respectively. The more used habitats have been the Mediterranean scrub and the forests of pinus haleppensis.

The daily rate of activity throughout the period of study follows an unimodal pattern, where the hours of greater activity are the central hours of the day, between the 12 and the 14 in solar time, and those of smaller activity are during the first and last hours of the day.

The pair of Bonelli'ss eagles studied, in spite of having the nesting area within the Park, uses specially the areas outside to hunt, since it is there where they have the most optimal habitats and their preys are more abundant. It is also in these external areas, outside the Park and relatively moved away, where the eagles sleep and where they remain during long seasons specially in the interbreeding period. In this sense, to establish measures of conservation in these external areas of the Park (maintenance of the habitats adapted for its preys, correction of electrical lines and arrangement of the territory) is essential to maintain this species.

1. Department of Animal Biology. University of Barcelona
2. └rea d'Espais Naturals. Diputaciˇ provincial de  Barcelona