Breeding and hunting habitat of the Montagu´s Harrier Circus pygargus in La Mata-Torrevieja Natural Park (Alicante, SE of Spain): Effects of habitat structure and prey density.

Full article

Published:

Volume 46(2), December 1999. Pages 205-212.

Language:

Spanish

Original title:

Hábitat de caza y nidificación del Aguilucho Cenizo Circus pygargus en el Parque Natural de La Mata-Torrevieja (Alicante, SE de España): Efectos de la estructura de la vegetación y de la densidad de presas.

Keywords:

breeding, habitat change, habitat selection, habitat structure, hunting, prey density, salt marsh.

Abstract:

We studied hunting and breeding habitat selection of the Montagu´s Harrier in the Parque Natural de las Lagunas de la Mata-Torrevieja (Alicante) in 1997. We calculated the Ivlev´s selection index for every habitat type available in the study area from the time spent by Harriers hunting in each habitat type. The selection index was positive for the natural habitat types of the area and negative for man-made habitats (Fig. 1). Prey density varied between habitats (Table 1), but we did not find any correlation between the amount of time spent by Harriers hunting and prey densities across habitats. We suggest that habitat structure would be more important than relative prey abundance in the choice of hunting grounds. For instance, although prey density peaked in lemon groves, a manmade habitat that has replaced large areas of natural vegetation, prey availability in this habitat was surely very low for Harriers due to the dense canopy of lemon tree cultivation. Logistic regression models showed that the presence of salt marshes with sparse reedbeds increased the probability of finding a Montagu´s Harrier nest, while the development of unpaved roads reduced that probability (Table 2). Reduction of the natural habitat types and increasing human presence will then have negative effects on both the hunting and breeding habitats of the Montagu´s Harrier.