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1 Polish Journal of Ecology

1 2008

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Hunting habitat preferences of raptors in a mountainous area (Northwestern Spain)

Tapia L., Dominguez J., Rodriguez L.

Polish Journal of Ecology

2008

Vol. 56, nr 2

323-333

The hunting habitat preferences of six diurnal raptors (see below) were studied during spring-summer and autumn-winter periods in a mountainous area of northwestern Spain (the Baixa Limia-Serra do Xures Natural Park). For this, 15 counting-points were established (at 800 m a.s.l.) in the study area between February 1997 and January 1998. Each point was sampled 4 hours per month. The dependent variables used were presence-absence and specific relative abundance (number of birds hr[^-1]km[^-2]). Seventeen environmental variables (number of settlements, surface area occupied by settlements, road length, minimum altitude, maximum altitude, max-min altitude, mean altitude, min slope, max slope, max-min slope, mean slope, surface area occupied by scrub-pasture, surface area occupied by forest, scrub-forest edge, number of people hr[^-1] km[^-2], livestock hr[^-1] km[^-2], vehicles hr[^-1] km[^-2]) were used as predictors for characterizing the hunting habitat patterns between March and August (spring-summer period) and between September and February (autumn-winter period). Information regarding each independent variable in the monitoring areas was obtained from 1:50000 digital maps. We analysed the habitat selection patterns of six raptor species, using univariate and multivariate analysis. The PCA generated three factors that accounted for 84% of the variance in spring-summer and 81% of the variance in autumn-winter. The Short-toed Eagle Circaetus gallicus (Gmelin) did not show any pattern in their habitat selection. The Hen Harrier Circus cyaneus (L.) and Montagu's Harrier Circus pygargus (L.) were more often observed in higher, more gently sloping areas. The spring-summer abundance of the Common Buzzard Buteo buteo (L.) was positively correlated with the surface area occupied by human settlements and the surface area occupied by forest, and in the autumn-winter period its abundance was negatively correlated with the mean slope. The Golden Eagle Aquila chrysaetos (L.) showed similar hunting habitat selection patterns in both periods, with a preference for shrub areas and weak presence of human settlements. The Common Kestrel Falco tinnunculus (L.) did not show any pattern of habitat selection in the spring-summer period but its abundance was negatively correlated with the mean slope in the autumn-winter period.