Home range in genus Capra: from polygons to Brownian bridges of scabietic and healthy Iberian ibexes (Capra pyrenaica)

Abstract

Home range and home range overlap can be used to describe use of space and movement of wildlife. During the last years, advancements in technology have greatly improved our understanding of animal movement, especially among large herbivores. Wild ungulate abundance and distribution have increased in temperate areas. Moreover, their diseases-including sarcoptic mange in the Iberian Ibex (Capra pyrenaica)-have become a cause of concern for livestock, public health, and wildlife conservation. In this study, we first reviewed existing literature on the home range of species in the genus Capra. We then analyzed data from 52 GPS-GSM-collared Iberian ibexes, of which 33 were healthy and 19 were affected by sarcoptic mange from 3 different populations in the southeastern Iberian Peninsula to analyze: (1) differences in size and characteristics of home ranges obtained by the 3 most commonly used methodologies-minimum convex polygon, kernel density estimation, and Brownian bridges movement models (BBMMs); and (2) the impact of endemic sarcoptic mange on Iberian Ibex home range. The literature review revealed that available information on spatial behavior of Capra spp. was based only on 3 species, including the Iberian Ibex, estimated through a diversity of methods which made it difficult to compare results. We found positive correlations among the different home range estimation methods in the Iberian Ibex, with BBMMs proving to be the most accurate. This study is the first to use BBMMs for estimating home range in this species, and it revealed a marked seasonal behavior in spatial use, although sarcoptic mange smoothed such seasonal pattern. The seasonal overlaps obtained suggest that core areas of the Iberian Ibex change within wider home range areas, which are ecological parameters relevant to identifying key areas for species management and conservation.

Keywords: Brownian bridge; Capra pyrenaica; GPS-GSM; kernel density estimation; minimum convex polygon; sarcoptic mange; spatial behavior; systematic review.

Fig. 1.

(A) Study area in the Iberian Peninsula (square). (B) Shadow areas are each particular mountain systems where animals were monitored: Sierras de Cazorla, Segura y las Villas Natural Park (SCSV), Sierra Nevada Natural Space (SN), and Orce Massif (OM).

Fig. 2.

Seasonal core areas (KDE50) and home ranges (KDE95) of Iberian Ibex populations from Sierras de Cazorla, Segura y las Villas Natural Park (SCSV), Sierra Nevada Natural Space (SN), and Orce Massif (OM) by sex and by season.

Fig. 3.

Annual core areas (KDE50) and home ranges (KDE95) of Iberian Ibex by sex and populations from Sierras de Cazorla, Segura y las Villas Natural Park (SCSV), Sierra Nevada Natural Space (SN), and Orce Massif (OM).

Fig. 4.

Boxplot of the seasonal core areas (KDE50) and home ranges (KDE95) overlaps of Iberian Ibex by sex and populations. SCSV: Sierras de Cazorla, Segura y las Villas Natural Park; SN: Sierra Nevada Natural Space; OM: Orce Massif.