Spatial ecology of Eurasian badger (Meles meles) in a high bovine tuberculosis incidence area from Asturias (Northern Spain)

Abstract

Bovine tuberculosis (TB) is a chronic infectious disease caused by Mycobacterium bovis. In Asturias (Northern Spain), TB in cattle declined from a herd incidence of 0.32% in 2002 to 0.18% in 2015, although geographical pockets remained where the incidence was up 5.38% in 2013. Recent studies suggest that badgers may be a potential reservoir of M. bovis in these areas. The objective of this study was to investigate the spatial ecology of badgers around infected farms in order to extract information of relevance to understand this complex epidemiological system. The study area is located in Parres, Asturias, northern of Spain ( 43 o 23 'N; 5° 14 'W), and extended o ver 17 km2• Forty five farms are settled in tbe area, of whicb eleven had tested positive for TB at the official single intradermal cervical tuberculin test (STD) between 2013 and 2015. Approximately 60% of the territory is fanned grasslands and tillage, while 30 % of land cover is forested. A total of 19 setts were found in the area (1.12 setts/knl), and the badger population density estimated on D0 of main setts and captured was 6 badgerslkm . Nine badgers were captured between 2013 and 2015. Trapped badgers were anaesthetised and their location, sex, age and body condition were scored. Each badger was implanted with a CRG250G collar transmitter. In total 6,736 locations events were recorded during the study period. Plots of positive farms tended to be closer to a setts the negative holdings. The frequency of badger locations in the prairies of positive farms was significantly higher tban those in the negative farms. No differences in the size of seasonal home range, daily movements and seasonal maximum dispersa! between sexes neither among seasons were found. One relevant finding was the presence of one long-distance dispersa! male (13,652.32 m of maximum seasonal dispersa! distance). Excluding this rare individual, the average seasonal home range was (Kernel 95 %) 128.26 ha (21.65- 203.42), daily movements of 1,842 m (803.40 - 2861.28) and dispersa! distance of 2,060.64 m (633.39 - 6100.60). The implications of these results on badger's spatial ecology for designing TB intervention strategies in the study area are potentially significant.