Winter-gebruik van natuurlijke versus artificiële beschutting door runderen in natuurgebieden

Cattle in nature reserves are exposed to aversive weather. Whether artificial shelter (AS) (man-made) should be provided in addition to natural shelter (NS) (vegetation) is a topic of debate. It’s also unknown which of both cattle prefer. In seven reserves with varying degrees of NS and one AS, we fitted a GPS-collar onto one cow to monitor terrain use during one (n=3) or two (n=4) winters. Weather stations registered local open-field climatic parameters that allowed calculation of the Wind Chill Index (WCI) and Comprehensive Climate Index (CCI). Animal positions were plotted onto digital maps of the reserves, to determine when different shelter types were used. Here we present exploratory analyses. In most reserves AS and its immediate surroundings were used little (mean±SE: 2.8±1.1% of recordings/winter). We found no clear diurnal pattern in use of different shelter types, though in most reserves open area was used less at night, when mostly NS was used. We explored - per reserve- whether air-temperature, black-globe-temperature, wind-speed, WCI or CCI differed when cows used open area and different shelter types. In most reserves no such differences were found. In one reserve, though, WCI differed between shelter types (P=0.043): WCI was slightly higher when the cow used NS (5.7±0.2) vs. 5m around it (5.6±0.2) or open area (5.6±0.2). In another reserve, black-globe-temperature differed between shelter types (P=0.028): it was slightly lower when the cow used AS (4.3±0.3°C) vs. <5m around AS (4.4±0.3°C), NS (4.4±0.3°C), <5m around NS (4.5±0.3°C) or open area (4.4±0.3°C). It’s hard to make generalizing statements on use of/preference for NS vs. AS in relation to climatic conditions based on these preliminary results. Cows’ sheltering behaviour is reserve-dependent and likely influenced by availability of NS. Further analyses will be conducted before advising legislators and reserve managers concerning wintertime protection for cattle kept outdoors.