Monitoring effects of highway traffic on wild reindeer
- Author(s): Iuell, Bjørn;
- Strand, Olav
- et al.
Some of the major wildlife problems associated with transport infrastructure development in Norway involve the negative effects on reindeer populations. Documented effects include barrier effects resulting in fragmented populations and indirect impacts on reindeer grazing caused by disturbance from road traffic and human activities in general. Wild reindeer are sensitive to disturbance and are known to have high alertness ageinstagainsttend to be extremely shy of human activities. The disturbance caused by road traffic and human activities can reduce the reindeer h habitat use at relatively ’s use of areas for large distances (several kilometreskilometers) on either side of roads. The result of this avoidance is a reduction in the available grazing resources, which during the winter consist mainly of lichens, in wide zones parallel to roads, and an equivalent increase in grazing pressure in a zone at some distance from roads in undisturbed areas. Because lichens needs 20 – 30 years to recover after periods of intensive grazing, the wild reindeer are regarded as especially vulnerable to barriers that reduce their possibilities to reach new grazing grounds. At the Hardangervidda, the biggest mountain plateau in Southern Norway, the functional use of the wild reindeer area has probably changed from being a large-scale rotation in the use of the food resources and calving areas, to a more restricted use of a smaller and central area. become an overexploitation of a too small area. The northern parts of the Hardangervidda isparts of the Hardangervidda are, for example, functionally parted from the rest by Highway (Hw) 7 and the railroad. This situation is not unique to the northern parts of Hardangervidda, but appears to be a general problem for most of the edges , and many of the surrounding of the plateauareas that also happens to be most affected by humans and less are no longer used by the reindeer. The Norwegian directorate for nature management has suggested closing down a stretch of about 40 km of Hw 7 crossing the Hardangervidda, during the winter months, hoping to . The aim is to resume reindeer habitat use in this partsthese parts of the areathe original use of the whole mountain plateau. Even if the road has very low traffic in the winter months (ADT 300-400), the suggestion has caused a lot of protests and discussions locally. In 2002 scientists from the Norwegian Institute of Nature Research (NINA) were engaged by the Norwegian Public Roads Administration (NPRA) in a five-year study to undertake research on patterns of reindeer habitat use and utilization of the lichen grazing resources and on the movements of wild reindeer in the aareas believed to be influenced by the road close to the road. The main purpose of the project is to find out to which degree the road and/or the traffic generated by the road constitute a barrier for the wild reindeer, and if it has a repelling effect on the animals. The NPRA will draw up its recommendation to the Parliament on the future management of the road based on the results of the project. The project has equipped a total of more than 20 animals with GPS transmitters, providing continuous detailed and accurate data on their habitat use and movementsposition. The GPS units are where programmed to register localize each animal every the localisation of the animal each third hour. The data are stored in the computer in the collar, which includes a possibility for remote data transfer, and the computer is programmed to deliver the data for the last two weeks every second week. The collar also sends out a VHF signal, so the animal can be tracked, and the data downloaded to a portable computer. Since the expressed effects in reindeer behaviourbehavior and habitat use are Because the fragmentation is the result of the cumulative effects of different disturbance sources, the project also aims to disentangle looks into the relative contribution level of disturbance to disturbance from other sources than road traffic, e.g.,xamples as such are pPower lines, the settlement of cottages and alpine resorts, and recreational use by skiers and snow scooters. all contribute to the disturbance of the wild reindeer. Maps of the distribution of different reindeer the food resources (e.g., lichens) have been produced both by using field surveys and by the use of satellite imagesphotos. When the preliminary GPS data are compared with the distribution of lichen resources, in the area, it is very appears that clear that the animals do not use the areas richest in lichens: oin the outskirtsfringe of the plateau and in a zone 5 – 7 km from the road. This zone of avoidance also strengthens the barrier effect of the road such that the migration routes to and from the North are more or less cut off. This is both a problem of reduced genetic flow, and the availability of winter grazing resources. The field work closes in 2005, and the results will be presented in 2006. The data will hopefully also also give us valuable information about the relative disturbance from other all the different disturbance factors, so that action can be taken based on the right factors. Future research should focus more on the relative and cumulative effects of different disturbance factors, and whether placing selected stretches of the road in tunnels can eliminate or reduce the negative effects on reindeerthe disturbance from the road. Keywords: wild reindeer, roads, barrier, fragmentation, disturbance, GPS