Sindre Eftestøl

Behavior responses of wild reindeer to direct provocation by a snowmobile or skier

To better understand the effect of winter tourism and public recreation on wild mountain reindeer (Rangifer tarandus tarandus), we compared reindeer response distances after direct provocations by skiers and snowmobiles during 3 winters in Setesdal-Ryfylke, southern Norway. Reindeer being provoked by a snowmobile discovered the observer at longer distances than reindeer being provoked by a skier (370 [skier] vs. 534 [snowmobile] m; P = 0.002), while total flight (756 vs. 570 m; P = 0.037) and total distance moved (970 vs. 660 m; P= 0.008) by reindeer were shorter for snowmobile than skier provocation. The fright (328 [skier] vs. 328 [snowmobile] m), flight (281 vs. 264 m), and escape (543 vs. 486 m) distances due to skier or snowmobile provocation were not different (P > 0.05). For pooled data, fright distances of reindeer were affected by 2 other independent variables. Fright distance was longer when the animals were provoked from below rather than from above (P= 0.046), while their escape distances were longer when the animals were lying rather than when grazing prior to being provoked (P < 0.05). Based on maximum and minimum distance moved for all provocations pooled, daily estimated energy expenditure of reindeer increased between 31 and 590 kJ, representing 0.2 and 2.9% of their estimated total daily energy expenditure. Overall, provocations by skiers or snowmobiles revealed similar behavioral responses. An estimated maximum rate of 3 daily encounters between reindeer and skiers or snowmobiles during winter vacation and Easter would result in moderate energy costs that should be easily compensated for and thus have no demographic consequences. Increasing snowmobile use will, however, significantly expand the area where humans are in contact with reindeer during winter and spring, a period of negative energy balance for reindeer.

Effects of Hunting on Response Behaviors of Wild Reindeer

Abstract Because wild reindeer (Rangifer tarandus) are hunted in southern Norway, reindeer may perceive all recreationists as threats. Potential adverse effects of hunting on reindeer behavior may be exacerbated by other forms of recreation because the number of skiers and hikers in areas inhabited by reindeer has also increased. The Norefjell–Reinsjøfjell wild reindeer area is used extensively for recreation and tourism. Reindeer hunting was introduced in the area in 1992, and harvest rate has been stable at about 38% of winter herd size. We recorded behavioral responses of reindeer to a person approaching directly on foot or skis during 1992 and again in 2002–2006. Compared to 1992, flight-initiation distance increased and fewer groups assessed the observer before taking flight during 2002–2006. In winter, when reindeer are usually comparably more vigilant than in other seasons, flight-initiation distance increased from only 60 m to 115 m and escape distance decreased from 400 m to 210 m. Neither alert distance, calf carcass weights (23.6 ± 0.7 [SE] kg to 22.4 ± 0.2 kg), nor reindeer herd size (661 ± 73 to 579 ± 15) changed during the 15 years of our study. Reindeer appeared to habituate to the observer because they initiated flight at shorter distances as the number of approaches on the same day increased. In Norefjell–Reinsjøfjell, encounters with a person on foot or skis did not result in behavioral responses likely to entail substantial energy costs for reindeer; therefore, hunting at current levels appears compatible with other recreational activities.

Flight by feral reindeer Rangifer tarandus tarandus in response to a directly approaching human on foot or on skis

Abstract Increasing outdoor activities by humans could negatively influence reindeer and caribou Rangifer tarandus populations. We recorded the behaviour of feral reindeer R. t. tarandus when a person directly approached them on foot or on skis in Forolhogna, Norway, during March, July and September–October 1996. The farther away the person was when first sighted, the greater the distance the reindeer group fled. The distance the reindeer moved away in response to the approaching person was greatest in July and least in September–October during autumn rut and shortly after the hunting season closed. In September–October rutting activities affected reindeer behaviour more than the disturbance caused by the directly approaching human. Both the distance at which the reindeer group responded by flight and the distance they moved away decreased with increasing group size. Upon flight, when all escape options were available, reindeer more often escaped uphill and into the wind than along level ground, downhill, down wind or crossways to the wind. All reindeer in a group moved towards the approaching human before taking final flight during 50% of 82 disturbance events, the closest approach was within 43 m in March, 24 m in July, and 13 m in September–October. No reindeer group responded by flight when the approaching human was still > 310 m away in March, > 351 m in July, and > 180 m in September–October. In relation to the current level of human activity in the area, our observations indicate no serious negative consequences for the reindeer following disturbance from a directly approaching human, not even shortly after the hunting season.

Is a wind-power plant acting as a barrier for reindeer Rangifer tarandus tarandus movements?

Reindeer herdsmen and authorities in Scandinavia fear detrimental effects from wind-power plants (WPs) on movements and area use of reindeer Rangifer tarandus tarandus. We tested the extent to which a WP represented a behavioural barrier for reindeer movement by comparing two neighbouring areas; one peninsula with and one without a WP. Both peninsulas had a parallel road and a power line bisecting them in a north-south direction. Presence of a larger or similar number of reindeer on the outer western compared to the inner eastern sections in both areas indicated no barrier effect from the WP. Furthermore, no clear barrier effects were found for reindeer movements during summer in the WP or neighbouring area, as reindeer have continued to cross back and forth between the inner and outer sections of the two areas. Contrary to our expectation, our finding contrasted with previous studies finding negative barrier effects from linear structures such as power lines and roads, suggesting considerable variation in the extent to which infrastructure acts as barriers.

Effects of wind turbines on area use and behaviour of semi-domestic reindeer in enclosures

In recent decades, industrial developments have expanded into reindeer ranges in the arctic and adjacent higher latitudes in search for energy, minerals, timber and other resources. Several wind turbine parks are under planning in reindeer ranges in Norway, and there is concern about possible negative effects on behaviour and area use of wild and semi-domestic reindeer. We tested whether a wind turbine and its rotor movement had any effect on area use, activity changes, vigilance bouts, and restless behaviour like running, walking, and standing for enclosed semi-domestic reindeer. Five different groups of reindeer in a 450 m long, 8 hectare, enclosure close to a wind turbine were manipulated by turning the wind turbine rotor on and off, and compared with reindeer in a control enclosure without wind turbine exposure. When exposed to rotor movement, two groups used locations farther from the wind turbine, two groups showed no shift, while one group moved closer to the wind turbine. The reindeer showed no systematic differences in the measured behaviour patterns between the two enclosures that could indicate fright or stress as a consequence of the wind turbine or rotor movement. We conclude that semi-domestic reindeer in an enclosure showed no negative behavioural response and little or no aversion towards a wind turbine. The possibility of rapid habituation in a small enclosure with continuous wind turbine exposure suggests that effects on area use should be studied at a larger scale or with free-ranging reindeer. Abstract in Norwegian / Sammendrag: I lopet av de senere tiar har industriell utbygging til utnytting av energi, mineraler, tommer og andre ressurser ekspandert inn i reinens beiteomrader i nordomradene. Flere vindmolleparker er under planlegging i norske reinbeiteomrader, og det spekuleres i mulige konsekvenser av disse pa atferd og arealbruk hos villrein og tamrein. Vi testet om en vindmolle og dens rotorbevegelse hadde noen effekt pa arealbruk, aktivitetsskifter, vaktsomhetsatferd, og rastloshetsatferd i form av lop, gange og staing for tamrein i innhegning. I en 450 m lang innhegning pa 8 hektar som var plassert tett opp til en vindmolle, ble fem forskjellig grupper av reinsdyr manipulert ved a sla vindmollerotoren av og pa. Reinsdyrene i innhegningen ved vindmollen ble sammenlignet med reinsdyr i en kontrollinnhegning som var uten pavirkning fra vindmoller. Nar reinsdyrene ble utsatt for vindmollerotoren i bevegelse, viste to grupper av dyr et skifte i arealbruk til omrader av innhegningen som var lenger unna mollen, to grupper av dyr viste ikke noe skifte i arealbruk, mens en gruppe dyr beveget seg naermere vindmollen. Sammenligning av atferden hos reinsdyrene i vindmolleinnhegningen og kontrollinnhegningen viste ingen systematisk forskjell som kunne indikere frykt eller stress som en effekt av vindmollen eller rotorbevegelsen. Vi konkluderer med at tamrein i innhegning ikke viser negative atferdsresponser og viser lite eller ingen reduksjon i arealbruken tett opp til en vindmolle. Muligheten for at det skjer en rask tilvenning i en liten innhegning der dyrene er i kontinuerlig pavirkning av vindmollen betyr at effekter pa arealbruk bor studeres i et storre arealperspektiv eller pa frittgaende rein.

Measuring effects of linear obstacles on wildlife movements: accounting for the relationship between step length and crossing probability

Animal movements in the landscape are influenced by linear features such as rivers, roads and power lines. Prior studies have investigated how linear features, particularly roads, affect movement rates by comparing animals movement rate measured as step lengths (i.e., the distance between consecutive observations such as GPS locations) before, during and after crossing of a linear feature. The null hypothesis has been that the length of crossing steps should not differ from other steps, and a deviation from this, mainly that steps are longer during crossing, has been taken as support for a disturbance effect of the linear feature. However, based on the simple relationship between the length of a step and its probability to cross a linear feature, we claim that this assumption is inappropriate to test for behavioural responses to linear features. The probability is related to the proportion of the total length of the trajectory (i.e., the path of movement) a step constitutes. Consequently, care should be taken when formulating hypotheses about how animal moves in relation to linear features in the landscape. Statistical tests should be set up with respect to the expected length based on the distribution of step lengths in the trajectory. We propose two methods that accounts for the bias in crossing frequency that is caused by step lengths, and illustrates their applications by using simulated animal trajectories as well as empirical data on reindeer in an area with a power line.

Response Behaviors of Svalbard Reindeer TOwards Humans and Humans Disguised as Polar Bears on Edgeøya

Abstract Due to observed interactions between Svalbard reindeer (Rangifer tarandus platyrhynchus) and polar bears (Ursus maritimus) during field work on Edgeøya, Svalbard, we measured response distances for reindeer from a stalking polar bear and improvised five approaches from a person disguised as a polar bear for comparison with human encounters. The alert, flight initiation and escape distances were 1.6, 2.5 and 2.3 times longer, respectively, when Svalbard reindeer were encountered by a person disguised as a polar bear compared to a person in dark hiking gear. Population increase of polar bears on Svalbard and decrease in sea-ice cover in the Arctic region during summer probably results in more frequent interactions with reindeer on the archipelago. Similar reindeer response behavior from encounters with a polar bear and persons disguised as polar bears indicate a predator-prey relationship between the two species on Edgeøya.