Jonathan E. Colman

Multiple Effects of Changes in Arctic Snow Cover

Snow cover plays a major role in the climate, hydrological and ecological systems of the Arctic and other regions through its influence on the surface energy balance (e.g. reflectivity), water balance (e.g. water storage and release), thermal regimes (e.g. insulation), vegetation and trace gas fluxes. Feedbacks to the climate system have global consequences. The livelihoods and well-being of Arctic residents and many services for the wider population depend on snow conditions so changes have important consequences. Already, changing snow conditions, particularly reduced summer soil moisture, winter thaw events and rain-on-snow conditions have negatively affected commercial forestry, reindeer herding, some wild animal populations and vegetation. Reductions in snow cover are also adversely impacting indigenous peoples’ access to traditional foods with negative impacts on human health and well-being. However, there are likely to be some benefits from a changing Arctic snow regime such as more even run-off from melting snow that favours hydropower operations.

Reindeer and caribou ( Rangifer tarandus ) response towards human activities

We address the question of how human activities and infrastructure influence reindeer/caribou’s ( Rangifer tarandus ) behaviour and habitat use and review studies based on current methodologies. Anthropogenic activities have a direct affect on Rangifer behaviour through the senses hearing, sight and smell, and all of these are important tools for behavioural risk assessment. Short term indirect responses, such as habituation, sensitisation, avoidance, and displacement, develop through neutral, positive or negative associations towards stimulus in terms of Rangifer ’s ability to experience, learn, and remember. Long term behavioural responses develop through interaction with predators and, for reindeer, also domestication. A survey of the literature dealing with behavioural studies reveals that although Rangifer in most cases retreat from anthropogenic activities, comfort distances (i.e. distances beyond which animal behaviour or activity are not influenced) are relatively short. In most cases, energetic implications appear moderate and small compared to other natural, biotic influences such as disturbance (and death) caused by insect and/or predator harassment. Unless obstructing access, physical constructions of various kinds apparently have limited effects on Rangifer behaviour or habitat use. On the other hand, constructions that do obstruct or limit access and recreational or other motorized and non-motorized activities appear to have stronger impacts on avoidance and redistribution of Rangifer . Behavioural effects that might decrease survival and reproduction include retreat from favourable habitat near disturbance sources and reduction of time spent feeding with resulting energy depletion over time. Rangifer habitat use, habitat avoidance, and feeding preferences are governed by a complexity of natural interacting factors. Domestication, habituation and sensitisation are essential in shaping Rangifer ’s adaptability, and should be included in future studies on reindeer and caribou responses towards various anthropogenic activities. Although cumulative effects from human activities are likely, it remains difficult to separate these from natural variations in Rangifer habitat use and demography. Habitat avoidance towards various human infrastructures and activities is reported, but most studies reporting relatively far (4-25 km) avoidance distances relied on measurements of range properties and animal distribution recorded on 1-2 days annually in winter to induce a potential response from the animals and lack important environmental variables and/or alternative hypothesises. This methodology should be improved in order to enable identification of correlation versus causation. Studies relying on animal behaviour measurements can more correctly identify and test responses to various stimuli while also controlling for degree of domestication and other various environmental variables, but only in a limited time and spatial scale. Furthermore, such studies may not necessarily capture potential population consequences from disturbances. Thus, there are important weaknesses in the two leading methodologies (measuring animal behaviour and indirectly mapping regional/population movements and habitat use through measurements of range properties). To best study Rangifer ’s responses towards anthropogenic infrastructure and activities, we propose that the two methodologies be combined and supplied with modern GPS/telemetry. Abstract in Norwegian / Sammendrag: Rein og caribous reaksjon pa forskjellige menneskelige aktiviteter og installasjoner Vi adresserer sporsmalet om hvordan menneskelig aktivitet og infrastruktur pavirker rein/caribous ( Rangifer tarandus ) atferd og omradebruk og gjennomgar publiserte arbeider basert pa aktuelle metoder. Antropogene aktiviteter har direkte effekt pa reinens atferd via horsel, syn og lukt; alle er viktige for deres risikovurdering. Kortsiktige indirekte reaksjonsmonstre, slik som habituering, sensitivisering, unnvikelse og fortrengning utvikles gjennom noytrale, positive eller negative opplevelser av stimuli i henhold til erfaring, laering og hukommelse. Utviklingen av permanente atferdsmonstre skjer ved samvirke med predatorer og for reinens del, ogsa ved domestisering. En litteraturoversikt om atferdsstudier viser at selv om Rangifer i de fleste tilfeller unnviker antropogene virksomheter, sa er de avstander dyrene velger a ha mellom seg og infrastruktur uten at normalatferden endres, relativt korte. De energimessige implikasjonene er ogsa beskjedne sammenlignet med virkningen av naturlige stressfaktorer sa som forstyrrelser (og dod) forarsaket av insekter og predatorer. Fysiske installasjoner av ulik art har ogsa begrenset effekt med mindre de fysisk hindrer Rangifer s omradebruk. Pa den annen side vil fysiske installasjoner, som hindrer eller begrenser bruken av omrader, og trafikk, bade fottrafikk og trafikk med motorkjoretoy, kunne ha sterkere virkning pa unnvikelsesatferd og omradebruk. Atferdsmessige effekter som kan redusere overlevelse og reproduksjon omfatter unnvikelse fra beiteomrader naer forstyrrelseskilder. For Rangifer er det negative resultatet av dette oket aktivitet, redusert beitetid og nedbygging av energireserver. Rangifer s omradebruk, unnvikelsesatferd og naeringspreferanser bestemmes ut fra et kompleks av naturlige og gjensidig pavirkende faktorer. Domestisering, habituering og sensitivisering som er sentrale begrep i utformningen av Rangifer s tilpasningsevne, bor inkluderes i fremtidige studier av rein og caribous reaksjon pa antropogene aktiviteter. Selv om en kumulativ atferdseffekt av menneskelige aktiviteter er mulig, er det vanskelig a skille slike fra naturlige variasjoner som folge av variasjoner i omradebruk og bestandsdynamiske forhold. Habitatunnvikelse som folge av menneskelig pavirkning er rapportert. De fleste studiene som rapporterer relativt lange unnvikelsesavstander (4-25 km) er imidlertid basert pa malinger av beiteslitasje og lokalisering av dyr registrert i lopet av 1-2 dager arlig i lopet av vinteren og mangler viktige miljoparametere og/eller alternative hypoteser. Denne metoden bor forbedres for a kunne skille mellom korrelasjon og kausalitet. Malinger av atferd gjor mulig en mer korrekt testing av Rangifer s reaksjon pa ulike antropogene stimuli samtidig som man kontrollerer for graden av domestisering og forskjellige miljofaktorer. Atferdsstudiene avgrenses imidlertid i bade tid og rom og vil vanligvis ikke fange opp eventuelle bestandsdynamiske konsekvenser av forstyrrelser. Det hefter folgelig svakheter ved begge de to dominerende metodene som i dag anvendes; maling av atferd og bestandsfordeling og indirekte kartlegging av omradebruk ved maling av beiteslitasje. For a oppna en bedre studiedesign for maling av Rangifer s reaksjon pa antropogen infrastruktur og tilknyttede aktiviteter foreslar vi at de to metodene kombineres og suppleres med GPS/telemetri teknologi.

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.

Summer response distances of Svalbard reindeer Rangifer tarandus platyrhynchus to provocation by humans on foot

The objective of our study was to examine response distances of Svalbard reindeer Rangifer tarandus platyrhynchus to direct provocation by humans on foot during summer in areas subject to combinations of high or low human activity, and hunting or no hunting. We hypothesised that Svalbard reindeer can become habituated to human activity even when hunted. Reindeer sight, fright, flight and running response distances were measured in response to direct provocation by humans on foot in five areas chosen for their degree of human activity and hunting. No differences in sight distance were found among the five areas. Reindeer in the area with the most human activity in summer and no hunting (Adventdalen) had shorter fright, flight and running distances than reindeer in the area with little human activity and no hunting (Reinsdyrflya). Reindeer response distances in the three areas with hunting and moderate human activity were similar and intermediate to areas with high and low human activity and no hunting There were significant negative correlations between the fright, flight and running distances and the amount of human activity in an area, and with the exception of running distance having a borderline significant value, there were no correlations with intensity of hunting. Our findings suggest that Svalbard reindeer become habituated to human activity and that hunting probably has only a weak or even no influence on it. Furthermore, these findings do not lend support to the hypothesis that reindeer that are hunted by humans are less likely to habituate to human activity than those that are not hunted.

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.

Reindeer (Rangifer tarandus) avoidance of a highway as revealed by lichen measurements

Reindeer and caribou Rangifer tarandus are reported to avoid human infrastructure such as roads, high-voltage power lines, pipelines, and tourist resorts. Lichens are important forage for reindeer during winter, and their relatively slow growth rates make them vulnerable to overgrazing. Height and volume of lichens are often used as an indicator of grazing pressure by reindeer and, thus, as an indirect measure of Rangifer avoidance of human infrastructure. We sampled lichen height in Cetraria nivalis-dominated communities along 4 and 3 parallel transects located on two parallel mountain ridges in Hardangervidda, south central Norway. The lichen measurements were analyzed in relation to altitude and the distance from four tourist cabins in the area and a highway (Rv7) running perpendicular to the 7 transects. The mountain ridge with 4 transects is part of a much used migratory corridor for wild reindeer R. tarandus tarandus. Along the nonmigratory ridge, lichen height decreased 35% over an 8-km distance from Rv7 and a tourist cabin, indicating reindeer aversion toward Rv7 and/or a tourist cabin. No similar relationship was found for the migration ridge in relation to distance from Rv7 or the tourist cabins. Our results suggest that avoidance of human infrastructure by wild reindeer might be limited where reindeer use of winter pastures is influenced by herd traditions and/or motivation to follow established migration corridors. This has important implications for addressing the use of similar pasture measurements when testing for Rangifer aversion toward human disturbances.

Persistence of vigilance and flight response behaviour in wild reindeer with varying domestic ancestry

Knowledge about changes in behavioural traits related to wildness and tameness is for most mammals lacking, despite the increased trend of using domestic stock to re‐establish wild populations into historical ranges. To test for persistence of behavioural traits of wild reindeer (Rangifer tarandus L.) exposed to hunting, we sampled DNA, vigilance and flight responses in wild reindeer herds with varying domestic ancestry. Analyses of 14 DNA microsatellite loci revealed a dichotomous main genetic structure reflecting their native origin, with the Rondane reindeer genetically different from the others and with least differentiation towards the Hardangervidda reindeer. The genetic clustering of the reindeer in Norefjell‐Reinsjøfjell, Ottadalen and Forollhogna, together with domestic reindeer, supports a predominant domestic origin of these herds. Despite extensive hunting in all herds, the behavioural measures indicate increasing vigilance, alert and flight responses with increasing genetic dissimilarity with domestic herds. Vigilance frequency and time spent vigilant were higher in Rondane compared to Hardangervidda, which again were higher than herds with a domestic origin. We conclude that previous domestication has preserved a hard wired behavioural trait in some reindeer herds exhibiting less fright responses towards humans that extensive hunting has, but only slightly, altered. This brings novel and relevant knowledge to discussions about genetic diversity of wildlife in general and wild reindeer herds in Norway in specific.

Sexual dimorphism and intercorhort variation in reindeer calf antler length is associated with density and weather

We analysed intercohort variability of live weight and antler length of 5,123 reindeer calves. We further assessed the influence of climate and density on the interannual variation in antler length, and discussed sex-specific resource allocation and response to climate variability. Antler length varied significantly among years and between sexes, with interaction between year and sex. Body weight and antler length were highly positively correlated, showed similar intercohort variability, and had a strong allometrical link, suggesting that antler length could be an equally reliable measure of calf condition as live weight. We found a relative measure of antler length (i.e. antler length corrected for the allometric effect of body mass) to be positively influenced by increasing density and May–June precipitation, and also decreasing May–June temperature. We attributed the effect of early summer weather to its influence on forage availability and quality as well as the level of parasitic insect harassment. Gender difference in both the allometric exponents and the interannual variability suggest that young males and females may have different tactics for relative resource allocation towards growth of antlers as compared to body mass. Because antlers are costly to produce, they may be an honest signal of individual quality for both sexes. However, we found gender-specific allometry, as female calves more than males appear to prioritize their antler growth over body mass, especially when resources are limited. Thus, our results suggest that environmental variation may influence the extent of sexual dimorphism in antler length.

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.

Effects of Power Lines on Area Use and Behaviour of Semi-Domestic Reindeer in Enclosures

We conducted large-scale, replicated experiments to test the effects of two parallel power lines on area use, behaviour, and activity of semidomestic reindeer in enclosures. Yearling female reindeer were released into four m enclosures; two treatment enclosures with power lines and two control enclosures. Reindeer from two herds, one from Kautokeino (domestic tame) and one from Vaga, (domestic wild) were tested separately and compared. Individual location within the enclosures was not affected by the power lines. Effects on restless behaviour were ambiguous, with slightly more restless behaviour in the treatment enclosures for the domestic tame reindeer, while the domestic wild reindeer maintained a stable level in the treatment enclosures, increasing with time in the control enclosures. Activity changes were slightly more common among animals within treatment enclosures for both herds, with no indication of habituation during the experiment. The domestic wild reindeer had more than three times the amount of restless behaviour than the domestic tame reindeer. Our study indicates that for reindeer in enclosures, the disturbance from a power line construction is negligible. This suggests that power lines are a minor disturbing factor compared to human handling when using fenced in areas like grazing gardens in reindeer husbandry.