Reindeer and caribou (<em>Rangifer tarandus</em>) response towards human activities

Abstract

<p>We address the question of how human activities and infrastructure influence reindeer/caribou&rsquo;s (<em>Rangifer tarandus</em>) behaviour and habitat use and review studies based on current methodologies. Anthropogenic activities have a direct affect on <em>Rangifer</em> 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 <em>Rangifer</em>&rsquo;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 <em>Rangifer</em> 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 <em>Rangifer</em> 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 <em>Rangifer</em>. 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. <em>Rangifer</em> habitat use, habitat avoidance, and feeding preferences are governed by a complexity of natural interacting factors. Domestication, habituation and sensitisation are essential in shaping <em>Rangifer</em>&rsquo;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 <em>Rangifer</em> 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 s...

Do human activity and infrastructure disturb domesticated reindeer? The need for the reindeer’s perspective

“…In many of the local-scale studies, the animals were either restricted to a small area or were individuals that, for some reason, have taken up residence in the neighbourhood of the disturbance source (e.g. Baskin and Hjältén 2001; Reimers and Colman 2006). In the latter case, it is usually unclear if, or how, the studied individuals differ from other reindeer from the same herd, e.g.…”

“…An early review within this field pointed out that knowledge of domesticated reindeer in Scandinavia could aid in predicting potential problems for caribou in North America (Klein 1971). Nonetheless, it has been questioned whether conclusions from studies on wild reindeer can be applied to herded reindeer, where the animals have been exposed to domestication and may be more or less used to the presence of humans (Reimers and Colman 2006). Wild reindeer derived from domesticated populations have been shown to have a shorter flight distance than fully wild reindeer (Reimers and Svela 2001;Reimers et al 2012), suggesting differences depending on degree of domestication.…”

“…Consequently, recent reviews (Wolfe et al 2000;Reimers and Colman 2006; refer mainly to wild reindeer. An early review within this field pointed out that knowledge of domesticated reindeer in Scandinavia could aid in predicting potential problems for caribou in North America (Klein 1971).…”

“…Aastrup 2000;Reimers et al 2009;Skarin et al 2010), road traffic, helicopters and aircraft (e.g. Klein 1971;Harrington 2003;Reimers and Colman 2006), infrastructure and industrial development, such as mining, hydropower and, more recently, wind power (e.g. Wolfe et al 2000;Nellemann et al 2003;Colman et al 2012;Panzacchi et al 2012;Skarin et al 2013).…”

Spatial factors influencing northern mountain caribou (Rangifer tarandus) survival and distribution in the Telkwa Range

“…The influence of disturbance on the distribution or habitat selection of caribou may change over time. It is possible that habituation, where animals show a decreased response to human disturbance, may occur after long-term exposure (Reimers and Colman 2006). Apart from a study by Johnson and Russell (2014), who showed that avoidance of human development by Porcupine caribou weakened over time, there is little documentation of a habituation response by caribou (Colman et al 2001).…”