Habitat use by semi-domesticated reindeer, estimated with pellet-group counts

Habitat selection theory predicts that herbivores should select for or against different factors at different spatial scales. For instance, quantity of forage is expected to be a strong factor influencing habitat choice at large scales, while forage quality may be important at finer scales. However, during summer, herbivores such as reindeer (Rangifer tarandus tarandus) can be limited in their grazing time by insect harassment, and do not always have the possibility to select for high quality forage. Human disturbances from hikers, etc., can also have a limiting effect on the possibility for reindeer to graze in high quality foraging habitats. Reindeer habitat selection at the landscape level was investigated through faecal pellet-group counts during the summers of 2002 and 2003 in two reindeer herding districts in Sweden. Resource utilization functions (RUFs) were developed using multiple linear regressions, where the pellet densities were related to vegetation types, topographic features, distances to tourist resorts, and distances to hiking trails. Validations of the models were performed through cross-validation correlations. Results show that high altitudes with high quality forage were important habitats. Areas that offer both snow patches and fresh forage plants for the reindeer were used in relation to their availability. The reindeer also seemed able to habituate to human intervention to a certain extent. The predictive capabilities of the RUF models were high and pellet-group counts seemed well suited to study how abiotic factors affect the habitat use at large temporal and spatial scales Abstract in Swedish / Sammanfattning: Renens användning av sommarbetesområdet, uppskattat med spillningsinventeringar Hierarkiskt habitatval innebär att djur väljer för och emot olika faktorer beroende på den rumsliga skalan. Mängden bete kan t ex spela stor roll för en växtätares habitatval på en stor skala medan kvalitén på betet kan ha större betydelse på en mindre skala. För renar (Rangifer tarandus tarandus), kan betestiden och möjligheten att hitta bra bete sommartid begränsas både på stor och liten skala pga. störningar från insekter och mänsklig aktivitet. Här studerades renarnas val av betesområde på landskapsnivå med hjälp av spillningsinventering under somrarna 2002 och 2003 i två samebyar i Sverige. Spillningstätheten för respektive område och år undersöktes statistiskt med hjälp av multipel linjär regression eller sk ”resource utilisation functions” (RUF). Där relaterades spillningstätheten till vegetationstyp, olika topografiska faktorer, avstånd till vandringsleder, stugplatser och fjällstationer. Resultaten visade att områden högt upp i terrängen med hög beteskvalitet var attraktiva. Vegetationstypen moderat snölega som anses ha hög beteskvalitet användes av renarna i relation till dess förekomst. Däremot verkade renarna undvika områden kring välbesökta fjällstugor och fjällstationer medan de däremot t o m föredrog områden nära vandringsleder. Det kan bero på att vandringslederna går genom attraktiva vegetationstyper. RUF-modellerna hade en hög prediktiv förmåga vilket visar att spillningsinventeringar är användbara när man önskar studera hur djuren använder ett betesområde i relation till olika faktorer på en relativt stor rumslig och temporal skala

Decay rate of reindeer pellet-groups

Counting of animal faecal pellet groups to estimate habitat use and population densities is a well known method in wildlife research. Using pellet-group counts often require knowledge about the decay rate of the faeces. The decay rate of a faecal pellet group may be different depending on e.g. substrate, size of the pellet group and species. Pellet-group decay rates has been estimated for a number of wildlife species but never before for reindeer (Rangifer tarandus). During 2001 to 2005 a field experiment estimating the decay rate of reindeer pellet groups was performed in the Swedish mountains close to Ammarnäs. In total the decay rate of 382 pellet groups in three different habitat types (alpine heath, birch forest and spruce forest) was estimated. The slowest decay rate was found in alpine heath and there the pellet groups persisted for at least four years. If decay was assumed to take place only during the bare ground season, the estimated exponential decay rate was -0.027 pellet groups/week in the same habitat. In the forest, the decay was faster and the pellet groups did not persist more than two years. Performing pellet group counts to estimate habitat use in dry habitats, such as alpine heath, I will recommend using the faecal standing crop method. Using this method makes it possible to catch the animals’ general habitat use over several years. Abstract in Swedish / Sammanfattning:Nedbrytningshastighet av renspillningInom viltforskningen har spillningsinventeringar använts under flera årtionden för att uppskatta habitatval och populationstäthet hos olika djurslag. För att kunna använda data från spillningsinventeringar krävs ofta att man vet hur lång tid det tar för spillningen att brytas ner. Nedbrytningshastigheten är olika beroende på marktyp och djurslag. Nedbrytningshastighet på spillning har studerats för bland annat olika typer av hjortdjur, men det har inte studerats på ren (Rangifer tarandus) tidigare. I området kring Ammarnäs genomfördes under åren 2001- 2005 ett fältexperiment för att uppskatta nedbrytningshastigheten av renspillning. Under tre somrar lades totalt 382 renspillningar ut i hägn i tre olika typer av habitat (fjällhed, fjällbjörkskog och granskog). Det visade sig att nedbrytningshastigheten var långsammast på fjällheden, där spillningshögarna fortfarande var kvar efter fyra år. Den exponentiella nedbrytningshastigheten beräknades till -0.027 högar/vecka om nedbrytningen antas ske under barmarksperioden. I skogshägnen gick nedbrytningen snabbare och alla högar var borta inom två år. Vid spillningsinventeringar på kalfjällsområdet eller områden med liknande marktyp, där syftet är att studera djurens habitatval över en längre tid rekommenderas att använda den så kallade ”faecal accumulation rate”-metoden, där man inventerar orensade ytor. Det ger en generell bild av hur djuren använt området under en längre period, eftersom nedbrytningen av spillning är långsam i sådana habitat

Herbivore diversity effects on Arctic tundra ecosystems: a systematic review

Background Northern ecosystems are strongly influenced by herbivores that differ in their impacts on the ecosystem. Yet the role of herbivore diversity in shaping the structure and functioning of tundra ecosystems has been overlooked. With climate and land-use changes causing rapid shifts in Arctic species assemblages, a better understanding of the consequences of herbivore diversity changes for tundra ecosystem functioning is urgently needed. This systematic review synthesizes available evidence on the effects of herbivore diversity on different processes, functions, and properties of tundra ecosystems.Methods Following a published protocol, our systematic review combined primary field studies retrieved from bibliographic databases, search engines and specialist websites that compared tundra ecosystem responses to different levels of vertebrate and invertebrate herbivore diversity. We used the number of functional groups of herbivores (i.e., functional group richness) as a measure of the diversity of the herbivore assemblage. We screened titles, abstracts, and full texts of studies using pre-defined eligibility criteria. We critically appraised the validity of the studies, tested the influence of different moderators, and conducted sensitivity analyses. Quantitative synthesis (i.e., calculation of effect sizes) was performed for ecosystem responses reported by at least five articles and meta-regressions including the effects of potential modifiers for those reported by at least 10 articles.Review findings The literature searches retrieved 5944 articles. After screening titles, abstracts, and full texts, 201 articles including 3713 studies (i.e., individual comparisons) were deemed relevant for the systematic review, with 2844 of these studies included in quantitative syntheses. The available evidence base on the effects of herbivore diversity on tundra ecosystems is concentrated around well-established research locations and focuses mainly on the impacts of vertebrate herbivores on vegetation. Overall, greater herbivore diversity led to increased abundance of feeding marks by herbivores and soil temperature, and to reduced total abundance of plants, graminoids, forbs, and litter, plant leaf size, plant height, and moss depth, but the effects of herbivore diversity were difficult to tease apart from those of excluding vertebrate herbivores. The effects of different functional groups of herbivores on graminoid and lichen abundance compensated each other, leading to no net effects when herbivore effects were combined. In turn, smaller herbivores and large-bodied herbivores only reduced plant height when occurring together but not when occurring separately. Greater herbivore diversity increased plant diversity in graminoid tundra but not in other habitat types.Conclusions This systematic review underscores the importance of herbivore diversity in shaping the structure and function of Arctic ecosystems, with different functional groups of herbivores exerting additive or compensatory effects that can be modulated by environmental conditions. Still, many challenges remain to fully understand the complex impacts of herbivore diversity on tundra ecosystems. Future studies should explicitly address the role of herbivore diversity beyond presence-absence, targeting a broader range of ecosystem responses and explicitly including invertebrate herbivores.A better understanding of the role of herbivore diversity will enhance our ability to predict whether and where shifts in herbivore assemblages might mitigate or further amplify the impacts of environmental change on Arctic ecosystems

Register-based studies of hypospadias

Hypospadias is a common genital malformation ofcomplex origin. It is characterized by misplacement of the urethral orifice, proximal to the tip of the glans penis, and is most often accompanied by a cleaved prepuce and varying degrees of ventral penile curvature. The phenotype ranges from distal hypospadias, where the misplacement of the urethral orifice is small, to more proximal cases where the urethral orifice may be located in the perineum and lead to uncertain sex at birth. This thesis aims to elucidate aspects of the etiology, and increase the knowledge concerning the consequences of being born with hypospadias. All studies are based on information collected from national population-based Swedish registers, containing healthcare and demographic data. In Study I we investigated associated risk factors, in terms of parental and perinatal characteristics, and the prevalence of hypospadias. We found an increased prevalence of boys assigned with hypospadias during the late 20th century. Further, we found that boys born small for gestational age, as twins, as a result of ART, or by parents from greater Europe (excluding the Nordic countries) or Asia were at an increased risk of being registered with a diagnosis of hypospadias. The trend in prevalence was not attributable to temporal changes in the investigated risk factors. Study II highlighted the association between hypospadias and the neuromuscular disorder known as spinal-bulbar muscle atrophy (SBMA), for which the common denominator is a CAG repeat expansion in the androgen receptor (AR) gene. We described one clinical case; a boy born with proximal hypospadias who was found to have 42 CAG repeats in the AR gene, which is a mutation known to cause SBMA later in life. In Swedish health care registers we found four potential cases of SBMA and hypospadias in individuals and within families. In Study III we investigated socioeconomic outcomes in men born with hypospadias as a proxy of well-being in adulthood. We found that men born with hypospadias displayed a similar level of education and income, and were as likely to be married as non-affected men. Men with proximal hypospadias did, however, suffer a greater risk of receiving a disability pension. This risk may be due to the effect of unmeasured psychiatric comorbidity, conditions related to androgen deficiency, or hypospadias as a part of unrecognized syndromes. In Study IV we aimed to assess the fertility of adult men born with hypospadias. We found a lower probability of registered paternity among men with hypospadias; the association was most prominent in men with proximal hypospadias and of small magnitude in distal hypospadias. Men with hypospadias were more likely to being diagnosed with male infertility and of conceiving through ART. The overall results imply that fertility is impaired in men with distal and proximal hypospadias, probably as a result of anatomic features, gonadal dysfunction, psychological, or genetic factors

Reindeer behavioural ecology and use of pastures in pastoral livelihoods

Reindeer pastoralists have, for centuries, followed free-roaming animals throughout the Eurasian Arctic. The closing of national borders about a century ago forced the reindeer pastoralists to adapt to new conditions. Today, environmental conditions are changing rapidly with climate and land use change. Local history, migration and pasture use strategies of reindeer herding, and also the biogeography of grazing grounds during summer and winter, differ considerably between the countries. These differences also affect interactions with other forms of land use. Coexistence between reindeer husbandry and other interests requires an understanding of the differing preconditions in the natural environment. The main scope of this chapter is reindeer forage selection and adaptation to the arctic environment, as well as the use of pastures by reindeer and for reindeer husbandry and what affects their use during different seasons

Reindeer husbandry vs. wind energy: analysis of the Pauträsk and Norrbäck court decisions in Sweden

In 2019, the Land and Environmental Court of Appeal, Sweden’s highest court in environmental matters, authorized the establishment of two wind energy projects in the Norrbäck and Pauträsk areas on the winter grazing lands of Vapsten sameby in northern Sweden. These decisions overturned previous court rulings that rejected the two wind energy projects due to the expected impacts on nature and cultural values, and because the projects were seen to harm the interests of reindeer husbandry. In the analysis of these two legal cases, we seek to understand and explain the judicial conflicts between Sámi samebyar and wind energy developers. Based on the interpretation of the court decisions, we focus on the main features of the courts’ reasoning and examine how the courts have assessed the impact of wind turbines on reindeer husbandry. This chapter thus explains the main factors that have influenced and limited the court decisions and also concludes that these court decisions have failed to guarantee the right of the Sámi Indigenous people to practice sustainable reindeer husbandry in Sweden

Reindeer husbandry vs. wind energy : Analysis of the Pauträsk and Norrbäck court decisions in Sweden

In 2019, the Land and Environmental Court of Appeal, Sweden’s highest court in environmental matters, authorized the establishment of two wind energy projects in the Norrbäck and Pauträsk areas on the winter grazing lands of Vapsten sameby in northern Sweden. These decisions overturned previous court rulings that rejected the two wind energy projects due to the expected impacts on nature and cultural values, and because the projects were seen to harm the interests of reindeer husbandry. In the analysis of these two legal cases, we seek to understand and explain the judicial conflicts between Sámi samebyar and wind energy developers. Based on the interpretation of the court decisions, we focus on the main features of the courts’ reasoning and examine how the courts have assessed the impact of wind turbines on reindeer husbandry. This chapter thus explains the main factors that have influenced and limited the court decisions and also concludes that these court decisions have failed to guarantee the right of the Sámi Indigenous people to practice sustainable reindeer husbandry in Sweden.Peer reviewe

Insect avoidance may override human disturbances in reindeer habitat selection

Habitat selection of semi-domesticated reindeer (Rangifer tarandus tarandus) was investigated through faecal pellet- group counts and by direct observations of reindeer from helicopter in the Långfjället area in Idre reindeer herding district (62˚10’N) and in Mittådalen reindeer herding district (62˚50’N, aerial observations only). Reindeer pellets were found to be most abundant in habitats at high altitudes, and in some vegetation types. Pellet-group densities tended to be higher near the tourist trails, which often follow higher altitudes in the terrain. The aerial surveys showed that the reindeer moved towards higher altitudes when the wind speed was low and the temperature was high both in June and July. In June they moved towards lower regions when temperature was low and the wind speed was strong. The conclusion is that the reindeer use Långfjället to escape insect harassment and warm weather, even though disturbance by tourism sometimes is high.Abstract in Swedish / Sammanfattning:Habitatval hos tamren (Rangifer tarandus tarandus) undersöktes genom att göra en spillningsinventering och genom att göra flygobservationer från helikopter. Studien gjordes på Långfjället (62˚10’N) i Idre nya sameby och i Mittådalens samebys sommarbetesområde (62˚50’N, endast flygobservationer). På Långfjället finns det vandringsleder som är frekventerade av vandrare från juni månad fram till september. Spillningen visade att renarna föredrog höjderna i området samt en del av vegetationstyperna. Det var också mer spillning närmare vandringslederna. Detta kan förklaras av att vandringslederna följer höjderna i terrängen. Flyginventeringarna under både juni och juli visade att renarna rörde sig mot högre terräng när det var varmt och lugnt väder. I juni rörde dom sig också i lägre terräng när det var stark vind och kallt väder. Slutsatsen är att renarna väljer att vistas i högre terräng för att undvika störningar från insekter och för att finna svalka trots att det är mänsklig aktivitet i området

Identification of reindeer fine-scale foraging behaviour using tri-axial accelerometer data

Animal behavioural responses to the environment ultimately affect their survival. Monitoring animal fine-scale behaviour may improve understanding of animal functional response to the environment and provide an important indicator of the welfare of both wild and domesticated species. In this study, we illustrate the application of collar-attached acceleration sensors for investigating reindeer fine-scale behaviour. Using data from 19 reindeer, we tested the supervised machine learning algorithms Random forests, Support vector machines, and hidden Markov models to classify reindeer behaviour into seven classes: grazing, browsing low from shrubs or browsing high from trees, inactivity, walking, trotting, and other behaviours. We implemented leave-one-subject-out cross-validation to assess generalizable results on new individuals. Our main results illustrated that hidden Markov models were able to classify collar-attached accelerometer data into all our pre-defined behaviours of reindeer with reasonable accuracy while Random forests and Support vector machines were biased towards dominant classes. Random forests using 5-s windows had the highest overall accuracy (85%), while hidden Markov models were able to best predict individual behaviours and handle rare behaviours such as trotting and browsing high. We conclude that hidden Markov models provide a useful tool to remotely monitor reindeer and potentially other large herbivore species behaviour. These methods will allow us to quantify fine-scale behavioural processes in relation to environmental events

Animal Welfare Implications of Digital Tools for Monitoring and Management of Cattle and Sheep on Pasture

Simple SummaryMonitoring the welfare of cattle and sheep in large pastures can be time-consuming, especially if the animals are scattered over large areas in semi-natural pastures. There are several technologies for monitoring animals with wearable or remote equipment for recording physiological or behavioural parameters and trigger alarms when the acquired information deviates from the normal. Automatic equipment allows continuous monitoring and may give more information than manual monitoring. Ear tags with electronic identification can detect visits to specific points. Collars with positioning (GPS) units can assess the animals' movements and habitat selection and, to some extent, their health and welfare. Digitally determined virtual fences, instead of the traditional physical ones, have the potential to keep livestock within a predefined area using audio signals in combination with weak electric shocks, although some individuals may have difficulties in responding as intended, potentially resulting in reduced animal welfare. Remote technology such as drones equipped with cameras can be used to count animals, determine their position and study their behaviour. Drones can also herd and move animals. However, the knowledge of the potential effects on animal welfare of digital technology for monitoring and managing grazing livestock is limited, especially regarding drones and virtual fences.The opportunities for natural animal behaviours in pastures imply animal welfare benefits. Nevertheless, monitoring the animals can be challenging. The use of sensors, cameras, positioning equipment and unmanned aerial vehicles in large pastures has the potential to improve animal welfare surveillance. Directly or indirectly, sensors measure environmental factors together with the behaviour and physiological state of the animal, and deviations can trigger alarms for, e.g., disease, heat stress and imminent calving. Electronic positioning includes Radio Frequency Identification (RFID) for the recording of animals at fixed points. Positioning units (GPS) mounted on collars can determine animal movements over large areas, determine their habitat and, somewhat, health and welfare. In combination with other sensors, such units can give information that helps to evaluate the welfare of free-ranging animals. Drones equipped with cameras can also locate and count the animals, as well as herd them. Digitally defined virtual fences can keep animals within a predefined area without the use of physical barriers, relying on acoustic signals and weak electric shocks. Due to individual variations in learning ability, some individuals may be exposed to numerous electric shocks, which might compromise their welfare. More research and development are required, especially regarding the use of drones and virtual fences