Wild Forest Reindeer Research Articles

Pure wild forest reindeer (Rangifer tarandus fennicus) or hybrids? A whole-genome sequencing approach to solve the taxonomical status

AbstractIn Finland, the geographic distribution of domestic reindeer (Rangifer tarandus tarandus) and Finnish wild forest reindeer (Rangifer tarandus fennicus) partly overlap in the vicinity of the southern border of the reindeer herding area. Additionally, domestic reindeer are occasionally kept as pets within the distribution range of the wild forest reindeer. Hybridisation of these two subspecies is one of the major threats for the wild forest reindeer population. Concerns about potential hybridisation served as the catalyst also for this study, which we aimed to clarify the taxonomic status of presumed wild forest reindeer individuals intended as founder individuals for a reintroduction project. To do this, we resequenced genomes of four Rangifer tarandus individuals with unknown taxonomical status and investigated their ancestries by comparing the genomic data with the existing resequenced data of the Finnish domestic reindeer and Finnish wild forest reindeer. The genetic relationship investigations indicated that all individuals we analysed were pure wild forest reindeer, making them suitable as founder individuals for the reintroduction project. Thus, our study provided critical knowledge for practical conservation action, where it was essential to recognise each individual’s origin. In the future, it will also offer novel insights into the spread of native wild forest reindeer to new geographic regions in Finland. For subsequent studies, additional resequenced genomic data of Rangifer individuals will be needed to develop an ancestry information marker panel of single nucleotide polymorphisms for rapid and cost-effective identification of hybrid individuals of these subspecies.

Space use and seasonal migrations of the wild forest reindeer (<i>rangifer tarandus fennicus</i> (Lönnb. 1909)) in the republic of Karelia

The results of studying the space use and seasonal migrations of the Topozero territorial group of wild forest reindeer females in the Republic of Karelia are presented. Telemetry (GPS-collars) was used to assess the migration of the wild forest reindeer. Individual variations were noted in seasonal migrations: two individuals were relatively sedentary, whereas the third moved long distances during the year, with the distance between the extreme locations amounting to more than 70 km. The timing of the start of seasonal migrations varied between years. The use of the same summer habitats in different years was revealed, but the territories of the rut and winter pastures were different for the same animals. Movements of animals over fairly long distances have been noted, which is probably associated with the disturbance factor on the part of predators and/or humans.

To the History of Reindeer and Reindeer Husbandry in Eastern Fennoscandia

The hypotheses of the reindeer appearance in Eastern Fennoscandia are discussed. Probably, reindeer appeared in the south of the Scandinavian Peninsula and then moved along the coast of the Norwegian Sea. Further, it dispersed along the Barents Sea to the north of Finland and to the northwest of the Kola Peninsula. The occupancy of the central and northeastern parts of the Kola Peninsula, apparently, took place along the mainland of the peninsula, fi rst in the southern and then in the eastern direction. Forest reindeer entered Eastern Fennoscandia 8–9 thousand years ago: fi rst in central Karelia, much later in Finland, and, possibly, to the south of the Kola Peninsula (Siivonen, 1979; Rankama, Ukkonen, 2001). Currently, Eastern Fennoscandia is inhabited by three subspecies of reindeer: European tundra deer (Rangifer tarandus tarandus (L.)), forest reindeer (Rangifer tarandus fennicus Lönnb.), and Siberian tundra reindeer (Rangifer tarandus sibiricus (L.)) appeared here in 1887 with the arrival of reindeer herders from the Bolshezemelskaya tundra. The existence of wild reindeer in Fennoscandia is closely related to domestic reindeer husbandry. Reindeer husbandry severely limited the distribution of the wild form, and as a result, the European tundra reindeer survived in Fennoscandia in the form of geographically isolated pockets of various sizes only in Norway and on the Kola Peninsula. Genetic studies have shown that, despite the longterm coexistence of the domesticated tundra reindeer and the native wild form in the eastern part of the Kola Peninsula, the wild reindeer preserved his genetic uniqueness. To the south, in Karelia, the main tasks now should be the protection and restoration of wild forest reindeer

Whole-genome sequencing provides novel insights into the evolutionary history and genetic adaptation of reindeer populations in northern Eurasia

Domestic reindeer (Rangifer tarandus) play a vital role in the culture and livelihoods of indigenous people across northern Eurasia. These animals are well adapted to harsh environmental conditions, such as extreme cold, limited feed availability and long migration distances. Therefore, understanding the genomics of reindeer is crucial for improving their management, conservation and utilisation. In this study, we have generated a new genome assembly for the Fennoscandian domestic reindeer with high contiguity, making it the most complete reference genome for reindeer to date. The new genome assembly was utilised to explore genetic diversity, population structure and selective sweeps in Eurasian Rangifer tarandus populations which was based on the largest population genomic dataset for reindeer, encompassing 58 individuals from diverse populations. Phylogenetic analyses revealed distinct genetic clusters, with the Finnish wild forest reindeer (Rangifer tarandus fennicus) standing out as a unique subspecies. Divergence time estimates suggested a separation of ~ 52 thousand years ago (Kya) between the northern European Rangifer tarandus fennicus and Rangifer tarandus tarandus. Our study identified four main genetic clusters: Fennoscandian, the eastern/northern Russian and Alaskan group, the Finnish forest reindeer, and the Svalbard reindeer. Furthermore, two independent reindeer domestication processes were inferred, suggesting separate origins for the domestic Fennoscandian and eastern/northern Russian reindeer. Notably, shared genes under selection, including retroviral genes, point towards molecular domestication processes that aided adaptation of this species to diverse environments.

Survival and cause-specific mortality in adult females of a northern migratory ungulate

Survival of ungulates can vary seasonally due to changing environmental conditions, e.g. weather or predation pressure. The wild forest reindeer (Rangifer tarandus fennicus, “WFR”) migrate between calving and wintering grounds. The annual cycle of female WFR includes four main seasons (wintering, calving, rutting and autumn migration) during which they are subject to different conditions, but almost nothing is known about their survival or mortality patterns. We measured survival in 305 GPS-tagged female WFR in two subpopulations in Finland (2010–2022). Data were analysed for inter-annual and seasonal patterns in survival and cause-specific mortality (predation, traffic, accidents and unknown causes) with known-fate models. Inter-annual survival in Suomenselkä (mean 0.90) showed an increasing trend during the study and was higher than in Kainuu (mean 0.84) which showed a declining trend. Seasonal variation in survival was population dependent. Survival was lowest in Kainuu during the winter while in Suomenselkä, it was lowest during autumn migration. Concerning cause-specific mortality, seasonal variation mirrored variation in predation that was the primary cause of mortality (55% of cases). Wolves (Canis lupus) killed the majority of predated individuals (58%). Predation rates were two times higher in Kainuu where the wolf density was higher. We provide the first adult survival estimates for WFR and show that the seasonal variation in survival is clearly different between these two northern ungulate populations. This indicates that seasonal variation in survival is determined by site-dependent factors and cannot be generalised across populations.

Homecoming without Nostalgia: Local Communities and the Reintroduction of the Wild Forest Reindeer (Rangifer tarandus sennicus) in Finland

Wildlife translocations often raise concerns about the purpose and impact among people living in target locations. We applied the integrated impact assessment in planning the reintroduction of wild forest reindeer in Finland. We investigated the variety of expected socioecological impacts, the relative importance of these impacts and local willingness to participate in local-level reintroduction activities. The reintroduction project organised interactive forums in 2013 and 2016 in each of the four regions suitable for wild forest reindeer. The variety of recognised potential impacts was high, but the relative importance given to the expected impacts varied relatively little from forum to forum. Importantly, we found a contextual and relational value of wild forest reindeer that extended beyond their intrinsic and instrumental value. The results indicate high local acceptance of reintroduction and willingness to participate in it.

Calf/female ratio and population dynamics of wild forest reindeer in relation to wolf and moose abundances in a managed European ecosystem.

The alternative prey hypothesis describes the mechanism for apparent competition whereby the mortality of the secondary prey species increases (and population size decreases decreases) by the increased predation by the shared predator if the population size of the primary prey decreases. Apparent competition is a process where the abundance of two co-existing prey species are negatively associated because they share a mutual predator, which negatively affects the abundance of both prey Here, we examined whether alternative prey and/or apparent competition hypothesis can explain the population dynamics and reproductive output of the secondary prey, wild forest reindeer (Rangifer tarandus fennicus) in Finland, in a predator-prey community in which moose (Alces alces) is the primary prey and the wolf (Canis lupus) is the generalist predator. We examined a 22-year time series (1996-2017) to determine how the population size and the calf/female ratio of wild forest reindeer in Eastern Finland were related to the abundances of wolf and moose. Only moose population size was regulated by hunting. Summer predation of wolves on reindeer focuses on calves. We used least squares regression (GLS) models (for handling autocorrelated error structures and resulting pseudo-R2s) and generalized linear mixed (GLMs) models (for avoidance of negative predictions) to determine the relationships between abundances. We performed linear and general linear models for the calf/female ratio of reindeer. The trends in reindeer population size and moose abundance were almost identical: an increase during the first years and then a decrease until the last years of our study period. Wolf population size in turn did not show long-term trends. Change in reindeer population size between consecutive winters was related positively to the calf/female ratio. The calf/female ratio was negatively related to wolf population size, but the reindeer population size was related to the wolf population only when moose abundance was entered as another independent variable. The wolf population was not related to moose abundance even though it is likely to consist the majority of the prey biomass. Because reindeer and moose populations were positively associated, our results seemed to support the alternative prey hypothesis more than the apparent competition hypothesis. However, these two hypotheses are not mutually exclusive and the primary mechanism is difficult to distinguish as the system is heavily managed by moose hunting. The recovery of wild forest reindeer in eastern Finland probably requires ecosystem management involving both habitat restoration and control of species abundances.

Covariation between entheseal changes and cross-sectional properties of reindeer long bones – Considering bone functional adaptation as partial contributing factor

Entheseal changes and bone cross-sectional properties are used as skeletal activity markers for different animal species, although most studies are targeted on humans. While there is compelling evidence on the association between activity and bone cross-sectional properties, studies on association of entheseal changes to activity have presented more contradictory results. In previous research, covariation between entheseal changes and bone cross-sectional properties is considered a possible result of common underlying factor. However, these studies are performed predominantly on human material. We provide beyond-species scope by studying this covariation in reindeer skeleton. The results will provide platform for discussing bone functional adaptation pathway in which activity modifies entheseal appearance. The material are wild forest reindeer, domesticated free-ranging reindeer and zoo reindeer of Northern and North-East Finland. We found that bone formation in most studied entheses (25 out of 27) were associated with increased values in bone cross-sectional properties and proxies of bone/body size. Features of bone resorption, when significant, were also associated with increased values in bone cross-sectional properties and bone/body size. We conclude that as entheseal changes were associated with bone cross-sectional properties and bone/body size, the observed variation at reindeer entheses likely reflects skeletal robusticity. While causal factors resulting in association between skeletal robusticity and entheseal appearance cannot be evidenced, bone functional adaptation can be hypothesized as at least a partial contributing mechanism to entheseal appearance.

The wild forest reindeer, Rangifer tarandus fennicus, in the Metsola Biosphere Reserve, Northwest Russia

The wild forest reindeer, Rangifer tarandus fennicus, in the Metsola Biosphere Reserve, Northwest Russia

Origins of Chinese reindeer (Rangifer tarandus) based on mitochondrial DNA analyses.

The most southern population of reindeer (Rangifer tarandus) inhabits northeastern China, but the migration route and origin of this population have not been confirmed. The sequences of mitochondrial DNA control regions from domestic and wild herds from Eurasia and China were analysed. The results showed that the Chinese reindeer population originated independently from north-central Russian domestic herds, belonging to a large reindeer population that was present across Beringia during the last glacial period. Some studies have reported that the Chinese reindeer population is closely related to wild forest reindeer herds in Russia. Our results, however, indicate that wild forest reindeer herds of southeastern Russia contributed little or nothing to the Chinese reindeer herd gene pool. Chinese reindeer herds have a much greater genetic similarity to more northerly distributed tundra-type herds that inhabit open areas. The present findings will be essential for future conservation planning for Chinese reindeer.

FEATURES OF UNGULATES DISTRIBUTION IN THE KARELIAN PART OF THE GREEN BELT OF FENNOSCANDIA

The study of the distribution and abundance of ungulate mammals in the Karelian part of the Green Belt of Fennoscandia (GBF) showed that these characteristics are subject to significant influence of natural and anthropogenic factors. GBF territory is a complex set of landscapes belonging to northern, middle and partly southern taiga, shaping the distribution of ungulates within it. High, compared to the regional average, moose and wild boar track densities are recorded in the North-Western Ladoga region (Lahdenpohsky, Sortavalsky Districts). A large share of the wild forest reindeer population is concentrated in northern districts of the Republic of Karelia (Louhsky, Kalevalsky), including their border zone with Finland. One core area of this North European endemic has been preserved at the southern limit of its distribution range within GBF, in Muezersky District. Protected areas within GBF are essential for the conservation and restoration of the wild forest reindeer. Currently, human impact has the decisive importance for the populations of both hunted (moose, wild boar) and rare (wild forest reindeer, roe deer) species. Since the southern part of the republic is quite extensively used in agriculture, the wild boar abundance there is higher than in other parts of Karelia. Heavy logging in vast areas in the north alters wild forest reindeer habitats, which inevitably affects the movement and distribution of the animals, and can lead to a decline in their numbers. There are boreal (ecological) wildlife corridors in the study area. They secure the connection between animals living in Finland and Russia. They act as channels for the arrival of new species (roe deer, wild boar) and for seasonal movements of native species (moose, forest reindeer). Along with the positive aspects, the migratory activity of ungulates brings about the risk of disease spread (chronic wasting disease, African swine fever).

STATE AND MANAGEMENT OF CERVID (CERVIDAE FAMILY) POPULATIONS IN THE REPUBLIC OF KARELIA

The Cervidae family in the Republic of Karelia is represented by three species: moose ( Alces alces L.), wild forest reindeer ( Rangifer tarandus fennicus Lonnb.) and European roe deer ( Capreolus capreolus L.). The first two species are representatives of the native fauna, the latter is a species new for the republic and does not reside in the territory but numerous encounters of the animals are registered every year. after more than a decade of the positive trend, the process of population growth in the republic’s main harvestable species, the moose, has halted in the past few years. In 2016 the species abundance was estimated at 21,000 individuals. The harvesting of the moose population in Karelia is minor, not exceeding 4 % of the total in the last five years. In addition to legal hunting, poaching, which has intensified in recent years, and predation by large carnivores have had a significant effect on the population size. The existence of the forest reindeer in Karelia is under threat and the species abundance is low. according to the results of the aerial survey of 2014, the population of these animals in the republic was 2300–2400 individuals. The status of the species in the regional Red Data Book (2007) was changed from category 4 to 3, and in the next edition of this book the change to category 2 is planned. The main factors that produce a negative impact on the population are illegal hunting and tourism. Ro e deer encounters have been registered in different seasons of the year in all parts of the republic. We assume that the relatively mild winters in recent years have allowed a small group of animals to gain a foothold in the Lahdenpohsky District, which explains the increasingly frequent encounters of these animals in the area. The frequent observations of the animals in the territory of Karelia are probably due to the growth of the roe deer population in the adjacent parts of Finland and the Leningrad Region.

A lymphatic dwelling filarioid nematode, Rumenfilaria andersoni (Filarioidea; Splendidofilariinae), is an emerging parasite in Finnish cervids.

BackgroundRecent studies revealed expansion of filarioid nematodes into northern Finland. In addition to Setaria tundra, an abundant filarioid, Rumenfilaria andersoni, was found inhabiting the lymphatic vessels of reindeer. Our study explores the dynamics of the rapid geographic expansion of R. andersoni, defining prevalence and density of microfilariae among 4 new cervid host species in Finland while developing a context for host-parasite ecology in Fennoscandia and more broadly in the Arctic and boreal regions.MethodsBlood samples were evaluated for presence of microfilariae from 1576 semi-domesticated reindeer, 8 captive reindeer, and free-ranging cervids including 105 wild forest reindeer, 862 moose, 114 white tailed deer and 73 roe deer in 2003–2006 (−2010). Additionally, the prepatent period and the efficacy of ivermectin treatment were investigated.ResultsRumenfilaria andersoni was found to be a common and abundant parasite in reindeer (0-90%) and wild forest reindeer (41-100%). Also moose (0-12%), white-tailed deer (15-22%) and roe deer (3%) were revealed as definitive hosts. Ivermectin was not effective against adult parasites. The prepatent period was estimated to be about five months.ConclusionsRumenfilaria andersoni was identified in 3 endemic cervid species and the introduced white-tailed deer, all constituting previously unrecognized host species in the Palearctic. Among moose, the prevalence and intensity were substantially lower than levels observed among subspecies of reindeer. White-tailed deer had a relatively high prevalence and density of R. andersoni microfilariae (rmf), whereas our limited data for roe deer indicated that the nematode may not have been abundant. Density and prevalence of rmf in moose and white tailed deer suggests the nematode may be adapted to these species, and that these cervids may be among the primary hosts of R. andersoni and reservoirs for transmission in Finland. Our current data suggest that R. andersoni became established in Finland recently, coincidental with introduction of white-tailed deer from North America in 1935; subsequent invasion and emergence in the past 70–80 years appears driven by climate-related factors. An alternative hypothesis for a temporally deeper occurrence for R. andersoni in Fennoscandia, representing post-Pleistocene range expansion with moose tracking deglaciation, is not firmly supported.

Response distances of wild forest reindeer (Rangifer tarandus fennicus Lönnb.) and semi-domestic reindeer (R. t. tarandus L.) to direct provocation by a human on foot/snowshoes

The objective of the study was to examine response distances of wild forest reindeer (Rangifer tarandus fennicus Lönnb.) and semi-domestic reindeer (R. t. tarandus L.) in Finland and Norway to direct provocation by a human on foot/snowshoes in 5 areas and in 15 reindeer herding cooperatives during different seasons in 2010-12. There were no significant differences in mean herd size or in sight, alert, flight and closest response distances of wild forest reindeer in the Kuhmo and Suomenselkä areas. The encounter distance in wild forest reindeer was significantly (P< 0.005) longer than in semi-domestic reindeer in Finland and in Finnmark, Norway, and it increased with the group size. The sight and the alert distances in wild forest reindeer were significantly (P< 0.001) longer than in semi-domestic reindeer. In addition, the flight distance for wild forest reindeer (mean 192 m) was significantly (P< 0.001) and almost three times longer than in semi-domestic reindeer in Finland (mean 68 m). The closest mean distance was in wild forest reindeer 191m (range 100-320 m) but only 44 m (range 2-110 m) in semi-domestic reindeer (P< 0.001). The sight, alert, flight and closest response distances were slightly longer in Norwegian than in Finnish semi-domestic reindeer. However, these distances were significantly (P<0.005) longer in Pohjois-Salla (no supplementary feeding) than in other Finnish reindeer herding cooperatives and at the Kaamanen experimental station. The mean flight distance of reindeer in Pohjois-Salla was 115 m but only 65 m in other cooperatives (P< 0.001). The closest distance of semi-domestic reindeer in Pohjois-Salla (mean 105 m) was more than 2.5 times longer than in other reindeer herding cooperatives (mean 40 m). The mean sight, alert and flight distances in wild forest reindeer in autumn and winter were significantly longer (P<0.005) than in semi-domestic reindeer in Finland. However, during summer these distances in wild forest reindeer herds with young calves were significantly longer (P<0.005). The mean herd size of Finnish semi-domestic reindeer was almost the same in different seasons, but in wild forest reindeer it was slightly bigger during winter and spring and smaller during summer and autumn, only 7-23 reindeer. The mean encounter and sight distances in semi-domestic reindeer were significantly longer (P<0.005) in winter, but the mean alert and flight distances were almost the same in winter and summer and slightly longer than during other seasons. The results suggest that the supplementary feeding practice during winter may likely cause a reduction in flight distances in semi-domestic reindeer.

Users or producers of ecosystem services? A scenario exercise for integrating conservation and reindeer herding in northeast Finland

Abstract Nature conservation is often seen as incompatible with pastoralism: conserved predators can cause significant harm to livestock, or livestock may conquer space from natural species. Currently, nature conservation and related policies are increasingly framed through the notion of ecosystem services, which form basis for human well-being. What are the implications of this framing in the relationships between pastoralism and conservation? To answer this question, we draw from our previous research to build four scenarios on the relationships between reindeer herding and nature conservation in northeast Finland. In the two ecosystem service, ‘user’ scenarios reindeer herders are seen to degrade nature, and thus should be controlled. In the first scenarios, reindeer herding is still compensated for its losses to predation, but in the second scenario, ‘reindeer farming’ and free grazing practises are eroded for achieving conservation objectives. If herding is viewed as a producer of ecosystem services, the herders' incentivised function would be to sustain predator populations and resemble natural species (wild forest reindeer). In our two ‘producer’ scenarios, new professions as ecosystem stewards or as ecotourism entrepreneurs emerge and herding changes from meat production priority to supporting the production of other ecosystem services. Novel solutions to conservation-pastoralism dilemmas might emerge if pastoral communities are seen as potential producers of ecosystem services. However, ‘producer-based’ conservation practises also include various uncertainties and might have negative impacts on pastoral communities' well-being, especially on the continuity of social and cultural traditions.

Geographical variation in host use of a blood-feeding ectoparasitic fly: implications for population invasiveness

Invasive generalist ectoparasites provide a tool to study factors affecting expansion rates. An increase in the number of host species may facilitate geographic range expansion by increasing the number of suitable habitats and by affecting local extinction and colonization rates. A geographic perspective on parasite host specificity and its implications on range expansion are, however, insufficiently understood. We conducted a field study to explore if divergent host specificity could explain the observed variation in expansion rates between Fennoscandian populations of the deer ked (Lipoptena cervi), which is a blood-feeding ectoparasitic fly of cervids. We found that the rapidly expanding eastern population in Finland appears to specialize on moose, whereas the slowly expanding western population in Norway breeds successfully on both moose and roe deer. The eastern population was also found to utilize the wild forest reindeer as an auxiliary host, but this species is apparently of low value for L. cervi in terms of adult maintenance, reproductive output and offspring quality. Abundant numbers of roe deer and white-tailed deer were observed to be apparently uninfected in Finland, suggesting that host use is not a plastic response to host availability, but rather a consequence of population-level evolutionary changes. Locally compatible hosts were found to be the ones sharing a long history with the deer ked in the area. Cervids that sustained adult deer keds also allowed successful reproduction. Thus, host use is probably determined by the ability of the adult to exploit particular host species. We conclude that a wide host range alone does not account for the high expansion rate or wide geographic distribution of the deer ked, although loose ecological requirements would increase habitat availability.

Vector-borne nematodes, emerging parasites in Finnish cervids

Vector-borne nematodes, emerging parasites in Finnish cervids

European Wild Forest Reindeer and Wolves: Endangered Prey and Predators

Managers are sometimes faced with a situation where one endangered species increases the vulnerability of another one. According to our late-winter helicopter survey of Finland's two small populations of wild-forest reindeer (Rangifer tarandus fennicus), the eastern one decreased by half during the last 7 years. This is probably due to the return of the wolf (Canis lupus) to the area. Our data show that the annual recruitment rate of reindeer is strongly correlated with wolf density. Calf mortality was high and stable during the first months after birth. The wolf is classified as an endangered species in Finland. Thereby, our study area provides an example of a triggered situation in which a locally abundant, endangered predator increases the vulnerability of a threatened prey. There are basically two policy options for avoiding extinction: (1) to directly control the predation risk or (2) to reach further out into the ecosystem to control those factors that have led to high abundance of predators. One potential direct management action is increased wolf control in the primary summer home ranges of female reindeer. In the long term, wolf predation on wild-forest reindeer would decline if the abundance of moose (Alces alces) could be lowered, because high moose density supports high abundance of wolves. Another noteworthy option is the reintroduction of reindeer into regions where the wolf still exists at low densities.

Identification of semi-domesticated reindeer ( Rangifer tarandus tarandus, Linnaeus 1758) and wild forest reindeer ( R.t. fennicus, Lönnberg 1909) from postcranial skeletal measurements

Reindeer bones are common finds from archaeological sites from prehistoric and historic Fennoscandia. The interpretation of the reindeer bone finds, however, is often hindered by the difficulty to separate the different subspecies of reindeer using the postcranial skeletal morphology. In this paper, skeletal measurements of modern semi-domesticated reindeer and wild forest reindeer are explored with multivariate statistical methods in order to find suitable methods for subspecies identification. The results are then applied to archaeological reindeer bone finds from Northern Finland and archaeological implications of the results are discussed.

Papillar Morphology of the Rumen of Forest Reindeer (Rangifer tarandus fennicus) and Semidomesticated Reindeer (R. t. tarandus)

The papillar morphology of the ventral and dorsal rumen of the wild forest reindeer (Rangifer tarandus fennicus Lönn.) and semidomesticated reindeer (R. t. tarandus L.) was studied in October and November 1996. The morphological measurements which were carried out were: the lengths of the papillae, the number of the papillae per square centimetre, the cross-sectional area and perimeter of sections cut from the middle of papillae. From these measurements mean papillar volume, areal papillar volume, mean papillar (epithelial) surface area, areal papillar surface and surface enlargement factor were calculated. No differences in these measurements between ventral and dorsal walls of the rumen were evident. The semidomesticated reindeer had longer papillar perimeters, larger mean and areal papillar surface areas, larger mean papillar volumes, and a larger surface enlargement factor in the ventral rumen than did forest reindeer. This may be a result of differences between feeding habits, the semidomesticated reindeer preferring a diet including more plants rich in carbohydrates e.g. lichens, which has resulted in a high production of volatile fatty acids and thus stimulation of papillar growth.