Composition of late summer diet by semi-domesticated reindeer in different grazing conditions in northernmost Finland

Abstract

This study aims to investigate the diet composition of semi-domesticated reindeer (Rangifer tarandus tarandus) in late summer in different kinds of grazing conditions in northernmost Finland. The composition of diet by reindeer was determined on the grounds of microhistological analysis of feces samples collected in early August in different seasonal grazing areas (winter or summer/year-round grazing areas) in three reindeer management districts. Although the proportion of different plant groups varied between the studied districts, the quantified group of ground lichens (which also contained small amounts of mushrooms) was the most abundant, varying from 33.0 to 46.4% in the analyzed samples. In general, there were significant differences in the proportions of lichen between districts, but not between grazing areas. The proportion of lichen in samples increased significantly when the amount of lichen pasture around a sample site increased. The proportion of dwarf shrubs and leaves in samples varied from 24.9 to 37.9% and differed significantly between districts, but not between grazing areas. In the same way, the proportion of graminoids varied between 20.9 and 36.2% and differed significantly between districts and also between grazing areas. Higher amounts of graminoids in feces were observed in summer/year-round grazing areas than in winter grazing areas. Finally, the proportion of bryophytes varied between 2.9 and 6.5% and was significantly different between districts, but not between grazing areas. An increase in old and mature coniferous forest around a sample site significantly increased the amounts of bryophytes in samples. The results indicate that reindeer adapt their summer diet composition according to the availability of food plants. The results also show that when reindeer are allowed to select their summer ranges freely, reindeer tend to use lichen pastures intensively also during summer, which causes a considerable reduction in lichens due to grazing and trampling. Therefore, a proper seasonal pasture rotation system to protect lichen pastures from grazing and trampling, from early spring to late autumn, is an essential part of sustainable pasture use in reindeer herding.

Reindeer management and winter pastures in the presence of supplementary feeding and government subsidies

“…These value estimates are based on the observed differences of lichen biomass between different seasonal reindeer grazing areas (Kumpula et al, 2011 and lichen vulnerability to trampling due to the common weather conditions and their moisture content during each season. The parameter values for the importance of lichen as an energy resource outside the winter period are also presented in Table 2 and are based on the general food selection by reindeer during each season (Nieminen and Heiskari, 1989;Ophof et al, 2013;Bezard et al, 2015). Table 2 additionally shows unit costs and producer meat prices for the 20 northernmost herding districts (years 2010-2011), which are based on data from the Reindeer Herder's Association.…”

Recent changes in mountain birch forest structure and understory vegetation depend on the seasonal timing of reindeer grazing

“…This synchronized association between lichens and mountain birch seedlings rather suggests that the importance of plant consumption and trampling outweighed that of plant competition. The reasons for our findings may derive from facts that reindeer graze on lichens in dry habitats to some extent also during summer (Bezard et al, 2015). Further, the vulnerability of lichens to increasing plant competition may vary among the lichen species (Martin St & Mallik, 2017) and be lower in dry and semi-dry habitats that usually have less developed plant cover compared with habitats with more prostate plants (Cornelissen et al, 2001;Ylänne et al, 2015).…”

“…Bryoria ssp.). During the summer, reindeer habitat selection depends not only on forage availability but also insect avoidance, resulting in that the semi‐dry and dry mountain birch forests are used especially in early and late summer (Bezard et al., 2015). The importance of reindeer grazing and browsing for the vegetation in these systems is well documented (Kumpula et al., 2011; Lempa et al., 2005; Oksanen & Virtanen, 1995; Sundqvist et al., 2019).…”

Getting the dietary knowledge to restore a missing species: seasonal diet of Atlas deer Cervus elaphus barbarus in Tazekka National Park, Morocco

“…Only fresh faeces were collected (Malan et al 2012, Zweifel-Schielly et al 2012, Bezard et al 2015, Ferretti et al 2015, Ben Mimoun and Nouira 2016, García-González et al 2016) because this is important for assessing temporal diet changes (García-González et al 2016). The age of faeces was determined from smell, humidity and presence of mucus (Bezard et al 2015). Stenset et al (2016) estimated the age of the faeces on the basis of recent weather conditions in order to better assign the samples to the corresponding season.…”

“…Stenset et al (2016) estimated the age of the faeces on the basis of recent weather conditions in order to better assign the samples to the corresponding season. Aryal et al (2015) and Bezard et al (2015) observed and followed the animals and collected fresh samples in order to ensure that faeces belong to both sexes (Bezard et al 2015); but faeces collected without any observation most likely represent both sexes (Bezard et al 2015). On the other hand, it is impossible to separate faeces of different individuals (Malan et al 2012).…”