Using a proxy of plant productivity (NDVI) to find key periods for animal performance: the case of roe deer

Animals in seasonal environments are affected by climate in very different ways depending on season and part of the climatic effects operates indirectly through the plants. Vegetation conditions in spring and summer are regarded as decisive for the reproductive success and the offspring's condition of large herbivores, but objective ways to determine key periods during the growing season have not been done often due to limitations in plant data. Using satellite data (NDVI), we determined how plant productivity from birth to fall influences the following winter body mass of roe deer fawns. We do this in two populations, the first inhabiting the low productive Chizé reserve in south western France with an oceanic climate and the second from Trois Fontaines, a highly productive forest with continental climate in east France. The effect of plant productivity was similar for male and female fawn mass, as expected from the weak intensity of sexual selection in roe deer life history traits. We found contrasting results between sites, with a strong effect of plant productivity in spring (April-May) in the Chizé population, but no effect in the Trois Fontaines population. The relatively low variability in winter fawn body mass could account for the absence of NDVI effects at Trois Fontaines. However, such results might also point to a limitation in the use of the NDVI, since the relationship between the canopy and the plant productivity at the ground level might be weak in the highly productive forest of Trois Fontaines.     

Predation has a greater impact in less productive environments: variation in roe deer, Capreolus capreolus, population density across Europe

Aim We aimed to describe the large‐scale patterns in population density of roe deer Caprelous capreolus in Europe and to determine the factors shaping variation in their abundance. Location Europe. Methods We collated data on roe deer population density from 72 localities spanning 25° latitude and 48° longitude and analysed them in relation to a range of environmental factors: vegetation productivity (approximated by the fraction of photosynthetically active radiation) and forest cover as proxies for food supply, winter severity, summer drought and presence or absence of large predators (wolf, Canis lupus, and Eurasian lynx, Lynx lynx), hunter harvest and a competitor (red deer, Cervus elaphus). Results Roe deer abundance increased with the overall productivity of vegetation cover and with lower forest cover (sparser forest cover means that a higher proportion of overall plant productivity is allocated to ground vegetation and thus is available to roe deer). The effect of large predators was relatively weak in highly productive environments and in regions with mild climate, but increased markedly in regions with low vegetation productivity and harsh winters. Other potentially limiting factors (hunting, summer drought and competition with red deer) had no significant impact on roe deer abundance. Main conclusions The analyses revealed the combined effect of bottom‐up and top‐down control on roe deer: on a biogeographical scale, population abundance of roe deer has been shaped by food‐related factors and large predators, with additive effects of the two species of predators. The results have implications for management of roe deer populations in Europe. First, an increase in roe deer abundance can be expected as environmental productivity increases due to climate change. Secondly, recovery plans for large carnivores should take environmental productivity and winter severity into account when predicting their impact on prey.     

Fitness outcomes in relation to individual variation in constitutive innate immune function

Although crucial for host survival when facing persistent parasite pressure, costly immune functions will inevitably compete for resources with other energetically expensive traits such as reproduction. Optimizing, but not necessarily maximizing, immune function might therefore provide net benefit to overall host fitness. Evidence for associations between fitness and immune function is relatively rare, limiting our potential to understand ultimate fitness costs of immune investment. Here, we assess how measures of constitutive immune function (haptoglobin, natural antibodies, complement activity) relate to subsequent fitness outcomes (survival, reproductive success, dominance acquisition) in a wild passerine (Malurus coronatus). Surprisingly, survival probability was not positively linearly predicted by any immune index. Instead, both low and high values of complement activity (quadratic effect) were associated with higher survival, suggesting that different immune investment strategies might reflect a dynamic disease environment. Positive linear relationships between immune indices and reproductive success suggest that individual heterogeneity overrides potential resource reallocation trade-offs within individuals. Controlling for body condition (size-adjusted body mass) and chronic stress (heterophil-lymphocyte ratio) did not alter our findings in a sample subset with available data. Overall, our results suggest that constitutive immune components have limited net costs for fitness and that variation in immune maintenance relates to individual differences more closely.     

Mismatch Between Birth Date and Vegetation Phenology Slows the Demography of Roe Deer

Marked impacts of climate change on biodiversity have frequently been demonstrated, including temperature-related shifts in phenology and life-history traits. One potential major impact of climate change is the modification of synchronization between the phenology of different trophic levels. High phenotypic plasticity in laying date has allowed many bird species to track the increasingly early springs resulting from recent environmental change, but although changes in the timing of reproduction have been well studied in birds, these questions have only recently been addressed in mammals. To track peak resource availability, large herbivores like roe deer, with a widespread distribution across Europe, should also modify their life-history schedule in response to changes in vegetation phenology over time. In this study, we analysed the influence of climate change on the timing of roe deer births and the consequences for population demography and individual fitness. Our study provides a rare quantification of the demographic costs associated with the failure of a species to modify its phenology in response to a changing world. Given these fitness costs, the lack of response of roe deer birth dates to match the increasingly earlier onset of spring is in stark contrast with the marked phenotypic responses to climate change reported in many other mammals. We suggest that the lack of phenotypic plasticity in birth timing in roe deer is linked to its inability to track environmental cues of variation in resource availability for the timing of parturition.     

Stress-Induced Tradeoffs in a Free-Living Lizard across a Variable Landscape: Consequences for Individuals and Populations

Current life history theory suggests that the allocation of energetic resources between competing physiological needs should be dictated by an individual’s longevity and pace of life. One key physiological pathway likely to contribute to the partitioning of resources is the vertebrate stress response. By increasing circulating glucocorticoids the stress response can exert a suite of physiological effects, such as altering immune function. We investigated the effects of stress physiology on individual immunity, reproduction and oxidative stress, across an urban landscape. We sampled populations in and around St. George, Utah, examining corticosterone in response to restraint stress, two innate immune measures, reproductive output, and the presence of both reactive oxygen metabolites and antioxidant binding capacity, in populations of common side-blotched lizards (Uta stansburiana) experiencing variable levels of environmental stress. Additionally, using capture-mark-recapture techniques, we examined the relationships between these physiological parameters and population-level differences. Our results reveal elevated physiological stress corresponds with suppressed immunity and increased oxidative stress. Interestingly, urban populations experiencing the most physiological stress also exhibited greater reproductive output and decreased survival relative to rural populations experiencing less physiological stress, demonstrating a tradeoff between reproduction and life maintenance processes. Our results suggest that environmental stress may augment life history strategy in this fast-paced species, and that shifts in life history strategy can in turn affect the population at large. Finally, the urban environment poses definite challenges for organisms, and while it appears that side-blotched lizards are adjusting physiologically, it is unknown what fitness costs these physiological adjustments accrue.     

Temporal variation in habitat selection breaks the catch‐22 of spatially contrasting predation risk from multiple predators

Predator avoidance depends on prey being able to discern how risk varies in space and time, but this is made considerably more complicated if risk is simultaneously present from multiple predators. This is the situation for an increasing number of mammalian prey species, as large carnivores recover or are reintroduced in ecosystems on several continents. Roe deer Capreolus capreolus in southern Norway illustrate a case in which prey face two predators with contrasting patterns of predation risk. They face a catch‐22 situation: spatially avoiding the risk from one predator (lynx Lynx lynx in dense habitat) implies exposure to the other (hunters in open habitat). Using GPS‐data from 29 roe deer, we tested for daily and seasonal variation in roe deer selection for habitat with respect to the habitats’ year‐round average risk level. Generally, roe deer altered their habitat selection between night and day in a pattern consistent with being able to avoid predicted risk from the nocturnal lynx during night and predicted risk from human hunters during day. However, seasonal variation in habitat selection only partially corresponded with the predicted seasonal variation in risk. Whereas roe deer avoided areas with high risk from hunters more strongly during the hunting season than in other seasons, there was a lack of selection towards areas and time periods lowering the risk of lynx predation during winter. It seems likely that the risk of starvation and thermal stress constrain roe deer habitat selection during this energetically challenging season with cold temperatures, snow cover and limited natural forage. The habitat selection pattern of roe deer fits thus only partly with the two contrasting risk gradients they face. Adjusting risk‐avoidance behavior temporally can be an adaptive response in the case of several predators whose predation patterns differ in space and time.     

Influence of weather and phenotypic characteristics on pregnancy rates of female roe deer in central Italy

In many ungulates, female fecundity is influenced by weather, population density and body condition. Based on a six-year survey of the reproductive tracts of adult female roe deer (Capreolus capreolus) harvested in the province of Pisa (Tuscany, central Italy), we evaluated the influence of weather, population density and individual characteristics on pregnancy rates. Eighty-five percent of females were pregnant, with a median litter size of two (range one—three). We found that pregnancy rate was positively correlated with summer rainfall and body mass of females, whereas early-winter conditions, spring rainfall, the age of females and density-dependent factors did not appear to influence pregnancy rate. These results reflect the particular seasonal variation in the abundance and quality of resources in Mediterranean habitats and show that heavier females (high-quality mothers) are more productive than lighter females.     

Achieving landscape-scale deer management for biodiversity conservation: The need to consider sources and sinks

Hyper-herbivory following predator removal is a global issue. Across North America and Europe, increasing deer numbers are affecting biodiversity and human epidemiology, but effectiveness of deer management in heterogeneous landscapes remains poorly understood. In forest habitats in Europe, deer numbers are rarely assessed and management is mainly based on impacts. Even where managed areas achieve stable or improving impact levels, the extent to which they act as sinks or persist as sources exporting deer to the wider landscape remains unknown. We present a framework to quantify effectiveness of deer management at the landscape scale. Applied across 234 km² of Eastern England, we assessed management of invasive Reeve's muntjac (Muntiacus reevesi) and native roe (Capreolus capreolus), measuring deer density (using thermal imaging distance transects 780 km/year), fertility, neonatal survival, and culling to quantify source-sink dynamics over 2008–2010. Despite management that removed 23–40% of the annual population, 1,287 (95% CI: 289–2,680) muntjac and 585 (454–1,533) roe deer dispersed annually into the wider landscape, consistent with their ongoing range expansion. For roe deer, culled individuals comprised fewer young deer than predicted by a Leslie matrix model assuming a closed population, consistent with age-dependent emigration. In this landscape, for roe and muntjac, an annual cull of at least 60% and 53%, respectively, is required to offset annual production. Failure to quantify deer numbers and productivity has allowed high density populations to persist as regional sources contributing to range expansion, despite deliberative management programs, and without recognition by managers who considered numbers and impacts to be stable. Reversing an unfavorable condition of woodland biodiversity requires appropriate culls across large contiguous areas, supported by knowledge of deer numbers and fertility. © 2013 The Wildlife Society.     

Effects of cohort,sex, and birth date on body development of roe deer (Capreolus capreolus) fawns

We investigated the effects of the year of birth (cohort effect), sex and birth date on the variations observed in birth weight and postnatal growth rate in 209 newborn fawns marked during eight consecutive fawning seasons from a highly productive roe deer population under good nutritional conditions. Roe deer exhibited a fast body development with a birth weight of 1628 g and a postnatal growth rate of 139 g/day constant over the first 20 days of their life. As previously reported for dimorphic and polygynous ungulates, there was a marked cohort effect on the rate of body development. This variability was partly explained by climatic conditions during late gestation. When fewer than 5 days with rainfall over 5 mm occurred in April, fawns were heavier. High temperatures during April and during the winter could also be involved in fast body development of roe deer fawns. Sex of fawn did not affect roe deer growth pattern. This was expected on the basis of low sexual dimorphism in size and low polygyny level characteristic of roe deer. Lastly, the date of birth did not affect the body development of roe deer fawns. High constancy of mean birth dates and high synchrony of births observed in this population could account for this result.     

Food–niche relationships within a guild of alpine ungulates including an introduced species

To assess competition for trophic resources within a guild of ungulates, we studied the food niches of sympatric ungulates in an alpine area of the Italian Western Alps and evaluated the extent of their dietary overlap, especially with regard to the presence of the introduced mouflon Ovis musimon . The roe deer Capreolus capreolus had the most diverse diet including dicotyledons, young sprouts of trees and an unusually high percentage of graminoids. The red deer Cervus elaphus and chamois Rupicapra rupricapra mainly consumed graminoids, supplemented with dicotyledonous herbs and woody plants. The mouflon was a grass feeder, with graminoids representing the majority of items ingested in all seasons. Among the native species, we recorded a high overlap of feeding choices between red deer and chamois, which frequently used the same areas and are both intermediate feeders. The mouflon showed considerable dietary overlap with the chamois and red deer in all seasons, while the similarity with roe deer was low. High food–niche overlap can imply competition but only if resources are limited and the species use the same habitats.     

老爷岭南部狍冬季移动、卧息生境选择及其适宜性评价

在动物生境研究中,移动生境和卧息生境是生境研究的焦点。开展移动生境和卧息生境选择,并在此基础上进行生境评价,有利于深入了解动物对移动和卧息生境条件的需求,制定科学合理的栖息地保护计划。以东北虎（Panthera tigris altaica）的主要猎物物种之一-狍（Capreolus pygargus）为研究对象,于2017-2019年冬季积雪覆盖期在老爷岭南部通过随机布设28个大样方和84条用于足迹链跟踪的样线收集狍的移动点和卧息点信息,再结合近年来收集的东北虎出现点,利用广义可加模型（GAM）和最大熵模型（MaxEnt）进行狍移动、卧息生境选择及评价研究。移动生境选择研究表明,狍在移动的过程中偏好选择坡度小、距农田距离>500 m、远离道路、居民点和低海拔或较高海拔的区域;移动生境评价分析表明,移动适宜和次适宜生境面积之和为1318.16 km²,占研究区域面积的51.28%,当加入虎活动点影响因子后,狍移动适宜和次适宜生境面积之和为901.52 km²,适宜和次适宜生境面积之和减少了31.61%。狍卧息生境选择研究表明,水源、农田、道路和雪深是影响狍卧息的关键因素,其中雪深对狍卧息生境选择的贡献率达到70.13%;卧息生境评价表明,卧息适宜和次适宜生境面积之和为1243.77 km²,占研究区域面积的48.39%,当加入虎出现点因子后,适宜生境和次适宜生境面积之和减少了61.00%,仅为485.02 km²。研究认为,虎的出现对狍移动和卧息生境选择均产生影响,虎的活动及捕食行为可能会减少狍的活动范围和频次,狍远离虎活动区域卧息休息,压缩了狍适宜卧息的空间。     

The effect of environmental gradients on the bed site selection of roe deer (<Emphasis Type="Italic">Capreolus capreolus</Emphasis>)

A wildlife species’ selection of bedding sites is often characterised by strong trade-offs, as habitat quality, predator avoidance and foraging needs should be achieved simultaneously. Human activities often represent major threats in addition. In areas of intensive agriculture, e.g. mowing is one of the main causes of mortality of roe deer (Capreolus capreolus) fawns due their hiding strategy. For a species’ offspring, the selection of bedding sites is particularly crucial and thus, identifying how and when animals use such habitats is important for management. We used a long-term dataset of marked roe deer fawns in Switzerland (1971–2015) to reveal the characteristics of optimal bedding sites within the first two weeks of a fawn’s life in three contrasting landscapes and the potential trade-offs that may occur. We hypothesised that roe deer adjust the selection of bedding sites to current environmental conditions and available habitat to achieve sufficient levels of predator avoidance and thermoregulation necessary for the fawn’s survival, as well as the availability of sufficient food resources for the mother doe. We found that, in general, grassland habitats with medium vegetation height (20–50 cm) and habitats in close proximity to the edge of the forest were favoured to achieve those basic requirements. However, the use of bed site habitats differed between the three contrasting landscapes in dependence of elevation and hence vegetation phenology. Our results provide essential information to reduce mortality rates caused by mowing and improve the reproductive success of this species.     

Parasite abundance contributes to condition‐dependent dispersal in a wild population of large herbivore

Parasite abundance has been shown to have major consequences for host fitness components such as survival and reproduction. However, although natal dispersal is a key life history trait, whether an individual's decision to disperse or not is influenced by the abundance of parasites it carries remains mostly unknown. Current and opposing hypotheses suggest that infected individuals should either be philopatric to avoid the energetic costs of dispersal (condition dependence) or disperse to escape from heavily parasitised habitats. From intensive monitoring of a roe deer population inhabiting a multi‐use and spatially heterogeneous agricultural landscape, we evaluated the link between an individual's parasite abundance and its propensity to disperse, while accounting for confounding effects of body mass. Dispersal propensity generally decreased with both increasing nematode abundance and with decreasing body mass. Within the dispersing segment of the population, individuals with high nematode abundance left their natal home range later in the season than less parasitised deer. These results clearly show that parasite abundance is an important component of condition‐dependent dispersal in large herbivores. However, unexpectedly, three individuals that were both heavily parasitised and of low body mass dispersed. We suggest that this ‘leave it’ response to high parasite levels in the natal habitat could represent a last ditch attempt to improve reproductive prospects, constituting a form of emergency life history strategy.     

FITNESS TRADE-OFFS MEDIATED BY IMMUNOSUPPRESSION COSTS IN A SMALL MAMMAL

Trade-offs are widespread between life-history traits, such as reproduction and survival. However, their underlying physiological and behavioral mechanisms are less clear. One proposed physiological factor involves the trade-off between investment in male reproductive effort and immunity. Based on this hypothesis, we investigated differences in fitness between artificially selected immune response bank vole groups, Myodes glareolus . Significant heritability of immune response was found and a correlated response in testosterone levels to selection on immune function. Male reproductive effort, reproductive success, and survival of first generation offspring were assessed and we demonstrate a relationship between laboratory measured immune parameters and fitness parameters in field enclosures. We identify a trade-off between reproductive effort and survival with immune response and parasites as mediators. However, this trade-off results in equal male fitness in natural conditions, potentially demonstrating different male signaling strategies for either reproductive effort or survival. Females gain indirect genetic benefits for either genetic disease resistance or male reproductive effort, but not both. Immune response is genetically variable, genetically linked to testosterone and may indirectly maintain genetic variation for sexually selected traits. Evidence for both a genetic and a field trade-off between reproductive effort and survival indicates an evolutionary constraint on fitness traits.     

Stress-dependent trade-off Between Immunological Condition and Reproductive Performance in the Polygynous Red Bishop (<Emphasis Type="Italic">Euplectes orix</Emphasis>)

According to life-history theory, a condition-dependent trade-off between reproductive performance and immune function might be expected, with only superior individuals being able to allocate many resources into reproduction without having detrimental effects on their immune system. However, little attention has been paid to the possibility that annual variations in environmentally and socially induced stress levels modify this trade-off. We analysed haematological parameters and investigated the relationship between male immunological condition and reproductive performance as measured by reproductive effort and success in a colony of the highly polygynous red bishop (Euplectes orix) for five consecutive breeding seasons. Haematological parameters can be used to assess an individuals’ stress level, and especially the heterophile/lymphocyte ratio (H/L ratio) is known to increase in response to a wide variety of stressors. Relative basophile counts, heterophile counts, lymphocyte counts, absolute leukocyte counts and H/L ratios of territorial males varied significantly among seasons. Both relative heterophile counts and H/L ratios were significantly positive related to overall breeding activity within the colony as measured in terms of total number of nests accepted and total number of eggs laid in the study colony within a breeding season. The relationship between immunological condition (as assessed by relative lymphocyte and heterophil counts and the H/L ratio) and both male reproductive effort (as measured by the number of nests built by the territorial males) and reproductive success (as measured by the number of nests accepted) varied considerably among seasons, ranging from significant negative to significant positive correlations. Across seasons, we found a significant negative relationship between the within-season correlation coefficients of individual H/L ratios against reproductive performance and the average H/L ratio of all territorial males in that season. Thus, a positive association between the immunological condition of a male and his reproductive performance (indicated by a negative correlation between H/L ratio and reproductive performance) exists only in seasons with high average H/L ratios (i.e. high average stress levels). We conclude that the trade-off between immunological condition and male reproductive performance might be important only in seasons with an overall reduced level of male immunological condition due to environmentally and/or socially induced stress and immunosuppressive conditions.Co-ordinating editor: L.D. Hurst     

Immune Phenotype and Body Condition in Roe Deer: Individuals with High Body Condition Have Different,Not Stronger Immunity

An efficient immunity is necessary for host survival, but entails energetic costs. When energy is limited, immunocompetence and body condition should co-vary positively among individuals and, depending on body condition, individuals should allocate more either in innate immunity or in adaptive response. We tested whether immune phenotype depends on body condition in large mammals, using data from two contrasted populations of roe deer Capreolus capreolus in France. Roe deer living at Chizé, a forest with poor habitat quality, were expected to show lower values for body condition and immune parameters than roe deer at Trois Fontaines, a forest with high habitat quality. From 285 blood samples collected between December 2009 and March 2011, we measured seven metabolic parameters and ten immunological parameters. A Principal Component Analysis showed that all indicators of body condition co-varied positively and were lowest at Chizé. Several immunological indicators correlated to body condition and differed between Trois Fontaines and Chizé. However, high body condition was not associated to a high average level of immunocompetence, but instead to high levels of indicators of acute inflammatory innate response, while low body condition was associated to high levels of monocytes and lymphocytes, possibly reflecting adaptive immunity. Limited data suggest that the difference between populations was not related to the presence of specific parasite species, however parasite exposure and stress have to be investigated to gain a more complete understanding of the determinants of immunity.     

Seasonal variation of activity patterns in roe deer in a temperate forested area

We investigated the activity patterns of a European roe deer (Capreolus capreolus) population living in a forested Apennine area in central Italy, in order to shed light on the environmental and biological factors that were expected to account for the observed activity patterns on daily and yearly bases. Daily and seasonal activity patterns of 31 radio-collared roe deer were assessed through sessions of radio tracking for a total period of 18 consecutive months. Roe deer showed bimodal activity patterns throughout the year, with the two highest peaks of activity recorded at dawn and dusk. Activity patterns of males and females differed during the territorial period (from early spring to late summer), whereas they did not during the nonterritorial period. Most likely, behavioral thermoregulation can be held responsible for variation of daily activity patterns in different seasons. In winter, for instance, activity during the dawn period was significantly higher than in other seasons and daylight activity was significantly higher than at night. Nocturnal activity was highest in summer and lowest in winter. During the hunting season, moreover, roe deer showed lower activity levels than during the rest of the year. The prediction that roe deer would show lower activity levels during full moon nights, when the predation risk was assumed to be higher, was not confirmed by our data. Activity rhythms in roe deer were thus subjected to both endogenous and environmental factors, the latter working as exogenous synchronization cues. Accordingly, in changing environmental and ecological conditions, a circadian cycle of activity could be seen as the result of complex interactions among daily behavioral rhythm, digestive physiology, and external modifying factors.     

In vitro digestibility of seasonal forages used by wapiti and roe deer in northeastern China

Seasonal changes in in vitro dry matter digestibility (IVDMD) of five forage classes (browses, sedges, forbs. ferns and the bark of Ulmus spp.) used by wapiti and roe deer were determined in relation to chemical composition, using the two-stage technique of in vitro trial with rumen inocula from one wapiti and one roe deer captured in winter. Wapiti and roe deer showed remarkable fluctuation in IVDMD among seasons and forage classes. IVDMD decreased from 43.8-64.3% in spring to 29.4-40.5% in winter for wapiti, and from 52.4-77.4% in spring to 25.9-36.5% in winter for roe deer. There was significant variation in IVDMD among species of browses for wapiti and roe deer. IVDMD ranged from 28.5% to 58.7% in twigs and from 39.8% to 58.2% in leaves for wapiti, and from 24.1% to 67.7% in twigs and from 40.0% to 71.7% in leaves for roe deer. Roe deer had higher IVDMD (40.0-71.7%) in both leaves and twigs of browses than wapiti (35.9-58.7%) during snow-free seasons, but IVDMD of twigs was lower for roc deer (25.9-36.5%) than wapiti (29.4-38.4%) in winter. Significant multiple correlation was found between NDF and ADF, and IVDMD in sedges, forbs and ferns for both wapiti and roe deer, whereas only roe deer showed the significant multiple correlation for leaves of browses.     

Life at the edge: Roe deer occurrence at the opposite ends of their geographical distribution,Norway and Portugal

In the face of climate change and habitat fragmentation there is an increasingly urgent need to learn more about factors that influence species distribution patterns and levels of environmental tolerance. Particular insights can be obtained by looking at the edges of a species range, especially from species with wide distributions. The European roe deer was chosen as a model species due to its widespread distribution. By using pellet group counts, we studied summer and winter habitat use of this herbivore at two of the extreme edges of its distribution – southwest of Portugal, and northeast of Norway – in relation to a range of fine-scale environmental factors including forest structure, vegetation characteristics and human disturbance. Our first prediction that roe deer would respond differently to human activity in both counties was supported. While in Norway roe deer are always close to houses, in Portugal they are either far (in summer) or indifferent (winter). However, everywhere and in every season, roe deer are far from roads. Our second prediction that roe deer better tolerate anthropogenic disturbances in the area where the importance of limiting factors is higher (Norway) was validated. However, our third prediction that anthropogenic disturbance would be less tolerated by roe deer outside the limiting seasons in each country was not supported. Our results suggest that roe deer perceive human activities differently in the two countries and that roe deer better tolerate anthropogenic disturbances in Norway.     

The relative densities of red (Cervus elaphus) and roe (Capreolus capreolus) deer and their relationship in Scottish plantation forests

Population densities of red and roe deer were estimated in 20 conifer plantations throughout central and northern Scotland. Ten forests were selected on the basis of culling records that were considered likely to cover the range of possible densities. Ten further forests were selected at random to investigate the relationship between red and roe deer densities. Density assessment was by standing-crop dung-group counts, on 1.5 x 100 m transects. Dung decay rates were estimated in four areas and used to convert the values to deer densities. Red deer densities were estimated to range from 0.3-35 km⁻²; roe deer densities ranged from 0.5-25 km⁻². Preferences for different structural habitats within individual forests (i.e. blocks with different age classes of tree) were inferred from dung densities. Red deer preferred unplanted ground, open-thicket, and prethicket; roe deer likewise preferred prethicket (highly) and open-thicket. Both species avoided closed-canopy habitats. Red and roe deer densities were negatively correlated and the relationship was significant when the data were log transformed ( P < 0.05).