Factors affecting the seasonal distribution of red deer (Cervus elaphus) at Glen Dye, north-east Scotland

Part of a red deer herd found on an estate in north-east Scotland in summer spent more time on neighbouring ground during the winter where they damaged farms and woods. Factors associated with the deer's seasonal distribution were studied to help understand how to keep more deer on the estate in winter. There were no indications that food species or food quality were responsible for the observed changes in deer distribution, or that other animals or disturbance influenced distribution over a long period. Deer sought shelter from chilling winds, and areas occupied by deer in winter had more sheltered ground from wind, and the quality of this shelter was higher than on the areas little used. Home-range behaviour and tradition appeared to determine which areas particular deer occupied in winter. The main recommendation for management was to re-open mature woodland to provide more and better shelter on the estate in order to get more control over the deer stock and to reduce marauding.     

Linking moose habitat selection to limiting factors

It has been suggested that patterns of habitat selection of animals across spatial scales should reflect the factors limiting individual fitness in a hierarchical fashion. Animals should thus select habitats that permit avoidance of the most important limiting factor at large spatial scales while the influence of less important factors should only be evident at fine scales. We tested this hypothesis by investigating moose Alces alces habitat selection using GPS telemetry in an area where the main factors limiting moose numbers were likely (in order of decreasing importance) predation risk, food availability and snow. At the landscape scale, we predicted that moose would prefer areas where the likelihood of encountering wolves was low or areas where habitats providing protection from predation were dominant. At the home‐range scale, we predicted that moose selection would be driven by food availability and snow depth. Wolf territories were delineated using telemetry locations and the study area was divided into 3 sectors that differed in terms of annual snowfall. Vegetation surveys yielded 6 habitat categories that differed with respect to food availability, and shelter from predation or snow. Our results broadly supported the hypothesis because moose reacted to several factors at each scale. At the landscape scale, moose were spatially segregated from wolves by avoiding areas receiving the lowest snowfall, but they also preferentially established their home range in areas where shelter from snow bordered habitat types providing abundant food. At the home‐range scale, moose also traded off food availability with avoidance of deep snow and predation risk. During winter, moose increased use of stands providing shelter from snow along edges with stands providing abundant food. Habitat selection patterns of females with calves differed from that of solitary moose, the former being associated primarily with habitats providing protection from predation. Animals should attempt to minimize detrimental effects of the main limiting factors when possible at the large scale. However, when the risk associated with several potential limiting factors varies with scale, we should expect animals to make trade‐offs among these.     

Variation in the size of foxes in Scotland

Foxes become larger from south to north in Scotland, independently of the climate, the prey taken or the productivity of the areas in which each population lives. In areas where fluctuating vole populations are important as food, foxes born in high vole years are no larger than those born in poor years. However foxes became smaller after a severe winter in north-east Scotland, followed by a gradual increase in the size of each year class through a series of years with mild winters and expanding rabbit populations. It is suggested that food availability is determining the average size of foxes through selection, and the north/south cline in size is the result of increased hunting hours at higher latitudes during winter. The selective advantage of different size animals under conditions of different food availability is discussed.     

The use of natural shelter by Red deer (Cervus elaphus) in relation to weather in North-east Scotland

The use of natural shelter in relation to weather by Red deer on open moorland is described. Most shelter-seeking behaviour in winter was associated with the chilling effects of wind. Although deer sheltered from both wind speed and temperature individually, the combined effect of these (i.e. "windchill") was likely to be most important. The most important individual factor was wind. In winter, resting deer sheltered from the wind by lying on lee slopes, in long vegetation, on dry ground and in places with small amounts of geomorphic shelter; they sought very sheltered places only during blizzards. Deer were found in more shelter as windchill increased, and did not appear to seek constant conditions from day to day. They put up with worse conditions when feeding than when resting. On summer days with high temperatures and strong sun, deer were seen standing when at rest, and were found in the shade, and on wet or bare ground; they also lay in the wind, bathed in water or stood on patches of old snow.     

Evaluation of Shifts in White-Tailed Deer Winter Yards in the Adirondack Region of New York

ABSTRACT In the Adirondack region of northern New York, USA, severe weather and deep snow typically force white-tailed deer (Odocoileus virginianus) to congregate in areas of dense coniferous cover and along watercourses at lower elevations. We examined 16 yards in the Adirondacks and explored the observation that deer have changed their movement behavior to incorporate residential communities within their wintering areas. We compared locations of deer herds in 2003 and 2004 to deer wintering areas mapped during the 1960s and 1970s. Deer were predominantly absent in 9 of 16 historical yards but were present in residential communities within the same drainage. Yarding areas to which deer shifted contained more residential, deciduous, and mixed cover than yards where no shift occurred, indicating that deer in residential areas were using conifer and mixed cover at a finer scale than deer in nonresidential areas. Smaller winter ranges and core areas of marked deer in a residential winter yard further imply greater concentration of resources available in these areas. Marked deer demonstrated flexibility in core winter range fidelity, a behavior that allows for more permanent shifts as habitat and food resources change or as new areas with appropriate resources are encountered. Our study suggests that low-density residential areas in lowland conifer forests may provide an energetic advantage for deer during winter due to the assemblage of quality habitat interspersed with open areas and a variety of potential food sources in environments where movement is typically constrained by deep snow. Managers should consider the potential for changes in use of deer wintering areas prior to land conservation efforts and may need to adapt management strategies to reduce conflicts in communities occupied by deer during winter.     

Effects of food availability on temporal activity patterns and growth of Atlantic salmon

1. Patterns of sheltering and activity are of fundamental importance in the ecology of animals and in determining interactions among predators and prey. Balancing decreased mortality risk when sheltering with increased feeding rate when exposed is believed to be a key determinant of diel patterns of sheltering in many animals. 2. Despite lower foraging efficiency at night than during the day, Atlantic salmon Salmo salar parr are nocturnal during winter and at low summer temperatures. Nocturnal activity also occurs at warm water temperatures during summer, but little is known about the functional significance of this behaviour. 3. This study aimed to determine: (1) the preferred activity and shelter pattern of Atlantic salmon parr during warm summer months, and (2) their response to variations in food availability when balancing growth rate (G) and mortality risk (M), as expressed through time out of shelter. We differentiated among four potential responses to reduced food availability: (1) no response; (2) G decreases but M remains constant; (3) G remains constant but M increases; and (4) G decreases and M increases. 4. Time exposed from shelter was inversely related to food availability. Fish subject to high food availability were significantly less active during the day than those with restricted rations. However, food availability had no significant effect on the extent to which fish were active at night. There was no evidence of variation in growth rate with food availability. 5. Salmon were predominantly nocturnal at high ration levels, consistent with their previously reported behaviour during winter. Rather than switching to diurnal behaviour at high temperatures per se, as previously was supposed, it appears that the fish are diurnal only to the extent needed to sustain a growth rate, and this extent depends on food availability. 6. Atlantic salmon parr modulate the amount of time they are active rather than growth when responding to variations in food availability over an order of magnitude.     

Effects of discharge and local density on the growth of juvenile Atlantic salmon Salmo salar

The study explored the combined effects of density, physical habitat and different discharge levels on the growth of juvenile Atlantic salmon Salmo salar in artificial streams, by manipulating flow during both summer and winter conditions. Growth was high during all four summer trials and increased linearly with discharge and mean velocity. Differences in fish densities (fish m^?3) due to differences in stream volume explained a similar proportion of the variation in mean growth among discharge treatments. Within streams, the fish aggregated in areas of larger sediment size, where shelters were probably abundant, while growth decreased with increasing densities. Fish appeared to favour the availability of shelter over maximization of growth. Mean growth was negative during all winter trials and did not vary among discharge treatments. These results suggest that increased fish densities are a major cause of reduced summer growth at low discharge, and that habitat‐mediated density differences explain the majority of the growth variation across habitat conditions both during summer and winter.     

植被结构对严寒地区城市居住区冬夏微气候的影响研究

城市绿地对于改善城市微气候、缓解城市热岛效应有重要作用,且不同的植物配置、绿地形态以及植被结构所产生的效果不同。以严寒地区典型城市哈尔滨为例,采用现场实测的方法,针对不同植被结构的居住区绿地进行冬夏两季微气候现场实测,对不同植被结构的微气候调节性能进行深入研究,比较分析不同植被结构影响下的空气温度、相对湿度和风速。结果表明：随着植被结构趋于复杂,植被对于冬季冷风的遮挡作用和夏季的降温增湿作用均随之增强。该研究为严寒地区城市居住区景观设计提供参考依据。     

Investigations into depth and temperature habitat utilization and overwintering grounds of juvenile sandbar sharks, Carcharhinus plumbeus: the importance of near shore North Carolina waters

Defining the location and habitat characteristics of areas of aggregation of Atlantic shark species has been identified as an important information need for current and future management efforts. The primary objective of this project was to investigate the depths and temperatures of the waters occupied by large juvenile sandbar sharks of the northwest Atlantic population during the winter months and the overwintering localities of these animals using a fishery independent method. During the summer of 2003, 21 sandbar sharks captured in the Eastern Shore of Virginia bays and lagoons were outfitted with satellite transmitters that were programmed to detach during the following winter. The sharks occurred in significantly colder and deeper waters during the winter period than during the summer nursery period with a mean depth and temperature recorded by the transmitters during the winter period of 19.9°C and 20.8 m and a mean depth and temperature recorded during the summer period of 24.0°C and 4.3 m. Despite this decrease in temperature and increase in depth of occurrence, the sharks remained in relatively warm waters and shallow depths throughout the overwintering period. Satellite pop-off locations during the overwintering period were concentrated in central North Carolina coastal waters, where a unique combination of shallow depths and warm temperatures may contribute to the survivorship of these animals while they overwinter in these waters.     

Improving housing conditions for laboratory mice: a review of "environmental enrichment"

Laboratory animal facilities have been designed to provide a standard environment where animals can be kept in good physical health at the same time as economic and ergonomic considerations are met. Recognizing the potential welfare problem associated with behavioural restriction in such housing systems, a number of attempts have been made to improve this environment, generally described under the term "environmental enrichment". Modifications of cages for mice usually consist of providing material for nest building and structures which can serve as hiding places and/or for climbing. We have reviewed 40 studies carried out between 1987 and 2000, in which preferences as well as the effect of housing modifications have been studied. Mice will work for access to nesting material and make use of this material to make nests in which they rest. They prefer a more complex cage to the standard cage and will also work for access to cages with shelter and raised platforms. On the basis of present knowledge, it is recommended that mice should have access to nesting material. Strategies for future research are outlined in the article.     

白马雪山黑白仰鼻猴(Rhinopithecus bieti)垂直迁移

2000-2001年间,在白马雪山国家级自然保护区南任村附近,通过在四个山坡每隔海拔100米的样带(宽5.0米)内搜集黑白仰鼻猴的粪便来研究猴群不同季节的垂直迁移模式。同时,通过在每个地区山脊上和山沟内搜集2.5米宽垂直样带内的粪便,来研究猴群不同季节对山脊和山沟的选择性。结果表明:猴群在海拔3500-4300米的区域活动。虽然猴群全年集中利用3900-4200米的林带;但是具有季节性差异:夏季最高(4200米),依次是秋季(4100米)和冬季(4000米),夏季最低(3900米)。另外,冬季山沟中的粪便多于山脊说明猴群在沟中停留时间长,这与沟中少风且温度高有关。不同海拔带上的粪便密度和松萝量间正相关,这意味着食物资源的垂直分布是影响猴群垂直迁移的重要因素。春季,猴群会下到低海拔采食嫩芽/叶,而冬季则下到低海拔处躲避首次大雪,这很可能导致猴群集中利用第二个海拔带。     

Sage-Grouse Habitat Selection During Winter in Alberta

ABSTRACT Greater sage-grouse (Centrocercus urophasianus) are dependent on sagebrush (Artemisia spp.) for food and shelter during winter, yet few studies have assessed winter habitat selection, particularly at scales applicable to conservation planning. Small changes to availability of winter habitats have caused drastic reductions in some sage-grouse populations. We modeled winter habitat selection by sage-grouse in Alberta, Canada, by using a resource selection function. Our purpose was to 1) generate a robust winter habitat-selection model for Alberta sage-grouse; 2) spatially depict habitat suitability in a Geographic Information System to identify areas with a high probability of selection and thus, conservation importance; and 3) assess the relative influence of human development, including oil and gas wells, in landscape models of winter habitat selection. Terrain and vegetation characteristics, sagebrush cover, anthropogenic landscape features, and energy development were important in top Akaike's Information Criterion-selected models. During winter, sage-grouse selected dense sagebrush cover and homogenous less rugged areas, and avoided energy development and 2-track truck trails. Sage-grouse avoidance of energy development highlights the need for comprehensive management strategies that maintain suitable habitats across all seasons.     

An experimental study of translocation success and habitat improvement in wild rabbits

The translocation of wild animals is a strategy frequently used in the conservation and management of natural populations. The aim of this study was to evaluate the impact of translocation (population supplementation) and habitat improvement on the abundance of European wild rabbit Oryctolagus cuniculus . We used eight open plots with different habitat treatments: two with increased shelter, two with increased food, two with increased shelter and food and two without habitat treatment (control plots). We translocated wild rabbits during 3 consecutive years, each year in four of the eight plots, with the remaining plots serving as control for the translocation treatment. Rabbit abundance (translocated plus native rabbits) was calculated by means of pellet counts, and the results were evaluated mainly by generalized linear mixed models. We found that rabbit abundance was determined primarily by habitat improvement. Rabbits were more abundant in treated than in control plots, and most abundant in the plots where food availability was increased. This effect persisted throughout the year. Translocation also increased abundance, but this effect was the strongest where shelter and food had also been improved and declined and disappeared after breeding. These findings suggest that the habitat is an important factor for rabbit abundance, with food availability being the prime factor regulating densities. Moreover, translocations on their own are only effective in the short term in situations in which factors limiting population growth (e.g. disease and predation) have not been corrected. Translocations should be carried out in conjunction with improvements in release habitat as rabbit densities will depend on the maximum carrying capacity of the habitat.     

Detailed model of shelter areas for the Cantabrian brown bear

We propose a methodology to determine critical areas for brown bear (Ursus arctos) in the Cantabrian Mountains (Spain), considered as shelter areas in which there are concentrations of winter dens and groups of resting sites. We assessed a function which enabled a precise spatial distribution model to be constructed. This function helps to explain the present division of the range of the bears into two isolated populations and to identify areas for protection with the aim of increasing their probabilities of survival or connection.

This has been done using a multivariate analysis and by applying the results to variables modelled on a geographic information system. We took a location containing 161 bear dens and resting sites. These positions have been characterised by modelling variables in a grid of 50-m cells derived from the topography (digital model of elevations, orientations, slopes, altitude variability in an area around each location). The variables include those that quantify distance weighting according to difficulties associated with access to different disturbance elements (infrastructures or buildings), variables that quantify distances to refuges (forests, scrubs, and rocky areas) and their shape (perimeter, thickness, eccentricity or shape of the forest and type of rocky areas). We constructed a logistic regression model with this data that locates and highlights shelter areas with an 86% average rate of precision. This result reveals that the eastern population has shelter areas around the present range, indicating a possible expansion area; however, there is a gap measuring close to 30 km between both populations that is almost entirely lacking in shelters and that contains important infrastructures. Increasing refuge conditions in the gap to connect shelter areas will make it possible to recover the area as a corridor.     

Seasonal variation in the range areas of the diurnal rodent Octodon degus

Both breeding activity and abundance and quality of available food are expected to influence daily movements of animals. Animals are predicted to range over large areas to meet high energy demands associated with reproduction (females) or to increase mating success (males). However, animals should expand their range areas whenever food conditions deteriorate. To examine the extent to which breeding activity versus food availability influence space use, we compared the size and location of range areas (home ranges) of the degu (Octodon degus), a diurnal rodent from semiarid environments of north-central Chile, during the austral winter and summer seasons. Degus produce young during the austral spring (September-October) when high-quality food is readily available. In contrast, degus do not breed during the austral summer (January-March) when food is scarce and of low quality. We predicted that degus would range over smaller areas in winter if the availability of food has a greater influence on space than breeding activity. Individuals were radiotracked in winter and the following summer over a 3-year period. Surveys of herbaceous cover were conducted during winter and summer to determine seasonal changes in the abundance and quality of primary food. In summer degus expanded and moved the location of their range areas to locations with available food. Given that preferred food was less abundant in summer than winter, we suggest that degu range areas are strongly influenced by food conditions.     

Evolution of chain migration in an aerial insectivorous bird,the common swift Apus apus

Spectacular long-distance migration has evolved repeatedly in animals enabling exploration of resources separated in time and space. In birds, these patterns are largely driven by seasonality, cost of migration, and asymmetries in competition leading most often to leapfrog migration, where northern breeding populations winter furthest to the south. Here, we show that the highly aerial common swift Apus apus, spending the nonbreeding period on the wing, instead exhibits a rarely found chain migration pattern, where the most southern breeding populations in Europe migrate to wintering areas furthest to the south in Africa, whereas the northern populations winter to the north. The swifts concentrated in three major areas in sub-Saharan Africa during the nonbreeding period, with substantial overlap of nearby breeding populations. We found that the southern breeding swifts were larger, raised more young, and arrived to the wintering areas with higher seasonal variation in greenness (Normalized Difference Vegetation Index) earlier than the northern breeding swifts. This unusual chain migration pattern in common swifts is largely driven by differential annual timing and we suggest it evolves by prior occupancy and dominance by size in the breeding quarters and by prior occupancy combined with diffuse competition in the winter.     

Landscape topography and the distribution of Lahontan cutthroat trout (Oncorhynchus clarki henshawi) in a high desert stream

Lahontan cutthroat trout, Oncorhynchus clarki henshawi, are currently limited in their distribution to a patchwork of small isolated populations, the result of habitat degradation and natural variation in landscape and in-stream conditions. The objectives of this study were to determine if landscape topography influences trout distribution, and if water temperatures control this response. The work was carried out in a sub-basin of the Quinn River system, McDermitt Creek, which drains the sagebrush desert of southeastern Oregon and northern Nevada. Headwater tributaries of this creek consist of alternating canyon-confined and valley bounded reaches. Trout within these systems are challenged by low discharge and high temperatures during the summer, and anchor ice during the winter. Contiguous whole stream surveys were used to look at trout distribution during the summer of 2003 and spring and fall of 2004. Our results suggested that topography can affect trout distribution. Trout numbers were highest in areas with greater numbers of nick-points (the transition zones between less confined and more confined valley segments) and greater valley confinement. Additionally, in the downstream portion of our headwater reaches, more trout were found in nick-points than expected based on the availability of this habitat type. Our data suggest that hyporheic inputs may be high in such areas, thus providing trout with shelter from warm water in the summer, anchor ice in the winter, and shallow stream depths during all seasons. Spatial occurrence of these areas of refugia can be taken into consideration when planning land use activities and restoration efforts. Further research is required to confirm that topography can affect the distribution of Lahontan cutthroat trout in other systems, and to better understand the mechanisms behind these patterns.     

Intraspecific differentiation of social behavior and shelter selection in Mesobuthus gibbosus (Brullé, 1832) (Scorpiones: Buthidae)

We compared seasonal shelter selection and social behavior of Mesobuthus gibbosus from autumn to mid-summer in two similar phryganic ecosystems, in continental Greece (near Volos city) and in insular Greece (eastern Crete), and in the laboratory under simulated abiotic conditions. Our results showed that shelter selection is a critical indicator of the seasonal social behavior of the species. The abrupt climatic changes in spring caused a differentiation in shelter selection between the cold period (November–February) and the warm period (March–June) at both sites. Sociality was exhibited only during winter in the field and was more extensive under cold conditions in the laboratory. Co-occurrence of scorpions proved to be age-specific, facilitated by population density and by harsh abiotic conditions during winter, and negatively influenced by intraspecific competition, which was higher in continental Greece. The response of scorpions to changes of abiotic factors reveals synchronization of seasonal shelter selection with climatic changes.     

Be cool: A review of hydro-physical changes and fish responses in winter in hydropower-regulated northern streams

Winter is an ecologically challenging season for ectothermic cold-water fish in natural streams because of reduced flow and freezing. Hydropower regulation in many northern rivers increase winter stream flow and temperatures, and reduce ice formation and surface ice cover. From a background review of knowledge about e.g. Atlantic salmon (Salmo salar) and brown trout (Salmo trutta) winter survival strategies, we explore responses to hydropower impacts as a basis for adaptive management, mitigating strategies, and future research. Winter intensity and duration, hydrologic conditions and channel characteristics drive complex ice processes which become more complex and pervasive in smaller, high-gradient streams. Stream ice formation may be divided into the dynamic period ‘freeze-up’ in early winter with sub-surface ice, more stable ‘mid-winter’ with surface ice, and the ecologically challenging ‘ice break-up’ in winter-spring with potential mechanical ice runs and scouring. The characteristics of periods vary depending on climate and hydropower regulation. In reaches downstream of power-plant outlets water temperature may increase and reduce surface ice formation. The mid-winter period destabilize or become absent. In bypass reaches flows decrease and facilitate freezing and ice production. Knowledge about longitudinal water temperature changes is limited. Hydro-peaked systems may aggravate high-low flow effects. A basic winter survival strategy in salmon and trout is energy storage, but also reduced metabolism, tolerance and starvation effected by quiescence. Energy storage may depend on local conditions, but there is little indication of adaptation to local thermal climates. Intraspecific phenotypic plasticity is important. The main behavioural strategy is risk-reducing sheltering in the substratum or deep areas, and nocturnal activity. Local movements between daytime refuges and nighttime slow-current activity areas are usually limited to meters. Larger fish may move more and aggregate in restricted suitable deep-slow refuge habitats such as pools and deep glides. Fish cope with ordinary thermal ice phenomena, and do not appear to become trapped in ice. Surface ice may reduce fish metabolism, but other factors, e.g. availability of substrate shelter, may override this effect. Mechanical ice break-ups and less surface ice may reduce survival. An adaptive mitigating strategy may be higher regulated flows in winter which increase rearing and/or resting habitat and survival, but studies are few and knowledge is limited. However, higher regulated flows also affect temperature regime. Low flows increase ice formation, reduce and fragment available habitat, and may reduce egg and fish survival. Influx of ground water may mitigate these impacts, as will stabilize minimum flows. Sudden drops in regulated water discharge should be avoided. Fish may strand, in particular at low temperatures in the daytime when fish are less mobile and seek shelter. The challenging winter season is understudied, and important management considerations and future research areas for better adaptive management are suggested.     

Espaces de réclusion et de rassemblement et expression graphique au Néolithique

Space is an inescapable data to analyse the schematic graphic expression in the Neolithic age and the practices, which are linked with it. A sign has meaning according to its place on the wall, in the shelter and in the area of decorated sites. We suppose that these painted shelters, and widely, the space where they are included, are visited during transition rites. Some of these sites have probably been used for persons in cloistered status. Others shelters are more areas for the gathering of an important group of men. We think that cloistering and gathering are adaptable with the diversity of environment. The Van Gennep's explanation of transition rites in three parts and the spatial analysis allow us to explain the transition and transformation of men on the decorated sites.