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1.
Ultrasonic telemetry was used to record simultaneously, over one complete April day, the movements of four adult brown trout, Salmo trutta , which were residents of a shallow Scottish loch. The daily movements were generally along linear tracks. The home ranges are described as standard and 95% confidence ellipses. The area of standard ellipses ranged from 330 to 633 m 2 while 95% confidence ellipses were larger, ranging from 513 to 979 m 2. The distances separating individuals, which ranged from 1 to 70 m, were greatest during peaks of activity. Although there was considerable spatial overlap of individual home ranges, the trout were not within visual range for most of the tracking period. Close encounters (proximity <2.5m) occurred most frequently and lasted longest at night. It is concluded, from this study, that brown trout in small productive lochs are solitary but may hold temporary station within widely overlapping home ranges. 相似文献
2.
Summary Two aspects of the use of space were studied for two species of horned lizard: (1) Do they restrict their movements to limited areas or do they wander more or less randomly? (2) Is overlap between home ranges reduced below what it would be if home ranges were placed at random with respect to one another?Forty-nine individuals were tagged with radiotransmitters or radioactive tags and their movements compared to a computer-generated random model. It was found that horned lizards typically occupy areas much smaller than they would if they moved randomly, that is, they occupy a limited home range. Home ranges calculated from location points generated by computer randomizations share several characteristics with the limited home ranges of lizards not moving randomly. Randomly derived location points can be surrounded by a minimum convex polygon, or characterized by a probability density function or utilization distribution, and lead to a percent-change in area vs. capture number curve very similar to that shown by lizards not moving randomly. Therefore, none of these techniques distringuishes between home ranges that result from nonrandom use of space and those that result from a randomly moving animal. Previous studies have failed to draw the distinction between these two types of home range. This distinction should be recognized, however, because the underlying processes differ so dramatically.Observed home range overlap was compared with overlap that would be expected if home ranges were located at random with respect to one another. In one of the years tested, reduced overlap was detected at a marginally significant level. This pattern becomes stronger if only overlap with conspecifics is considered. This strongly suggests that home range overlap is reduced between horned lizards. Contrary to expectation, overlap between individuals of opposite sex tended to be less than overlap between individuals of the same sex. 相似文献
3.
Home ranges, relationships between individuals and dispersal among raccoon dogs ( Nyctereutes procyonoides ) were studied in southern Finland in 1989-91. The average maximum home range, calculated by the harmonic mean method. was 9·5 km 2 and the core area (85% utilization) 3·4 km 2. There were no statistically significant annual. seasonal or sexual differences in the size of the average core area of adults, but the home ranges of juveniles in autumn were larger than those of adults. However. the maximum home ranges of adults were larger in autumn than in summer, especially those of males, which were conspicuously small in summer and large in autumn. The core areas of adjacent pairs did not usually overlap in the pup-rearing season. but in autumn some home ranges shifted and there was much more overlap. The home ranges of the male and female of a pair overlapped almost totally, and a male and a female sharing the same home range also travelled together or close to each other, thus supporting the idea that the raccoon dog is monogamous in Finland. None of the adults left the study area, but 38% of the juveniles were recovered further than 10 km from the marking place during the first autumn. 相似文献
4.
The seasonal home range size and spatial relationships of 16 adult genets Genetta genetta Linnaeus, 1758 (6 males and 10 females) were estimated in a Mediterranean habitat of northeastern Spain. Genets minimum density
was estimated as 0.98/km 2. Mean annual home range was 113.1 ha in males and of 72.0 ha in females. Males had larger home ranges than females in all
seasons, but differences were only significant in winter. Home range size changed seasonally and showed a similar pattern
in both sexes, with lower values in summer (males — 41.2 ha, females — 29.0 ha) and maximum ones in spring (males — 78.8 ha,
females — 56.1 ha). Animals displayed spatial fidelity throughout the year. Core areas (MCP50) represented 27% and 19% of
total home range size for males and females, respectively. Resting home ranges (based on locations of inactive animals) were
9 times lower than overall home range size. Individuals of the same sex overlapped less than individuals of different sexes,
especially with regard to core areas, which showed almost no overlap. The results obtained suggest that (1) different factors
are likely to affect the space use of genets, such as body mass, food abundance and reproductive cycle; (2) genets use space
in a heterogeneous way, with areas of greater activity than others within their home range; (3) there was intrasexual segregation
with regard to space use. 相似文献
5.
Direct underwater observation of micro‐habitat use by 1838 young Atlantic salmon Salmo salar [mean LT 7·9 ± 3.1(s.d.) cm, range 3·19] and 1227 brown trout Salmo trutta ( LT 10·9 ± 5·0 cm, range 3·56) showed both species were selective in habitat use, with differences between species and fish size. Atlantic salmon and brown trout selected relatively narrow ranges for the two micro‐habitat variables snout water velocity and height above bottom, but with differences between size‐classes. The smaller fishes <7 cm held positions in slower water closer to the bottom. On a larger scale, the Atlantic salmon more often used shallower stream areas, compared with brown trout. The larger parr preferred the deeper stream areas. Atlantic salmon used higher and slightly more variable mean water velocities than brown trout. Substrata used by the two species were similar. Finer substrata, although variable, were selected at the snout position, and differences were pronounced between size‐classes. On a meso‐habitat scale, brown trout were more frequently observed in slow pool‐glide habitats, while young Atlantic salmon favoured the faster high‐gradient meso‐habitats. Small juveniles <7 cm of both species were observed most frequently in riffle‐chute habitats. Atlantic salmon and brown trout segregated with respect to use of habitat, but considerable niche overlap between species indicated competitive interactions. In particular, for small fishes <7 cm of the two species, there was almost complete niche overlap for use of water depth, while they segregated with respect to water velocity. Habitat suitability indices developed for both species for mean water velocity and water depth, tended to have their optimum at lower values compared with previous studies in larger streams, with Atlantic salmon parr in the small streams occupying the same habitat as favoured by brown trout in larger streams. The data indicate both species may be flexible in their habitat selection depending on habitat availability. Species‐specific habitat overlap between streams may be complete. However, between‐species habitat partitioning remains similar. 相似文献
6.
Movement by the larger more mobile species of coral reef fish plays a significant role in determining patterns in abundance
and population structure. Fish movement is also relevant to the use and effectiveness of marine reserves in managing fish
populations. Coral trout are large piscivorous serranids supporting major fisheries on the Great Barrier Reef (GBR). This
study reports on the within-reef movement of the common coral trout, Plectropomus leopardus, at Heron Reef, southern GBR, over a twelve month period, investigated by tagging and underwater tracking. Tracking of coral
trout revealed no apparent relationship between the area moved and stage of tide or time of day. However, movement areas were
affected by the size of fish: in spring a linear relationship between fish size and area of movement was measured, but in
summer the largest (male) fish moved over significantly smaller areas than medium-sized fish. Movement of males may be related
to cleaning behaviour and spawning. Fifty nine percent ( n=101) of the tagged fish were resighted over periods of 4–5 months, in “home sites” measuring ∼2000 m 2. Coral trout were not restricted to home sites, but moved on average 2 km along the reef slope; maximum distances of 7–7.5 km
were measured. Coral trout appear to range as mobile, opportunistic predators, but also maintain home sites for access to
shelter and cleaning stations.
Accepted: 1 August 1996 相似文献
7.
Where animal home ranges overlap extensively, objectively identifyingexclusive areas within individual ranges has been difficult,particularly in species lacking overt territorial behaviors.By analyzing the overlap between successively smaller core areasamong individuals in a population of the long-lived Australianskink, the sleepy lizard ( Tiliqua rugosa), we objectively determinedexclusive areas within animal ranges. Using 4-year radio trackingdata, we found that ranges consisted of relatively large sallyzones (mean 6680% total range), around home ranges withmultinucleate cores strongly associated with key refuge sites.Total range and home range area varied significantly among years,being smaller in a drought year. Total ranges overlapped extensivelybetween and within sexes, but for both sexes, intrasexual overlapof inner range cores rapidly approached zero, suggesting intrasexualterritoriality. Intersexual inner core overlap reflected thisspecies socially monogamous mating system. But, male overlapof female ranges and inner cores was consistently higher thanfemale-male overlap. Refuges and/or mates may be defended resourceswithin these core areas, although aggressive behavioral interactionswere rarely observed. In the extensively overlapping sally zones,males shared space with females other than their principal partner.In productive years, with larger home ranges and more extensiveoverlap, some lizards associated with extra partners, suggestingthat males opportunistically use sally zones for polygyny. Consequently,we suggest that benefits to females from male association maychange with environmental quality, such that if food resourcesare low, monogamy may be favored if females increase foragingefficiency as a consequence of male vigilance during pairing. 相似文献
8.
The variation in diel activity patterns was determined by implanting transmitters in adult brown trout of various sizes in two montane streams in two summers in the central Rocky Mountains, U.S.A. More brown trout tended to be active, and to move greater distances, each hour during twilight and night than during the day. Mean hourly light intensity was significantly negatively correlated with the proportion of fish active and with the distance moved. Maximum water temperature was not correlated with any measure of diel activity. Brown trout displayed fidelity to diurnal positions within a given diel cycle. Overall, fish were active an average of 11 h, had an average home range of 41 m, and moved an average of 121 m over the diel cycle. Fish length and distance moved were significantly positively correlated. Water temperature, predator avoidance, and foraging tactics may influence these patterns of diel behaviour in adult brown trout in U.S. streams. 相似文献
9.
In a radiotelemetric study, we analysed space use of 24 female specimens (14 family groups and 14 nonreproductive yearling
females) out of 23 wild boar groups for periods between 3 and 39 months. Generally, wild boar used relatively small areas,
showed high site fidelity but also a strong individual variation of home ranges, indicating a high flexibility in space use.
Although age-specific differences were not statistically significant, female yearlings tended to have larger mean annual home
ranges (1,185 ha MCP) than animals ranging in family groups (771 ha). Yearlings also showed a stronger shifting from spring
to summer home ranges (2,345 m) and a tendency towards larger home range sizes in summer (791 ha MCP), compared to family
groups (shift 1,766 m, MCP 461 ha). Yearlings displayed a dislocation of about 1 km of the annual centre in the first year
after dividing from the mother. In contrast, in adults older than 2 years, the dislocation of the annual center was only 240 m. 相似文献
10.
Factors controlling brown trout Salmo trutta recruitment in Mediterranean areas are largely unknown, despite the relevance this may have for fisheries management. The
effect of hydrological variability on survival of young brown trout was studied during seven consecutive years in five resident
populations from the southern range of the species distribution. Recruit density at the end of summer varied markedly among
year-classes and rivers during the study period. Previous work showed that egg density the previous fall did not account for
more than 50% of the observed variation in recruitment density. Thus, we expected that climatic patterns, as determinants
of discharge and water temperature, would play a role in the control of young trout abundance. We tested this by analyzing
the effects of flow variation and predictability on young trout survival during the spawning to emergence and the summer drought
periods. Both hatching and emergence times and length of hatching and emergence periods were similar between years within
each river but varied considerably among populations, due to differences in water temperature. Interannual variation in flow
attributes during spawning to emergence and summer drought affected juvenile survival in all populations, once the effect
of endogenous factors was removed. Survival rate was significantly related to the timing, magnitude and duration of extreme
water conditions, and to the rate of change in discharge during hatching and emergence times in most rivers. The magnitude
and duration of low flows during summer drought appeared to be a critical factor for survival of young trout. Our findings
suggest that density-independent factors, i.e., hydrological variability, play a central role in the population dynamics of
brown trout in populations from low-latitude range margins. Reported effects of hydrologic attributes on trout survival are
likely to be increasingly important if, as predicted, climate change leads to greater extremes and variability of flow regimes. 相似文献
11.
The study investigated the relationship between home range and food abundance in a population of the southern brown bandicoot. Isoodon obesulus, in Western Australia. Home range areas were estimated seven times between 1986 and 1988 by live-trapping, spool-and-line devices and fluorescent pigment tracking. The abundance of invertebrate food was measured simultaneously by placing pitfall traps within the home ranges of individual animals, and by sampling invertebrates in topsoil and litter. Home range areas tended to be negatively correlated with food abundance, especially in the autumn and winter of 1986 and 1987. The influence of food on home range was investigated further in September 1988 by providing eight individual I. obesulus with a supplementary food mixture. Contrary to expectation, the added food caused an increase in home range area, home range overlap and displacement, as well as an influx of new individuals to food stations. In contrast, home range parameters in control (non-fed) individuals changed little during the experiment. The shuffling of home ranges due to feeding suggests that the home range system of I. obesulus is relatively flexible, with individuals monitoring and exploiting resources in an opportunistic manner. In contrast to previous studies, we found no evidence that I. obesulus was territorial. We speculate that individuals may be territorial at low population density if resources are defendable and intruder pressure is low, but occupy overlapping ranges if population density is high. 相似文献
12.
Two populations of beluga whales ( Delphinapterus leucas), the Eastern Beaufort Sea (BS) and Eastern Chukchi Sea (ECS), make extensive seasonal migrations into the Pacific Arctic. However, the extent to which these populations overlap in time and space is not known. We quantified distribution and migration patterns for BS and ECS belugas using daily locations from whales tracked with satellite-linked transmitters. Home ranges and core areas in summer (July and August) and in each month (July–November), daily displacement, dispersal from core areas, and autumn migration timing were estimated. Distinct summer and fall distribution patterns and staggered autumn migration timing were identified for BS and ECS whales. Summer home ranges for each population had less than 10 % overlap. Monthly home ranges were also relatively distinct between populations except in September (up to 88 % home range overlap). A distinct east–west shift in focal area use occurred in September that persisted into October, with the two populations essentially switching longitudinal positions. Highest daily displacements occurred during the migratory period in September for BS whales and October for ECS whales, further indicating westward fall migration was offset between populations. Sexual segregation of males and females within a population also varied monthly. Autumn migration timing as well as differences in spatial and temporal segregation between BS and ECS beluga populations may be a result of maternally driven philopatry and population-specific adaptations to dynamically available resources. Our results contribute to the management of these populations by identifying seasonal area use and differences in migration patterns. 相似文献
13.
We examined polymorphism at seven microsatellite loci among sea trout (Salmo trutta) (n = 846) collected from three areas in the Limfjord (Denmark). We then assessed their potential population source by comparing, using a mixed stock analysis (MSA) Bayesian framework, their genetic composition to that of brown trout collected from 32 tributaries pooled into nine geographical regions (n = 3801) and two hatcheries (n = 222) used for stocking. For each of the three regional sea trout groups (western, central and eastern Limfjord, n = 91, n = 426, n = 329, respectively), MSA was conducted with (i) all individuals in the group, (ii) with the subset of spawning sea trout only and (iii) with the subset of foraging, nonspawning individuals only, a subset that consisted primarily of sea trout caught during their first year at sea. For all three regional sea trout groups, a higher proportion of individuals (regardless of whether they were foraging or spawning) appear to have originated from the rivers that drain locally, than from the rivers that drain in other parts of the Limfjord. This suggests (1) that sea trout, at least during their first year at sea, undertake limited migrations within the Limfjord system and (2) that sea trout on their spawning run were caught close to their natal rivers. The proportion of sea trout of hatchery origin varied widely among all three Limfjord areas and broadly reflected regional stocking histories, with high proportions of sea trout of domestic origin in the east (39.3%), where stocking with domestic trout was practised intensely at the time of sampling, and in the west (57.2%), where a programme of coastal stocking of post smolts took place over several years in the early 1990s. In contrast, in the central Limfjord, where stocking with domestic trout was largely abandoned in the early 1990s, the proportion of sea trout of domestic origin was only 8.5%. Interestingly, for all three regional sea trout groups, virtually no sea trout of hatchery origin were found among the spawning individuals, which were on average larger than the nonspawning sea trout. These results suggest that stocked domestic brown trout that become anadromous experience high mortality at sea and are therefore largely absent among the larger, spawning individuals. We conclude that sea trout of domestic origin exhibit much reduced ability to reproduce and are unlikely to contribute significantly to the local gene pool largely because of a relatively high mortality at sea before the onset of maturity. 相似文献
14.
Populations on the limits of species’ distribution can show different behavioral adaptations to strong ecological pressure
than in the central part of the range. We investigated space use patterns of alpine mountain hare ( Lepus timidus) at two areas on the southern edge of the species’ range. We monitored 34 hares between 2005 and 2008, estimating home range
size, overlap, and site fidelity, and compared our results with space use in Scottish and North-European populations. Home
ranges of mountain hares did not differ between two study areas with different habitat types. Subadult animals used larger
ranges than adults and both age groups reduced home range size in autumn, a period that might be critical for hares due to
changes in diet and/or high energy expenditure during the previous breeding season. Home ranges in these alpine populations
were smaller than in Scandinavian populations but within the range of populations in different habitat types in Scotland.
Seasonal home ranges overlapped considerably, but differed among the sexes: male–female overlap was higher than same sex (male–male
and female–female) spatial overlap. Seasonal shifts of home ranges were small, and site fidelity remained high over the seasons,
suggesting that resource distribution remained constant throughout the year and that the knowledge of an intensively frequented
area is an important element of habitat quality. We concluded that habitat structure and availability of mates interact in
affecting mountain hare space use in alpine habitats. 相似文献
15.
Red foxVulpes vulpes (Linnaeus, 1758) are generally regarded as strictly territorial animals, inhabiting distinct and well-separated ranges. The home ranges of these predators can vary in size from a few dozen hectares to as much as 20–30 km2. Because it seemed impossible that foxes could defend areas so different in size with the same intensity, the published data were analysed in order to see how changes in home range size could affect the following parameters: home range overlap, the area visited daily and the distance travelled by animals during 24 h. It was found that the overlap between fox families (groups) occupying large ranges was much greater than between foxes living in small ranges. The ratio of the area visited daily to the seasonal home range size was greater in small ranges than in large ones. No significant correlation was found between the mean distance moved daily and home range size (r = −0.118,p = 0.75). These results suggest different patterns of the use of space and differences in territorial defence by red foxes inhabiting large and small ranges. The implications of home range overlap and intensity of contacts between foxes occupying neighbouring ranges for the spread of disease are discussed. The significant overlap between large ranges found in this paper is discussed in the light of Andrzejewski’s (2002) home range concept. 相似文献
16.
Populations of brown trout Salmo trutta were monitored at a number of sites within a single stream, using an individual marking technique and recapturing uniquely marked fish repeatedly over a period of 12 months. Individual 1 + and 2 + resident brown trout in the Glenfinish River were found to consist of stationary and mobile component populations. The latter population consisted of a number of individuals observed moving mostly in an upstream direction, within a range of 0.03–2.24 km. On a large spatial scale, individuals in the stationary component population exhibited some degree of home site fidelity within the stream, over a period of 3–4 months, after which the fish tended to move from the site. Within sites, fidelity to either riffle or pool habitats, mostly the latter, was apparent in a proportion of the population. On a smaller scale, fidelity to the exact position with respect to boulders in the stream was also evident in a number of individuals. Home range size was calculated amongst these individuals, with ranges of up to 20 m recorded. 相似文献
17.
The migratory behaviour, habitat use, home range and temporal and spatial variability of migrations of the potamodromous asp ( Aspius aspius L.) in the large Elbe River, Germany, were studied in the years 1997–2000. Fifty‐three asp were tagged with surgically implanted radio transmitters and individually hand‐tracked usually once per week for about 1 year; 50% of the asp exclusively inhabited the main channel, 22% moved for short visits into other habitats and 24% changed between winter habitats in a harbour or oxbow and summer habitats in the main channel where they spawned in late March/April. The migratory behaviour of asp was highly variable; 34 asp observed for more than 1 year lived in home ranges of 1 to >100 stream kilometres (skm) mostly near their capture site. Longest observed migration from summer habitat in the Tidal Elbe back to the spawning ground in the Middle Elbe was 166 skm. After the spawning period or the spawning period thereafter, nine of these 34 fish left their home ranges for a long downstream migration without returning during the observation period. From these results we conclude that populations of rheophilic, potamodromous fish use a surprisingly long river section and that weirs have a strong impact on migration patterns and, ultimately, on population dynamics of these species. 相似文献
18.
Relationships between neighboring groups feature prominently in socioecological theory, but few empirical studies have focused on the effects of neighbors on the behavior of primates. Interactions between neighboring groups are most conspicuous during intergroup encounters, but the likelihood of encounters with neighbors can also affect ranging and activity patterns indirectly, and, as a result, behavioral patterns in areas of exclusive use may differ from those in overlap areas of adjacent home ranges. The aim of this study was to examine intergroup relations and spatial variation in home range use in Verreaux's sifaka (Propithecus verreauxi) during the annual mating season. Based on 230 hr of focal animal data collected from ten members of five adjacent groups, we found that behavioral patterns and patterns of resource utilization were not markedly different between areas of exclusive use and overlap areas of adjacent home ranges. Group cohesion tended to be higher in overlap than in core areas, but the proportion of time spent resting and foraging did not differ between these two areas. However, dominant males exhibited a higher scent-marking rate in overlap areas. Observations during intergroup encounters revealed that chases between males occurred frequently, whereas fights involving physical contact were not observed. We also found that the intergroup dominance hierarchy depended on the relative group size or the number of males in each group, with groups of lower dominance rank exhibiting a tendency to sleep proportionally more often in their core areas. The results of this study suggest that in primate species with a moderate level of intergroup aggression, such as Verreaux's sifaka, the possibility of encountering neighbors in areas of home range overlap does not exert strong influence on their behavior and resource utilization. 相似文献
19.
The Aransas-Wood Buffalo population (the only non-reintroduced, migratory population) of endangered whooping cranes ( Grus americana) overwinters along the Texas Gulf Coast, USA. Understanding whooping crane space use on the wintering grounds reveals essential aspects of this species' ecology, which subsequently assists with conservation. Using global positioning system telemetry data from marked whooping cranes during 2009–2017, we fit continuous-time stochastic process models to describe movement and home range using autocorrelated kernel density estimation (AKDE) and explored variation in home range size in relation to age, sex, reproductive status, and drought conditions. We used the Bhattacharyya coefficient of overlap and distance between home range centroids to quantify site fidelity. We examined the effects of time between winter home ranges and the sex of the crane on site fidelity using Bayesian mixed-effects beta regression. Winter whooping crane 95% AKDE home range size averaged 30.1 ± 45.2 (SD) km 2 (median = 14.3, range = 1.1–308.6). Home ranges of sub-adult females were approximately 2 times larger than those of sub-adult males or families. As drought worsened, home ranges typically expanded. Between consecutive years, the home ranges of an adult crane exhibited 68 ± 31% overlap (site fidelity), but fidelity to winter sites declined in subsequent winters. The overlap of adult home ranges with the nearest unrelated family averaged 33 ± 28%. As a whooping crane aged, overlap with its winter home range as a juvenile declined, regardless of sex. By 4 years of age, a whooping crane had approximately 14 ± 28% overlap with its juvenile winter home range. Limited evidence suggested male whooping cranes return to within 2 km of their juvenile home range by their fifth winter. Previous data obtained from aerial surveys led ecologists to assume that whooping crane families normally used small areas (~2 km 2) and expressed persistent site fidelity. Our analyses showed <8% of families had home ranges ≤2 km 2, with the average area 15 times greater, and waning site fidelity over time. Our work represents an analysis of whooping crane home ranges for this population, identifying past misconceptions of winter space use and resulting in better estimates of space requirements for future conservation efforts. 相似文献
20.
Understanding patterns of animal space use and range fidelity has important implications for species and habitat conservation. For species that live in highly seasonal environments, such as mountain goats ( Oreamnos americanus), spatial use patterns are expected to vary in relation to seasonal changes in environmental conditions and sex‐ or age‐specific selection pressures. To address hypotheses about sex, age, and seasonality influence on space‐use ecology, we collected GPS location data from 263 radio‐collared mountain goats (males, n = 140; females, n = 123) in coastal Alaska during 2005–2016. Location data were analyzed to derive seasonal and sex‐specific fixed‐kernel home range estimates and to quantify the degree of seasonal range and utilization distribution overlap. Overall, we determined that home range size was smallest during winter, expanded coincident with the onset of green‐up and parturition, and was largest during summer. Home range size of males and females did not differ significantly during winter, but females had larger home ranges than males during summer, a relationship that was switched during the mating season. Pairwise comparisons involving individual females across subsequent years indicated home ranges were significantly smaller during years when they gave birth to offspring. Mountain goats exhibited a strong degree of range fidelity, and 99% ( n = 138) of individual animals returned to their previous year''s seasonal range with an average annual Bhattacharyya''s affinity utilization distribution overlap index of 68%. Similarity of seasonal home range utilization distributions varied in relation to sex and season in some respects. Home range overlap was highest during the summer vegetation growing season, particularly among females. These findings advance our understanding about how environmental variation and sex‐ and age‐related reproductive constraints influence space use and range fidelity among alpine ungulates. Documentation of the high degree of range fidelity among mountain goats has important conservation implications in landscapes increasingly altered by anthropogenic activities. 相似文献
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