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1.
Threatened populations are vulnerable to the effects of genetic drift and inbreeding, particularly when gene flow is low and the effective population size is small. Estimates of effective population size (N e ) provide important information on the status of endangered populations that have experienced severe fragmentation and serve as indicators of genetic viability. Genetic data from microsatellite loci were used to estimate N e for the 2 remaining populations of the endangered ocelot (Leopardus pardalis albescens) occurring in the United States. Several methods were used to calculate N e , resulting in estimates ranging from N e  = 8.0 (95% CI: 3.2–23.1) to 13.9 (95% CI: 7.7–25.1) for the population located at the Laguna Atascosa Wildlife Refuge in Cameron County, Texas. The ocelot population in Willacy County, Texas, had N e estimates of 2.9 (95% CI: 1.7–5.6) and 3.1 (95% CI: 1.9–13.5), respectively. Estimates of N e in both populations were below the critical value recommended for short-term viability.  相似文献   

2.
Breeding dispersal can be of significant ecological and evolutionary importance. Yet, it is seldom considered in mammals. I present data on male red deer (Cervus elaphus) movements between sub-populations in southern Sweden during the rut. I investigated whether these movements could be breeding dispersal driven by mate competition. During the ruts of 1998–2009, I recorded 91 movements of males. The longest movement distance was 18.5 km. Dispersal was not restricted to yearlings or sub-adults, but also observed among adult stags. Of 91 movements observed, 7 were made by yearlings, 46 by sub-adults and 38 by adults. There was a significant move among yearlings and sub-adults towards areas with a higher ratio of females/adult males and towards areas with more females. The movements between rutting areas thereby seemed driven by sexual competition.  相似文献   

3.
Chemical repellents are promoted as a method to reduce ungulate–vehicle collisions and ungulate browsing damages to agricultural and forestry resources. We tested the effectiveness of two odour repellents (Mota FL and Wolf Urine) on the foraging behaviour and area avoidance of free-ranging roe deer (Capreolus capreolus) and red deer (Cervus elaphus). The effects of the repellents were assessed by comparing deer visitation rates to sand arenas before and after application of repellents and visitation rates to control arenas. Neither of the tested products reduced deer visitation rates. Rapid habituation to olfactory stimuli and lack of sensitivity to predator odours may explain the ineffectiveness of the repellents to alter the behaviour of the deer. The results indicate that the tested products have no effects on roe deer and red deer behaviour and suggest that the effectiveness of the chemical area repellents as a measure to reduce deer–vehicle collision risk and browsing damages is questionable.  相似文献   

4.
Piroplasms from Theileria genus were detected in blood and spleen of red deer Cervus elaphus culled during the months of September 2004–January 2005 in northwestern Poland. The polymerase chain reaction revealed the presence of Theileria deoxyribonucleic acid in 88% (36 of 41) of the animals examined. Molecular characterization of the parasites based on large piece of 18S ribosomal ribonucleic acid gene containing hypervariable region V4 showed 99.9% similarity to two Theileria spp. sequences: Theileria sp. 3185/02 and Theileria capreoli BAB1158. Phylogenetic analysis confirmed that the three isolates cluster together with high bootstrap support. It is supposed that those pathogens can be classified as one group characteristic for the Eurasian continent, contrary to protozoon of Theileria from the T. cervi group, which are often found on the North American continent and can also infect the representatives of Cervidae. In conclusion, this study suggested that free-living C. elaphus in northwestern Poland are a competent reservoir of Theileria sp. ZS T04 C.e. parasites, although the vector of the piroplasms is still unknown.  相似文献   

5.
Habitat fragmentation is known to generally reduce the size of plant populations and increase their isolation, leading to genetic erosion and increased between-population genetic differentiation. In Flanders (northern Belgium) Primula vulgaris is very rare and declining. Populations have incurred strong fragmentation for the last decades and are now restricted to a few highly fragmented areas in an intensively used agricultural landscape. Previous studies showed that small populations of this long-lived perennial herb still maintained high levels of genetic variation and low genetic differentiation. This pattern can either indicate recent gene flow or represent historical variation. Therefore, we used polymorphic microsatellite loci to investigate genetic variation and structure in adult (which may still reflect historical variation) and seedling (recent generation, thus affected by current processes) life stages. The recent generation (seedlings) showed a significant loss of observed heterozygosity (H o) together with lower expected heterozygosity (H e), a trend for higher inbreeding levels (F IS) and higher differentiation (F ST) between populations compared to the adult generation. This might result from (1) a reduction in effective population size, (2) higher inbreeding levels in the seedlings, (3) a higher survival of heterozygotes over time due to a higher fitness of heterozygotes (heterosis) and/or a lower fitness of homozygotes (inbreeding depression), (4) overlapping generations in the adult life stage, or (5) a lack of establishment of new (inbred) adults from seedlings due to degraded habitat conditions. Combining restoration of both habitat quality and gene flow between populations may be indispensable to ensure a sustainable conservation of fragmented populations.  相似文献   

6.

Background

Bovine spongiform encephalopathy (BSE), a member of the transmissible spongiform encephalopathies (TSE), primarily affects cattle. Transmission is via concentrate feed rations contaminated with infected meat and bone meal (MBM). In addition to cattle, other food animal species are susceptible to BSE and also pose a potential threat to human health as consumption of infected meat products is the cause of variant Creutzfeldt-Jakob disease in humans, which is invariably fatal. In the UK, farmed and free ranging deer were almost certainly exposed to BSE infected MBM in proprietary feeds prior to legislation banning its inclusion. Therefore, although BSE has never been diagnosed in any deer species, a possible risk to human health remains via ingestion of cervine products. Chronic wasting disease (CWD), also a TSE, naturally infects several cervid species in North America and is spreading rapidly in both captive and free-ranging populations.

Results

Here we show that European red deer (Cervus elaphus elaphus) are susceptible to intra-cerebral (i/c) challenge with BSE positive cattle brain pool material resulting in clinical neurological disease and weight loss by 794–1290 days and the clinical signs are indistinguishable to those reported in deer with CWD. Spongiform changes typical of TSE infections were present in brain and accumulation of the disease-associated abnormal prion protein (PrPd) was present in the central and peripheral nervous systems, but not in lymphoid or other tissues. Western immunoblot analysis of brain material showed a similar glycosylation pattern to that of BSE derived from infected cattle and experimentally infected sheep with respect to protease-resistant PrP isoforms. However, the di-, mono- and unglycosylated bands migrated significantly (p < 0.001) further in the samples from the clinically affected deer when compared to BSE infected brains of cattle and sheep.

Conclusion

This study shows that deer are susceptible to BSE by intra-cerebral inoculation and display clinical signs and vacuolar pathology that are similar to those of CWD. These findings highlight the importance of preventing the spread to Europe of CWD from North America as this may necessitate even more extensive testing of animal tissues destined for human consumption within the EU. Although the absence of PrPd in lymphoid and other non-neurological tissues potentially limits the risk of transmission to humans, the replication of TSE agents in peripheral tissues following intra-cerebral challenge is often limited. Thus the assessment of risk posed by cervine BSE as a human pathogen or for environmental contamination should await the outcome of ongoing oral challenge experiments.
  相似文献   

7.
Bovine tuberculosis (bTB), widely considered a disease of livestock, can also affect large game species despite their poorly understood role in the epidemiology of the endemic state of the disease. The Idanha-a-Nova County, situated in the eastern region of central Portugal, is one of the most important regions for large game hunting activity. In order to investigate the role of large game and the presence of bTB in Idanha-a-Nova, 132 wild boar (Sus scrofa) and 339 red deer (Cervus elaphus) were inspected for bTB-compatible lesions (bTBCL) during the 2008–2009 hunting season. Tissue samples with bTBCL were collected and processed for bacteriological confirmation and spoligotyping of Mycobacterium bovis isolates. In wild boar, bTB lesions were single, mostly calcified (21/29, 72.4%) and situated in the mandibular lymph nodes. Lesions were more severe and largely non-calcified (36/40, 90%) in red deer. Wild boar presented a consistently higher bTB infection rate than the red deer; however, the difference was only significant in the southern B area. This area was significantly affected by bTB for both animal species (up to 72.7% in wild boar and 34.8% in red deer) and requires the urgent implementation of intervention measures to contain the disease. Wild boar may assume an important role in the emergence of new disease foci in distant areas that infected red deer cannot reach. Spoligotyping of M. bovis isolates grouped the strains into three clusters, revealing patterns common to wild boar, red deer, and also to local cattle, indicating possible transmission among different animal species.  相似文献   

8.
The effect of various supplementary feeds on bark browsing was studied in red deer under controlled conditions. Fifteen female red deer were randomly assigned to five dietary treatments (n = 3 animals each): meadow hay as a control (C), combinations of meadow hay with grass silage (GS), maize silage (MS), maize silage with oats (MSO) or a pelleted concentrate (PC). The deer were kept in enclosures where we offered fresh spruce stems daily. The experiment consisted of two periods. In the first period (A), the animals had free access to food during 24 h, while in the second period (B), the access was restricted to night hours only. In both periods, the supplementary feeds were available ad libitum. Mean daily consumption of browsed bark in the control group in period A was 1,053 g while in the remaining groups it ranged from six to 20 g. In period B, simulating the conditions in disturbed hunting areas, bark consumption in all groups increased considerably, the highest increase being found in groups GS (430 vs. 19 g/day) and MS (101 vs. 6 g/day). In period A, the highest dry matter (DM) intake including browse was found in group MS (2,816 g/day) and the lowest one in group GS (2,307 g/day). In period B, the highest (2,763 g/day) and the lowest (2,153 g/day) DM intake was observed in groups PC and MSO, respectively. If red deer is fed supplementary, meadow hay should be combined with maize silage, grass silage or concentrate to reduce bark browsing in forests. The bark browsing rate may increase considerably if red deer are disturbed or their grazing cycle is impaired.  相似文献   

9.
We recorded 30 24-h monitoring periods with 10-min sampling intervals on seven (three female; four male) Global-Positioning-System-collared adult free-ranging red deer (Cervus elaphus), from June 1999 to December 2000, in the Parc National des Cévennes, France. We observed the duration of resting bouts (n = 385) and then microhabitat variables (aspect, slope, presence of edge and litter, visibility, abundance of vegetation consumed or not) at 178 resting places. Resting bouts were shorter during the night than during the day from June to October but did not vary between sexes. Resting place visibility was lower during the day, especially in August. Daytime resting places generally offered more litter. Females used steeper slopes than males. We found higher variability in visibility and slope during the night. Aspect used did not vary from month to month or between day and night. Observed differences between day and night resting place characteristics suggest that red deer were probably facing a tradeoff between feeding and cover. Use of cover prevailed during the daytime whereas night resting place characteristics were more variable, indicating less constrained behaviour. Thus, cover (as a protection from disturbance), as well as food, is an important factor in red deer habitat use (at least during the day in disturbed areas) and should not be neglected in forest carrying capacity management.  相似文献   

10.
Red deer (n = 149) from eight geographical locations, including the endangered endemic populations from the Tyrrhenian islands (Sardinia and Corsica), were analysed at eight polymorphic microsatellite loci. Two questions were addressed: (1) Is there a founder effect in the Corsican population, which was reintroduced to the island using Sardinian deer after the species’ extinction on Corsica? (2) What is the origin of the Tyrrhenian or Corsican red deer (Cervus elaphus corsicanus)? Our results showed signs of a founder effect for the red deer on Corsica in that these deer showed differentiation from the Sardinian population as measured by FST values, assignment tests (with and without a priori definition of populations) and individual-based dendrograms. Genetic variability, however, did not differ significantly between the two populations. With respect to the phylogeography of C. e. corsicanus we found that both deer from North-Africa and Mesola on the Italian mainland were genetically close to the Corsican red deer, but phylogenetic trees based on genetic distances were only poorly supported statistically. Among all populations studied the Mesola red deer showed the lowest distance values from Corsican red deer and yielded allele frequencies that were more similar to those of C. e. corsicanus than were those of North-African red deer. These results are in line with recent palaeontological and archaeozoological findings which suggest that the Corsican red deer is derived from small Italian red deer introduced from the mainland to Sardinia and Corsica during the Late Neolithic and just before the beginning of Classical Antiquity, respectively. They also suggest a possible recent introduction of Tyrrhenian red deer to North-Africa (rather than the other way around), thus accounting for the close genetic relationship (especially based on mitochondrial DNA) that has repeatedly been found between C. e. corsicanus and C. e. barbarus.  相似文献   

11.
Red deer Cervus elaphus is a highly appreciated and intensively managed game species throughout Europe. A common management objective is a sustainable harvest of large trophies. In southern Sweden, management has mainly aimed at preserving the nominate subspecies C. elaphus elaphus. Seasonal migration of red deer males may, however, complicate both harvest management as well as conservation efforts. I used individually identified male red deer in southern Sweden to observe distance travelled from rutting areas to areas used by males in summer and winter. Adult males were identified by antler shape and photo-documented during rut. Photos from the rut were compared to trophies of deer harvested or found dead, to found cast antlers and to stags photographed during summer. From 1969 to 2007, a distance between rutting ground and summer/winter quarters was established for 96 identified stags. An average distance of 14 km and a maximum distance of 47 km were recorded between rut and summer/winter observations. The seasonal migration of males increases the risk of overexploitation of males with harvest in both rutting areas and wintering areas. Harvest management and conservation efforts may fail if males seasonally migrate outside the management unit. The results suggest that seasonal migration must be considered in harvest management and conservation and that there is a need for a regulation of male harvest. Furthermore, the study stresses that the success in deer management of single hunting units, may be largely dependent on the harvest policies in the near surroundings as well as in areas tenths of kilometres away, suggesting that a successful management must rely on co-operation and co-ordination on a landscape scale.  相似文献   

12.
We surveyed microsatellite variation from 22 spawning populations of coho salmon (Oncorhynchus kisutch) from the Oregon Coast to help identify populations for conservation planning. All of our samples were temporally replicated, with most samples obtained in 2000 and 2001. We had three goals: (1) to confirm the status of populations identified on the basis of spawning location and life history; (2) to estimate effective population sizes and migration rates in order to determine demographic independence at different spatial scales; and (3) to determine if releases of Washington hatchery coho salmon in the 1980's into Oregon Coast streams resulted in measurable introgression into nearby wild Oregon Coast coho populations. For the last question, our study included a hatchery broodstock sample from 1985, after the Puget Sound introduction, and a 1975 sample taken from the same area prior to the introduction. Our results generally supported previously hypothesized population structure. Most importantly, we found unique lake-rearing groups identified on the basis of a common life-history type were genetically related. Estimates of immigrant fraction using several different methods also generally supported previously identified populations. Estimates of effective population size were highly correlated with estimates of spawning abundance. The 1985 hatchery sample was genetically similar to contemporary Washington samples, and the contemporary Oregon Coast samples were similar to the 1975 Oregon Coast sample, suggesting that introductions of Washington coho salmon did not result in large scale introgression into Oregon populations.  相似文献   

13.
Numerous studies have addressed the question of whether hunting is capable of limiting the abundance of ungulates in the northern hemisphere. We investigated whether the hunting of red deer (Cervus elaphus) has reduced their abundance in the Southern Black Forest (area 17,500 ha), Southern Germany, since 2006. Red deer abundance was estimated using data obtained from visual counts at winter feeding sites, track counts, and bag records. An age- and sex-structured population model to estimate the winter population size was also constructed using bag records. The estimated red deer population size was evaluated according to a non-invasive genetic mark-recapture approach. The results showed that the hunting of red deer can reduce their population size if the hunting regime is part of a holistic management concept that takes into account the uncertainty of population size estimates and is implemented at scales appropriate to the management of this species.  相似文献   

14.
Michaels HJ  Shi XJ  Mitchell RJ 《Oecologia》2008,154(4):651-661
We investigated the relationships among population size, offspring performance, and inbreeding depression (δ) in Lupinus perennis by examining the effect of population size category (large vs. small) on seed production and offspring performance for three pollination treatments (open pollination, hand crossing and hand selfing). In each of our four pairs of populations, one member of the pair was substantially larger than the other. We then grew seeds from this factorial design (2 sizes × 4 pairs × 3 pollination treatments) in the greenhouse to investigate whether population size affects offspring performance in a common environment, and how small size affects purging of the inbreeding load. Multiplicative performance across four early life-stage components (seed production, seedling emergence, seedling survival and seedling growth) of smaller populations was not significantly lower, although biomass of seedlings declined in smaller populations. Self-pollination reduced seed production, seedling emergence and seedling growth, reflecting substantial inbreeding depression (δ = 0.404 ± 0.043). Population size categories did not consistently differ in levels of inbreeding depression, suggesting that purging of genetic load in smaller populations has been limited, and that all populations still harbor inbreeding load. We also found a significant decrease in log performance with increases in the population inbreeding coefficient. These results indicate that even in seemingly large populations, lupines are susceptible to considerable fitness declines through both inbreeding load within populations, and drift load via genetic erosion and fixation of deleterious alleles between populations.  相似文献   

15.
We examined the genetic population structure of Lefua echigonia (Japanese name, hotoke-dojo) using polymerase chain reaction restriction-fragment length polymorphisms (PCR-RFLPs) of the mitochondrial cytochrome b gene and two allozymic loci. The phylogenetic relationships of L. echigonia and those among L. echigonia, Lefua sp. (nagare hotoke-dojo), and L. nikkonis (ezo hotoke-dojo) were also investigated based on the nucleotide sequences of the cytochrome b gene. PCR-RFLP analysis revealed 18 mitotypes in L. echigonia, 2 in Lefua sp., and 1 in L. nikkonis. Phylogenetic trees based on the cytochrome b sequences indicated that the 18 mitotypes in L. echigonia were divided into five distinct groups (South-Kanto, North-Kanto, Tohoku, Echigo, and Tokai-Kinki clades) that differed by 8.5–15.3%, reflecting region-specific geographic distributions. The distributions of alleles in two allozymic loci roughly corresponded to those of the mitotype groups. The divergence times of the five groups were estimated to be about 3.4–7.7 million years ago by applying a general rate for mitochondrial DNA, suggesting that the divergence among them might have occurred in the late Tertiary. It can be inferred that the regional differentiation of each group was mainly due to geographic isolation and that this has been maintained, because the boundaries among the groups corresponded to geological features. The trees also supported the existence of three taxa, L. echigonia, Lefua sp., and L. nikkonis. We concluded that Lefua sp. was distinguished from other species in Lefua by morphological and ecological characters and also by genetic divergences of the cytochrome b gene. Our study also demonstrated the superior efficacy and simplicity of PCR-RFLP analysis as a method for detecting genetic variation in L. echigonia.  相似文献   

16.
We studied the walking activity over the year of free-ranging adult red deer (Cervus elaphus) in a mountainous area with the aim of describing the dynamics of movement patterns at the individual level. We monitored the distance walked by two males and two females fitted with global positioning system collars to test the hypothesis that deer adopt behaviours to reduce costs of locomotion. We predicted that both sexes would travel less in winter when disadvantageous environmental conditions occurred. We also predicted that the males would (1) reduce their movement soon after the rut due to very high energy expenditure during the breeding season and (2) travel less than the females due to their larger body mass. As we expected, minimum walking activity occurred after the rut from November to February for the males and in late February for the females. The walking activity of males peaked during the rut whereas that of females decreased. But compared to males, females moved more both during winter and daylight hours. Although our study stems from just four individuals, these results and the methodology used can be inspirational for red deer research as well as for ungulate research in general.  相似文献   

17.
Conservation of 16 nuclear microsatellite loci, originally developed for Quercus macrocarpa (section Albae), Q. petraea, Q. robur (section Robur), and Q. myrsinifolia, (subgenus Cyclobalanopsis) was tested in a Q. infectoria ssp. veneris population from Cyprus. All loci could be amplified successfully and displayed allele size and diversity patterns that match those of oak species belonging to the section Robur. At least in one case, limited amplification and high levels of homozygosity support the occurrence of “null alleles” caused by a possible mutation in the highly conserved primer areas, thus hindering PCR. The sampled population exhibited high levels of diversity despite the very limited distribution of this species in Cyprus and extended population fragmentation. Allele sizes of Q. infectoria at locus QpZAG9 partially match those of Q. alnifolia and Q. coccifera from neighboring populations. However, sequencing showed homoplasy, excluding a case of interspecific introgression with the latter, phylogenetically remote species. Q. infectoria ssp. veneris sequences at this locus were concordant to those of other species of section Robur, while sequences of Quercus alnifolia and Quercus coccifera were almost identical to Q. cerris.  相似文献   

18.
The aims of this study were to describe first antler growth rate and the factors affecting it. Growth rate reached a peak in week 14. Mean first antler growth rate during the whole growing period was 1.95 ± 0.05 cm/week. Lactation influenced antler growth rate as this was positively affected by total protein yield, while antlers grew at a lower rate the later they started to grow.  相似文献   

19.
Hair tubes are often used to monitor red squirrel in fragmented landscapes, where presence/absence data are gathered to determine its distribution and factors affecting it. Despite many applications and evaluation of this technique for density estimation, the reliability of absence data has been overlooked, as no rigorous statistical estimate has been attempted both on the survey duration and on the reliability of absences. Accurate determination of the duration of a survey (e.g. how many visits should be carried out to consider the species absent rather than non-detected) will affect total costs and number of monitored sites; moreover, false absences will bias the distribution estimates. By applying some recently developed occupancy models, we estimated detection probability and sampling size required to infer red squirrel absence. Application of this sampling and data analysis protocol allows to infer the species absence at a reasonable cost and thus to evaluate the reliability of a presence/absence dataset.  相似文献   

20.
Using data from a global positioning system (GPS), seven adult red deer (Cervus elaphus L.) were tracked in the Parc National des Cévennes, southern France, between November 1998 and December 2000 to assess the factors affecting large-range movement patterns and habitat use. The home range varied from a single compact area for females to three distinct seasonal ranges for males, which used alternative migratory strategies (i.e. non-, downward- and upward-migrants). The migrants used mainly southerly and easterly aspects, and wintered in areas having steeper slopes than were used during summer or the rut season. For males, the time of rut migration was mid-September and they finally entered wintering ranges from mid-December to the beginning of January. Exploratory behaviour (i.e. individuals found outside the limits of their familiar area but returning to it a few days later) occurred in both sexes and for all individuals monitored during at least a 6-month period. Velocity and efficiency of exploratory movements were higher than usual movements. During these exploratory movements, hinds may have used different landscape attributes (elevation, slope, canopy cover) while stags did not. These results provide new empirical information that could be used for building and applying broad-scale spatial and landscape use models in ecological research.  相似文献   

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