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1.
European rabbits (Oryctolagus cuniculus), a keystone species in the Iberian Mediterranean ecosystem, are the staple prey of the Iberian lynx (Lynx pardinus) and the Spanish imperial eagle (Aquila adalberti). These predators require medium to high rabbit densities and a low degree of human disturbance. We compared rabbit abundances in areas of central-southern Spain under three levels of protection and management: protected areas, intensively managed (nonprotected) hunting estates, and other nonprotected areas. We used pellet abundance indices to estimate rabbit density in 118 surveys conducted during the summers of 2002 and 2003. We observed greater rabbit abundance in intensively managed hunting estates compared to protected areas and other nonprotected areas, perhaps because policy makers did not consider rabbit numbers when selecting priority areas. Alternatively, differences in game management practices (e.g., predator control or habitat management) may explain the higher rabbit densities observed in managed hunting estates. Our results suggest that the best feeding conditions for the Iberian lynx and the Spanish imperial eagle occur in intensively managed hunting areas, where such predators are frequently persecuted. The conservation of these endangered predators may require efforts to increase rabbit densities in protected areas.  相似文献   

2.
Rabbit restocking is widely used in Spain for conservation and/or hunting purposes; however, the success of rabbit restocking is generally low. Thus, many studies have assessed ways to reduce this problem, one of which is the use of a “soft-release” procedure whereby rabbits are acclimated to their release site for a variable time period prior to release. This study assessed the short-term effects of two soft-release confinement periods on the survival of rabbits during an experimental restocking program carried out in southwest Spain. The post-release survival rate of rabbits confined at the release site for six nights was significantly higher than that of rabbits confined for three nights. The longer acclimation period after rabbit translocation minimized mortality while rabbits adapted to their new environment.  相似文献   

3.
Over recent decades wild rabbit populations have undergone a sharp decline in Spain with consequent negative impact both on a game-based economy, and on the conservation of threatened species that depend on rabbits. We investigated the relationships between rabbit population change and habitat and game management in central-southern Spain. To determine recent rabbit population changes we revisited 60 localities during summer 2002 to repeat surveys previously carried out in 1993. Each survey consisted of 4-km walked transects to record indices of rabbit abundance. The percentage of vegetation cover and of different soil types were also estimated during these transects. In the same areas, the type and intensity of game management practices were obtained by interviewing hunting managers, hunters or gamekeepers. Rabbit populations were stable or increasing only in 26.6% of the studied populations, more commonly in areas with soft soils where warren building is easier for rabbits and where rabbits were an important game species and managed to increase their numbers. Although we could not establish causality, habitat management and predator removal were the main management practices related to rabbit population change. Rabbit scarcity in Spain constitutes a serious problem for conservation, so hunters, researchers and policy makers need to reach a consensus to establish a long-term program to monitor rabbit population trends and share results obtained, especially when intense manage programs are being carried out to improve rabbit abundance.  相似文献   

4.
Some populations of European wild rabbit (Oryctolagus cuniculus) in Spain have recovered after rabbit hemorrhagic disease, but others (the majority) have not recovered. The European wild rabbit is a keystone species in Spain’s Mediterranean ecosystems, and several factors have been studied to determine what will stabilize populations and possibly propagate recovery. Many of the previous efforts to determine these pivotal factors have been short-term studies focused on few localities. Most management efforts and studies focused on the well-preserved habitats of southwestern Spain. Our objective was to examine spotlight counts from 60 localities over the past 13 years following the arrival of rabbit hemorrhagic disease in Aragón, northeastern Spain, to estimate rabbit population trends using linear regressions. The number of rabbits seen was transformed into a rough kilometric abundance index. With this data, we calculated a population trend index only for those localities with 6 or more years of data (n=42). No clear population trends were observed for the study period at a regional scale [±SE, range]; (0.065±0.081 from −0.860 to 0.915). We also examined factors that potentially influence regional rabbit population trends, including vegetation, topography, soil softness, climate, predator population trends, and hunting pressure. Our results indicate that rabbit trends have their strongest positive correlation with low hunting pressure and are negatively affected in areas of hard soils. In Aragón, the best populations of endangered raptors are concentrated in the Central Valley, which is the same area where rabbit populations are currently increasing.  相似文献   

5.
European rabbit translocation is an extended practice in Spain, France, and Portugal, for both conservation and hunting purposes. Some of these translocations are carried out with the aim of reinforcing existing rabbit populations. In these cases, some of the new rabbits are released into warrens already occupied by resident conspecifics. This could have a negative impact upon both the released and the resident individuals owing to the “dear enemy” effect and the territoriality of the resident rabbits. In this study, we evaluated the effect of rabbit release into occupied warrens, in small areas populated by low-density resident rabbit populations. We observed negative effects at two different levels: the number of active entrances per recipient warren and the number of active warrens per reinforced plot, in addition to a general lack of increase in rabbit abundance in the area and, therefore, the failure of the reinforcement actions. Our results strongly suggest that the release of European rabbits into warrens occupied by resident rabbits is contraindicated if the objective is to recover rabbit populations in the area.  相似文献   

6.
The Wild rabbit (Oryctolagus cuniculus) is an endemic species of the Iberian Peninsula and is essential for the conservation of endangered predators. Rabbits are also of high importance as a hunting species. From 1988, rabbits suffered the severe effects of rabbit hemorrhagic disease, which caused large declines in most populations. Despite this fact, the National Red Data Lists continued to classify rabbits as a “Least Concern” species. We used available hunting bag data from 1973 to 2002 to model national trends of rabbit abundance and to evaluate the conservation status according to the criteria of the National Red Data List and the World Conservation Union (IUCN). Generalized Additive Models were used as the statistical framework. The rabbit population of Spain suffered a large decline of about 71% between 1973 and 1993. This decline was 49% in the period 1980–1990. Based on both Spanish and World Conservation Union criteria, rabbits should be listed as ‘Vulnerable’, which demands a Conservation Plan Program. We suggest that the lack of concordance between the best available evidence and the conservation status of the species is a consequence of sociological constraints in conservation decisions. Rabbit conservation could face strong opposition from important socio-economic lobby groups (hunters and farmers). As such, governments and researchers may prefer to exclude rabbits from any status category requiring conservation action, despite the evidence of decline. We call for the urgent development of a nation-wide conservation program for rabbits which includes both socioeconomic constraints and the available biological data on population trends.  相似文献   

7.
The red-legged partridge (Alectoris rufa) is the most important gamebird in Spain. Due to population declines in recent decades, management approaches increasingly include the release of farm-reared partridges and the establishment of so-called intensive estates, where hunting is based on put-and-take partridges. The release of farm-reared partridges is controversial because these birds negatively affect wild populations. However, according to managers, releases are necessary to maintain commercial hunting. We analysed economic parameters using data provided by 20 red-legged partridge hunting estates with different management and economic aims in central Spain. We calculated total revenues, total expenses, benefits and profitability of these estates and simulated results under two different scenarios (prices for buying farm-reared partridges being 15 % higher and prices for hunting in estates not using releases being 15 % higher) attempting to mimic the internalization of some ecological costs of farm-reared birds or possible rewards from using wild populations sustainably. Non-commercial estates (n = 5), as expected, just broke even, with almost no benefits. Benefits of intensive estates, where massive releases throughout the hunting season allow a much higher harvest, were on average an order of magnitude higher (20,404 ± 24,413 €/km2, n = 8) than those of other commercial estates (1713 ± 1280 €/km2, n = 7). Benefits of non-intensive commercial estates using releases were on average lower than those of commercial estates without releases. In fact, profitability of non-intensive commercial estates not using releases was similar to that of intensive estates. Any of the two price scenarios considered led to non-intensive commercial estates not using releases being the most profitable on average. Thus, efforts should be made to identify ways of improving economic profitability of non-intensive estates, which may be important for promoting hunting management styles that are ecologically more beneficial.  相似文献   

8.
Wild predators are targeted if they are perceived to affect game species or domestic animals. Over the last century, the direct persecution of birds of prey and mammalian carnivores has led to their widespread decline, even local extirpations. Many such cases involved the illegal use of poisoned bait. We used 1,305 detected poisoning events and 59 biophysical variables to construct a distribution model of illegal poisoning throughout Andalusia, southern Spain. We chose this region because the largest number of poisoning events recorded in Spain were detected in Andalusia during the period 1990–2005. Our results showed greater incidence of poisoning was correlated with areas of high predator richness and high wild rabbit hunting yields. Thus, we hypothesize that wildlife managers should be able to estimate current and potential poisoning areas using frequency of poisoning events data. Managers can then focus control within those areas identified as conflict zones and establish surveillance schemes that prevent the loss of wildlife within the targeted areas. Our results have potential application in strategic planning for conservation of vulnerable high-profile species such as birds of prey and mammalian carnivores in southern Spain and other regions. © 2012 The Wildlife Society.  相似文献   

9.
About half a million rabbits are translocated in southwestern Europe every year for conservation and hunting purposes. However, the success of traditional rabbit restocking is generally extremely low, and this has been attributed to short-term predation by mammalian carnivores. Hence, recent recovery programs have tackled the problem of terrestrial predators with the use of exclusion fences, but no additional measures have been employed to avoid aerial predation. In this study, we have therefore conducted a field experiment to test the short-term effect of total predation exclusion in rabbit restocking enclosures, comparing rabbit abundance in plots which are only accessible to raptors (top-open plots) and plots which are accessible to neither carnivores nor raptors (top-closed plots). The results showed that the top-closed plots had higher rabbit abundance in the short term, and the highest difference in rabbit abundance between the two kinds of fences was attained in the first 2 weeks. We therefore conclude that the top-closed plots were an effective tool to increase rabbit abundance during the first weeks after release through the exclusion of raptor predation.  相似文献   

10.
Pulmonary intravascular macrophages (PIMs) are present in species such as cattle, sheep and horse and promote acute lung inflammation (ALI). Rabbits are often used as a model of ALI but there is controversy about the presence of PIMs in these species. Rabbits were treated with 10 mg/kg of gadolinium chloride intravenously (GC; n?=?6) or saline (n?=?6) followed by euthanasia at 48 h post-treatment to determine the presence of PIMs. In a subsequent study, rabbits were pre-treated with GC or 0.9 % saline followed by 100 μg/kg of E. coli lipopolysaccharide intravenously 48 h later. Rabbits were euthanized 24 h post-LPS treatment. Light and electron microscopy showed that PIMs attached to the capillary endothelium and were positive for RAM-11 anti-macrophage antibody. While GC treatment induced apoptotic PIMs, there was no difference in the PIM number between control and GC-treated rabbits. Rabbits administered with LPS were 3.5 times more likely to die before the end of the 24-h period than those pre-treated with GC. Lung heterophil accumulation and IL-1β, TNFα and IL-6 mRNA expression were significantly higher in rabbits administered with LPS compared to those administered with GC before the LPS injection. PIMs from the LPS-treated rabbits were positive for TNFα. Lung, BAL and serum IL-8 and MCP-1 expression was not different between LPS rabbits with or without pre-treatment with GC. We conclude that rabbit lungs contain PIMs and that their depletion reduces endotoxin-induced lung inflammation. The presence of PIMs in rabbit lungs may need to be considered while using rabbit to model acute lung injury.  相似文献   

11.
Task-shifting in mental health such as engaging Traditional Health Practitioners (THPs) in appropriate management of mental disorders is crucial in reducing global mental health challenges. This study aims to determine the outcomes of using evidence-based mental health Global Action Programme Intervention guide (mhGAP-IG) to provide psychosocial interventions among depressed patients seeking care from THPs. THPs were trained to deliver psychosocial interventions to their patients screening positive for mild to severe depression on Beck’s Depression Inventory (BDI). Assessments were conducted at 0, 6 and 12 weeks and Analysis of Variance (ANOVA) performed to determine the change in depression scores over the three time period. BDI mean score was 26.52 before intervention and reduced significantly at 6 (13%) and 12 (35%) weeks after intervention. 58 and 78% of patients showed reduction in symptoms of depression at 6 and 12 weeks. It is therefore crucial to engage THPs in the care of patients with depression and the need for inclusion of training packages; and other mental disorders in order to establish and maintain collaboration between THPs and conventional health workers and promote evidence-based care among marginalized populations. Moreover, further research on randomized control trials of mhGAP-IG intervention versus usual care is required.  相似文献   

12.
Rabbits can successfully avoid their enemies by evaluating the risk of predation. They have various defensive strategies, such as morphological adaptations and behaviours patterns, which enable them to perceive their predators and thus reduce the risk of predation. It is well documented that rabbits recognise the scats of terrestrial predators and avoid those areas in which they are present. However, few studies show whether the prey species can recognise the presence of congeners in carnivores’ scats, which would allow them to identify their predators in a more efficient manner. We have carried out a comparative analysis of the use of space made by rabbits on plots on which a neutral odour (water) or the odours of the ferrets’ scats that had consumed either rabbit or another mammal (beef) were applied. Our results showed a lower number of rabbit pellets on those plots containing predator odours than on the control plots. During the first 6 days after applying the first odour, the number of rabbit pellets was lower on plots on which rabbit had been included in the diet when compared with scats obtained from a beef diet. However, no differences between the two experimental plots were recorded during the third visit (9 days after applying the first odour). Our results suggest that rabbits may be able to detect congeners in their predators’ scats, thus leading them to, in the short term, avoid areas in which their terrestrial predators’ diet is based on conspecifics, probably as the result of them perceiving a higher risk of predation.  相似文献   

13.

The European wild rabbit (Oryctolagus cuniculus) is a keystone species in the Iberian Mediterranean ecosystems being the staple prey of protected and endangered predators. Wild rabbits were once widespread, but the introduction of two viral diseases, myxomatosis in the 1950s and the rabbit hemorrhagic disease in 1989, resulted into a dramatic decline of its populations. Sarcoptic mange is a highly contagious parasitic infection caused by Sarcoptes scabiei. The first cases of sarcoptic mange in a wild rabbit population are recorded from a hunting area in Majorca (Balearic Islands, Spain). Five of 32 inspected rabbits (14.7%) were affected, with similar prevalences in summer and autumn. Sarcoptes scabiei were obtained from the edge of the lesions of two of the rabbits. The most frequently observed lesions were small areas of alopecia and crusts in the limbs. Affected limbs presented also a marked hypertrichosis and an apparent abnormal growth of the nails. One rabbit also presented lesions around mouth and nostrils. Parasitized rabbits were in significant lower body condition than healthy ones. According to previous reports of mange epizooties in other naïve wild species that caused marked short-term effects in their populations, this disease may pose a risk for the conservation of wild rabbit and their predators. Whether mange is endemic in rabbits from Majorca or it has been introduced is unknown. Game managers are encouraged to be aware of introducing sarcoptic mange during rabbit translocations.

  相似文献   

14.
Rabbit hemorrhagic disease (RHD) became endemic in wild rabbit (Oryctolagus cuniculus) populations in the Iberian Peninsula after its first arrival in 1988. This had significant implications for both the economy and environmental conservation because rabbits are one of the main game species in the Iberian Peninsula and a keystone species in the Mediterranean ecosystems. As a consequence, it is planned to include RHD surveillance in the Spanish Wildlife Disease Surveillance Strategy. Nevertheless, there is no practical methodology included in this program to help conservationists and gamekeepers understand the impact of disease on wild rabbit populations. Results from sera collected during the hunting season from 11 rabbit populations of Central and South Spain, which differed in their population abundance and trends, allowed us to use mathematical models to interpret the serological results gathered and determine the best strategy for finalizing a plan of RHD surveillance. Put simply, we focused our field surveys within the hunting season (October-January), and those times when the rabbit populations are at their highest (June or July). Field results showed that both rabbit abundance and population trend are closely related to the prevalence of RHD antibodies when rabbit abundance was at its annual low point (usually October-November). Rabbit population trends were positive only if antibody prevalence was high (>40%), and always negative if prevalence was low. Moreover, rabbit populations where abundance was low always showed low antibody prevalence. Since our models predicted a low variability in the prevalence obtained during the hunting season, it is suggested that future serological surveys should be carried out within this period to avoid problems related to the low sample size in low density rabbit populations.  相似文献   

15.
Although habitat management practices focussed on the enhancement of hunting and protection of threatened species are common, the scientific validation of such practices is scarce. The wild European rabbit Oryctolagus cuniculus L., a hunted and threatened species in its native range, is at the same time a key species for the preservation of threatened Mediterranean predators. Cereal sowing is one of the most common practices to augment the food supply of rabbits, and it is used not only by hunters but also by conservationists. At present, limited scientific information is available regarding the effectiveness of cereal sowing. To evaluate its effectiveness, we analysed data on sowing trials conducted in 125 plots, located in 14 private estates throughout central Spain, most of them with low density populations. Brush was cleared from 44 of these plots prior to sowing. Our results indicated that rabbits preferentially selected sown areas over control (unsown) areas. This selection increased in plots that represented suitable habitats for rabbits, such as pasturelands, as well as when thicket islands and natural or artificial shelters were available within the sown plots. Local enhancement of rabbit populations was also observed. These positive results were also obtained regardless of the initial habitat conditions, not only in the treatment plots but also in the surrounding area. Our recommendations can be broadly applied for managing rabbit-dependent threatened species.  相似文献   

16.
Management of harvested wildlife populations aims to protect species from overexploitation and ultimately extinction, by regulating exploitation towards achievable sustainable levels. However, assessments of impact and sustainability of implemented management actions on a population level are scarce. This study assesses effects of changes in hunting season length imposed on the Baltic-Wadden Sea Common Eider Somateria mollissima population, including differential restriction on hunting of the sexes. The potential impact of these changes on the population was assessed by simple demographic matrix projections. Since the early 1990s, this population has declined at ca. 6.3 % per annum, and the male/female ratio among shot birds has fallen from 3:2 to about 3:1. Concerns in Denmark regarding the conservation status and sustainability of contemporary levels of exploitation resulted in shortening the open season by 44 and 46 days for females and 13 and 15 days for males from the hunting seasons 2004/2005 and 2011/2012 onwards, respectively. These reduced the kill of adult females by 82 %, adult males by 31 %, juvenile females by 58 % and juvenile males by 55 %. The observed reduction in the kill of adult females following both changes in 2004/2005 and 2011/2012 matched the expected changes based on the seasonal distribution of sexes in the bag prior to the change. Post 2004/2005 hunters killed more adult males, but shot markedly fewer juvenile birds than expected. Demographic modelling of the female population showed that the effects of the reduced hunting would correspond to an increase in the annual population growth rate from the previous ?6.3 to ?3.6 % (post 2004) and ?1.6 % (post 2011). The model also predicted that a full ban on hunting female eiders (adults and juveniles) would lead to a positive population growth rate of 0.7 %. Taking into account the conservative model estimates and natural variations in annual breeding success, the implemented changes in sex-specific regulation of hunting may potentially be an effective management tool to halt the decline of the Baltic-Wadden Sea eider population, potentially rendering such levels of hunting sustainable under prevailing conditions.  相似文献   

17.
Wild rabbits (Oryctolagus cuniculus) in Australia are the descendents of 24 animals from England released in 1859. We surveyed rabbits and rabbit fleas (Spilopsyllus cuniculi) in Australia for the presence of trypanosomes using parasitological and PCR-based methods. Trypanosomes were detected in blood from the European rabbits by microscopy, and PCR using trypanosome-specific small subunit ribosomal RNA (SSU rRNA) gene primers and those in rabbit fleas by PCR. This is the first record of trypanosomes from rabbits in Australia. We identified these Australian rabbit trypanosomes as Trypanosoma nabiasi, the trypanosome of the European rabbit, by comparison of morphology and SSU rRNA gene sequences of Australian and European rabbit trypanosomes. Phylogenetic analysis places T. nabiasi in a clade with rodent trypanosomes in the subgenus Herpetosoma and their common link appears to be transmission by fleas. Despite the strict host specificity of trypanosomes in this clade, phylogenies presented here suggest that they have not strictly cospeciated with their vertebrate hosts. We suggest that T. nabiasi was inadvertently introduced into Australia in the 1960s in its flea vector Spilopsyllus cuniculi, which was deliberately introduced as a potential vector of the myxoma virus. In view of the environmental and economic damage caused by rabbits in Australia and other islands, the development of a virulent or genetically modified T. nabiasi should be considered to control rabbits.  相似文献   

18.
Understanding the relationship between spatial patterns of landscape attributes and population presence and abundance is essential for understanding population processes as well as supporting management and conservation strategies. This study evaluates the influence of three factors: environment, habitat management, and season on the presence and abundance of the wild rabbit (Oryctolagus cuniculus), an important prey species for Mediterranean endangered predator species. To address this issue, we estimated wild rabbit presence and abundance by latrine counting in transects located in 45 plots within a 250?×?250 m grid from June 2007 until June 2009 in a 1,200 ha hunting area in southern Portugal. We then analyzed how wild rabbit presence and abundance correlate with the aforementioned factors. Our results showed that the main variable influencing wild rabbit presence and abundance was the distance to the artificial warrens. North and northeast slope directions were negatively related to wild rabbit presence. Conversely, rabbit presence was positively correlated with short distances to ecotone, artificial warrens, and spring. Regarding rabbit abundance, in addition to artificial warrens, soft soils, bushes, and season also had a positive effect. We found that environmental variables, management practices, and season each affect wild rabbit presence and abundance differently at a home range scale in low-density population. Thus, our major recommendations are reducing the distance to artificial warrens and ecotone, ideally to less than 100 m, and promoting habitat quality improvement on slopes with plenty of sun exposure.  相似文献   

19.
Records of official deer control operations in the Kaweka Range between 1958 and 1988 have been used to describe the pattern of official hunting, to indicate changes in hunting efficiency, and to show trends in the proportions of sika and red deer in sympatric populations. The pattern of hunting largely reflected wild animal control priorities, and to some extent the resources available. Whereas hunting effort was concentrated in Block 1 (of three) during the 1960s to protect catchment values, changes in the rationale for wild animal control and the efforts of commercial and recreational hunters in the more accessible areas led to a more even spread of the hunting effort from the early 1970s. Hunting efficiency also varied between the three h unting blocks, probably reflecting differences in the ease with which particular habitats could be hunted. A decline in hunting efficiency over the study period was interpreted as an overall decrease in the density of the deer population. The proportion of sika among the deer shot in the Kaweka Range has increased steadily from about 10-20% in the early 1960s to 70% in 1987-88. A competitive advantage over red deer because of their different digestive physiology is suggested as the main reason. The most rapid increases in the proportion of sika were associated with two Peaks in commercial venison and live-capture operations that concentrated on red deer, indicating that commercial hunting has also been a factor. It is likely that sika will continue icreasing in proportion to red deer in areas already inhabited. In addition, sika will probably continue to disperse into new areas as they competitively displace red deer.  相似文献   

20.
In this study we resequenced 1729 bp of the rabbit melanocortin 4 receptor (MC4 R) gene in 31 rabbits from different breeds/lines and identified ten polymorphisms: one was an indel and 9 were single nucleotide polymorphisms (SNPs). The indel and 5 SNPs were in the 5′-flanking region, 3 were synonymous SNPs and one was a missense mutation (c.101G>A; p.G34D), located in a conserved position of the extracellular tail of the MC4 R protein. The missense mutation was analyzed in a panel of 74 rabbits of different breeds and in 516 performance tested rabbits of a commercial paternal line under selection for growth efficiency. Association analysis indicated that rabbits with the less frequent genotype in this population (DD) had a lighter weight at 70 postnatal days than animals with genotype GD (P < 0.10) and animals with genotype GG (P < 0.05). This is the third study on candidate genes, after those on GH1 and IGF2 that reported a marker associated with finishing weight. Therefore, it seems that a candidate gene approach in rabbit based on previous information accumulated in other livestock species could be useful to identify genes explaining a fraction of variability of performance traits with potential application on rabbit breeding and selection.  相似文献   

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