Clinical infection of Cantabrian chamois (Rupicapra pyrenaica parva) by louping ill virus: new concern for mountain ungulate conservation?

Louping ill virus (LIV) was recently involved in an outbreak of encephalitis in domestic goats from Asturias region, northwestern Spain. Since livestock and wildlife in Asturias are frequently in close contact, we designed a retrospective survey for LIV antibody prevalence in wild ungulates by testing sera from 51 red deer (Cervus elaphus), 19 Cantabrian chamois (Rupicapra pyrenaica parva) and 8 roe deer (Capreolus capreolus) by the haemagglutination inhibition (HI) test. Only two Cantabrian chamois out of the 78 tested (2.6?±?3.5 %) gave positive results. Seroprevalence in chamois was 10.5?±?13.8 %. One of these chamois was found dead after falling down a cliff and the other one was found alive but with neurological signs. Histological examination of brain samples revealed that both animals showed severe inflammatory lesions compatible with a viral encephalitis caused by LIV, but LIV antigen was not detectable by specific immunohistochemistry. Real time RT-PCR was performed on formalin-fixed paraffin embedded sections of brain but was unable to confirm the presence of LIV RNA due to poor sample quality. By testing one of two HI positive sera from chamois by virus neutralization test and plaque reduction neutralization test against West Nile virus, Bagaza virus, Usutu virus, LIV and tick-borne encephalitis virus, we confirmed the presence of high antibody titres (1:10240) against LIV in the absence of antibodies to another Flavivirus. This work describes the first association between LIV and clinical encephalitis in chamois, which suggests that special attention should be paid to the impact on chamois conservation and management in Asturias, and perhaps in other European regions.     

Detection of a newly described pestivirus of Pyrenean chamois (Rupicapra pyrenaica pyrenaica) in France

A pestivirus was detected and characterized in chamois (Rupicapra pyrenaica pyrenaica) originating from the French part of the Pyrenees. Phylogenetic analysis of the pestivirus was done on the basis of a fragment from the 5' noncoding region including 22 published nucleotide sequences of different pestivirus strains. Our strain was grouped within the clade of border disease viruses (BDV). However, it had an intermediate position between clade BDV and classical swine fever viruses representing a basal position to BDV strains of domestic sheep. Our strain was grouped as a sister unit to a novel pestivirus (Chamois-1) recently described from chamois in Spain. Therefore, we postulate that this virus occurs in the entire population of Pyrenean chamois. On the basis of the phylogenetic grouping of this isolate, a postulated cross-species transmission of pestivirus from domestic sheep to chamois via shared pastures seems to be unlikely.     

Mycoplasma conjunctivae infection is not maintained in alpine chamois in eastern Switzerland

The occurrence of infectious keratoconjunctivitis (IKC) was assessed in alpine chamois (Rupicapra rupicapra rupicapra) in Grisons (Switzerland) from 1950 to 1999. The first IKC outbreaks were reported in the 1950's. Since then, the number of affected subpopulations constantly increased and, by 1999, IKC outbreaks were reported in 39 of 51 (77%) chamois sub-populations. From 1992-99, a total of 243 chamois which died of the consequences of IKC were recorded. The number of cases differed between years, and a distinct seasonal trend was observed. Infectious keratoconjunctivitis was more common during summer and autumn, with 48% of the cases recorded in August-October. Juveniles (< 4 yr of age) were mostly represented. To verify the presence of Mycoplasma conjunctivae in chamois we analyzed conjunctival swabs taken from animals affected with IKC. Among a sample of 28 affected chamois, M. conjunctivae was identified 14 times (50%). An indirect enzyme-linked immunosorbent assay (ELISA) was developed to detect specific M. conjunctivae antibodies in sera of alpine chamois with IKC. We performed a serologic investigation to assess whether M. conjunctivae infection is self-maintained in the chamois population in Grisons. In subpopulations with IKC oubreaks, seroprevalence was low (8%). Seroprevalence was even lower in subpopulations with recent IKC outbreaks (3%). We concluded that the M. conjunctivae infection is not self-maintained in alpine chamois in Grisons. The agent may originate in domestic sheep living in proximity to chamois during summer. Control of IKC in chamois should consider immunoprophylaxis in sheep or limiting interspecific transmission of M. conjunctivae.     

Serosurveillance for Livestock Pathogens in Free-Ranging Mule Deer (Odocoileus hemionus)

Routine disease surveillance has been conducted for decades in mule deer (Odocoileus hemionus) in California for pathogens shared between wildlife and domestic ruminants that may have implications for the animal production industry and wildlife health. Deer sampled from 1990 to 2007 (n = 2,619) were tested for exposure to six pathogens: bluetongue virus (BTV), epizootic hemorrhagic disease virus (EHDV), bovine viral diarrhea virus (BVDV), Leptospira spp., Anaplasma spp. and Brucella spp. We evaluated the relationship between exposure to these pathogens and demographic risk factors to identify broad patterns in seroprevalence across a large temporal and spatial scale. The overall seroprevalence for the entire study period was 13.4% for BTV, 16.8% for EHDV, 17.1% for BVDV, 6.5% for Leptospira spp., 0.2% for Brucella spp., and 17% for Anaplasma spp. Antibodies against BTV and EHDV were most prevalent in the deer populations of southern California. Antibodies against Leptospira spp. and Anaplasma spp. were most prevalent in coastal and central northern California whereas antibodies against BVDV were most prevalent in central-eastern and northeastern California. The overall seroprevalence for Anaplasma spp. was slightly lower than detected in previous studies. North and central eastern California contains large tracts of federal land grazed by livestock; therefore, possible contact between deer and livestock could explain the high BVDV seroprevalence found in these areas. Findings from this study will help to establish baseline values for future comparisons of pathogen exposure in deer, inform on long-term trends in deer population health and provide relevant information on the distribution of diseases that are shared between wildlife and livestock.     

Latent class evaluation of the performance of serological tests for exposure to Brucella spp. in cattle,sheep, and goats in Tanzania

BackgroundBrucellosis is a neglected zoonosis endemic in many countries, including regions of sub-Saharan Africa. Evaluated diagnostic tools for the detection of exposure to Brucella spp. are important for disease surveillance and guiding prevention and control activities.Methods and findingsBayesian latent class analysis was used to evaluate performance of the Rose Bengal plate test (RBT) and a competitive ELISA (cELISA) in detecting Brucella spp. exposure at the individual animal-level for cattle, sheep, and goats in Tanzania. Median posterior estimates of RBT sensitivity were: 0.779 (95% Bayesian credibility interval (BCI): 0.570–0.894), 0.893 (0.636–0.989), and 0.807 (0.575–0.966), and for cELISA were: 0.623 (0.443–0.790), 0.409 (0.241–0.644), and 0.561 (0.376–0.713), for cattle, sheep, and goats, respectively. Sensitivity BCIs were wide, with the widest for cELISA in sheep. RBT and cELISA median posterior estimates of specificity were high across species models: RBT ranged between 0.989 (0.980–0.998) and 0.995 (0.985–0.999), and cELISA between 0.984 (0.974–0.995) and 0.996 (0.988–1). Each species model generated seroprevalence estimates for two livestock subpopulations, pastoralist and non-pastoralist. Pastoralist seroprevalence estimates were: 0.063 (0.045–0.090), 0.033 (0.018–0.049), and 0.051 (0.034–0.076), for cattle, sheep, and goats, respectively. Non-pastoralist seroprevalence estimates were below 0.01 for all species models. Series and parallel diagnostic approaches were evaluated. Parallel outperformed a series approach. Median posterior estimates for parallel testing were ≥0.920 (0.760–0.986) for sensitivity and ≥0.973 (0.955–0.992) for specificity, for all species models.ConclusionsOur findings indicate that Brucella spp. surveillance in Tanzania using RBT and cELISA in parallel at the animal-level would give high test performance. There is a need to evaluate strategies for implementing parallel testing at the herd- and flock-level. Our findings can assist in generating robust Brucella spp. exposure estimates for livestock in Tanzania and wider sub-Saharan Africa. The adoption of locally evaluated robust diagnostic tests in setting-specific surveillance is an important step towards brucellosis prevention and control.     

Brucella melitensis in France: Persistence in Wildlife and Probable Spillover from Alpine Ibex to Domestic Animals

Bovine brucellosis is a major zoonosis, mainly caused by Brucella abortus, more rarely by Brucella melitensis. France has been bovine brucellosis officially-free since 2005 with no cases reported in domestic/wild ruminants since 2003. In 2012, bovine and autochthonous human cases due to B. melitensis biovar 3 (Bmel3) occurred in the French Alps. Epidemiological investigations implemented in wild and domestic ruminants evidenced a high seroprevalence (>45%) in Alpine ibex (Capra ibex); no cases were disclosed in other domestic or wild ruminants, except for one isolated case in a chamois (Rupicapra rupicapra). These results raised the question of a possible persistence/emergence of Brucella in wildlife. The purpose of this study was to assess genetic relationships among the Bmel3 strains historically isolated in humans, domestic and wild ruminants in Southeastern France, over two decades, by the MLVA-panel2B assay, and to propose a possible explanation for the origin of the recent bovine and human infections. Indeed, this genotyping strategy proved to be efficient for this microepidemiological investigation using an interpretation cut-off established for a fine-scale setting. The isolates, from the 2012 domestic/human outbreak harbored an identical genotype, confirming a recent and direct contamination from cattle to human. Interestingly, they clustered not only with isolates from wildlife in 2012, but also with local historical domestic isolates, in particular with the 1999 last bovine case in the same massif. Altogether, our results suggest that the recent bovine outbreak could have originated from the Alpine ibex population. This is the first report of a B. melitensis spillover from wildlife to domestic ruminants and the sustainability of the infection in Alpine ibex. However, this wild population, reintroduced in the 1970s in an almost closed massif, might be considered as a semi-domestic free-ranging herd. Anthropogenic factors could therefore account with the high observed intra-species prevalence.     

Influence of cohabitation between domestic goat (Capra aegagrus hircus) and Iberian ibex (Capra pyrenaica hispanica) on seroprevalence of infectious diseases

We have investigated the prevalence of infection with different pathogens in domestic goat (Capra hircus) and Iberian ibex (Capra pyrenaica hispanica) populations from two neighbouring geographical zones (with or without cohabitation between wild and domestic species) in Spain. No ibexes were found to be seropositive for Brucella melitensis, Mycoplasma mycoides supspecies mycoides (Mycoplasma mycoides), bovine leukaemia virus, and Chlamydophila abortus or bovine herpes virus type 1 (BHV-1). Domestic goats from both zones were detected with antibodies to Chlamydophila abortus and BHV-1. The percentage seroprevalence against Coxiella burnetii, Mycoplasma agalactiae, Mycobacterium avium subspecies paratuberculosis (MAP), caprine arthritis encephalitis virus (CAEV) and bluetongue virus (BTV) was clearly higher in domestic goats compared to wild ibexes in both zones, although CAEV showed negative results in a zone where species were isolated from each other. Moreover, Borrelia burgdorferi and Pestivirus infection showed moderate seroprevalence differences between domestic and wild goats in cohabitation zones, with the highest prevalence found in wild ibexes from a non-cohabitation zone. Our results showed that cohabitation between species was a risk factor (P?<?0.05) in Q fever infection.     

Molecular identification of a new pestivirus associated with increased mortality in the Pyrenean Chamois (Rupicapra pyrenaica pyrenaica) in Spain

Pestivirus infection was identified in 16 of 17 chamois during an outbreak of a previously unreported disease in Pyrenean chamois (Rupicapra pyrenaica pyrenaica) in northeastern Spain in 2001-02. By analysis of the 5' noncoding regions of the virus, we assigned it to the border disease virus cluster with pairwise similarity values ranging from 82.1% to 88.1%. It will be important to investigate the association of this pestivirus with disease in Pyrenean chamois.     

Brucellosis Seropositivity in Animals and Humans in Ethiopia: A Meta-analysis

BackgroundThe objectives of this study were to assess the heterogeneities of estimates and to estimate the seroprevalence of brucellosis in animals and humans in Ethiopia.ConclusionsThe seroprevalence of brucellosis is higher in goats than in other species. Its occurrence is evocative of its importance in the country in general and in the pastoral system in particular. Public awareness creation could reduce the transmission of Brucella spp. from animals to humans and the potential of livestock vaccination as a means of control of brucellosis needs to be assessed.     

Survey of Pestivirus infection in wild and domestic ungulates from south-western Italian Alps

The transmission of pestiviruses between domestic and wild ruminants has not been documented in communal alpine pastures shared between wildlife and livestock. The aim of this study was to investigate the role of domestic and wild ungulates species from Varaita Valley (SW Italian Alps) in the epidemiology of Pestivirus infections. Sera from free-ranging alpine chamois (Rupicapra rupicapra) and roe deer (Capreolus capreolus) were collected from 1994 to 2009 and 2001 to 2009, respectively. Also, sera from cattle and sheep sampled in 2009 were studied. Sera were tested for the presence of antibodies against pestivirus with an ELISA assay. Sera from positive animals were subsequently tested with a comparative virus neutralisation test using the BVDV-NADL and BDV-137/4 strains. Sera were tested for the presence of pestiviral antigen and the presence of viral RNA with a commercial ELISA assay and RT-PCR. Antibodies against Pestivirus were detected in 132 out of 312 (42%) chamois, in 30 out of 175 (17%) cattle and 6 out of 24 (25%) sheep. No antibodies were found in roe deer. No Pestivirus antigen or RNA was detected in any of the samples. Results indicate circulation of pestiviruses among the studied chamois, cattle and sheep populations. However the role of wild ungulates in the dynamics of Pestivirus infection is still unknown and monitoring the presence of these viruses in wild ungulates would be of importance, especially in the chamois population, where pestiviruses seem to circulate extensively.     

Increased hormonal stress response of Apennine chamois induced by interspecific interactions and anthropogenic disturbance

Responses of animals to environmental changes and their interactions with other species play an important role in conservation. Sharing a common habitat may lead to interspecific competition for resources, but field assessment of these biological events is not always easily accomplished. By using a non-invasive method, we evaluated the physiological stress responses of Apennine chamois (Rupicapra pyrenaica ornata) to the presence of cattle, sheep and goat, red deer (Cervus elaphus), people (hikers), and predators to identify which factors may affect this endangered species. During September 2012, November 2012, and July 2013, a total of 318 faecal samples were collected in representative sites and analysed for faecal cortisol metabolites (FCM). FCM concentration was analysed through linear mixed-effect models. A significant increase in FCM values in Apennine chamois sharing their habitat with domestic animals was recorded during all study periods. On the contrary, stress responses to red deer and people were limited in time and emerged only during summer months, when hikers are more frequent and red deer extend their altitudinal range reaching chamois’ habitat. The observed effects of domestic animals, red deer, and hikers should be considered in future Apennine chamois management plans, which should include the regulation of pastured domestic livestock, anthropogenic disturbances, and possible interferences with other wild species within parks.     

Seroepidemiological study of Toxoplama gondii in small ruminants (sheep and goat) in different provinces of Mongolia

Toxoplasmosis is caused by the protozoan parasite Toxoplasma gondii. Consumption of raw or undercooked meat is the main risk factor for acquiring T. gondii infection in humans. Meat and meat products derived from goats and sheep are mainly consumed in Mongolia; however, there is limited epidemiological information on T. gondii infection in small ruminants in this country. The main objective of the present study was to investigate the seroprevalence of T. gondii in sheep and goats in Mongolia. The seroprevalence of T. gondii IgG antibodies was determined by an indirect enzyme-linked immunosorbent assay based on the recombinant antigens of dense granule protein 7 of T. gondii. A total of 1078 goat and 882 sheep blood samples were collected from 17 of 21 provinces and the capital city of Mongolia. Overall, the seroprevalence of T. gondii among the goat and sheep samples was 32% and 34.8%, respectively. The seroprevalence among goat samples was significantly higher in western (42.7%) and eastern (45.6%) regions compared with other regions (24%). Additionally, the seroprevalence among sheep was significantly higher in eastern regions (55.4%) compared with other regions (26%–33%). Age, but not sex, was considered a risk factor for T. gondii seropositivity in goats, whereas no statistically significant differences were observed in sheep for age or sex. In conclusion, the present study demonstrates the high seroprevalence of T. gondii in small ruminants in Mongolia. Our results highlight that country-wide control measures are required to minimize infections in livestock.     

Recombination and the origin of sequence diversity in the DRB MHC class II locus in chamois (Rupicapra spp.)

We examined the evolutionary processes contributing to genetic diversity at the major histocompatibility complex (MHC) class II DRB locus in chamois (Rupicapra spp., subfamily Caprinae). We characterised the pattern of intragenic recombination (or homologous gene conversion) and quantified the amount of recombination in the genealogical history of the two chamois species, Pyrenean chamois (Rupicapra pyrenaica) and Alpine chamois (Rupicapra rupicapra). We found evidence for intragenic recombination, and the estimated amount of population recombination suggests that recombination has been a significant process in generating DRB allelic diversity in the genealogical history of the genus Rupicapra. Moreover, positive selection appears to act on the same peptide-binding residues in both analysed chamois species, but not in identical intensity. Recombination coupled with positive selection drives the rapid evolution at the peptide-binding sites in the MHC class II DRB gene. Many chamois MHC class II DRB alleles are thus much younger than previously assumed.     

Determination of age in Cantabrian chamois (Rupicapva pyvenaica pavva) from jaw tooth-row eruption and wear

A tooth eruption and wear pattern useful to determine ten age classes when the horns are not available for this purpose, is described for Cantabrian chamois ( Rupicapra pyrenaica parva ) inhabiting the Cantabrian Mountains (north of Spain). In animals under eight years old, age is not significantly over- or under-estimated when using the method, however, the age of animals older than eight years is significantly under-estimated.     

Ecological correlates of a tick-borne disease, Anaplasma phagocytophilum, in moose in southern Norway

As the distribution and abundance of ticks increase, so do the risks of tick-borne diseases. Anaplasma phagocytophilum, transmitted by Ixodes spp. ticks, is a widespread tick-borne infection causing tick-borne fever (TBF) in domestic ruminants and human granulocytic anaplasmosis. However, the role of wildlife in its epidemiology is poorly understood. Evidence of infection has been detected in wild cervids, but the pathogenicity and ecological consequences are unknown. We conducted a serological study of moose (Alces alces) in two populations in southern Norway, one where TBF was endemic (Telemark) and the other where sheep ticks (Ixodes ricinus) were essentially absent (Hedmark). Seroprevalence to A. phagocytophilum antibodies was 79 and 0 %, respectively. In Telemark, seroprevalence was significantly higher among females that calved successfully (85 %) than among others (50 %). Body mass and winter mass change were unrelated to serostatus. Relative abundance of questing ticks in Telemark was highest in deciduous forest and lowest in mature coniferous forest and higher at easterly aspects and altitudes below 350 m. Habitat factors associated with high tick abundance were risk factors for seropositivity among moose. Our findings were consistent with anaplasmosis causing a persistent subclinical infection in moose without population-level effects. Further work is needed to establish the importance of moose as a reservoir for the disease in sympatric domestic livestock.     

Description and epidemiological implications of <Emphasis Type="Italic">S. scabiei</Emphasis> infection in roe deer (<Emphasis Type="Italic">Capreolus capreolus</Emphasis>) originating from chamois (<Emphasis Type="Italic">Rupicapra rupicapra</Emphasis>)

The authors describe a case of Sarcoptes scabiei transmission from a chamois (Rupicapra rupicapra) kid to three roe deer (Capreolus capreolus) fawns kept in captive cohabitation in a wildlife rehabilitation centre for approximately 4 months. Symptoms in the two male fawns started developing 1 week after skin lesions were noticed in the kid, whereas a delayed (75 days later) appearance of scabies signs was observed in the female fawn. A severe generalised form of scabies rapidly developed in a male fawn, but lesions in the other two healed after triple inoculation of ivermectin at 15 days intervals. These roe deer were monitored for specific anti-S. scabiei antibodies with an immunoblotting technique. The strongest antibody response was exhibited during the clinical phase of the infection and then rapidly declined post-treatment. Interestingly, the female fawn developed immunoglobulin G to S. scabiei proteins more than 2 months before the onset of clinical scabies. Since all captive roe deer appeared sensitive to infection with S. scabiei var. rupicaprae, the authors hypothesise that the sporadic frequency of spontaneous scabies in this Cervid host may be attributed to avoidance of direct contacts with moribund or recently dead scabietic chamois, and/or to a self-limiting (and therefore difficult to detect) course of the disease after infrequent infectious contacts and/or exposure to lower infectious doses than in the described episode.     

Serosurvey of Smooth Brucella,Leptospira spp. and Toxoplasma gondii in Free-Ranging Jaguars (Panthera onca) and Domestic Animals from Brazil

This study investigated the exposure of jaguar populations and domestic animals to smooth Brucella, Leptospira spp. and Toxoplasma gondii in the Cerrado, Pantanal and Amazon biomes of Brazil. Between February 2000 and January 2010, serum samples from 31 jaguars (Panthera onca), 1,245 cattle (Bos taurus), 168 domestic dogs (Canis lupus familiaris) and 29 domestic cats (Felis catus) were collected and analysed by rose bengal test for smooth Brucella, microscopic agglutination test for Leptospira spp. and modified agglutination test for T. gondii. Cattle populations from all sites (9.88%) were exposed to smooth Brucella, but only one jaguar from Cerrado was exposed to this agent. Jaguars captured in the Cerrado (60.0%) and in the Pantanal (45.5%) were seropositive for different serovars of Leptospira spp., cattle (72.18%) and domestic dogs (13.1%) from the three sites and one domestic cat from Pantanal were also seropositive for the agent. The most prevalent serotype of Leptospira spp. identified in jaguars from the Cerrado (Grippotyphosa) and the Pantanal (Pomona) biomes were distinct from those found in the domestic animals sampled. Jaguars (100%), domestic dogs (38.28%) and domestic cats (82.76%) from the three areas were exposed to T. gondii. Our results show that brucellosis and leptospirosis could have been transmitted to jaguars by domestic animals; and jaguars probably play an important role in the maintenance of T. gondii in nature.     

Effects of livestock and non-native mouflon on use of high-elevation pastures by Alpine chamois

Interspecific interference among livestock, native and non-native large herbivores is a key management and conservation issue, and little is known about its dynamics and implications. We investigated whether native Alpine chamois (Rupicapra r. rupicapra) modify their spatial distribution when non-native mouflon Ovis orientalis musimon and livestock (domestic sheep Ovis aries, and domestic goats Capra hircus) inhabit the same areas in the Alpine meadows of Italian Eastern Alps. We walked 5 hiking trails (5.0 ± 0.1 km) at dawn, twice a month during summers 2007 and 2008. During these surveys, we located each group of free-ranging ungulates (chamois, mouflon, and livestock). We also estimated the quality of meadows, finding that forage availability increased linearly as the distance from rocks (i.e., chamois refuges) increased. We predicted that the linear distance between chamois groups and rocks would depend on the co-presence of livestock and mouflon groups. Our results showed that chamois were more likely to be observed in areas with low food availability, but safer (i.e., closer to the rocks), whenever the nearest livestock group was larger and closer, especially if the shepherd's dog was present. Avoidance of the best feeding patches by the wild species is presumably due to spatial interference (e.g. visual and acoustic disturbance) and/or predation risk perception caused by the presence of shepherd's dogs. Similarly, the larger was the nearest group of mouflon, the closer to rocks was located the chamois group. Interestingly, mouflon group vicinity induced chamois to move closer to rocks only if mouflon rams were within the group. This suggests that physical displacement of the smaller species (i.e. chamois) is likely to occur to avoid direct disturbance of larger mouflon rams. Our study clearly showed how a native herbivorous species adjusts its spatial distribution and decreases the likelihood of using areas with higher food availability when livestock and/or a non-native species co-occur.     

Increasing Himalayan tahr and decreasing chamois densities in the eastern Southern Alps, New Zealand: evidence for interspecific competition

There is anecdotal evidence that increasing densities of Himalayan tahr (Hemitragus jemlahicus) are associated with declining densities of chamois (Rupicapra rupicapra) in the Southern Alps, New Zealand. To examine this phenomenon, densities of tahr and chamois were measured at 53 sites within their sympatric range in the eastern Southern Alps during 1978–1979. In sites where only one species was present, tahr density was significantly higher than chamois density (P=0.032), probably reflecting species differences in sociality. Chamois density was higher in catchments without tahr than in those with tahr (P=0.012). Similarly, tahr density was significantly higher at sites without chamois than at those with chamois (P=0.033). Sites with both species present (termed sympatric) were significantly larger than those with only chamois or tahr (P<0.001). Following the prohibition of aerial hunting of tahr in 1983, 16 of the 17 sites where tahr and chamois were sympatric during 1978–1979 were recounted during 1991–1996. There was a 6-fold increase in the mean density of tahr between the two counts (P=0.001), whereas chamois density had declined significantly (P=0.006). Chamois persisted at only three sites, two of which had the highest chamois densities in 1978–1979. This is evidence that increasing densities of tahr exclude chamois from all but the `best' habitats. We conclude that intensive aerial hunting of tahr during 1967–1983 reduced tahr densities such that chamois could co-exist with tahr. Received: 20 March 1997 / Accepted: 8 September 1997