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1.
Translocation programs releasing animals into the wild need to assess the potential risks associated with the exchange of parasites and other pathogens between native and translocated species. We assessed the composition of the parasite communities in sympatric native and introduced primates. Over a 3-yr period we monitored the gastrointestinal parasites of 3 primate species living in the isolated ecosystem of Rubondo Island National Park, Tanzania: translocated chimpanzees (Pan troglodytes) and guerezas (Colobus guereza) and the indigenous vervets (Chlorocebus aethiops pygerythrus). We detected Troglodytella abrassarti and Enterobius cf. anthropopitheci only in chimpanzees and Chilomastix mesnili in chimpanzees and guerezas. In vervets, we recorded Anatrichosoma sp. and Subulura sp., previously reported in Rubondo chimpanzees. We found Blastocystis sp., Giardia sp., Iodamoeba buetschlii, Entamoeba coli, Entamoeba spp., Trichuris sp., Strongyloides spp., spirurids (cf. Protospirura muricola), and undetermined strongylids in all 3 primate species. Considering the absence of Protospirura muricola in other wild populations of chimpanzees and guerezas, it has probably been acquired from the native vervets, as have Anatrichosoma sp. and Subulura sp. Lower parasite load in Rubondo chimpanzees, in comparison with wild populations at other study sites of this species, might be due to their stay in captivity in Europe before being released on the island. Despite a lack of any apparent health problems from infections in introduced Rubondo primates, parasite monitoring during reintroduction/introduction projects is necessary to decrease potential risks resulting from the exchange of parasites between translocated and native species.  相似文献   

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We identified 3 nematodes not previously reported in chimpanzees (Pan troglodytes) introduced on Rubondo Island, Tanzania: Protospirura muricola, Subulura sp., and Anatrichosoma sp. Vervet monkeys (Cercopithecus aethiops pygerythrus), rodents, and intermediate insect hosts might maintain Protospirura muricola and Subulura sp., and indigenous monkeys on the island might also maintain Anatrichosoma sp. Low prevalence of Subulura sp. and Anatrichosoma sp. suggests that chimpanzees acquired them from ingestion of contaminated food.  相似文献   

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Northeastern Pacific Ocean and northwestern Atlantic Ocean populations of Chorda species, which have not been examined in previous phylogenetic studies, were investigated. All specimens that were collected in Hood Canal, Puget Sound, WA, USA, Pacific coast of North America, showed identical ITS‐5.8S rDNA sequences, and they were included in the clade of Japanese Chorda asiatica. With morphological data added to the molecular data, they were identified as C. asiatica and were concluded to be non‐indigenous populations, most likely introduced with oyster spat together with Sargassum muticum. Specimens collected in New York, NY, USA, Atlantic coast of North America, were genetically closest to C. filum from Newfoundland and were identified as C. filum. The genetic divergence of the North Atlantic populations of C. filum was relatively small compared to that of Japanese C. asiatica considering their broader distributional ranges on both sides of the Atlantic.  相似文献   

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Aim To use a comparative approach to understand parasite demographic patterns in native versus introduced populations, evaluating the potential roles of host invasion history and parasite life history. Location North American east and west coasts with a focus on San Francisco Bay (SFB). Methods Species richness and prevalence of trematode parasites were examined in the native and introduced ranges of two gastropod host species, Ilyanassa obsoleta and Littorina saxatilis. We divided the native range into the putative source area for introduction and areas to the north and south; we also sampled the overlapping introduced range in SFB. We dissected 14,781 snails from 103 populations and recorded the prevalence and identity of trematode parasites. We compared trematode species richness and prevalence across the hosts’ introduced and native ranges, and evaluated the influence of host availability on observed patterns. Results Relative to the native range, both I. obsoleta and L. saxatilis have escaped (lost) parasites in SFB, and L. saxatilis demonstrated a greater reduction of trematode diversity and infection prevalence than I. obsoleta. This was not due to sampling inequalities between the hosts. Instead, rarefaction curves suggested complete capture of trematode species in native source and SFB subregions, except for L. saxatilis in SFB, where infection was extremely rare. For I. obsoleta, infection prevalence of trematodes using fish definitive hosts was significantly lower in SFB compared to the native range, unlike those using bird hosts. Host availability partly explained the presence of introduced trematodes in SFB. Main conclusions Differential losses of parasite richness and prevalence for the two gastropod host species in their introduced range is probably the result of several mechanistic factors: time since introduction, propagule pressure, vector of introduction, and host availability. Moreover, the recent occurrence of L. saxatilis’ invasion and its active introduction vector suggest that its parasite diversity and distribution will probably increase over time. Our study suggests that host invasion history and parasite life history play key roles in the extent and diversity of trematodes transferred to introduced populations. Our results also provide vital information for understanding community‐level influences of parasite introductions, as well as for disease ecology in general.  相似文献   

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This study examined inter‐period changes over two to three decades in the fish fauna of an urbanized estuary experiencing rapid population growth and a drying climate (Swan–Canning Estuary, Western Australia). Responses were compared at the fish community level (species composition; 1978–2009 in the shallows and 1993–2009 in deeper waters) and at the population and individual levels of an estuarine indicator species, black bream Acanthopagrus butcheri (biomass–abundance and per capita mass at age, respectively; 1993–2009). All three levels showed distinct shifts from earlier to later periods, but their patterns, sensitivity and breadth differed. Community composition changed markedly in the shallows of the lower‐middle estuary between the late 1970s and all later periods and moderately between more disparate periods from 1995 to 2009. Several species trends could be linked to the increasing salinity of the estuary or declining dissolved oxygen levels in its middle–upper reaches. Community changes were, however, small or insignificant in the shallow and deeper waters of the upper estuary and deeper waters of the middle estuary, where environmental perturbations are often most pronounced. This may reflect the resilience of the limited suite of species that typify those reaches and thus their lack of sensitivity in reflecting longer‐term change at the coarser level of mean abundance. One such species, the selected indicator, A. butcheri, did, however, show marked temporal changes at both the population and individual levels. Biomass decreased markedly in deeper waters while increasing in the shallows from earlier to later periods, presumably reflecting an onshore movement of fish, and per capita body mass in the 2+, 3+ and 4+ year classes fell steadily over time. Such changes probably indicate deteriorating habitat quality in the deeper waters. The study outcomes provide support for a multifaceted approach to the biomonitoring of estuaries using fishes and highlight the need for complementary monitoring of relevant stressors to better disentangle cause–effect pathways.  相似文献   

8.
Frequent hunting of red colobus monkeys (Procolobus rufomitratus) takes place at all long-term chimpanzee (Pan troglodytes) study sites where both species are present. Red colobus are the most commonly selected prey of chimpanzees even when other monkey species are more abundant. In particular, the chimpanzee community at Ngogo, Kibale National Park, Uganda, preys heavily on red colobus monkeys: the chimpanzee hunting success rate is extremely high, and chimpanzees kill many individuals per successful hunt. Census data had suggested that the red colobus population is declining and that predation by chimpanzees may be contributing to this decline. In this paper, I address the impact of hunting on the red colobus population at Ngogo. To test the hypothesis that chimpanzee hunting is sustainable, I am using demographic data collected on red colobus monkeys over a period of 3 years, as well as fecundity and mortality data from previous studies of this species. I apply matrix models and vortex analyses using a sensitivity analysis approach to project future population development. Results show that current rates of hunting are not sustainable, but that chimpanzees are neither more “noble”, nor more “savage” than humans are, but that they also hunt to ensure maximum benefit without regard for the consequences for the prey population.  相似文献   

9.
The spread of Anguillicola crassus was documented and showed an increase in both prevalence (9·9%) and mean intensity (6·7). Infected eels Anguilla anguilla were recorded 30 km downstream of the first recorded sites of infection. Migrating silver eels from commercial nets near the outlet of the Erne during October-December 1999 were also infected. Continued spread of A. crassus through Ireland's major wild eel fisheries now appears likely.  相似文献   

10.
Proximity partner choice by male chimpanzees of various age classes was analyzed in relation to their spatial positioning. Field work was carried out twice at the Mahale Mountains National Park, Tanzania. Proximity data were recorded at 3 and 10m from the focal animal. The data for the proximity between the focal male and other individuals allowed the males to be classified into two categories according to both criteria: early adolescence to young adult, and prime to old age. Between the males, the 3m proximity data permitted a classification into two categories as above, but those for 10m did not. These two spatial distances thus probably have different meanings for the males. The numbers of male proximity partners and proximity with the alpha male also allowed the males to be classified into two categories: early and late adolescence, and young adult to old age. Together, the above results support the classification of males into three age-graded categories: (1) early and late adolescence, (2) young adult, and (3) prime to old age. This does not arise because the males of each category form an age group. Prime or older males are most frequently in proximity, while their juniors consistently attempt to approach them. However, even prime or older males are not equally in proximity with one another. Their proximity partners change as time passes. Probably recognizing such changes, they form coalitions or are in rivalry. The sexual interest of adolescent males is probably a factor stimulating them to separate from their mothers, and to approach older males. Young adult males, even though physically mature, do not have equal proximity relations with older males. They are not yet sufficiently qualified to join the coalitions formed by their seniors.  相似文献   

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Wildlife management policies are often based on expert perceptions of the ecological importance of certain species and poorly informed perceptions of how public attitudes toward management are formed. Little is known about why preferences vary greatly and how this affects support for management actions. This paper explores preferences for a range of wildlife species among a sample of the rural population adjacent to Serengeti National Park in Tanzania. We also examine the degree of acceptance for alternative management interventions when potentially dangerous animals pose different levels of problems to human beings, and the extent to which these attitudes are related to species preferences. Gender has a significant effect on species preferences. Men like most species better than women. Age has no significant effect, but level of education affects preference level for some species. Species preferences have a positive effect on support for management intervention when dangerous animals cause small or moderate problems to humans, i.e. there is a higher degree of acceptance of problems caused by animals that are well liked. In situations where human life is threatened, species preferences have no effect on preferred management actions. Appreciation of animals is a combination of functional, consumptive and cultural dimensions, and there is no simple link between species preferences and attitudes toward management actions. The local context and concrete experience with wildlife encounters is more important for shaping normative beliefs like attitudes towards management actions than global wildlife attitudes.  相似文献   

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From February 1988 though June 1990, 475 adult long-tailed macaques (Macaca fascicularis) were released on Tinjil Island to establish a breeding program that will provide monkeys for biomedical research while contributing to Indonesia's primate conservation efforts. A survey was conducted during the summer of 1990 to assess the status of the island's population. Basic demographic data were consistent with those from other field studies of long-tailed macaques, and estimates of reproductivity suggest a successful breeding program. The facility established on Tinjil Island should serve as a useful model for future primate resource and conservation programs. © 1993 Wiley-Liss, Inc.  相似文献   

15.
‘Ana‐aosa’, one of the most common marine green algae in Japan, was described as Ulva pertusa Kjellman in 1897 from Hakodate in northern Japan. Ulva pertusa was considered to be a temperate species, with its native distributional range restricted to northeastern Asia. Although this species has been reported from various regions outside northeastern Asia, these records have been explained as non‐indigenous populations. Recently, on the basis of genetic data and nomenclatural priority, U. pertusa was synonymized with U. australis Areschoug, a species described in 1851 from specimens collected in South Australia. Based on genetic studies, Australian populations identified as U. pertusa had been considered to have originated from Japan. However, the published genetic data on U. australis in Australia have been based only on recent collections and no historical specimens have been examined. We tested the hypothesis that native (true) U. australis is an independent species of very similar morphology to U. pertusa, but that its natural domination of shoreline habitats has been suppressed by introduced populations of U. pertusa from Asia. In the present study, we extracted DNA from the type specimen of U. australis housed in the Swedish Museum of Natural History (S) and obtained DNA sequences of the chloroplast rbcL gene and the nuclear rDNA ITS2 region. Our results show that U. australis and U. pertusa are genetically virtually identical, confirming that U. pertusa is a synonym of U. australis. This suggests that the introduction of U. australis to Australia occurred by the middle of the 19th century, when the type was collected and before there was a direct shipping route between Japan and Australia. We speculate that the introduction of U. australis to Australia occurred as a secondary introduction from non‐indigenous populations in northeastern Asia, but not directly from Japan.  相似文献   

16.
The behavior and social interactions of young male chimpanzees were studied in relation to their age change. The data were obtained at the Mahale Mountains National Park, during a four-month period in 1986. Early adolescent males, becoming independent of their mothers, spend a long time near adults of both sexes. Late adolescent males are not tolerated by the senior males. Although such animals do not stop traveling together with their seniors, they are separated from the other members including the males of their own age class, and each of them lives a relatively lonely life. Where seniors are not nearby, they perform charging displays in front of estrous females. Young adult males tend to remain in the proximity of the alpha male, and can associate with their seniors without pant-grunting. Although some young adult males dominate over some senior males, increasingly performing charging displays, they do not appear to be permitted to associate intimately with their seniors; they are not yet considered to have attained social maturity. Prime and senior males are strongly bonded with one another, being able to associate intimately with those of their own or senior age classes including the alpha male. A young adult male's rise in rank is not connected with joining the “adult male-cluster,” nor does a senior male's decline necessarily means his dropping out from the cluster: the social position of male chimpanzees cannot be understood solely from their agonistic dominance rank. The alpha male plays a leading part in integrating the males of the unit-group. Young adult males and their seniors tend to associate most frequently with him, and all the males of the early adolescent or senior age classes pay attention to his movements.  相似文献   

17.
Certain general facets of biotic response to climate change, such as shifts in phenology and geographic distribution, are well characterized; however, it is not clear whether the observed similarity of responses across taxa will extend to variation in other population‐level processes. We examined population response to climatic variation using long‐term incidence data (collected over 42 years) encompassing 149 butterfly species and considerable habitat diversity (10 sites along an elevational gradient from sea level to over 2,700 m in California). Population responses were characterized by extreme heterogeneity that was not attributable to differences in species composition among sites. These results indicate that habitat heterogeneity might be a buffer against climate change and highlight important questions about mechanisms maintaining interpopulation differences in responses to weather. Despite overall heterogeneity of response, population dynamics were accurately predicted by our model for many species at each site. However, the overall correlation between observed and predicted incidence in a cross validation analysis was moderate (Pearson's r = 0.23, SE 0.01), and 97% of observed data fell within the predicted 95% credible intervals. Prediction was most successful for more abundant species as well as for sites with lower annual turnover. Population‐level heterogeneity in response to climate variation and the limits of our predictive power highlight the challenges for a future of increasing climatic variability.  相似文献   

18.
The long‐distance migrant red knot (Calidris canutus ssp. rufa– Scolopacidae) alternates between the northern and southern ends of the New World, one of the longest yearly migrations of any bird and paradoxically overflying apparently suitable habitat at lower latitudes. This subspecies is sharply declining, with a major mortality event following 2000, attributed to commercial overharvesting of food resources at its Delaware Bay (USA) stop‐over site. A full understanding of this peculiar migrant requires an assessment of the foraging conditions at its southern hemisphere wintering sites. Here, for a major wintering site in Argentinean Tierra del Fuego (Río Grande), we describe and compare food abundance, diet and intake rates during January–February in 1995, 2000 and 2008. The two main prey types were the burrowing clam Darina solenoides and three species of epibenthic mussels Mytilidae. In the year 2000, food availability and intake rate were higher than those recorded at other sites used by knots anywhere else in the world, contributing to the explanation of why red knots carry out this impressive migration. Intake rate in 2008 on the two main prey types was dramatically reduced as a result of birds eating smaller prey and strongly increased human disturbance; the same year we also found a high prevalence of a digenean parasite in Darina. We suggest that during the strongly enhanced winter mortality in 2000, knots did not yet face ecological problems in their southernmost wintering area, consistent with the previous evidence that problems at northern stop‐overs negatively affected their numbers. However, in 2008 the ecological conditions at Río Grande were such that they would have facilitated a further decline, emphasizing the importance of a hemispheric approach to research and management.  相似文献   

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The number of African buffaloes (Syncerus caffer Sparrman, 1779) inhabiting Ruaha National Park, Tanzania, is thought to be declining, but little data exist to determine whether the population is actually in decline. As an initial phase of collecting population data, we conducted demographic surveys, faecal egg counts and gastrointestinal parasite identification in Ruaha's buffalo herds in September 2011 and 2013. Most herds encountered in the two surveys appeared to be in good health, but with fewer calves in 2013 compared with 2011. The herd‐level body condition score was positively associated with the number of calves per 100 cows after adjusting for year, and the lower number of offspring in 2013 could possibly be associated with a below average rainfall in the 2012–2013 rainy season. Mean herd‐level egg counts ranged from 83 to 140 and from 28 to 113 eggs per g faeces in 2011 and 2013, respectively. Haemonchus, Nematodirus, Cooperia and Oesophagostomum spp., as well as coccidian oocysts, were detected in the population. Monitoring herd demographics and baseline health parameters over time will provide insight into population performance, increase the understanding of population stressors and contribute to buffalo conservation within Ruaha National Park and other protected areas of Africa.  相似文献   

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