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Mexico, a rich country in terms of amphibian diversity, hosts about 375 described species. Population declines have been documented for several species where it is evident that their habitat is being destroyed or modified. However, other species which inhabit pristine areas are declining as well. It has been suggested that the chytrid fungus Batrachochytrium dendrobatidis (B.d.) may be one of the causes of the enigmatic declines in Mexico. We surveyed a total of 45 localities, in 12 states across Mexico, examining a total of 360 specimens representing 14 genera and 30 species. We also examined 91 specimens of Ambystoma mexicanum from a captive population in Mexico City as well as one Pachymedusa dacnicolor obtained in a pet shop. We used a two-tiered technique to detect the pathogen. For wild-caught specimens, we utilized light microscopy to identify presence of B.d. sporangia in amphibian skin. Then, to verify the infection, we used a quantitative real-time PCR assay on collected skin sections which is specific for B.d. For captive animals, we used a nonlethal version of the real-time PCR technique. We found evidence of B.d. infection in 111 animals comprising 14 species in 13 localities. A large percentage (84%) of Ambystoma mexicanum from the colony were infected with B.d. The two most highly infected individuals were the endangered Ambystoma mexicanum, from a captive colony, and Pachymedusa dacnicolor, purchased at a pet shop. The online version of this article (doi:) contains electronic supplementary material, which is available to authorized users.  相似文献   

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Sarcocystis sp. infection was investigated in 20 necropsied captive wild mammals and 20 birds in 2 petting zoos in Malaysia. The gross post-mortem lesions in mammals showed marbling of the liver with uniform congestion of the intestine, and for birds, there was atrophy of the sternal muscles with hemorrhage and edema of the lungs in 2 birds. Naked eye examination was used for detection of macroscopic sarcocysts, and muscle squash for microscopic type. Only microscopically visible cysts were detected in 8 animals and species identification was not possible. Histological examination of the sections of infected skeletal muscles showed more than 5 sarcocysts in each specimen. No leukocytic infiltration was seen in affected organs. The shape of the cysts was elongated or circular, and the mean size reached 254 × 24.5 µm and the thickness of the wall up to 2.5 µm. Two stages were recognized in the cysts, the peripheral metrocytes and large numbers of crescent shaped merozoites. Out of 40 animals examined, 3 mammals and 5 birds were positive (20%). The infection rate was 15% and 25% in mammals and birds, respectively. Regarding the organs, the infection rate was 50% in the skeletal muscles followed by tongue and heart (37.5%), diaphragm (25%), and esophagus (12.5%). Further ultrastructural studies are required to identify the species of Sarcocystis that infect captive wild animals and their possible role in zoonosis.  相似文献   

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Social relationships between female zoo elephants were analyzed on three different zoo groups. Interactions were defined as either affiliative or agonistic. The most frequent interactions were found to be touching of the partner's mouth, genital sinus, face and trunk. The calf was the individual involved in most social interactions. Placing the trunk tip into the partner's mouth is a well known behaviour, the correlation between this behaviour and aggression was analyzed and a further function is suggested. Aggressive behaviour was analyzed and the hypothesis derived that rank order has to be established and is flexible in a non-kin group. The hypothesis that Asian elephant females may form special relationships was tested and confirmed. The following behaviour patterns were determined as indicators of a special relationship: Spatial proximity, partner-specific reactions to arousal and to vocalizing, and omission of agonistic behaviour. An experiment confirmed the hypothesis that the removal of one member of a special relationship from the enclosure would elicit more arousal behaviour in the respective partner.  相似文献   

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目的观察人工饲养条件下实验恒河猴肺脏病理改变,探讨实验猴呼吸系统疾病分布规律和病理改变特点,丰富实验猴自发病变基本研究资料。方法对1998~2008年云南地区饲养的自然死亡的155只恒河猴(年龄2~20岁)的肺脏进行病理检查,按年龄分为幼年组、成年组、老年组,并对观察结果进行统计学分析。结果实验猴肺脏主要病变有大叶性肺炎、支气管肺炎、间质性肺炎、肺气肿、支气管扩张症、胸膜炎、肺肉芽肿性炎等12种,出现率最高的为支气管肺炎(18.71%)和大叶性肺炎(16.74%)。恒河猴肺脏病变在不同年龄阶段均有发生,老年猴组肺脏病变发生率最高,疾病类型和发生率在不同年组中分布不相同,统计学分析显示:支气管炎病变成年组发病率明显高于幼年组;肺气肿病变老年组明显高于成年组和幼年组,(P〈0.05)。结论人工饲养条件下死亡实验猴肺脏病变检出率较高,实验猴肺脏病变在不同年龄阶段存在差异,实验猴肺脏病理改变结果丰富了实验猴的基本研究资料,对实验猴的质量控制和相关动物实验有重要价值。  相似文献   

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During a 5-yr study of lion-tailed macaques in their natural habitat, we found that: 1) most births occurred from January to April (70%) and from September to December (19%), showing a bimodal pattern with a major and a minor birth peak; 2) the period of peaks remained the same over 5 yr; and 3) a similar pattern of birth peaks occurred both in groups in large forest complexes that had overlapping home ranges with other groups and in single groups that were isolated in forest fragments in the same region but with similar ecological conditions. The results suggest more of a birth seasonality than mere breeding synchronization in the wild lion-tailed macaques. We also analyzed data on births in captivity in European Zoos for 10 yr. We observed no seasonality or peaks in births, and the pattern was the same over the years. Data on rainfall suggest that resource availability in the wild habitat may not be uniform throughout the year; hence, ecological factors may play an important role in determination of birth patterns in the natural habitats of lion-tailed macaques.  相似文献   

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Morphological variation in natural populations is a genomic test bed for studying the interface between molecular evolution and population genetics, but some of the most interesting questions involve non-model organisms that lack well annotated reference genomes. Many felid species exhibit polymorphism for melanism but the relative roles played by genetic drift, natural selection, and interspecies hybridization remain uncertain. We identify mutations of Agouti signaling protein (ASIP) or the Melanocortin 1 receptor (MC1R) as independent causes of melanism in three closely related South American species: the pampas cat (Leopardus colocolo), the kodkod (Leopardus guigna), and Geoffroy’s cat (Leopardus geoffroyi). To assess population level variation in the regions surrounding the causative mutations we apply genomic resources from the domestic cat to carry out clone-based capture and targeted resequencing of 299 kb and 251 kb segments that contain ASIP and MC1R, respectively, from 54 individuals (13–21 per species), achieving enrichment of ~500–2500-fold and ~150x coverage. Our analysis points to unique evolutionary histories for each of the three species, with a strong selective sweep in the pampas cat, a distinctive but short melanism-specific haplotype in the Geoffroy’s cat, and reduced nucleotide diversity for both ancestral and melanism-bearing chromosomes in the kodkod. These results reveal an important role for natural selection in a trait of longstanding interest to ecologists, geneticists, and the lay community, and provide a platform for comparative studies of morphological variation in other natural populations.  相似文献   

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Captive studies and occasional trappings of wild individuals indicate that callitrichids have small size and body weight and lack sexual dimorphism. We compared body weights of captive and wild Callithrix jacchus obtained by repeatedly weighing subjects from two populations in Brazil. We obtained captive data by routinely weighing 138 individuals from the Universidade Federal do Rio Grande do Norte colony and wild data via regular trapping of 243 individuals in 15 free-ranging groups from IBAMA's field site in Nísia Floresta. We assigned all subjects to one of four age classes—infant, juvenile, subadult, and adult—according to their birth dates or size, reproductive status, and dental development. There is no significant difference between males and females in any of the four age classes, but captive subjects were heavier than wild ones in all age classes but infant. Reproductive and nonreproductive adult females showed no statistical difference in weight. These results accord with previous reports of lack of body size sexual dimorphism in common marmosets and suggest that differences between wild and captive common marmosets are not constitutional, but are instead a consequence of diet and physical activity. The absence of weight difference between reproductive and nonreproductive females suggests that any possible advantage from high rank is outweighed by the costs of reproduction in common marmosets.  相似文献   

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Music or other background sounds are often played in barns as environmental enrichment for animals on farms or to mask sudden disruptive noises. However, previous studies looking at the effects of this practice on nonhuman animal well-being and productivity have found contradictory results. This study monitored the vocal responses of piglets, as indicators of well-being, to evaluate the effect of various sounds played during 2 simulations of stressful farm procedures: (a) the 5 min the animals were held as if for castration and (b) the first 20 hr after weaning. The sound treatments included pink noise, music, vocalizations made by other piglets during actual castrations or the first hours after weaning, and silence (control). The study presented pink noise and music both with and without a binaural beat in the delta-theta frequency range. In both the handling and weaning situations, none of the sound treatments reduced the piglets' call rate below that heard during the control. Piglets vocalized most during playback of pink noise and least during silence and playback of calls from other pigs. These results suggest that playing music or other sounds provides no improvement in conditions for piglets during handling and weaning.  相似文献   

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The proliferation of camera-trapping studies has led to a spate of extensions in the known distributions of many wild cat species, not least in Borneo. However, we still do not have a clear picture of the spatial patterns of felid abundance in Southeast Asia, particularly with respect to the large areas of highly-disturbed habitat. An important obstacle to increasing the usefulness of camera trap data is the widespread practice of setting cameras at non-random locations. Non-random deployment interacts with non-random space-use by animals, causing biases in our inferences about relative abundance from detection frequencies alone. This may be a particular problem if surveys do not adequately sample the full range of habitat features present in a study region. Using camera-trapping records and incidental sightings from the Kalabakan Forest Reserve, Sabah, Malaysian Borneo, we aimed to assess the relative abundance of felid species in highly-disturbed forest, as well as investigate felid space-use and the potential for biases resulting from non-random sampling. Although the area has been intensively logged over three decades, it was found to still retain the full complement of Bornean felids, including the bay cat Pardofelis badia, a poorly known Bornean endemic. Camera-trapping using strictly random locations detected four of the five Bornean felid species and revealed inter- and intra-specific differences in space-use. We compare our results with an extensive dataset of >1,200 felid records from previous camera-trapping studies and show that the relative abundance of the bay cat, in particular, may have previously been underestimated due to the use of non-random survey locations. Further surveys for this species using random locations will be crucial in determining its conservation status. We advocate the more wide-spread use of random survey locations in future camera-trapping surveys in order to increase the robustness and generality of inferences that can be made.  相似文献   

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The behavior of 12 orangutans (three adult males, two adult females, two subadult males, three adolescent males, and two infant males) was observed on a 450-m2 island at the Singapore Zoological Gardens (SZG). Male orangutans (6–18 years old) showed less social and solitary play as they aged; adults (over 16 years old) were not seen to play. As they grew older males increasingly spent less time making physical contact, but the amount of time they spent in proximity (within arm's length) to others increased. Adult females regularly played with other group members. Contact, allogrooming, and social play showed nonrandom relationships between individuals. Adult females showed the most allogrooming and contact, adolescent and subadult males the most play. There was no obvious dominance hierarchy. One adult male spent about 10% of his time walking around the perimeter of the island. One-year-old infants rarely interacted with other individuals apart from their own and the other infant's mother. While orangutans lead relatively solitary lives in nature, it was concluded that the opportunities for social contact and play provided by the SZG orangutan island were beneficial to this species in captivity. Opportunities for social interaction provided the animals with a means of increasing the stimulus component of their environment, thus compensating for the inevitable restriction of complexity and unpredictability as compared with the wild state.  相似文献   

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Serum samples from 19 jaguars (Panthera onca), nine pumas (Puma concolor), and two ocelots (Leopardus pardalis) were collected between January 1999 and March of 2005 and tested for presence of canine distemper virus (CDV). All cats were free-ranging animals living in two protected areas in the Brazilian Atlantic Forest. In addition, 111 domestic dogs from nearby areas were sampled for CDV. Our results show the first evidence of CDV exposure in Brazilian free-ranging felids. From the 30 samples analyzed, six jaguars and one puma were tested seropositive for CDV. All seropositive large felids were from Ivinhema State Park, resulting in 31.5% of the sampled jaguars or 60% of the total jaguar population in Ivinhema State Park, and 11.28% of the sampled pumas. From the total 111 domestic dogs sampled, 45 were tested seropositive for CDV. At Morro do Diabo State Park, 34.6% of the dogs sampled were positive for CDV, and 100% at Ivinhema State Park. Canine distemper virus in wild felids seems to be related with home range use and in close association with domestic dogs living in nearby areas.  相似文献   

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Grooming is a complex set of motor actions, common in highly social primates. We tested for asymmetries in hand use during unimanual and bimanual allogrooming in 215 captive chimpanzees. In addition to hand use, we coded in the ethogram whether the manual grooming action co-occurred with the use of the mouth. Overall, grooming did not elicit strong handedness at the individual level, but there is a small yet significant population-level right-hand bias for bimanual grooming. Mouth use during grooming had no influence on hand use. A comparison of the findings with previously published data on handedness for grooming in wild chimpanzees suggests that wild apes are more right-handed than captive individuals are for allogrooming. Collectively, the results suggest that role differentiation of the hands is an important factor in the assessment of handedness for grooming, and perhaps additional manual actions of chimpanzees and other primates.  相似文献   

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百花山自然保护区具有优越的地理位置和良好的气候条件,其中孕育着丰富的植物资源,是北京著名的野生花卉种质资源库.在调查分析其野生植物自然分布情况的同时,对其中的重要花卉的潜在园林利用价值作了简要评价,期望加大对百花山野生花卉资源的开发利用.  相似文献   

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