首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
The adult greater Kudu antelope has two hemoglobin components, Hb A and Hb B, with one alpha and two beta chains. The complete amino-acid sequences of these three chains are presented. The two beta chains differ only in one residue at position 16 (Gly----Ser) and may be the product of two allelic genes. The primary structure of the chains was determined by sequencing the tryptic peptides after their isolation from the tryptic digest of the chains by high performance liquid chromatography. The alignment of these peptides was deduced from homology with the chains of bovine hemoglobin. Between the Kudu hemoglobins and those of cattle a high degree of homology was found.  相似文献   

2.
3.
4.
The activities and food selection of four hand-reared kudus were recorded in a large fenced enclosure containing natural savanna vegetation in the Nylsvley Nature Reserve, South Africa. Leaves of selected species were analysed chemically for crude protein, fibre constituents, phosphorus, condensed tannin and total polyphenols. Available protein and metabolizable energy were estimated allowing for potential antinutritional effects of tannins.
Leaves of palatable deciduous woody plants and herbaceous forbs formed the main dietary constituents during the late wet season. Foliage from palatable evergreens and robust forbs were added to the diet during the dry season. Towards the end of the dry season unpalatable species of evergreens were eaten. At the start of the growing season new leaves of otherwise unpalatable woody species formed the staple food source, together with fruits of Strychnos spp. Correspondingly, protein and digestible dry matter concentrations in the diet declined to reach a low at the end of the dry season.
Total daily food intake increased to compensate for reduced dietary quality during the dry season, until little edible foliage remained. While the estimated daily intake of protein remained well above maintenance requirements, the estimated metabolizable energy intake fell below requirements during the late dry season. Phosphorus intake may have been submaintenance in the dry season. Nutritional balance was dependent on the availability of particular vegetation components to serve as nutritional stepping stones during crucial times of the year. These included forbs during the late wet season, palatable evergreens in the dry season, and Strychnos fruits plus early-flushing woody plants during the dry season-wet season transition.  相似文献   

5.
Many ecotourism reserves in the Eastern Cape Province of South Africa have introduced large carnivores which prey on ungulates such as kudu. Kudu occupy thick vegetation and helicopter‐based counts are not appropriate. In this study we tested line transect counts of faecal pellets in conjunction with DISTANCE analysis as a method for assessing the abundance of kudu. Transects were undertaken in three regions of two game reserves and the results compared with helicopter based game counts (for two regions) and a known kudu population in the third region (an enclosed breeding centre). Estimates of kudu abundance were two to three times greater than the helicopter counts, but within the known number of kudu in the breeding centre. The increased accuracy in the breeding centre was probably because the transects covered a greater percentage of the available habitat (0.07%) than in the reserves (approximately 0.007%). We suggest that DISTANCE software and line transects counts of pellet groups can be used for kudu and probably for other ungulates in thicket‐type vegetations. Accuracy will depend on the percentage of the available habitat that is surveyed and on the accuracy of the defecation and decay rates.  相似文献   

6.
The helminth parasites of the greater kudu from the Kruger National Park (KNP), South Africa, and the Etosha National Park (ENP), Namibia, were examined to determine the major patterns of spatial and demographic variation in community structure and to evaluate nonrandomness in parasite community assembly. Nonmetric multidimensional scaling ordination procedures were used to test for differences in parasite community composition between hosts of the 2 parks and between hosts of different demographic groups within KNP. Infracommunities within KNP were also examined for patterns of nonrandomness using 2 null models, i.e., nestedness and species co-occurrence. Infracommunities of KNP and ENP were significantly different from each other, as were infracommunities of different host demographic groups within KNP. Parasite species in the greater kudu from KNP displayed significant levels of nestedness and were found to co-occur less frequently than expected by chance; however, this lack of co-occurrence was significant only when all demographic groups were considered. When restricted to any particular age class, co-occurrence patterns could not be distinguished from random. Overall, these data suggest that biogeography and host demographics are important factors in determining community organization of helminth parasites in the greater kudu.  相似文献   

7.
The lesser kudu (Tragelaphus imberbis) has been kept in North American zoological parks since 1930 but has never been a common species in collections. In 1987 this population totaled 28 animals: 15 males and 13 females. A pedigree evaluation in 1987 of the existing population indicated that eight effective founders and one potential founder were represented in the North American herd. Three new potential founders from European captive populations were added to the population in 1987 to increase the number of existing founder lines to 12 animals. As this species is not endangered or threatened in its native habitat, it is not a high priority to qualify for designation as an SSP species. Because of this, the institutions holding lesser kudu in North America decided to join informally and draft a breeding program to better manage this small captive population. This program was designed to minimize inbreeding and equalize genetic representation of founder animals to maximize genetic diversity. It requires a shift in management philosophy to establish stable groups of breeding females at participating institutions while rotating appropriate breeder males through these herds in a controlled manner to ensure minimization of inbreeding and maximization of genetic diversity. It is hoped that this program can serve as a model for the management of other small captive populations of non-SSP species.  相似文献   

8.
9.
Rabies in kudu is unique to Namibia and two major peaks in the epizootic have occurred since it was first noted in 1977. Due to the large numbers of kudu that were affected, it was suspected that horizontal transmission of rabies occurs among kudu and that rabies was being maintained independently within the Namibian kudu population – separate from canid cycles, despite geographic overlap. In this study, it was our aim to show, through phylogenetic analyses, that rabies was being maintained independently within the Namibian kudu population. We also tested, through complete genome sequencing of four rabies virus isolates from jackal and kudu, whether specific mutations occurred in the virus genome due to host adaptation. We found the separate grouping of all rabies isolates from kudu to those of any other canid species in Namibia, suggesting that rabies was being maintained independently in kudu. Additionally, we noted several mutations unique to isolates from kudu, suggesting that these mutations may be due to the adaptation of rabies to a new host. In conclusion, we show clear evidence that rabies is being maintained independently in the Namibian kudu population – a unique phenomenon with ecological and economic impacts.  相似文献   

10.
Semen collected by a combination of ampullary (rectal) massage and electroejaculation of a bongo bull was incidentally contaminated with urine (1:3.7). At 1.5h post-collection, progressive motility was 0% but some spermatozoa had intermittently twitching tails. Subsequent dilution with media and processing improved the progressive motility (up to 50%) and intact membranes (up to 71%) of spermatozoa. After thawing, the respective values were 35 and 70%. The osmolarity and pH of the contaminated supernatant was 151 mOsm and 7.45, respectively. Initial progressive motility in a non-contaminated portion of semen collected during the same procedure was 80%, and, after thawing, 60 and 90%, of the spermatozoa showed progressive motility and intact membranes, respectively. In conclusion, urine-contaminated bongo spermatozoa can regain progressive motility after dilution with isosmotic solutions and survive cryopreservation.  相似文献   

11.
Cowdria ruminantium was isolated from a natural infection of heartwater in a captive sitatunga (Tragelaphus spekei) which died after a short illness in Jos Zoo, Nigeria. The isolate killed laboratory mice in a shorter period of time than did isolates of C. ruminantium recovered from natural cases in cattle. This is the first confirmed case of heartwater in a captive wild ruminant in Nigeria, where the disease is endemic.  相似文献   

12.
Rabies in the greater kudu (Tragelaphus strepsiceros), one of the largest African antelopes, is a phenomenon unique to Namibia. Since the mid-1970s, the country has been plagued by two epizootics that claimed thousands of casualties among the indigenous kudu population. Reasons as to why kudus appear to be exceptionally susceptible to the disease still remain speculative at best. Because the Namibian economy relies heavily on trophy hunting, game meat hunting, and ecotourism, the current severe spread of rabies among kudus calls for effective measures to protect these antelopes. Oral vaccination of kudus may offer a possibility provided efficacious oral rabies vaccines are available. In this screening study, we explored options for attractive baits that facilitate optimal vaccine uptake by the target species and a bait distribution system that maximizes bait availability to the target species meanwhile minimizing bait depletion by non-target species. The results show that gelatin-based baits mixed with local (pods of the camel thorn tree) but also imported (apple-flavored corn meal) attractants are highly attractive for kudus providing a basis for future oral rabies vaccine baits.  相似文献   

13.
The limited availability of gametes is a major factor hindering the development and application of assisted reproductive technologies (ART) in large non-domestic ungulates. This is partly due to the small number of captive animals and handling difficulties associated with procedures for gamete recovery. In the present study, results are reported of multi-year studies on ovarian stimulation and oocyte retrieval by ultrasonographic-guided transvaginal follicular aspiration and subsequent in vitro maturation (IVM) in eland and bongo antelopes. All procedures were conducted on sedated females handled in a hydraulic chute without inducing general anesthesia. Five estrous synchronization/ovarian stimulation protocols were evaluated and data are presented on 73 and 15 procedures in eland and bongo, respectively. Repeating procedures (< or =once/month) on the same female did not affect ovarian response or number oocytes recovered in either species. Eland females, but not the ovarian stimulation treatment, affected ovarian response. Ovarian stimulation treatment affected oocyte recovery rate in eland, but not in bongo. In both species, ovarian hormone stimulation treatment affected the distribution of follicles by size and the status of expansion of the cumulus cell investment of oocytes, but not the frequency of metaphase II oocytes during IVM. The timing of extrusion of the first polar body during IVM was more synchronous in bongo than in eland oocytes. It is concluded that Transvaginal oocyte retrieval (TVOR) can be safely and repeatedly applied in gonadotropin-treated eland and bongo females to recover oocytes that can mature in vitro. The methods described for the present study can be adapted to improve the availability of non-domestic ungulate oocytes for basic and applied studies.  相似文献   

14.
15.
Observations were made on two populations of the greater kudu (Tragelaphus strepsiceros) in Namibia to investigate the influence of differing management strategies (trophy hunting vs. venison production) on the population structure, behaviour and ecology of these antelope with regard to population persistence. The population structure on both study sites was similar despite different management strategies. However, the percentage of males in respective age classes differed significantly. All sex ratios were clearly female-biased, even though at birth they are close to parity, indicating sex- and age-specific mortality. Matriarchal groups were larger than groups led by bulls. The group size reached a maximum during the breeding season (rut). The male age classes accompanying females in this season differed strongly between the two study sites. The behavioural patterns shown by kudu over the course of a 12-h period (esp. feeding and locomotion) were also significantly different for the two populations. The results suggest that the management strategies can have an impact on behaviour and population structure of T. strepsiceros and may affect the overall fitness of the population.  相似文献   

16.
17.
食草动物集群有利于降低被捕食的风险,同时集群也会增加感染和传播寄生物的风险。可可西里卓乃湖地区是雌性藏羚的重要产羔地,集群时间主要集中在6月上旬至7月上旬,停留时间不足30 d。区域内温度、湿度等气候因子对其粪便中的寄生虫卵发育到感染期可能存在重要影响。本研究于2018年6月9日在卓乃湖产羔地建立微气候观测仪收集当地气象数据的同时,收集新鲜藏羚粪便在当地室外分别放置0 d、10 d、15 d、20 d、25 d、30 d、35 d和约300 d,应用漂浮法检测35 d内不同时间段虫卵发育状况和放置近一年的存活幼虫数量。初步研究了卓乃湖区域内集群藏羚粪便中的优势寄生虫卵的发育及其越冬存活,探讨藏羚产羔地是否会增加藏羚胃肠道寄生虫传播和感染的风险。结果表明:(1) 6月9日至7月14日,藏羚产羔地平均温度为5℃,平均相对湿度81%;(2) 藏羚在卓乃湖产羔地集群期间,其粪便中的优势寄生虫卵不能发育到感染期 (第三期幼虫),如粪便中的优势线虫卵毛园属线虫 (Trichostrongylus sp.)、马歇尔属线虫 (Marshallagia sp.) 和细颈属线虫 (Nematodirus sp.) 在30 d内发育仅停留在第一期幼虫;优势种藏羚艾美耳球虫 (Eimeria pantholopensis) 和五道梁艾美耳球虫 (E.wudaoliangensis) 卵在25 d、30 d、35 d的孢子化率分别是0、18.9%、54.0%和0、13.5%、30.4%;(3) 很少有寄生虫卵能够越冬存活至第二年,在卓乃湖产羔地放置近一年的粪便中仅发现极少的马歇尔属线虫和细颈属线虫幼虫。研究认为藏羚在卓乃湖集群时发生胃肠道寄生虫传播和感染的风险较低,藏羚对产羔地的短时利用和迅速回迁是其避免增加胃肠道寄生虫病感染风险的重要行为策略,且产羔地的低温等气候环境利于对寄生虫的自然净化。  相似文献   

18.
19.
20.
《Zoology (Jena, Germany)》2015,118(3):192-202
Many studies have revealed the significant influence of the social nature and ecological niche of a species on the design and complexity of their communication sounds. The knowledge of communication sounds and particularly of the flexibility in their use among mammals, however, remains patchy. Being highly vocal and social, bats are well suited for investigating vocal plasticity as well as vocal diversity. Thus, the overall aim of this study was to test the presence of structural overlap between calls used in social communication and echolocation pulses emitted during foraging in greater tube-nosed bats (Murina leucogaster). Acoustic analysis and spectrotemporal decomposition of calls revealed a rich communication repertoire comprising 12 simple syllables and 5 composites with harmonics in the ultrasonic range. Simultaneous recording of vocal and social behavior in the same species yielded a strong correspondence between distinct behaviors and specific call types in support of Morton's motivation-structure hypothesis. Spectrographic analysis of call types also revealed the presence of modified components of echolocation pulses embedded within social calls. Altogether, the data suggest that bats can parse complex sounds into structurally simpler components that are recombined within behaviorally meaningful and multifunctional contexts.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号