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.
W. R. Siegfried 《Ostrich》2013,84(1-3):101-103
Siegfried, W. R. 1985. Relative abundance of cranes (Gruidae) in the Cape Province. Ostrich 56:101-103.

The results of monthly roadside counts of Crowned Cranes Balearica regulorum, Wattled Cranes Grus carunculatas and Blue Cranes Anthropoides paradisea show that Blue and Crowned cranes occurred most abundantly and densely in the eastern part of the Cape Province in 1965–1966. The Blue Crane's average relative abundance was approximately four times that of the Crowned Crane whose population occupied tend to breed in summer, the Blue Crane slightly earlier than the Crowned Crane. The population of the Wattled Crane was a small relict, occurrin in East Griqualand. Based on a rough estimate, there were about 1000–1500 Crowned Cranes and about 7000–10000 Blue Cranes in the Cape Province in the mid-1960s.  相似文献   

2.
Beilfuss, R.D., Meine, C.D., & Archibald, F.W. 2000. The World Crane Action Plan: implications for conservation of cranes and wetlands in Africa. Ostrich 71 (1 & 2): 227.

The IUCN Species Survival Commission recently published The Cranes: Status Survey and Conservation Action Plan. Prepared over the past three years by the IUCN Crane Specialist Group, the document reviews the status of the world's cranes (Family: Gruidae) and their habitats, summarises recent crane conservation actions, and specifies priority measures for the future. Eleven of the 15 crane species are now proposed for inclusion on the IUCN Red List of Threatened Animals, and several subspecies and populations are critically endangered. Africa supports six species of cranes in 39 countries. The Black Crowned Crane Balearica pavonina, national bird of Nigeria, is resident in western and central Africa. The Grey Crowned Crane B. regulorum, national bird of Uganda, spans eastern and southern Africa. The Wattled Crane Bugeranus carunculahrs, largest and. rarest of Africa's cranes, ranges from Ethiopia to South Africa. The Blue Crane Anthropoides paradiseus, national bird of South Africa, is endemic to South Africa and Namibia. The Demoiselle Crane A. Virgo and Eurasian Crane Grus grus are winter visitors. Cranes have been the focus of intensive captive propagation and reintroduction programs as well as extensive habitat protection efforts. They are also excellent umbrella species for ecosystem-level conservation efforts. Wetlands that provide a home for cranes include the floodplains of the great river systems of Africa, such as Kafue Flats and Zambezi Delta of the Zambezi River system, the Okavango River Delta, the Sudd of the Upper Nile River, the Bangweulu Basin and swamps of the Zaire River system, the Senegal River Delta, and the Inner Niger River Delta, and the wetlands of Lake Chad. Small, isolated wetlands provide vital breeding habitat. This presentation will provide an overview of the action plan for those interested in cranes in particular, as well as those working in ecosystems and regions where cranes occur.  相似文献   

3.
The iconic Grey Crowned Crane Balearica regulorum is facing an increase in threats to its wetland habitat and poaching for the captive trade market. This has resulted in an enduring long-term decline in population numbers, which led to the species being listed as Endangered in the IUCN Red List. In Rwanda, Grey Crowned Cranes are threatened by human factors often driven by conditions of poverty, livelihood disadvantage and lack of conservation awareness. Previous population estimates suggested there were fewer than 500 Grey Crowned Cranes left in Rwanda. The Rwanda Wildlife Conservation Association and its partners have been working to eliminate the illegal trade and boost the population numbers in Rwanda. In August 2017, the first national census of Grey Crowned Cranes in Rwanda was carried out to serve as a baseline and to increase the accuracy of previous estimations. The survey was conducted over three days using both aerial and ground survey techniques. The results show that at least 487 Grey Crowned Cranes occur in Rwanda and include details on distribution and habitat type. Challenges for Grey Crowned Crane conservation at different sites are discussed, such as wetland transformation for agriculture, and illegal activities in protected marshlands. To ensure the long-term viability of this species, there is a need for upscaling of conservation efforts in key crane areas, continued monitoring of the crane population including trans-boundary collaboration, and strategies to promote the sustainable use of wetlands.  相似文献   

4.
《Ostrich》2013,84(3-4):186-194
There The Wattled Crane Bugeranus carunculatus is one of the top five most threatened bird species in South Africa, with the main threat being the loss of undisturbed breeding habitat. A basic understanding of this species' use of its environment is needed to implement conservation action. This quantitative study focused on determining the home range size of active breeding pairs in the KwaZulu-Natal midlands of South Africa, and assessing the land use composition of these home ranges. Wattled Cranes were found to have an average home range size of 16.64km2, consisting mostly of open natural grassland (mean of 75.5% of the overall home range of pairs). Other significant land use contributions to the home ranges were temporary irrigated and dryland cultivated agriculture. The core breeding area (wetland) of the home range constituted only 2.3% of the overall home range size, consisting of similar proportions of both wetland (48.9%) and grassland (51.8%) habitat. This indicates the dependence of Wattled Cranes on specific wetland habitats, surrounded by natural grassland. Wattled Cranes show home range sizes larger than other similar-sized crane species, suggesting that this may be as a result of their large body size and their occupation of highly transformed and fragmented habitats in an agricultural landscape. However, the occurrence of transformed land use types in home ranges suggests that breeding pairs tolerate some degree of disturbance within their home ranges. The home ranges do not appear to be currently restricted by surrounding land use types, indicating that factors other than habitat loss may be contributing to breeding site losses. The study has therefore indicated the need for closer working relationships between conservationists and agricultural communities to promote the conservation of valuable natural grasslands surrounding wetlands.  相似文献   

5.
The Overberg wheatbelt population of Blue Cranes Anthropoides paradiseus in the Western Cape of South Africa is approximately half the global population of this vulnerable species. Blue Cranes are highly susceptible to collisions with overhead power lines, and a spatial model was developed to identify high‐risk lines in the Overberg for proactive mitigation. To ground‐truth this model, we surveyed 199 km of power lines. Although Blue Cranes were the most commonly killed birds found (54% of all carcasses), the model was unable to predict lines with high collision risk for Blue Cranes. Further Geographic Information System (GIS) modelling was undertaken to test a wider range of landscape and power‐line variables, but only the presence or absence of cultivated land could usefully identify lines posing a collision risk. Modelling was limited by a lack of detailed spatial habitat data and recent information on Crane numbers and distributions. We used recent carcass counts to estimate a Blue Crane collision rate, corrected for sample biases, of 0.31/km power line per year (95% CI 0.13–0.59/km/year), which means that approximately 12% (5–23%) of the total Blue Crane population within the Overberg study area is killed annually in power‐line collisions. This represents a possibly unsustainable source of mortality. There is urgent need for further research into risk factors and for mitigation measures to be more widely implemented.  相似文献   

6.
I report an instance of usurpation of a Crowned Lapwing Vanellus coronatus nest by a pair of African Wattled Lapwings Vanellus senegalensis. The nest, which originally contained a single Crowned Lapwing egg, eventually contained an additional three Wattled Lapwing eggs, before it was predated. Although parents of both species were observed in the vicinity of the nest, video monitoring showed that the Wattled Lapwings incubated all four eggs. Detection of embryonic heart rate suggested that all the eggs were probably viable up until the nest was destroyed. Nest usurpation in shorebirds is rare, and given the easily accommodated nest requirements and minimal costs of nest construction in these species, is difficult to explain. I speculate that the occurrence described here may represent a case of mistaken identity by the female Wattled Lapwing when choosing a nest scrape, since there seems to have been little benefit to the usurping species of taking over an already occupied nest.  相似文献   

7.
The spring mound deposit Florisbad (Free State, South Africa) yielded several bird remains dating to the late Middle Pleistocene. These specimens derive from spring vent structures and are the product of natural taphonomic processes relating to the spring as primary sampling agent. The bird fossils can be assigned to Ostrich, Struthio camelus; Greater Flamingo, Phoenicopterus ruber roseus; Wattled Crane, Bugeranus carunculatus; an anatine dabbling duck; and a francolin with strong resemblance to Shelley’s Francolin, Scleroptila shelleyi. As in the case of the large mammal record, the bird remains from the Florisbad spring reflect two components in the palaeoenvironment. Evidence for Greater Flamingo, Wattled Crane, and a dabbling duck strongly supports previous hypotheses regarding the presence of a palaeolake system, while records for Ostrich and a francolin, but also Wattled Crane accord with the presence of open landscapes, such as grasslands.  相似文献   

8.
W. R. Siegfried 《Ostrich》2013,84(1-2):136-137
Davenport, L.B.Jr. &; Urban, E.K. 2000. Time budgets for Captive Wattled Cranes Bugeranus carunculatus. Ostrich 71 (1 &; 2):136-138.

Time budgets for six pairs of captive Wattled Cranes were recorded in the years 1989–1991 at St. Catherine's Island, Georgia, U.S.A., using instantaneous sampling at 30 s intervals. Data were obtained to cover one complete day, from earliest light to obscuring dusk, for each month of the year. When not nesting, these cranes spent slightly more than half of their time standing, preening, and/or walking, and most of the rest of their time eating, searching, or sleeping. When nesting, both sexes engaged equally in nest building, egg turning, and arranging nest material with the female devoting 45% of her time to incubating, the male about 40%. Males spent about 13% and females 8% of their time during the nesting period confronting neighboring cranes or other large species such as Great Blue Herons. It is concluded that instantaneous sampling at 30 s intervals with one person watching and another recording one or two individual cranes is a reasonably satisfactory method for recording time budgets in captive and probably wild populations of Wattled Cranes.  相似文献   

9.
C. BUDDE 《Bioacoustics.》2013,22(2-3):161-173
ABSTRACT

The study describes the vocal repertoire of the Grey Crowned Crane Balearica regulorum gibbericeps and speculates on the purpose the calls serve. The repertoire consists of 4 tonal and 7 non-harmonic calls. Chicks have 3 different vocalizations.  相似文献   

10.
11.
The degree to which DNA similarity is related to kinship and population structure in natural populations was investigated for a small population of cooperatively-breeding Red-cockaded Woodpeckers (Picoides borealis) in the western Piedmont region of South Carolina. An independent pedigree was established from records of color-banded individuals. Results of DNA profiles were then examined relative to this pedigree. DNA similarity among unrelated woodpeckers averaged 0.55 ± 0.01 (SE). The mean number of DNA bands scored and similarity did not significantly differ between founders and the current population. Examination of parentage in 10 families indicated that multiple paternity did not occur when band by band comparisons or similarity values were compared among parents, helpers, and offspring. Thus, Red-cockaded Woodpeckers were monogamous in this population. DNA similarity among all individuals ranged from 0.32-0.78. Distribution of these similarity values by kinship resulted in some overlap with other kin values. Therefore, specific similarity values could not be assigned a kinship value without knowledge of the pedigree. However, least-squares linear regression indicated that similarity was significantly related to kinship (P < 0.05). These results indicate that use of DNA profiles may be important in quantifying population structure, however, they must be used in conjunction with a known pedigree before any assessment of kinship among individuals is made. Band by band comparisons remain a viable technique for examination of parentage when all putative parents have been sampled.  相似文献   

12.
William Olupot 《Ostrich》2016,87(3):263-270
The Grey Crowned Crane Balearica regulorum was uplisted to globally Endangered in 2012. There is urgent need to determine the threats they face at local levels for their conservation. I conducted formal point-count surveys around the wetlands of eastern Uganda and observed no cranes. Groups of cranes were encountered when following directions from local inhabitants. Results from a questionnaire survey suggested that cranes make use of most of the wetlands in the region, and that the birds occur in small flocks averaging 6–8 individuals. Wetland loss through farming was reported to be the main threat, but I also documented poisoning, roost disturbance, and the collection of eggs and chicks. Rigorous conservation and education programs are needed to ensure the long-term survival of cranes and storks in this region.  相似文献   

13.
笼养丹顶鹤成体与亚成体血液生理生化指标比较   总被引:2,自引:0,他引:2  
为了揭示丹顶鹤(Grus japonensis)不同年龄和性别个体之间血液生理生化指标的差异性,对沈阳动物园42只笼养丹顶鹤(成体24只,亚成体18只)的15项血液生化指标和13项血液生理指标进行了比较。所测得的血液生理生化指标在不同性别之间不存在显著差异(P0.05)。血清肌酐成体(37.05±17.03)mmol/L、亚成体(22.57±11.68)mmol/L,血清尿酸成体(878.22±514.41)mmol/L、亚成体(426.17±207.74)mmol/L,血清甘油三酯成体(7.73±4.75)mmol/L、亚成体(3.51±4.07)mmol/L,这3项指标均为成体高于亚成体,差异性显著(P0.05)。这几项指标的变化表明,丹顶鹤在成体和亚成体时期采取了相同或不同的生态适应策略。  相似文献   

14.
We performed breeding experiments with adders (Vipera berus) to determine whether multiple matings may result in multiple paternity. DNA fingerprinting of mothers, their offspring, and possible fathers using a polydinucleotide probe [(TG) n ] gave a low overall similarity between unrelated individuals (0.18±0.07; SD) and an average of 17 bands that were male-specific. In no cases were there fewer than seven paternal-specific bands present in the fingerprint of an offspring, enabling us unambiguously to identify the biological father among five males. Multiple paternity was detected in the investigated broods with offspring sired exclusively by the captive males. PCR amplification of random amplified polymorphic DNA (RAPD) using 16 decamer primers gave 76 bands and an average similarity of 0.95 (±0.01) between the males, which were collected at different, geographically well-separated localities. Although there were on average 8.3 (±1.9) bands that differ between males in pairwise comparisons, there were only 1.9 (±1.1) bands per male that are specific for a particular individual. Thus, RAPDs are adequate for paternity determination only in experiments with a low number of males, whereas DNA fingerprinting offers sufficient information to discriminate between large numbers of putative fathers.The Swedish Natural Science Research Council, the Nilsson-Ehle Foundation, and the Erik Philip-Sörensen Foundation supported our research.  相似文献   

15.
利用RAPD标记分析鸵鸟种群的遗传变异   总被引:5,自引:1,他引:5  
周霞  李宁  张劳  崔庆为 《遗传》2001,23(5):420-422
为探讨分子遗传标记在鸵鸟(Struthio camelus)育种中的应用,利用RAPD技术分析了我国养殖的三个主要要鸵鸟品种内和品种间的遗传变异。蓝颈鸵鸟、澳洲灰和非洲黑三个品种在品种内和品种间显示出低水平的变异。品种间的遗传距离好地说胆了三个品种的育种改良过程。同时预示出用澳洲灰与其他品种鸵鸟进行杂交育种的可行性。选择的20条在鸡中能稳定扩增的RAPD引物其75%能在鸵鸟基因组中扩增出产物。显示出两种禽类DNA具有同源性、为今后利用鸡的微卫星引物对鸵鸟进行基因扫描(genome scan)分析奠定基础。  相似文献   

16.
17.
In group‐living species with male dominance hierarchies where receptive periods of females do not overlap, high male reproductive skew would be predicted. However, the existence of female multiple mating and alternative male mating strategies can call into question single‐male monopolization of paternity in groups. Ring‐tailed lemurs (Lemur catta) are seasonally breeding primates that live in multi‐male, multi‐female groups. Although established groups show male dominance hierarchies, male dominance relationships can break down during mating periods. In addition, females are the dominant sex and mate with multiple males during estrus, including group residents, and extra‐group males—posing the question of whether there is high or low male paternity skew in groups. In this study, we analyzed paternity in a population of wild L. catta from the Bezà Mahafaly Special Reserve in southwestern Madagascar. Paternity was determined with 80–95% confidence for 39 offspring born to nine different groups. We calculated male reproductive skew indices for six groups, and our results showed a range of values corresponding to both high and low reproductive skew. Between 21% and 33% of offspring (3 of 14 or three of nine, counting paternity assignments at the 80% or 95% confidence levels, respectively) were sired by extra‐troop males. Males siring offspring within the same group during the same year appear to be unrelated. Our study provides evidence of varying male reproductive skew in different L. catta groups. A single male may monopolize paternity across one or more years, while in other groups, >1 male can sire offspring within the same group, even within a single year. Extra‐group mating is a viable strategy that can result in extra‐group paternity for L. catta males.  相似文献   

18.
7种鹤形目鸟类性别的分子鉴定   总被引:1,自引:0,他引:1  
生境破碎化和非法狩猎已经使很多鸟类陷入了濒危境地,笼养繁殖进行迁地保护及再引入的保护措施已经具有举足轻重的作用,鸟类性别鉴定对于有效的繁殖至关重要。然而对珍稀濒危鸟类进行安全、方便和准确的性别鉴定一直是个难题。本文运用CHD基因的一对引物2550F/2718R,对7种鹤形目鸟类:大鸨(Otis tarda)、丹顶鹤(Grus japonensis)、蓑羽鹤(Anthropoides virgo)、灰鹤(G.grus)、白鹤(G.leucogeranus)、白头鹤(G.monacha)和灰冠鹤(Balearica regulorum)共48只鸟,进行了有效的性别鉴定。研究结果不但对7种鹤形目鸟类的笼养繁殖和个体交换起到了指导作用,而且为今后的再引入提供了有利条件。本研究的性别分子鉴定方法适用于7种鹤形目鸟类,具有安全、方便、准确等特点,并且可以推广使用。  相似文献   

19.
Monogamy is a rare strategy among mammals but relatively common among primates. The study of the evolution of monogamy in mammals and primates is lacking empirical studies that assess the relationship between a pair‐living social organization and genetic monogamy. Sexual or genetic monogamy can only be assessed by performing molecular analyses and investigating rates of extra‐pair paternity (EPP). Studying the occurrence of EPP can provide valuable insights into reproductive strategies and their adaptive value. The indri is a pair‐living primate that lives in stable groups. Their social units are composed of the reproductive pair and up to four more individuals, but extra‐pair copulation (EPC) can occur. This raises the question of whether this event may or may not lead to EPP. Here, we investigated whether a pair‐living social organization corresponds to genetic monogamy in indris (Indri indri). We analyzed the paternity of 12 offspring from seven pairs using a set of six microsatellite loci on fecal samples (mean number of alleles 11.7 ± 1.8 (mean ± standard deviation). We found that in 92% of cases the genetic profile of the offspring matched the paired male of the group for all the loci considered. In the only case of paternity mismatch, the paternity assignment remained inconclusive. Our results show that I. indri genetic monogamy is the norm and supports the hypothesis that pair‐living social organization is associated with low EPP rate. Also, our results are in contrast with the hypothesis of infertility as a reason to engage in EPC for this species.  相似文献   

20.
Once nearly extirpated, the Eastern Population (EP) of Greater Sandhill Cranes (Grus canadensis tabida) has increased in number and expanded its range in breeding and wintering areas. Data from Christmas Bird Counts (CBCs) and Breeding Bird Surveys (BBSs) were used to delineate changes in the wintering and breeding area distributions during the period from 1966 to 2013. Crane densities were plotted to the centroid of CBC circles or BBS routes, and the Geographic Mean Centers (GMCs) for wintering and breeding populations were calculated. The number of Greater Sandhill Cranes detected during the breeding season has steadily increased since 1966, with just six birds observed in 1966 and 1046 observed in 2013. The GMC of the Sandhill Crane breeding population has remained in Wisconsin during the 47‐yr time frame. The total number of Sandhill Cranes counted in the eastern United States during CBCs grew from 423 in 1965–1966 to 46,194 in 2012–2013, with a peak number of 55,826 in 2011–2012. The GMC of wintering Greater Sandhill Cranes was located in Florida during the periods from 1966 to 1977 and 1978 to 1989, but shifted north‐northwest by nearly 4° of latitude (into Georgia) by 1990–2001. By 2002–2013, the GMC had shifted an additional degree north as well as almost a degree west in longitude. Greater Sandhill Cranes in the EP may continue to winter further north and remain in more northerly areas later in the fall before migrating further south. Factors such as annual weather, long‐term climate change, and changes in land use may influence future population trends and changes in both the breeding and wintering ranges of the EP of Sandhill Cranes.  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