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1.
Knowledge of the distribution and ecology of East African nightjars is, to a large extent, unknown. We collected ecological information on the diversity and microhabitat use of nightjars in Nechisar National Park in January 2015 by executing field captures and observations. We also attempted to find a live specimen of the Nechisar Nightjar Caprimulgus solala. During the course of 18 nights we observed five nightjar species, captured 49 individuals and observed that nightjars were closely associated with protective landscape elements. In spite of the intensity of our survey, we were not able to find a living specimen of the Nechisar Nightjar, which could indicate the species is either migratory or extinct.  相似文献   

2.
于2005年10月至2006年4月调查了埃塞俄比亚森可勒斯韦恩麋羚保护区旱季和湿季斯韦恩麋羚(Alcelaphus buselaphus swaynei)的种群现状与结构.根据植被类型、道路和沟谷,将研究区划分为5个区域,并且调查了保护区外的一块休耕农地.利用全部计数法计数了每个区域内的斯韦恩麋羚,在28 km2的区域内共统计到283只(湿季)和351只(旱季)麋羚,湿季和旱季的麋羚数量变化显著,其季节间差异是由旱季的出生高峰造成的.斯韦恩麋羚种群中雌性个体占42.7%、雄性占36.0%、幼羚占21.3%.某些区域的麋羚数量要高于其它区域,且无论湿季或旱季斯韦恩麋羚多集中在狼尾草高草地中.斯韦恩麋羚的种群结构随季节而变化,其大集群经常出现在湿季而旱季集群较小.斯韦恩麋羚的种群动态因保护程度的不同在不同时期呈不规则性变化  相似文献   

3.
西藏墨脱格当乡野生虎捕食家畜现状与保护建议   总被引:8,自引:2,他引:6  
曾经在西藏东南的阔叶林中广泛分布的孟加拉虎,目前仅有一个小种群残留在墨脱县境内。2000年5-6月间,在大型家畜遭受野生虎捕食最严重的墨脱县格当乡展开调查,试图寻找减轻虎害的方法。结果表明:1994-1995年虎的捕食率达到最高,对牛和骡马的捕食率分别是17.9%和9.4%;但1996年后,捕食率分别降低到7.8%和1.8%,这可能与1996年当地曾捕杀过一头虎有关。1993-1999年间,全乡牛的数量下降了11%,但骡马数量上升了23%,这是因为当地为增加运输能力而从别处购得骡马。据反映,目前格当乡境内大约有4-5头虎。1997年和1999年,均见母虎和小虎同行,说明该种群尚有繁殖。在抽样的21户居民家中,1999年4月到2000年5月间,66.6%的人家有大型牲畜遭虎捕杀,共损失牛27头,马12匹,而自1993年以来,21户中共有18户(85.8%),有牲畜被杀记录,共计损失117头。其中对牛的捕食率达19.7%,对马达11.9%,平均每户损失牛1.2头,骡马0.5匹。非法狩猎减少了虎的猎物如野猪、羚牛等的数量,是老虎转向家畜的主要原因之一。虎害已对格当乡群众的经济造成较大负面影响。但格当乡以及周边地区保护着中国最后的野生孟加拉虎种群,为确保虎的长期生存同时减少人-虎冲突,建议改变目前放牧方式,尽可能联合放牧、增加看护;改善放牧地条件,清除牧场周围蕨草丛;减少对羚牛等有蹄类的猎杀,以减少对老虎猎物种群的破坏;对部分家畜移入棚内试行圈养,既保护家畜,又提高乳制品产量和增加农家肥料;实行多种经营方法,建议养一些山羊和家禽;政府应该帮助安置好部分愿意外迁的居民,这样既满足这些居民的需要,同时也减轻对当地野生动物种群的压力。  相似文献   

4.
Ecological survey was executed to assess woody species encroachment into the grassland plain of Nechisar National Park (NNP). Forty‐one woody species were recorded. Dichrostachys cinerea Wight & Arn., Acacia mellifera (Vahl) Benth., Acacia nilotica (L) Willd., Acacia senegal (L.) Willd., Acacia seyal Del. and Acacia tortilis (Forssk.) Hayne were among the major encroaching woody species. The majority of the woody species were found to be highly aggregated in their pattern of distribution, while only few species showed some degree of randomness. The mean woody species density was ca. 1995 woody plants ha?1. Mean cover of woody, grass, unpalatable forbs and total herbaceous species were 31%, 58%, 68% and 121%, respectively. The woody species density and cover, unpalatable forbs and bare land cover were significantly higher in the highly grazed and fire‐suppressed part of the grassland plain. Pearson correlation coefficient matrix indicated that woody species cover and density were negatively correlated with total herbaceous and grass cover. The high woody, unpalatable forbs and bare land cover indicated the progressively increasing perennial grass species diversity deterioration in the grass plain of the Park. Decline in the grassland condition, unless reversed, will jeopardize the biological diversity as well as the aesthetic value of the NNP.  相似文献   

5.
The amount and nutritive value of forage plants, diet composition, digestibility of dry matter and nutrients were recorded for zebra. Grant's gazelle, Swayne's hartebeest and hippopotamus in November-December 1991 Besides, daily egest of feces, the level of food and nutrient consumption, energy and protein requirements were recorded for zebra and Grant's gazelle The digestibility of pasture forage was determined as a ratio of lignin concentration in food to the concentration m feces (lignin tracer technique), a daily intake was calculated on the basis of the daily feces egest Protein percentage m the diet of zebra and hartebeest consuming dry parts of grasses did not exceed 5% Gazelle diet consists of green parts of plants and included 18% of protein The digestibility of dry matter in nonruminants (zebra, hippopotamus) was 40-45%, in hartebeest - 50%, in gazelle - 60% Due to the abundance of dry grasses (3 7 ton ha-1) the daily food consumption of zebra was high - 7 2 kg ind-1 (dry weight), the metabolizable energy intake (ME) being 51 MJ Adult gazelles consumed 15-25 kg ind-1 of food and 14-24 MJ of ME The energy requirements of adult males and non-lactating females of zebras and gazelles (48 and 13 MJ respectively) were met, the energy balance berig negative for lactating animals The daily protein requirement was not met in zebra (392-704 g md-1 vs 134 g ind-1 of intake) and in lactating gazelles (250 g ind-1 vs 197 g md-1) Non-lactating gazelles consume sufficient amount of both energy and protein due to the high feeding selectivity of the species and thanks to the abundance of burnt areas with young green after-grass m the dry period  相似文献   

6.
普氏原羚(Procapra przewalskii)是青藏高原特有物种, 为了掌握该物种的分布和种群状况, 我们于2014-2015年采用全面调查和直接计数的方法, 对普氏原羚的分布、种群和保护现状进行了调查。结果如下: 普氏原羚分布在青海湖周边12个隔离的分布点, 与全国第一次野生动物资源调查的结果相比, 有多个新的分布点被发现, 分布范围和面积扩大; 调查共发现1,238只普氏原羚, 与2010年以后的调查结果相比, 种群数量维持在一个稳定的水平。然而, 仅有4个分布点位于青海湖国家级自然保护区范围内。尽管刚察县成立了青海湖普氏原羚特护区, 天峻县成立了普氏原羚自然保护站, 但现有的管护力度仍然不够, 且缺乏系统的管理规划。我们建议在天峻县布哈河上游的生格-快尔玛地区成立普氏原羚自然保护区; 同时建立适当的生态补偿机制, 协调保护与社区发展的矛盾; 鉴于目前圈养种群发展迅速, 建议在历史分布区选取合适的地点进行人工繁育个体的迁地放归。  相似文献   

7.
The aim of this study was to investigate population structure and group size of geladas (Theropithecus gelada) at Chenek, Simien Mountains National Park. The study was carried out from January 2010 to June 2011 using total count method by classifying the study site into five different blocks. Size of the group was determined by counting individuals of geladas within an hour interval. A total of 397 geladas were counted and the ratio of adult males to adult females was 1 : 1.25, and this difference showed statistical significant (t = 8.157, P < 0.05). There was also significant difference between adult females with juveniles and infants (t = 21.027, P < 0.05). Population structure of geladas in a band comprised a single reproductive male and a number of females, subadults, juveniles and infants. Fission and fusion of individual geladas among different bands were observed during the study period. Geladas at the study site showed population growth and were seen competing for available food. They also stole food from local people and tourists and were seen to be interactive with people. Thus, the interference of people and livestock within the geladas natural habitat should be minimized to avoid human disturbance on the species and its natural habitat.  相似文献   

8.
Human demand for livestock products has increased rapidly during the past few decades largely due to dietary transition and population growth, with significant impact on climate and the environment. The contribution of ruminant livestock to greenhouse gas (GHG) emissions has been investigated extensively at various scales from regional to global, but the long‐term trend, regional variation and drivers of methane (CH4) emission remain unclear. In this study, we use Intergovernmental Panel on Climate Change (IPCC) Tier II guidelines to quantify the evolution of CH4 emissions from ruminant livestock during 1890–2014. We estimate that total CH4 emissions in 2014 was 97.1 million tonnes (MT) CH4 or 2.72 Gigatonnes (Gt) CO2‐eq (1 MT = 1012 g, 1 Gt = 1015 g) from ruminant livestock, which accounted for 47%–54% of all non‐CO2 GHG emissions from the agricultural sector. Our estimate shows that CH4 emissions from the ruminant livestock had increased by 332% (73.6 MT CH4 or 2.06 Gt CO2‐eq) since the 1890s. Our results further indicate that livestock sector in drylands had 36% higher emission intensity (CH4 emissions/km2) compared to that in nondrylands in 2014, due to the combined effect of higher rate of increase in livestock population and low feed quality. We also find that the contribution of developing regions (Africa, Asia and Latin America) to the total CH4 emissions had increased from 51.7% in the 1890s to 72.5% in the 2010s. These changes were driven by increases in livestock numbers (LU units) by up to 121% in developing regions, but decreases in livestock numbers and emission intensity (emission/km2) by up to 47% and 32%, respectively, in developed regions. Our results indicate that future increases in livestock production would likely contribute to higher CH4 emissions, unless effective strategies to mitigate GHG emissions in livestock system are implemented.  相似文献   

9.
The wildlife populations of Northern Central African Republic experienced precipitous declines during the 1970s and 1980s. While anecdotes coming out of the region indicate that the wildlife populations remain under serious threat, little is known about their status. An aerial sample count was carried out in the Northern Central African Republic at the end of the dry season in June 2005 and covered an 85,000 km2 complex landscape containing national parks, hunting reserves and community hunting areas. Results show a dramatic decline of wildlife since the previous survey in 1985. In 20 years, large mammals’ numbers decreased by 65%, probably because of poaching and diseases brought by illegal cattle transhumance. Elephant (Loxodonta africana) and Buffon kob (Kobus kob) populations showed the greatest decline (over 80% each), while buffalo (Syncerus caffer), roan antelope (Hippotragus equinus) and Giant Lord’s Derby Eland (Taurotragus derbianus) populations seem stable or increasing over these last 20 years. The analysis of the wildlife population distribution by status of the different types of protected areas (national parks, hunting areas) showed that individual encounter rates of elephant and buffalo were lower in national parks than in neighbouring hunting areas, while those for roan, giraffe (Giraffa camelopardalis) and Buffon kob were higher in the national parks.  相似文献   

10.
2006年6月—2007年5月年对位于巴基斯坦自由克什米尔省穆扎法拉巴德市帕蒂卡(Pattika)休闲公园(EW:73°34′,纬度:NS:34°27′)内的栖息鸟类进行了调查,共有73种,分属10目35科。其中雀型目占73.55%,非雀型目占45%。其分布的多寡随该地区的季节而变化。大量物种出现在迁移繁殖的雨季。该公园处于人口密集之郊外,其间家畜的放养、灌木的砍伐及生境的干扰等人为因素都会对鸟类的分布和数量造成影响。  相似文献   

11.
Species diversity and abundance of small mammals were studied in Nechisar National Park, Ethiopia, during August 2008 – March 2009. Twenty species of rodents and four species of insectivores were recorded from the study area. Mastomys natalensis (17.37%), Arvicanthis dembeensis (17.09%), Mastomys erythroleucus (8.90%), Stenocephalemys albipes (8.76%), Arvicanthis niloticus (8.19%), Acomys cahirinus (7.34%), Lemniscomys striatus (6.92%), Gerbilliscus nigricauda (6.21%), Grammomys dolichurus (3.67%), Gerbilliscus robusta (2.12%), Mus proconodon (1.98%), Mus mahomet (1.41), Dendromus melanotis (1.27%), Arvicanthis abyssinicus (1.13%), Mus musculus (0.99%), Praomys fumatus (0.85%), Xerus erythropus (0.85%), Lemniscomys barbarus (0.71%), Mus tenellus (0.71%) and Otomys typus (0.28%) were the rodents and their respective relative abundance in the study area. Crocidura olivieri (1.55%), Crocidura fumosa (0.85%), Crocidura bicolor (0.57%) and Elephantulus rufescens (0.28%) were the insectivores recorded with their respective relative abundance. Mastomys natalensis was the most abundant and O. typus and E. rufescens were the least (two each). Diversity of small mammals ranged from 2.299 to 2.625 with an average of 2.412. The highest small mammal diversity was in grasslands and the lowest was in Lake Chamo shore. Small mammal density varied from 5 to 43 ha?1 and biomass varied from 244 to 2559 g ha?1 with significant changes in relation to seasons and habitats.  相似文献   

12.
The study on the population status and structure of mountain nyala (Tragelaphus buxtoni) was carried out in the Bale Mountains National Park, Ethiopia during the wet and dry seasons of 2000/2001. Total counts were carried out in an area of 13.1 km2. The count ranged between 682 and 732 individuals. Females comprised 62.9% while males 27.4%. The calf ratio was 9.7%. The group structure of the animals varied with season. Large herds were frequently observed during the wet season and smaller groups during the dry season. Group size changed seasonally. In both seasons, 7–12 individuals were the frequent group size formation. The maximum group (62) was observed during the wet season. The population trend of the animal from 1975 to 1990 indicated a recovery and increase. But between 1990 and 1995 the population showed a continuous and steep decline. However, between 1995 and 2000 the population trend showed a better condition when compared with the previous years.  相似文献   

13.
Lion populations in West and Central Africa are small and fragmented. In areas where park management is weak, threats will likely facilitate the extinction of the lion. Wildlife management requires knowledge of the population estimate. The population of lions in Waza National Park (Waza NP) was assessed by individual identification of members in the population. The population was assessed to comprise of 14–21 adult individual lions. The age structure was skewed towards adults; cubs comprised 22% of all lions identified while the sex ratio was 1 : 3. Two out of four collared lions were lost to illegal, retaliatory killings within 1 year; and probably two more males and one more female were also killed during this period. The lion population appears to have declined during the last 5 years with six lions dying per year, which is at a much higher rate than observed in the previous decades. Human‐livestock pressure has increased tremendously in this period, resulting to frequent human‐lion conflicts. To ensure the survival of the lion in Waza NP and in the entire region, management needs to intensify efforts to mitigate the pressure from humans and their livestock.  相似文献   

14.
Trees, forests and woodlands cover about 14% of Uganda’s land surface. Over the last 30–40 years, growth in human population and corresponding increase in demand for forest products for domestic and industrial use, expansion of agricultural land, illegal settlements and weak forest management capacity have adversely affected the status of natural forests in Uganda, particularly the biodiversity. Until recently, little attention had been paid to development of commercial forests which should have provided alternative forest products and services to relieve the pressure on natural forests and conserve biodiversity. As a result, Uganda’s forests have been degraded, and in some cases, the biodiversity has been eroded. There is a need for regular data collection and monitoring of the status of the forests in terms of areal extent, distribution, plantation species introductions and biodiversity.  相似文献   

15.
Water, forage and predation constrain ungulate distributions in savannas. To understand these constraints, we characterized distributions of 15 herbivore species from water, locations of peak density and degree of clustering around the peaks using zero-inflated count data models and mapping census data collected in the Mara reserve and the adjoining pastoral ranches in Kenya during a wet and dry year. Herbivores followed a humped pattern (n = 46), suggesting constrained foraging in which they balance the benefits of proximity to water with the costs of foraging where food is depleted near water and travelling to more abundant food distant from water; an exponentially decreasing pattern (n = 11), indicating strong attraction to water or vegetation near water; or a uniform (n = 3) pattern. The details rather than the types of these patterns varied between years. Herbivores concentrated farther from water and more tightly around locations of their peak densities in the ranches than the reserve. Herbivores were more abundant and widely distributed from water in the wet than the dry year, and segregated along the distance-to-water gradient, presumably to minimize interspecific competition for food. Pastoralism compressed herbivore distributions and partially excluded some species (warthog, hartebeest, topi, wildebeest, zebra, eland, buffalo and elephant) from, while attracting others (Grant’s and Thomson’s gazelles, impala, giraffe) to the ranches, relative to the reserve. Regulating cultivation, fencing, settlements and livestock stocking levels in the ranches would allow continued wildlife access to water, reduce competition with, displacement or harassment of wildlife by people, livestock and dogs near water.  相似文献   

16.
The African wolf (Canis lupus lupaster) was first identified in 2011 in the Ethiopian highlands, with its status as a new species confirmed in 2015. We studied the diet of a confirmed African wolf population in the Menz‐Guassa Community Conservation Area of central Ethiopia from scat samples collected by den sites from August to November 2010. Rodents were found to be the principal food items occurring in 88.1% of scats (n = 101), followed by plant material (34.7%) and insects (21.8%). Information on reported livestock predation and ensuing conflict with the agro‐pastoral community was obtained through a questionnaire survey. Interview respondents listed the African wolf as the most serious predator of livestock, accounting for 74.6% of the reported kills (n = 492) and 78.9% of the economic loss. Over 70% of reported livestock predation occurred during the dry season (January–April). Better livestock management during this period may significantly reduce conflict. As sympatric Ethiopian wolves primarily feed on rodents, further studies on the foraging ecology, niche overlap and interspecific interactions between the two species should be studied to determine the extent of competition between the two species.  相似文献   

17.
Capsule The fourth national survey of Hen Harrier showed that the population in the UK and the Isle of Man declined significantly between 2004 and 2010.

Aim To estimate the size of the breeding Hen Harrier population (with associated 95% confidence intervals) in the UK and Isle of Man, constituent countries and Scottish regions, in 2010 and calculate population change since previous surveys in 1998 and 2004.

Methods Complete surveys were made of 10-km squares likely to be occupied by breeding Hen Harriers in England, Wales, Northern Ireland and the Isle of Man, using standard methods developed for previous national surveys. In Scotland, a ‘census’ area was non-randomly selected for survey by volunteers, and randomly selected squares were surveyed in two strata covering the rest of the known range.

Results The UK and Isle of Man Hen Harrier population was estimated at 662 territorial pairs (95% confidence interval (CI): 576–770), a significant decline of 18% since 2004. Scotland holds the bulk (76%) of the population (505 territorial pairs; 95% CI: 417–612), with smaller numbers in Northern Ireland (59 pairs), Wales (57 pairs), the Isle of Man (29 pairs) and England (12 pairs). Declines of 49% and 20% were observed in the Isle of Man and in Scotland, respectively, whereas the Welsh population increased by 33%. A significant decrease was recorded in numbers of pairs using young and mature plantation forest in Scotland.

Conclusion The breeding population of Hen Harriers in the UK and Isle of Man declined between 2004 and 2010. Notable decreases in Scotland and the Isle of Man may be related to habitat change and illegal persecution. Illegal persecution continues to limit the population size of harriers in England to very low levels.  相似文献   

18.
Remedial sport hunting of predators is often used to reduce predator populations and associated complaints and livestock depredations. We assessed the effects of remedial sport hunting on reducing cougar complaints and livestock depredations in Washington from 2005 to 2010 (6 years). The number of complaints, livestock depredations, cougars harvested, estimated cougar populations, human population and livestock populations were calculated for all 39 counties and 136 GMUs (game management units) in Washington. The data was then analyzed using a negative binomial generalized linear model to test for the expected negative relationship between the number of complaints and depredations in the current year with the number of cougars harvested the previous year. As expected, we found that complaints and depredations were positively associated with human population, livestock population, and cougar population. However, contrary to expectations we found that complaints and depredations were most strongly associated with cougars harvested the previous year. The odds of increased complaints and livestock depredations increased dramatically (36 to 240%) with increased cougar harvest. We suggest that increased young male immigration, social disruption of cougar populations, and associated changes in space use by cougars - caused by increased hunting resulted in the increased complaints and livestock depredations. Widespread indiscriminate hunting does not appear to be an effective preventative and remedial method for reducing predator complaints and livestock depredations.  相似文献   

19.
Large population declines were reported for the thick-billed murre (Uria lomvia) in Greenland for the period 1930s–1980s, but no national status has been published for the past 20 years. Meanwhile, the murres have gained more protection and several human-induced mortality factors have been markedly reduced. Here, we give an updated status based on the past 30 years of murre count data. The total Greenland population in 2011 was estimated to 468,300 birds (95 % CI 430,700–505,900) or around 342,000 breeding pairs, distributed within 19 colonies. This represents an overall reduction of 13 % since the mid-/late 1980s. In the same period, five colonies went extinct. Large and apparently stable colonies in Qaanaaq (Northwest Greenland) account for more than half the population (68 %), but most other colonies declined heavily, with up to 6 % p.a. in the most critical areas. So far, nothing indicates that food is a limiting factor in Greenland during the breeding season, although rather few colonies have been studied in details. In contrast, illegal hunting and disturbances during the breeding season are still a problem in Greenland, despite more restrictive hunting regulations, and may explain much of the continued population decline. In addition, recent studies from Svalbard indicate that a large-scale deterioration of the marine environment in the North Atlantic, due to oceanographic changes, may impact recruitment to some of the Greenland colonies. Murre colonies in southern Upernavik, Disko Bay, South Greenland and East Greenland are in urgent need of additional conservation initiatives to avoid further declines and local extinctions.  相似文献   

20.
In the Web Valley of the Bale Mountains National Park, the pastoral people suffer from livestock predation by wild carnivores. A total of 704 livestock were reported to be killed by wild carnivores over a 3‐year period, causing a loss of potential revenue of 12 USD per year per household. Reported annual predation rates equated to 1.4% of the livestock population of the study area. Spotted hyaenas were responsible for most livestock predation (57%), followed by leopards (18%), common jackals (16%) and servals (9%). Hyaenas killed all livestock types (horses, donkeys, mules, cattle, goats and sheep) whilst leopards, common jackals and servals killed mostly goats and sheep. A survey of 362 households revealed that the pastoral people keep dogs to protect livestock from carnivores. During 250 nights of observation in the ten settlements, pastoralists were alerted to the presence of hyaenas on 80 occasions by the barking of their dogs. Such tradition of keeping dogs presents a threat to the persistence of the endangered Ethiopian wolf through diseases transmission. Given the frequency of carnivore attacks on livestock, it is desirable to develop alternative livestock protection methods that both minimize livestock losses and reduce the risk of disease transmission to Ethiopian wolves.  相似文献   

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