长光照诱导红腹锦鸡当年雌鸡冬季繁殖效果的实验研究

红腹锦鸡 (Ｃｈｒｙｓｏｌｏｐｈｕｓｐｉｃｔｕｓ)属鸡形目 ,锦鸡属 ,俗称锦鸡、金鸡 ,分布于我国北起宁夏固源 ,南到广西贺县 ,西至四川宝兴 ,东到湖北宜昌 ,即 :东经 10 2°40′～111°2 0′,北纬 2 4°39′～ 36°0 0′范围内 (余志刚等 ,1997)。红腹锦鸡为我国特产珍禽 ,国家Ⅱ级保护动物 ,因其羽色绚丽多姿、雍容华贵而著称于世 ,具有重要的经济价值 ,也是具有开发前景的特禽养殖新品种。已有的记述表明 ,红腹锦鸡雏鸡在第 2年 4～ 5月开始产卵 ,但是对此期间红腹锦鸡 1龄雌鸡的解剖观察发现 ,其卵巢尚未充分发育(吴至康 ,1991) ,还不…     

湖南莽山自然保护区的水生维管束植物——多样性及其生境特征

莽山自然保护区位于湖南省宜章县境内 (2 4°52′0 0″～ 2 5°0 3′12″N,112°4 3′19″～ 113°0 0′10″E) ,属南岭支脉。作者对该地区水生维管束植物及其生境进行了考察 ,采集到水生沼生维管束植物30科 4 7属 6 7种 ,其中 30种为莽山地区新记录。在比较沼泽和湖泊水生植物群落结构特点的基础上 ,讨论了沼泽作为水生植物重要生境的意义 ,建议对作为珍稀濒危水生植物重要产地的长江以南山地沼泽采取有效的保护措施     

梧桐科植物在中国的地理分布

对中国梧桐科植物的地理分布进行研究 ,指出中国梧桐科植物的分布区 ,东起台湾的北部 (1 2 2°1 0′E) ,西至西藏的墨脱 (95°3 0′E ,2 9°2 0′N) ,北起河北的东陵和小五台山 (约 40°2 0′N) ,南达西沙群岛的永兴岛(约 1 6°1 0′N)。其分布范围主要在热带、亚热带 ,只有少数种类可分布到温带。主要根据《中国种子植物属的分布区类型》的划分原则 ,把中国梧桐科植物野生各属划分为 1 0个类型。且对中国梧桐科植物一些属的分布格局进行探讨。     

内蒙古巴彦淖尔盟蒙古野驴的数量、分布和保护对策

20 0 0年 7月中旬至 8月上旬 ,大批蒙古野驴从蒙古共和国进入我国内蒙古自治区巴彦淖尔盟乌拉特中旗和乌拉特后旗境内。 2 0 0 0年 9月对该地区蒙古野驴的数量、分布和保护情况等进行了考察 ,发现蒙古野驴主要活动在巴彦淖尔盟乌拉特中旗和乌拉特后旗中蒙边境沿线的梭形狭长地带。蒙古野驴活动区东端最南点在乌拉特中旗敦德乌素嘎查 (42°1 7′N ,1 0 8°3 0′E) ,距边境 2 3km ,西端最南点在乌拉特后旗乌力吉图嘎查以西 (42°0 8′N ,1 0 6°3 6′E) ,距边境 1 2km。活动区中部的南限在北纬 42°0 1′,距正北方边境 44km ,活动区面积约 5 3 80km2 。根据样带法调查计算估计该分布区蒙古野驴总数约在 1 1 40 0头左右。目前蒙古野驴种群在该地区的分布尚未完全稳定。密集的人口 ,有限的食物资源和偷猎是影响蒙古野驴种群在该分布区稳定生存的主要因素     

广西(山王丌)岗石灰岩山森林类型的分类问题

<正> 广西(山王丌)岗自然保护区,是我国唯一的石灰岩山保护区,是以保护石灰岩山森林生态系统为主要目的的重点保护区之一。它位于广西南部龙州县和宁明县境内,地处北纬22°13′56″—22°33′19″、东经106°46′28″—107°4′19″之间,分成不连续的三片,总面积15万多亩。该地植被保存尚好,估计覆盖率可达80—90％,其中森林覆盖60—70％,是广西石灰岩地区有林面积最大的地方。而且森林类型复杂,把它的分类问题搞清了,对于广西南部石灰岩地区森林类型的分类作用很大。     

南岳自然保护区爬行动物资源调查

为了调查清楚南岳自然保护区的自然资源概况 ,我们受南岳区政府的委托 ,组织综合考察队于2 0 0 0年 6月至 2 0 0 2年 6月对南岳自然资源进行了考察 ,现将自然保护区的爬行动物资源调查情况报告如下。1　自然概况　　湖南省南岳衡山是一座孤山 ,地处北纬 2 7°2 0′1 0″～ 2 7°1 9′40″,东经 1 1 2°3 4′2 8″～ 1 1 2°45′3 6″,南岳自然保护区总面积为 1 1 991 .6 hm2 ,山体连绵起伏 ,系中同地貌 ,最底海拔 80 m,最高海拔 1 2 89.8m。山脉呈北北东至南南西走向 ,由东北向西倾斜 ,坡度一般为 3 0°～ 40°,南端边缘悬崖地带坡度最大可…     

海南省儒艮资源现状调查

为拟在海南省建立儒艮自然保护区提供科学依据,于2001 年11 月至2002 年10 月在海南省西部沿岸海域进行了为期一年的海洋环境综合调查和儒艮海上目视调查。此外还在海南省及广西壮族自治区、广东省进行了有关访问调查。调查结果表明,在广西沿岸合浦海域仍有儒艮存在。但在海南省西海域近岸未发现儒艮,且原有儒艮栖息地的海草均被破坏消失,认为目前建立海南儒艮自然保护区的条件尚不成熟。儒艮资源减少的主要原因是受人类活动加剧的影响,以及生态环境不断恶化,威胁着本种的生存。为此,亟待采取有效的管理措施和健全管理机制,加强对儒艮资源及其栖息地的保护。     

宁武县天池黑鹳种群数量及其保护

黑鹳 (Ｃｉｃｏｎｉａｎｉｇｒａ)属国家 1级重点保护动物 ,已被列为世界濒危物种保护对象 ,并列入在 1 998年出版的《中国濒危动物红皮书》(鸟类卷 )中。为了保护黑鹳资源 ,我们于 1 996～ 1 998年的 3～ 1 0月 ,在山西省宁武县天池曾对黑鹳的种群数量及其保护进行了调查研究 ,现报道如下。1　工作区概况工作区位于山西省宁武县东庄乡境内的天池 ,地处东经 1 1 2°1 2′～ 1 1 2°1 4′、北纬 38°51′～ 38°53′,海拔1 80 0ｍ ,是山西省著名的高山淡水湖泊。它由马营海、琵琶海、鸭子海等组成。其中马营海面积最大为80余ｈｍ2 ,水最深处…     

江西井冈山蕨类植物研究

井冈山地处中国南岭山地湘赣边境的罗霄山脉中段 ,北纬 2 6°2 2′～ 2 6°48′,东经 1 1 4°0 5′～ 1 1 4°2 3′。在植被分区上被认为是“中国亚热带常绿阔叶林区 ,东部 (湿润 )常绿阔叶亚地域的中亚热带南部亚地带”。该地植物种类繁多 ,区系成分复杂 ,保存着比较完整而古老的第三纪型的植物和森林生态系统 ,是许多古老植物种属的著名“避难所”〔1〕。笔者在多年野外调查和查阅标本及资料的基础上 ,系统分析了井冈山蕨类植物区系和生态分布特征。旨在为蕨类植物的研究、保护和开发利用提供理论依据。1 　井冈山的蕨类植物区系地理成分…     

太行山猕猴的肥满度

太行山猕猴自然保护区位于河南省西北部 ,已于 1 998年升格为国家级自然保护区。地理坐标为北纬 3 4°5 4′～ 3 5°2 0′,东经 1 1 0°0 2′～ 1 1 4°1 0′。保护区内生活有国家二级保护动物太行山猕猴约 1 5 0 0余只 ,现已成为我国乃至世界野生猕猴分布的最北限[1 ] 。该种群属华北亚种 (Ｍａｃａｃａｍｕｌａｔｔａｔｃｈｅｌｉｅｎｓｉｓ) ,为我国特产动物 ,不仅在生理、生态、行为、形态等方面与南方种群有明显差异 ,且具有独特的、其它地区猕猴无法替代的遗传多样性[2 ] 。近年来 ,由于环境恶化及诸多人为因素的影响 ,致使该区域猕猴…     

海南文昌椰林湾发现儒艮的尸体及死亡原因分析

<正>儒艮(Dugong dugon)隶属海牛目(Sirenia)儒艮科(Dugongidae)。广泛分布于印度洋、西太平洋热带及亚热带的大陆沿岸水域和岛屿间(周开亚等,2001),我国分布于广西、海南、广东和台湾省南部的沿岸海域,海南记录于东方北黎湾、儋州白马井洋浦港、澄迈东水港等地(王丕烈和孙建运,1986;周开亚等,2003;王丕烈等,2007)。     

Minimizing errors in the analysis of dive recordings from shallow-diving animals

Knowledge of the diving behaviour of aquatic animals expanded considerably with the invention of time-depth recorders (TDRs) in the 1960s. The large volume of data acquired from TDRs can be analyzed using dive analysis software, however, the application of the software has received relatively little attention. We present an empirical procedure to select optimum values that are critical to obtaining reliable results: the zero-offset correction (ZOC) and the dive threshold. We used dive data from shallow-diving coastal dugongs (Dugong dugon) and visual observations from an independent study to develop and test a procedure that minimizes errors in characterizing dives. We initially corrected the surface level using custom software. We then determined the optimum values for each parameter by classifying dives identified by an open-source dive analysis software into Plausible and Implausible dives based on the duration of dives. The Plausible dives were further classified as Unrecognized dives if they were not identified by the software but were of realistic dive duration. The comparison of these dive types indicated that a ZOC of 1 m and a dive threshold of 0.75 m were the optimum values for our dugong data as they gave the largest number of Plausible dives and smaller numbers of other dive types. Frequency distributions of dive durations from TDRs and independent visual observations supported the selection. Our procedure could be applied to other shallow-diving animals such as coastal dolphins and turtles.     

Reconstructing historical baselines for the Persian/Arabian Gulf Dugong,Dugong dugon (Mammalia: Sirena)

Retrospective estimates of historic abundances and distributions of marine organisms are crucial to understanding the anthropogenic impacts on the structure and species of coastal ecosystems, especially in the case of vulnerable species such as the Dugong (Dugong dugon). The Persian/Arabian Gulf is home to the second largest Dugong population in the world, yet little is known about their current or past abundance, distribution, and ecological role. Here, we examine historical changes in dugong distribution and estimate perceived changes in their abundance. We create a ‘dugong discovery curve’ and compile global density estimates as proxies for the overall health of the population in the Gulf. We find that since 1950 dugong range may have contracted by one quarter, and despite their large population, their overall densities in the Gulf are far lower than in other areas within their range. Basic understanding of historical trajectories for Dugongs is needed in order to develop appropriate management plans and conservation targets, particularly in light of large and wide-spread coastal development projects in the region.     

Diving behaviour of dugongs, Dugong dugon

The diving behaviour of 15 dugongs (Dugong dugon) was documented using time-depth recorders (TDRs), which logged a total of 39,507 dives. The TDRs were deployed on dugongs caught at three study sites in northern Australia: Shark Bay, the Gulf of Carpentaria and Shoalwater Bay. The average time for which the dive data were collected per dugong was 10.4±1.1 (S.E.) days. Overall, these dugongs spent 47% of their daily activities within 1.5 m of the sea surface and 72% less than 3 m from the sea surface. Their mean maximum dive depth was 4.8±0.4 m (S.E.), mean dive duration was 2.7±0.17 min and the number of dives per hour averaged 11.8±1.2. The maximum dive depth recorded was 20.5 m; the maximum dive time in water >1.5 m deep was 12.3 min. The effects of dugong sex, location (study site), time of day and tidal cycle on diving rates (dives per hour), mean maximum dive depths, durations of dives, and time spent ≤1.5 m from the surface were investigated using weighted split-plot analysis of variance. The dugongs exhibited substantial interindividual variation in all dive parameters. The interaction between location and time of day was significant for diving rates, mean maximum dive depths and time spent within 1.5 m of the surface. In all these cases, there was substantial variation among individuals within locations among times of day. Thus, it was the variation among individuals that dominated all other effects. Dives were categorised into five types based on the shape of the time-depth profile. Of these, 67% of dives were interpreted as feeding dives (square and U-shaped), 8% as exploratory dives (V-shaped), 22% as travelling dives (shallow-erratic) and 3% as shallow resting dives. There was systematic variation in the distribution of dive types among the factors examined. Most of this variation was among individuals, but this differed across both time of day and tidal state. Not surprisingly, there was a positive relationship between dive duration and depth and a negative relationship between the number of dives per hour and the time spent within 1.5 m of the surface after a dive.     

儒艮在中国近海的分布

儒艮Dugong dugon(Muller,1776)隶属海牛目Sirenia,儒艮科Dugongidae,俗称海牛,又称人鱼,海南岛渔民称海马。以往中国沿海产儒艮的研究甚少,只Hirasaka(1932)和寿振黄(1958)有过头骨及骨骼的描述报道,对其生态及分布方面的调查研究还没有深入的开展。1962年、1981年和1984年我们对儒艮在中国沿岸的分布进行了调查访问,并对近年所得儒艮的外形作了一些测量。现将所得资料整理报道。     

Echeneid–sirenian associations, with information on sharksucker diet

Association of the sharksucker Echeneis naucrates and whitefin sharksucker E. neucratoides with the West Indian manatee Trichechus manatus and the dugong Dugong dugon is presented and discussed. Alimentary tract-content analysis and field observations suggest that coprophagy (feeding on host faecal material) may be the primary food source for echeneids associated with sirenian hosts.     

Effects of age,body size and season on food consumption and digestion of captive dugongs (Dugong dugon)

Food consumption and digestion of male and female dugongs (Dugong dugon) was examined by analyzing long-term (1979–1998) feeding records at Toba Aquarium (Japan). Throughout all captive feeding periods, dugongs consumed eelgrass (Zostera marina) and showed steady increases in feed consumption with a consistent weight gain of 42–45?kg a year. The daily consumption of male and female dugongs increased from 10–15?kg to 23–26?kg of fresh eelgrass, accounting for approximately 14 and 7% of their body weight at one and seven years old, respectively. Both dugongs had a marginal dry matter digestibility of over 90%. Food consumption varied between seasons and individuals. There were major reductions (P<0.05) in consumption by the male in November and January and by the female in August and September. The seasonal reductions in food consumption coincided with high digestibility of eelgrass.     

Dugong habitat use in relation to seagrass nutrients,tides, and diel cycles

The dugong is the only herbivorous mammal that is strictly marine and a seagrass community specialist. The pasture available to the dugong varies with the tides because seagrass occurs in both intertidal and subtidal areas. We GPS-tracked seven dugongs within a 24 km², intensively used seagrass habitat in subtropical Australia in winter. We modeled resource selection within the habitat by comparing the dugongs’ use of space with the distribution of seagrass in an area defined using the combined space-use of the tracked animals. Selection by dugongs for seagrass quantity (biomass) and quality (nutrients) was analyzed within six time/tide combinations to examine the influences of tidal periodicity and the diel cycle on resource selection. Dugong habitat use was consistently centered over seagrass patches with high nitrogen concentrations, except during the day at low tides when the animals had fewer habitat choices and their space use was centered over high seagrass biomass. The association of dugongs with seagrass high in starch was positive during both day and night high tides when the animals could access the intertidal areas where seagrass biomass was generally low. Associations between dugongs and seagrass species were less definite, reflecting the potential for dugongs to exploit several species. Our model of dugong resource selection suggests that nitrogen is the primary limiting nutrient for dugong populations and also confirms the preference of dugongs for high-energy foods.