HOW SEDENTARY ARE GREYWING FRANCOLINS (FRANCOLINUS AFRICANUS)?

Phasianids are considered to be sedentary birds with limited dispersal so that populations may be expected to show genetic isolation by distance. To test this, we examined genetic variability in 618 greywing francolins (Francolinus africanus) at 24 localities over a 1,500 km² area. We subdivided the samples to measure genetic population structure among localities separated by 6–60 km, and among coveys separated by 0.1–6 km. Thirteen of 30 (43%) allozyme loci were polymorphic, and heterozygosity ranged from 5.3 to 8.5% over 24 localities and averaged 7.0%, a value much larger than that found for other phasianids. Significant allele-frequency heterogeneity was detected among localities and among coveys at several localities for several loci. Mantel's test, however, showed that there was no correlation between geographical distance and the allele-frequency difference between localities for all but one allele. Although spatial autocorrelation was detected with Moran's I and Geary's c for two alleles, the geographical patterns of I in correlograms of 18 independent alleles showed a “crazy-quilt” pattern of allele-frequency patches. This shows that the isolation-by-distance model of subpopulation structure is inappropriate for these birds. Individuals, therefore, appear to disperse far beyond neighboring populations. “Private-allele” and F_ST estimates of migration under the island model were 8–9 individuals between localities of each generation. Allele-frequency heterogeneity, large amounts of gene flow, and the general lack of spatial autocorrelation imply that the small, socially-structured populations of greywing are subject to high rates of turnover, founder effects, and random drift.     

运动昆虫密度和疾病传染数量估计的两类模型

根据推导,得到用于运动昆虫密度和疾病接触传染数量估计的二维和三维空间模型．两类模型分别适用于爬行昆虫和飞行昆虫的种群密度估计．二维空间模型可用于描述昆虫疾病的接触传染数量,针对不同的用途,将两类基本模型进行了数种拓广.两类模型的建立,为运动昆虫的密度估计及疾病流行研究提供了重要的定量工具．     

COMPARISON OF METHODS USED TO ESTIMATE NUMBERS OF WALRUSES ON SEA ICE

The US and former USSR conducted joint surveys of Pacific walruses on sea ice and at land haul-outs in 1975, 1980, 1985, and 1990. One of the difficulties in interpreting results of these surveys has been that, except for the 1990 survey, the Americans and Soviets used different methods for estimating population size from their respective portions of the sea ice data. We used data exchanged between Sovier and American scientists to compare and evaluate the two estimation procedures and to derive a set of alternative estimates from the 1975, 1980, and 1985 surveys based on a single consistent procedure. Estimation method had only a small effect on total population estimates because most walruses were found at land haul-outs. However, the Sovievr method is subject to bias that depends on the distribution of the population on the sea ice and this has important implications for interpreting the ice portions of previously reported surveys for walruses and other pinniped species. We recommend that the American method be used in future surveys. Future research on survey methods for walruses should focus on other potential sources of bias and variation.     

VOCAL AND OTHER BEHAVIOUR OF KENYAN BLACK-COLLARED BARBETS LYBIUS TORQUATUS

We describe 12 visual and six acoustical displays of Black-collared Barbets, all associated with interactions of these sexually monomorphic barbets in greeting ceremonies and in antiphonal duets. Certain of the displays, e. g., bill directing, smooth posture and chatter calls largely are associated with multiple-barbet interactions and greeting ceremonies involving more than two barbets, and seem to represent purely agonistic displays. Other displays, most notably the bobbing and floating flight displays, and the tyaw call, are associated with preduet greeting ceremonies involving the presumed pair. In every case duets were performed by a presumed pair, following a greeting ceremony and visual displays accompany the duetting, which usually becomes precisely synchronized after the initial few notes. Four to 17 notes of each of two types, a usually lower pitched, short and mainly double type A note that introduces most duets, and a higher pitched, usually single, clear type B note that often terminates the duet. Variation in the notes and in their tempos within duets suggests no clearly defined temporal indicators for achieving, maintaining, and concluding the duets. The A and B notes cannot yet be assigned to one or other sex and similarity in form and development of the notes, from notes of greeting ceremonies, suggests the possibility that under some circumstances a bird of one sex may be able to deliver notes of either type. The duets are delivered from singing posts within the group's (or pair's) territory and usually only one duet is uttered from a site before the birds shift to another singing post. The duetting is compared with that of other barbets and appears to be among the best synchronized and most precise in the family. Comparisons with non-barbet duetting species are difficult because of the special habits and ecology of the barbets and uncertainty as to the sexual rôle of the duetters.     

种群密度与施肥对垂穗披碱草刈割后补偿作用的影响

 以甘南亚高山草甸常见牧草垂穗披碱草(Elymus nutans)为对象,通过考察种群密度、施肥与刈割处理等对植物生长和生殖的影响效应,比较了垂穗披碱草在5个密度及2个施肥实验处理条件下对4种刈割处理的补偿性反应特点。结果表明,在所有密度及施肥处理条件下,早期轻度刈割处理 (分蘖期刈割,留茬4 cm) 都有利于植物的补偿作用,后期重度处理 (拔节期刈割,留茬2 cm) 可显著降低植物的地上部分生物量及生殖部分干重 (穗重)。在不施肥情况下,刈割对垂穗披碱草的影响程度随种群密度而加大,在低密度处理中早期轻度刈割的植物发生了超补偿。可以认为,低密度种群中植物具有较多的分蘖是植物在刈割后表现出较高补偿能力的一个重要生物学原因。实验还发现,施肥可提高植物个体的分蘖能力和秆叶再生能力,因而总体上可增强植物的补偿能力,并且在中等密度条件下垂穗披碱草的补偿能力较强,尽管没有发生超补偿现象。不过,施肥主要是有利于植物地上营养器官的补偿,生殖器官的补偿程度较小一些。试验结果对科学管理人工草场具有一定的指导意义。     

GREEN AUTOFLUORESCENCE OF DINOFLAGELLATE CYSTS CAN BE USED INSTEAD OF PRIMULINE STAINING FOR CYST VISUALIZATION AND ENUMERATION IN SEDIMENTS1

Primuline staining is widely used to visualize and enumerate dinoflagellate cysts in marine sediments. In staining cysts of Gymnodinium catenatum H. W. Graham, Scrippsiella trochoidea (F. Stein) A. R. Loebl., and cysts from estuarine sediments, we found their green fluorescence after primuline treatment to be seemingly no different from the green autofluorescence (GAF) inherent in vegetative cells and cysts of dinoflagellates fixed in formaldehyde. Although primuline subsequently proved to enhance green fluorescence of both species quantitatively, we nonetheless recommend taking advantage of dinoflagellates' GAF to detect and count their cysts in sediments. Doing so will reduce the time, chemical consumption, and possible loss of cells involved in the primuline‐staining procedure.     

雉鸡的活动痕迹及种群密度的初步研究

本文报道了在不同生境中采用样方法对雉鸡及其活动痕迹进行调查,并根据Ｄ＝Ｎ／Ｂ公式对所得的数据加以处理,其结果表明雉鸡在活动过程中所留下的巢、粪便等痕迹均以灌草丛为最多,而取食刨土所留下的痕迹则以农耕地为最多。其种群密度,在草坡为５６只／ｋｍ２,稀树灌丛草坡为７８只／ｋｍ２,灌丛草坡为１５６只／ｋｍ２。     

榆毒蛾生活习性和数量变动与气象因素的关系

1.榆毒蛾在北京地区,一年两代,每代的历期与季节性气候变化有关。第—代在夏季完成,卵期,约在7月上中旬,幼虫于7月中下旬孵化,至8月下旬化蛹,9月上旬羽化,历期约50日;第二代从秋末到次年春末夏初,卵期在9月上旬至下旬,幼虫9月中下旬孵化至10月中旬前后进入越冬,次年4月中下旬活动至6月下旬化蛹,7月上旬羽化,除越冬期外,历期约120日。 2.榆毒蛾的雌雄性比,1956年统计:第一代雌雄比例(%)为68:32,第二代为56.5:43.5。其产卵量,每雌最多215粒,少为26粒,平均79.1粒。成虫期遇天气晴朗,卵量较多,阴雨天气,产卵量减少。卵的孵化率,在自然条件下,每代都在90%以上。 3.榆毒蛾在北京地区,以2龄幼虫越冬。越冬场所主要在榆树洞穴、裂皮和树下的堆积物内。榆毒蛾成虫不取食,幼虫取食叶片;幼虫1-3龄,趋光性弱,大部在榆树下层,叶片背面,5-7龄,趋光性增强,栖居于榆树上部、叶片表面;成虫夜晚有趋光习性,白天在晴朗的中午前后飞翔数量较多,阴雨和风速在3级以上的夭气停止飞翔。 4.榆毒蛾虫口数量的变化与降雨量及其分布有关。少雨的世代,榆毒蛾数量上升,多雨的世代,其数量下降。如1955年第一代幼虫初期降雨125.5毫米。蛾量较越冬代增长11.8倍,1956年第一代幼虫期降雨529.0毫米,其蛾量较越冬代却有所下降。     

USING ISOLATION BY DISTANCE AND EFFECTIVE DENSITY TO ESTIMATE DISPERSAL SCALES IN ANEMONEFISH

Robust estimates of dispersal are critical for understanding population dynamics and local adaptation, as well as for successful spatial management. Genetic isolation by distance patterns hold clues to dispersal, but understanding these patterns quantitatively has been complicated by uncertainty in effective density. In this study, we genotyped populations of a coral reef fish (Amphiprion clarkii) at 13 microsatellite loci to uncover fine‐scale isolation by distance patterns in two replicate transects. Temporal changes in allele frequencies between generations suggested that effective densities in these populations are 4–21 adults/km. A separate estimate from census densities suggested that effective densities may be as high as 82–178 adults/km. Applying these effective densities with isolation by distance theory suggested that larval dispersal kernels in A. clarkii had a spread near 11 km (4–27 km). These kernels predicted low fractions of self‐recruitment in continuous habitats, but the same kernels were consistent with previously reported, high self‐recruitment fractions (40–60%) when realistic levels of habitat patchiness were considered. Our results suggested that ecologically relevant larval dispersal can be estimated with widely available genetic methods when effective density is measured carefully through cohort sampling and ecological censuses, and that self‐recruitment studies should be interpreted in light of habitat patchiness.     

A BAYESIAN ANALYSIS TO ESTIMATE LOSS IN SQUID CATCH DUE TO THE IMPLEMENTATION OF A SEA LION POPULATION MANAGEMENT PLAN

This study estimates the effect of a sea lion ( Phocarctos hookeri ) population management plan on both the sea lion population and the associated squid ( Nototodarus sloanii ) fishery. The goal of the management plan is to rebuild the sea lion population and involves closing the squid fishery when a threshold level of sea lions have been caught. The threshold level is calculated from a generalized simulation analysis which conservatively allows for adequate population rebuilding for a number of different species and populations. Our analysis uses Bayesian theory to describe uncertainty in the sea lion population site and squid catch under the implementation of the management plan. The priors represent this particular sea lion population, and the analysis represents expectation rather than calculating conservative levels of safe fishing-related mortality. The results show that the squid catch is very sensitive to whether or not the squid fishery is closed when it exceeds the threshold level for sea lion bycatch. The sea lion population size is much less sensitive to the closure of the squid fishery. For an economically important fishery, the estimates of uncertainty in both loss of catch and increase in sea lion population are needed to allow informed decision-making about trade-offs between sea lion conservation and full exploitation of the fishery.     

中华秋沙鸭在长白山地区的分布和种群数量

中华秋沙鸭(Mergus squamatus)主要分布在西伯利亚东南部、朝鲜和我国。是一种分布区域狭窄、数量稀少的珍稀濒危鸟类。已被列入世界濒危动物红皮书和我国Ⅰ级保护动物。据作者1962以来的调查资料表明,长白山是中华秋沙鸭在我国的本要繁殖地。主要分布在长白山东北坡的头道白河、三道白河、古洞河及其支流和西南坡的漫江、锦江及其支流。据我们1977—1978和1989—1991年调查约40—50对,种群数量呈减少趋势。原因是环境恶化和人为干扰。     

密度因素在布氏田鼠种群调节中的作用

对布氏田鼠栖息密度不同的种群同时进行取样,研究密度因素对布氏田鼠种群发展的调节作用。结果表明,在高密度区布氏田鼠种群繁殖强度受到抑制,雌鼠怀孕率、雄鼠睾丸下降率、贮精囊肥大率和睾丸长度都小于低密度种群。高密度种群繁殖季节结束时间早于低密度种群,幼鼠肥满度较小,性成熟速度较慢,种群年龄结构中,幼年鼠所占比例小于低密度种群。这些都是导致高密度种群增长速度减慢的因素。     

黄毛鼠数量季节变动的研究

黄毛鼠(Rattus rattoides)是华南地区农田主要害鼠,也是长江三角洲的优势鼠种,广泛分布于各类生境中,终年危害农作物(广东省昆虫研究所动物研究室编,1976;王耀培等,1965),且又是多种传染病(钩端螺旋体病、狂犬病等)的传播者。故研究黄毛鼠的数量季节变化,对农业生产和卫生防疫均有很大实践意义。     

WHY DOES A METHOD THAT FAILS CONTINUE TO BE USED? THE ANSWER

It has been claimed that hundreds of researchers use nested clade phylogeographic analysis (NCPA) based on what the method promises rather than requiring objective validation of the method. The supposed failure of NCPA is based upon the argument that validating it by using positive controls ignored type I error, and that computer simulations have shown a high type I error. The first argument is factually incorrect: the previously published validation analysis fully accounted for both type I and type II errors. The simulations that indicate a 75% type I error rate have serious flaws and only evaluate outdated versions of NCPA. These outdated type I error rates fall precipitously when the 2003 version of single-locus NCPA is used or when the 2002 multilocus version of NCPA is used. It is shown that the tree-wise type I errors in single-locus NCPA can be corrected to the desired nominal level by a simple statistical procedure, and that multilocus NCPA reconstructs a simulated scenario used to discredit NCPA with 100% accuracy. Hence, NCPA is a not a failed method at all, but rather has been validated both by actual data and by simulated data in a manner that satisfies the published criteria given by its critics. The critics have come to different conclusions because they have focused on the pre-2002 versions of NCPA and have failed to take into account the extensive developments in NCPA since 2002. Hence, researchers can choose to use NCPA based upon objective critical validation that shows that NCPA delivers what it promises.     

松嫩平原碱化草甸天然翅碱蓬种群的密度制约模型

翅碱蓬是一年生藜科植物,耐碱性极强。本文根据在单—种群落随机取样的调查数据,从种群水平分析了松嫩平原碱化草甸天然翅碱蓬种群的密度制约特征。结果表明,翅碱蓬种群在不同生长期及不同数量性状的密度制约模型均可由多种函数形式同时较好地表达出来。但本文仅以相关性最好的拟合方程作为种群某一性状密度制约特征的模型。孕蕾期的平均植株重和单位面积籽实重的密度制约表现为变形双曲线函数y=a+b/x形式;籽实成熟期的平均植株重、平均植株籽实重、平均植株种子数和单位面积种子数均表现为幂函数y=ax-b形式;地上生物量在孕蕾期为变形双曲线函数y=1/(a+bx)形式,在籽实成熟期为对数函数y=a-blnx形式。