草兔的年龄鉴定和种群的结构分析

根据１９９１年２－１０月猎自晋东南的２１２只的１９９０－１９９２年狩猎季节猎自山西和陕西省各地的１５１０只草兔眼晶体重的分布规律并参照繁殖资料,确定２２５毫克为区别１年以下及其以上个体的临界重量,秋－冬季种群中,当年兔占８６．３（７２．２－９３．５）％;随着繁殖季了的推移,当年兔的比例逐渐增加,在４０１１只标本中,雌性占５２．３％;其中１２２６只幼体和１９５只成体中分别在雌性５２．４％和５４．４％     

草兔繁殖生物学的初步研究

本文分析了１９９１年１－１０月获自山西省东南部丘陵山区以及１９９０－１９９３年１０月至翌年１月获自该省各地草兔的有关繁殖特征。草兔的繁殖季节为１－９月,雄性进入性活动的时间早于雌性。生殖腺测度有明显的季节变化,其峰值在４月和５月。当年兔３－４月龄时性可成熟,但达到性成熟月龄的当年兔只有５１．７％在７、８月参加繁殖。怀孕个体见于２－９月,３月怀孕率最高,此后逐渐下降。胎仔数１－７只,５月最多,年均值３．６只,每只雌兔年产幼兔１２．９只。     

洞庭平原黑线姬鼠繁殖特性研究

１９８６年１０月－１９９０年１０月在湖南省桃源县和汉寿县的稻作区逐月调查,夹捕黑线姬鼠长江亚种２７６８只,雌性占４５。６％。主要繁殖期３－１１月,研究期内的月平均怀孕率为４８．６±４．０％、平均胎仔数为５．３±０．２只。繁殖指数为２．３６±０．２９。以上３个参数及种群性性比有季节性变化,４－５月和７－１０月为２个妊娠高峰;雄性睾丸下位率和雌性怀孕率有同步变动的趋势。５年龄组之间,其性比、怀孕率和繁     

红隼的生态和繁殖生物学观察

１９８９－１９９１年的４－８月，在山西庞泉沟自然保护区，对红隼生态和繁殖生物学进行了观察。已知该鸟的栖息地有三种：营巢地、觅食地和短暂停息地，利用率分别为３９．４２％、４０．３７％和２０．１９％。该鸟的种群密度在繁殖前４月为２．０６，繁殖后的８月为２．８９，繁殖后比繁殖前的种群密度增加４０．２９％。该鸟营巢于悬崖峭壁的洞穴或石缝；产卵多在５月，产卵与孵卵同步；窝产卵３－６枚，孵化期２９－３０天。其食物组成为小型啮齿动物、小型鸟类和昆虫，分别占６４．２６％、３１．５０％和４．２６％。     

深圳湾大弹涂鱼种群结构与生殖特征

本文探讨了深圳湾大弹涂鱼种群结构和生殖特征。结果表明：该种群以１、２龄鱼组成为主,３龄鱼极少,表明种群结构简单,体长与体重的相关曲线方程为Ｗ＝４．１６１８×１０－５Ｌ２．７４５１（ｒ＝０．９５７６）。雌雄性比为３：２。一龄鱼开始性成熟。雌鱼性成熟最小生物学体长为６２ｍｍ,雄鱼为５９ｍｍ。个体绝对生殖力波动于１９５６—１４０５３粒,平均７２９３粒;个体相对生殖力Ｆ／Ｌ：２９．５—１００．５粒／ｍｍ,平均７９粒／ｍｍ;Ｆ／Ｗ：５１１．０—８０４．９粒／ｇ,平均７５２粒／ｇ。４—６月为繁殖盛期,７—８月为繁殖末期。雌性周年月平均成熟系数（ＧＳＩ）变动范围为０．２７％—４．３６％。大弹涂鱼在一个生殖季节中只能产卵一次,属于一次性排卵类型。     

洞庭湖区东方田鼠繁殖特性研究

１９９２年１月～１９９４年１２月,作者在东洞庭湖区岳阳县麻塘区调查,３年捕获并剖检东方田鼠１３９２只,其中雌鼠５９９只,雌性比♀／（♂＋♀）＝４３．０％。该鼠全年繁殖,盛夏５～７月怀孕率较低,冬季１２～２月怀孕率比同域其它鼠种显著偏高。３年合计总怀孕率为２９．２％．平均胎仔数（ｘ±ＳＥ）为５．１３±０．１２只,平均窝仔数４．６０±０．２７只,雌鼠和雄鼠的繁殖强度随年龄增长而递增。室内饲养的东方田鼠妊娠期约２０天,窝仔数４．３３±０．３３只,雌鼠５０～６０天成熟,雄鼠稍迟。枯水期（１１月～翌年４月）东方田鼠主要栖息于湖洲草地,汛期（５～１０月）主要栖息于过垸内稻田。在不同栖息地其繁殖力差别较大,湖洲的繁殖强度最高,稻田区次之,岗地最低,反映它在各栖息地生态适合度不同。文中还对全国４个亚种的繁殖参数作了比较。     

瓣结鱼的繁殖习性以及精子的活力与寿命

经组织学观察，研究了性成熟瓣结鱼的性腺发育的周期性变化，并初步分析了瓣结鱼的和。其繁殖盛期在４月下旬到５月上旬，繁殖群体♀：♂＝１：９．１，繁殖季节具有雌雄二态性，雄鱼绝大多数在２龄性成熟，雌鱼多在３性成熟。不同浓度的ＮａＣｌ溶液对精子活力和寿命有较大影响，成熟精子在０．４５－０．５５％的ＮａＣｌ溶液中剧烈运动时间最长，平均为１７２．５秒。     

卡氏小鼠种群数量变动特征及其与环境因子的关系

本文报道卡氏大鼠种群数量变动特征及其与环境因子的关系,种群数量年间变动较大,季节较化一般出现２个高峰。分别在５－６月和１１月,与农作物的成熟,收获以及小鼠繁殖活动有关,１月份的种群数量多及２、３月份的平均气温高低,对当年５月份种群数量有密切关系。本文提出了３个回归方程式,可初步估计当年５月的种群数量。     

香港桃金娘灌木群落植物生物量和净第一性生产量

本文研究香港桃金娘灌木林植物生物量和净第一性生产量。结果表明：（１）桃金娘茎的直径与高度与各组分的生物量有明显的相关关系。（２）桃金娘叶子占地上部活植物生物量的２０．２％,花和果如果以它的峰值计算,其占地上部活植物生物量的９．６％,茎和枝占７０．４％。（３）地上部和地下部活植物生物量分别为１５５３ｇｍ－２和１４０８ｇｍ－２,其中桃金娘分别占８５％和８２％。（４）桃金娘叶子生物量在研究期间的波动较大,但没有以年为周期的季节变化。花和果的变化则较有规律,花蕾通常于３或４月开始形成,到７月底达到峰值,然后开始下降。（５）桃金娘的净生产量为８２０ｇｍ－２ａ－１,其中,花和果占１５．２％,茎和枝占１８．８％,根和叶分别占２１．３％和４３．７％。灌木林的净第一性生产量为１０１０ｇｍ－２ａ－１。（６）由于未考虑草食和根系的枯死损失,本研究所得的净第一性生产量（尤其是根的生产量）可能偏低。     

小毛足鼠繁殖生态研究

１９９１￣１９９５年每年４￣１０月的各月中旬,在内蒙古伊克昭盟达拉特旗沙地草场上,不同生态环境中共布放１０１８４５个夹日,捕获鼠６３２５只,其中小毛足鼠（Ｐｈｏｄｏｐｕｓ ｒｏｂｏｒｏｖｓｋｉｉ）２２１７只,占３５．０５％。根据胴体重划分成４个年龄组,５年总的性比为４９．６１％,接近１：１,无季节差异。雄性繁殖期为９个月（２￣１０月）,有年间差异。雌性繁殖力随着年龄的增长而增高,亚成年组、成年Ⅰ组     

Weights and growth rates in the Mountain hare Lepus timidus scoticus

Mountain hares were weighed during live trapping on a study area near Dufftown, Banffshire, from June 1958 to August 1966. Hares shot or killed by other means on the study area and elsewhere were also weighed. Females were heavier than males throughout the year and this difference became apparent in juveniles by August of their year of birth. Male hares lost weight during the breeding season (January to June) but regained it in late summer. Young hares gained weight initially at about 14 g per day, then at about 6 g per day to adult weight. Small juveniles, or those born late in the season, tended to become small adults, large or early juveniles to become large adults. Small hares moulted less completely andjbegan to breed later in the season than large hares. The effects of disease, starvation, severe weather and injury on hare weights were considered. Female weights were greater when the population was small, due to more late pregnancies or more embryos per female. Weight could not be used to distinguish between adult and juvenile hares above 2.1 kg, nor between young and older adults.     

Interaction of the tick (Haemaphysalis leporispalustris) with a cyclic snowshoe hare (Lepus americanus) population

Prevalence and intensity of the tick, Haemaphysalis leporispalustris, were monitored during 1963 to 1976 in a cyclic snowshoe hare (Lepus americanus) population near Rochester, Alberta, Canada. Prevalence was near zero from December through March, and near 100% among adult hares from May through September. Prevalence among juvenile hares approached 100% by age 2 mo. Intensity peaked for both adults and juveniles during May-June and again in August. Mean intensities were significantly higher among adult males than adult females in 5 of 13 yr, and almost significant in two others. Tick intensities were lowest during 3 yr, 1969 to 1971, when hare densities were highest. Tick intensities in spring were correlated with intensities the previous fall. Survival of marked adult and juvenile hares was unrelated to intensities of infestation. Mean numbers of corpora lutea and embryos tended to be lower among adult females with heavy tick infestations, and intra-uterine losses rose steadily from about 3 to 13% as tick intensities increased from none to heavy. Comparison of average tick intensities on adults 1-, 2-, and greater than or equal to 3-yr-old yielded no evidence of increased immunity with age.     

Blood chemistry and endoparasites of the mountain hare (Lepus timidus L.) in high and low density populations.

In order to study the effect of high population density on the condition, blood characteristics and helminth parasitism of mountain hares (Lepus timidus), 12 specimens were shot in December 1982 and 12 more in February 1983 on the west coast of central Finland (group 1, dense population). In addition 14 hares were shot in December 1982 about 100 km from group 1 (group 2, dense population). Group 3 consists of 15 hares from stable, rather low density populations shot in southern Finland during three previous winters. The hares in group 1 were the lightest, had the least fat and were the most seriously infected with Protostrongylus pulmonalis and Trichostrongylus retortaeformis, while those in group 2 were the heaviest and had the highest Ca, Mg, alkaline phosphatase and creatinine values. The group 3 hares had the most fat. The group 1 animals shot in February 1983 had higher Ca, Mg, triglyceride and cholesterol values than those shot in December 1982. It seems that high population density combined with a lack of suitable food leads to poor condition and high endoparasite abundances. The differences in Ca and Mg are probably due to diet. The higher creatinine values in group 2 and in the hares with little or no T. retortaeformis infection may be due to the greater muscle mass.     

Annual patterns in reproduction and perirenal fat of hares (Lepus europaeus) in sub-alpine Canterbury, New Zealand

The aim of this paper was to describe how the age, sex and reproductive state of hares affected the amount of fat found around their left kidney. A total of 2208 hares ( Lepus europaeus ) was shot and autopsied over 13 years from sub-alpine grasslands in Canterbury, South Island, New Zealand. Adult females may be pregnant from July to mid-March. Adult males' testis weights were highest from July to January, and some fertile males may have been present in all months but April. The amount of perirenal fat in adults increased in autumn, peaked in early winter, and decreased thereafter to low levels through spring and summer. Autumn fat deposition in males was not clearly related to reproductive state in individuals, although it coincided with seasonal testicular development. Autumn fat deposition in females may have been caused in part by the cessation of lactation, but, like that in males, the increase was also part of an endogenous pattern. Fat utilization in winter was related to breeding. In males, utilization coincided with reproductive activity and the amount of perirenal fat remained consistently low throughout the breeding season. In females, net fat utilization was associated with lactation but this was balanced to some extent by fat deposition induced by pregnancy. Females simultaneously lactating and pregnant were in finer balance between utilization and deposition. Other factors, such as the number of embryos and the stage of gestation, altered the fat balance in these hares. Fat was also deposited as a 'yolk-sac' in embryos.     

中国更新世兔属化石的厘定

在对我国现生兔属各种骨骼特征研究的基础上,通过形态特征的观察与测量数据的分析,修订了已有的兔属化石材料。将周口店第1,2,6,20,山顶洞和东岭子洞等地点以及山东平邑发现的兔标本归入草兔Lepus capensis。以前被归入Lepus wongi种内的标本,除周口店第13地点及蓝田陈家窝子的应属于Lepus teilhardi外,其余地点的皆为Lepus capensis,因此L.wongi失去了原有的意义,为无效种。周口店第16地点的标本归入华南兔Lepus sinensis,是该种目前惟一的化石记录。辽宁营口金牛山的标本暂时归入东北兔Lepus mandschuricus。我国更新世共发现两个化石种和4个现生种。其中化石种Lepus teilhardi和L.ziboensis出现在早更新世晚期至中更新世早期,现生种L.capensis,L.mandschuricus,L.sinensis和L.comus分别出现在中更新世与晚更新世。初步讨论了兔属的起源,认为兔属可能起源于上新世的Trischizolagus。     

Growth and body weight of European hares in southern Sweden

Body weight and growth of European hares Lepus europaeus Pallas in relation to environmental conditions, population density, age, sex, and reproduction were studied in three populations in southern Sweden on the basis of hares shot during October-December. There were no significant differences in mean body weight of juveniles in the three areas. Differences in juvenile growth, as indicated by the correlation between eye lens weight (age indicator) and body weight, between areas and years were related to variations in nutrient conditions, in an island population it was probably also related to population density. Adult body weights did not differ between two mainland areas despite differences in food supply and population density, whereas island adult hares were, on average, significantly lighter than mainland hares. Also this difference was ascribed to nutrient conditions and/or population density. There were no significant differences in body weight between adult hares of different age classes. But reproductive females showed a significant positive correlation between number of litters produced annually and body weight. This relation indicates that reproduction is favoured by large body size and body weight, which also might explain the average higher mean body weight in females than in males. Juvenile hares showed no clear tendency in sex dimorphism of body weight.     

European brown hare syndrome virus in free-ranging European brown hares from Argentina

From 1998 to 2000, serum samples of 80 shot European brown hares (Lepus europaeus) from Argentina were examined for antibodies against European brown hare syndrome virus (EBHSV) and 80 spleen samples were tested for EBHSV-antigen by enzyme linked immunosorbent assay (ELISA). Nine hares were positive for EBHSV-antigen. Antibodies against EBHSV were detected in only one individual. Based on negative staining electron microscopy of spleen homogenates, we observed calicivirus in one of five EBHSV-antigen positive hares. However, EBHS has not been reported to cause abnormal mortality in these hares. This is the first report of antibodies to EBHSV, EBHSV-antigen, and electron microscopy findings in free-ranging European brown hares from South America.     

Effects of Protostrongylus sp. and Pneumocystis sp. on the pulmonary tissue and the condition of mountain and brown hares from Finland

Mountain hares (Lepus timidus) and brown hares (Lepus europaeus) shot by hunters in several game management districts in southern and central Finland during the hunting season from September to the end of February 1998-2001 were examined for Protostrongylus sp. and Pneumocystis sp. Of the mountain hares, 96.5% (194/201) were infected with the lungworm Protostrongylus sp. and 16.9% (32/189) had cyst forms of the fungus Pneumocystis sp. in the lungs. The prevalence of the lungworm and fungus in brown hares was 60% (18/30) and 20.0% (6/30), respectively. The tissue changes associated with the lungworms were macroscopically and microscopically well demarcated. The majority and most severe histopathologic changes were seen at the distal part of the caudal lobes. Inflammatory cells, mainly eosinophils and macrophages, and in lesser degree neutrophils, lymphocytes, and plasma cells were typical findings in the worm-infected tissue. The condition and weight of the hare did not show any significant association with the intensity of the lungworm infection. All Pneumocystis-infected mountain hares were young, and their condition and weight correlated negatively with the intensity of the infection. The intensity of the Pneumocystis infection did not correlate with that of the lungworm infection. Within a tissue section, a slight but significant positive correlation was observed between presence of cysts and inflammatory cells.     

Parasitism in a declining population of snowshoe hares

Prevalence and intensity of six endoparasites were determined in 346 snowshoe hares (Lepus americanus) obtained at Rochester, Alberta, during December-April 1981-1982, the second winter of a cyclic population decline. The data were analyzed for (1) differences among host sex and age classes, and among months and sample sources, and (2) evidence that parasitism was of demographic significance to the hare population. Prevalence and intensity of Obeliscoides cuniculi were consistently highest among adult hares, but rose most sharply from February to March among juveniles. In contrast, prevalence and intensity of Nematodirus triangularis were highest among juveniles; prevalence reached 90-100% by January, whereas intensity continued to rise through April. Prevalence and intensity of both Trichuris leporis and Protostrongylus boughtoni were highest also among juvenile hares; neither parameter exhibited a definite trend over time. Prevalences of Taenia pisiformis (cysticerci) and Eimeria spp. were unrelated to sex, age or month; but Taenia intensity was highest among juveniles, and Eimeria intensity tended to decrease from December to April. Intensities of Nematodirus, Protostrongylus and Eimeria were higher in male hares than in females. Prevalence and intensity were correlated directly in Obeliscoides, Nematodirus, Trichuris and Eimeria. Hares that died during trapping and handling, or from natural predation, had greater intensities of Obeliscoides than did animals killed on purpose. There was no indication, however, that risk of death was increased by the other parasitic infections. Age-related immune responses to parasitism (except Obeliscoides) were evidenced by reduced or stabilized prevalence and/or intensity among older hares. A multiple-regression model predicted depressed body weight with increasing intensities of Nematodirus, Trichuris or Protostrongylus. Other body-condition and reproductive indices were unassociated with parasite intensities. Within the hare population, Obeliscoides, Trichuris, Protostrongylus and Taenia had overdispersed distributions (typical of many endoparasites) that did not differ from a negative binomial. The frequency with which each possible combination of helminth species occurred within individual hares was consistent with the assumption that such infections occurred independently. There was no compelling reason to believe parasitism was a significant factor in the overwinter decline of this population of snowshoe hares.     

Female reproductive tract abnormalities in European hares (Lepus europaeus) in Australia. philip.stott@adelaide.edu.au

Populations of European hare (Lepus europaeus) are in decline in Europe, and populations in Australia remain at low densities. Populations are sensitive to size of the breeding stock, which is influenced by fertility in the females. From 1996 to 1999, a total of 272 adult female hares from three Australian populations were dissected and their reproductive systems examined for abnormalities. Cystic endometrial hyperplasia was relatively common and often accompanied by hydrosalpinx. Extrauterine fetuses, neoplasms, pseudopregnancies, and resorptions also were found. However, although pseudopregnancies and resorptions were found in young adults (<12 mo) as well as older hares, conditions possibly causing infertility were almost always in older hares with prevalences up to 46.2%. Only hares with access to known sources of estrogens exhibited pathologic conditions, but sympatric European rabbits (Oryctolagus cuniculus) did not, which is consistent with known difference in responses between the corpora lutea of the two species to exogenous estrogen. Infertility at such a high prevalence could compound and extend the impact of years of low juvenile survival on recruitment.