不育和"灭杀”对围栏内大仓鼠种群繁殖力和数量的影响

本文采用结扎不育的方法研究了不育和“灭杀”对围栏内大仓鼠（Cricetulus triton）实验种群繁殖力和数量的作用,主要验证模型的两个预测：不育能够达到灭杀的效果;双性不育优于单性不育,同时探讨了大仓鼠种群调节中的关键因子。本实验设4个处理（2个重复）来模拟67％的不育率或灭杀率：对照组（9正常♂,9正常♀）;灭杀组（3正常♂,3正常♀）;雌雄不育组（3正常♂,6不育♂;3正常♀,6不育♀）;雌性不育组（9正常♂;3正常♀,6不育♀）。研究结果表明：对照组和灭杀组的平均繁殖力接近且较高,雌性不育组居中,雌雄不育组最低,不育成体鼠与正常成体鼠、正常雄性成体鼠与正常雌性成体鼠、新生雄性与雌性幼鼠之间的存活率差异都不显著。新生幼鼠雌：雄性比为53：49＝1.0816,与1：1 无显著性差异。大仓鼠体重增长基本符合Logistic模型,不育雌鼠的体重相对增长率比正常雌鼠高,且最大体重也比正常雌鼠大;正常雌鼠的体重相对增长率比正常雄鼠较高,在食物和水分充分供应的情况下,围栏内种群密度的高低对雌鼠繁殖力的影响不大,说明食物可能是引起野外大仓鼠种群繁殖力变化的关键因素,而社群因素的作用不大。在围栏内,雄鼠的存活率比雌鼠略低,但幼鼠的存活率比成体鼠的存活纺低很多;围栏内大仓鼠成体的存活率与自然种群比较接近,而幼体存活率却比自然状况下低了很多,说明与密度关联的大仓鼠社群调节可能主要是通过影响存活率,特别是幼体存活率却比自然状况下低了很多,说明与密度关联的大仓鼠社群调节可能主要是通过影响存活率,特别是幼体的存活率而起作用。     

北京顺义区农田两大害鼠种群繁殖力比较

为了揭示顺义农田黑线姬鼠和大仓鼠两大害鼠种群繁殖力存在的差异及其对种群数量变化的影响,从而为制定科学灭鼠策略提供依据,1994-2014年,采用夹线法于每年3~11月(或1~12月)进行调查,每月上旬在5个监测点农田布放鼠夹500夹夜。捕获的样本测量体重、体长、尾长、耳高、后足长,解剖观察繁殖情况。以种群繁殖力为指标,分析黑线姬鼠与大仓鼠在繁殖力方面的差异,由此揭示出黑线姬鼠具有更强的竞争优势。黑线姬鼠和大仓鼠每年都有2个繁殖高峰期,并以成年以上个体为繁殖主体,分别占总胎仔数的94.5%和95.6%。黑线姬鼠的繁殖期和主要繁殖期均比大仓鼠延长1个月,且主要繁殖期的雌、雄繁殖鼠占比均高于大仓鼠,胎次数是大仓鼠的1.7倍,仅平均胎仔数低于大仓鼠,由此说明黑线姬鼠种群的繁殖力比大仓鼠更强,具有更大的竞争优势。     

黑线仓鼠种群年龄组成及其数量季节消长的研究

本文对黑线仓鼠的上臼齿磨损程度进行了系统观察,共采标本553只,结合生殖系统的解剖记录,确定以右侧上臼齿的磨损程度将黑线仓鼠划分为5个年龄组。探讨了年龄与体长、体重及繁殖力的相互关系,以及种群数量季节消长与气候条件及种群结构的关系。结果表明,黑线仓鼠年龄越大,雌鼠的繁殖力越高,但平均怀仔量并不随年龄增大而增加。体重、体长不易作为划分黑线仓鼠年龄组的指标。种群数量与大降雨量呈明显的负相关,但种群的年龄结构对数量消长起着主要作用。     

海南大田国家级自然保护区海南坡鹿容纳量的研究

以坡鹿采食的植物资源贮量及坡鹿日采食量的方法，估测海南大田国家级自然保护区的坡鹿容纳量，围栏内的坡鹿容纳量是每公顷１．０１－１．４２只，围栏外每公顷１．４０－１．８５只，在这一密度下，种群数量保持稳定，种群增长率等于零，为尽快增加种群数量改变坡鹿的濒危状态，应将坡鹿的数量控制在１／２容纳量以内，即围栏内容纳１５２－２１３只，围栏外容纳６９０－９０９只，应尽快扩大围栏面积并严格控制割取鹿茸的雄鹿比例     

EP-1不育剂对内蒙古沙地黑线仓鼠种群结构与繁殖的影响

2003年在内蒙古锡林郭勒盟浑善达克沙地进行了EP-1不育剂控制黑线仓鼠的野外实验,分析新型EP系列不育剂对黑线仓鼠种群结构和繁殖的影响。采用逐月夹线调查方法,监测EP-1不育剂对沙地黑线仓鼠种群结构与数量动态的作用。结果表明,投药区与对照区相比,不育剂对黑线仓鼠的性别比例没有影响,对照区域投药区相比雄性比例没有差异。投药区黑线仓鼠种群幼鼠比例下降,比对照区相比幼鼠比例下降40%—60%,持续时间达4个月以上。春季一次性投放EP-1不育剂,可实现对沙地黑线仓鼠整个繁殖季节的繁殖控制。此外,EP-1不育剂对沙地鼠类种群年龄结构与数量的作用成效,随着时间的推移逐渐下降,这可能跟沙地鼠类具有扩散迁移习性有关。     

黑线仓鼠种群数量动态预测研究

１９８４－１９９１年３－１０月,每月中旬在中国农科院草原研究所试验场的不同牧草和作物地进行调查,１９８４－１９９１年共捕获鼠４０９３只,其中黑线仓鼠２９２０只占７１．３４％。黑线仓鼠种群数量季节和年度变化明显,利用电子计算机对黑线仓鼠种数量进行分析,提出种群数量繁殖指数和动态模型以及短、中、长期预测公式、预测准确率为９０．０％。并对影响种群数量的因素进行了初步分析。     

食物及洞道密度对高原鼠兔冬季死亡率的影响

本研究在野外围栏条件下采用2×2 析因实验设计,通过最小存活数法分别统计冬季前后种群数量,测定附加食物及洞道密度对高原鼠兔冬季死亡率的影响,旨在检验栖息地质量对降低高原鼠兔冬季死亡率的效应。4种野外实验处理2 个重复的研究结果表明,夏季无附加食物与低密度洞道处理组高原鼠兔冬季死亡率为71% ;而附加食物和高密度洞道处理冬季死亡率仅为47% ;添加食物和低密度洞道及无附加食物和高密度洞道处理组种群死亡率分别为60% 和53% 。每一处理组雌性死亡率均显著低于雄性。夏季添加食物和增加洞道密度均能明显地降低高原鼠兔种群冬季死亡率,但无显著的交互作用。     

北京地区大仓鼠种群繁殖生态研究

1983-1985年,作者在北京农田区研究了大仓鼠的种群生态。获得标本1101号(♀497,♂604),解剖、观察、测量、记录雌雄生殖系统的变化及繁殖特征。对大仓鼠的雌雄性比、平均胎仔数、怀孕率等作了分析。结果:春季出生的雌鼠,两个月左右即达性成熟,并参加繁殖,在7月以后出生的雌鼠当年不参加繁殖。越冬鼠一年可繁殖2-3次。在数量较高的1983年,性比(♂/♀)为1.33,平均胎仔数为9.24;数量次高的1984年,性比为1.20,平均胎仔数为9.29;数量较低的1985年,性比为0.95,平均胎仔数为9.94。在数量较低的年份,大仓鼠种群的各项繁殖指标均优于数量较高的年份。     

安徽淮北农区三种鼠的种群数量动态与年龄结构的关系

本文对安徽省淮北农业区的黑线姬鼠、大仓鼠和黑线仓鼠的种群数量及与年龄组成变化的关系进行探讨。结果表明,其各鼠的年龄组成在每年的不同时段内的变化有一定的规律:各鼠主要繁殖群体的年龄组也是有区别的,如黑线姬鼠和黑线仓鼠主要是成年Ⅱ组,大仓鼠主要是成年Ⅰ组。如果种群中幼年组+亚成年组+成年Ⅰ组的比例高时,则当年数量就可能较高,如果种群中成年Ⅱ组和老年组的比例较高时,当年数量则低。     

针毛鼠的形态及其种群生态特征

为丰富针毛鼠种群生态学资料,给其测报及防治提供依据。对贵州省余庆县、岑巩县、雷山县、凯里市1984~2013年针毛鼠的形态及其种群生态特征统计分析,结果表明:雌、雄鼠形态特征无显著性差异。该鼠主要栖息于旱地耕作区,占总鼠数的3.84%,平均捕获率为0.19%。不同年度之间种群数量存在明显差异,全年种群数量在5月和10月出现2个数量高峰,平均捕获率均为0.27%,春季、夏季和秋季种群数量明显高于冬季。种群总性比为0.82,平均怀孕率为27.92%,平均胎仔数为5.12只,平均子宫斑数为5.36只,平均睾丸下降率为59.89%,平均繁殖指数为0.65。3~9月为主要繁殖期,其间在3~4月和7~8月出现2个种群繁殖高峰,春季和夏季为主要繁殖季节。每年4月和8月是防治该鼠的最佳时期,防治重点区域为旱地耕作区。     

复方避孕药物(EP-1) 对雄性大仓鼠繁殖器官的影响

鉴于传统化学灭杀方法存在的不足和缺陷,各国都在致力于研究无公害、可持续的鼠害防治技术与策略,其中不育控制是当前研究的一个热点：近年来我国在鼠类不育控制方面也开展了一些研究（张知彬等,1997a,1997b,2001;Shi et a1．．2002;Li et a1．,2006）。     

EP-1不育剂对黑线毛足鼠种群繁殖的影响

为检验EP-1 不育剂对野外鼠类的施用效果,2004 年在内蒙古锡林郭勒盟阿巴嘎旗白音图嘎800 hm² 草场进行了大田实验,并随后进行了逐月的夹线跟踪调查,分析了不育剂(EP-1) 对黑线毛足鼠种群繁殖的效应。结果表明,EP-1 不育剂对黑线毛足鼠种群繁殖的抑制效果良好,投药区与对照区相比,投药区黑线毛足鼠的子宫损伤率达到80% ,平均胎仔数下降到对照区的2 /3 水平,妊娠率也下降到对照区的20% 。但EP-1 不育剂对雄鼠睾丸下降率的作用不明显。一次性投放EP-1 不育剂,对黑线毛足鼠种群的繁殖作用时间可维持4 个月以上,基本可实现对整个繁殖期的控制成效,这可能与黑线毛足鼠具有储藏种子的习性,储藏药饵多次进食有关。     

The polymorphism and distribution of B chromosomes in germline and somatic cells of Tscherskia triton de Winton (Rodentia, Cricetinae)

The karyotypes of 13 greater long-tailed hamsters (Tscherskia triton de Winton, 1899) (eight males and five females) from Primorskii krai (Russia), including six males and one female from the vicinity of the city of Ussuriisk and two males and four females from the vicinity of the village of Pogranichnyi, have been studied. The karyotypes of five males (four from the vicinity of Ussuriisk and one from the vicinity of Pogranichnyi) have been found to contain one or two small acrocentric B chromosomes each. In males with B chromosomes, each germline cell contains one or two B chromosomes. The proportion of somatic cells carrying B chromosomes varies from 34.9 to 55.9% in these males. Karyological study of a total of 45 Tscherskia triton (30 males and 15 females) from Primorskii krai has been performed, B chromosomes being found in only five males (11.1%). In T. triton populations of Korea and China, also only a few animals have been found to carry one or two B chromosomes. The greater long-tailed hamster belongs to the monotypic genus Tscherskia; the animals described earlier under the names T. (Cricettilus) triton albipes Ognev, 1914 and T. (Cricettilus) triton nestor Thomas, 1907 belong to the only species in the genus, T. triton de Winton, 1899.     

高原鼠兔对炔雌醚、左炔诺孕酮和EP-1不育药饵适口性

采用单只饲养方法,选择燕麦(Arena nuda)、颗粒饲料和胡萝卜(Daucus carota)为基饵,分别测定了高原鼠兔(Ochotona curzoniae)对10mg/kg浓度的炔雌醚、左炔诺孕酮和EP-1药饵的适口性。结果表明,高原鼠兔对燕麦和颗粒基饵具有较高的取食偏好性;3种不育成分均未显著改变雄鼠对药饵的适口性;炔雌醚显著降低了雌性高原鼠兔对燕麦药饵的取食量(P=0.0128);但左炔诺孕酮和EP-1均未显著降低高原鼠兔对燕麦、颗粒饵料和胡萝卜药饵的取食量。总之,高原鼠兔对含有10mg/kg浓度3种不育成分的燕麦、颗粒饵料和胡萝卜药饵具有很好的适口性,具有潜在应用前景。     

Alloparental Responsiveness to Newborns by Nonreproductive,Adult Male,Common Marmosets (Callithrix jacchus)

Parental care in mammals is influenced by sensory stimuli from infants, and by changes in the hormone levels of caretakers. To determine the responsiveness to infant cues in nonreproductive adult male common marmosets (Callithrix jacchus) with and without previous experience in caretaking, we exposed 12 males to newborn marmosets and assessed their cortisol plasma levels and behavioral response. Newborn marmosets housed in transparent enclosures were placed inside the cages of the adult male subjects. Males were exposed four times to two different experimental conditions: (a) newborn enclosures remained closed during the observation period and (b) newborn enclosures were opened during the observation period to allow direct social interaction by the adult males. Blood samples from adult males were collected after each behavioral observation trial to measure the levels of cortisol. The behavioral responses of adult males exposed to the closed and open newborn enclosures showed a significant difference only with respect to the frequency of displacements, where males moved among the quadrants of their own cages with greater frequency when the newborn enclosure was sealed. Experienced males approached newborn enclosures more frequently, spent more time in close proximity, and carried and recovered newborns more quickly than inexperienced males. The successive exposure to newborns increased the responsiveness in inexperienced males. The highest levels of plasma cortisol in adult males were recorded following periods of exposure to the sealed newborn enclosures. This suggests that successive exposure to newborns and previous alloparental caregiving experience while living in family groups influences the responsiveness of male marmosets to the sensory cues of newborns. Am. J. Primatol. 75:145‐152, 2013. © 2012 Wiley Periodicals, Inc.     

重复遭遇战对雌性黑线仓鼠生理状态的影响

以独居型啮齿动物——黑线仓鼠(Cricetulus barabensis)为对象,主要测定了与优势-从属关系有关的体重、生理状态和粪便激素变化规律相关的参数。野生成年仓鼠捕获于鲁西南山区农田并于实验室内单独饲养。按照陌生和体重匹配的原则配对,实验动物在中立竞技场中每天进行15 m in的遭遇战并收集粪便,连续28 d。以攻击行为、防御行为、社会行为、非社会行为确定个体的优势-从属地位。用于实验的动物共33只。行为实验结束后,将动物解剖,确定其繁殖及生理状态。结果表明:4周重复遭遇战期间,(1)优势雌体体重显著增加;(2)肾上腺指数显著降低;(3)雌体肾上腺指数与卵巢指数无显著的相关关系;(4)雌体粪便皮质醇及雌二醇含量随时间表现出明显的波动,但优势与从属个体间差异不显著;(5)优势雌体的粪便雌二醇含量与皮质醇含量呈显著的正相关关系。研究结果提示,重复遭遇战未影响雌体的存活及潜在繁殖能力,这可能与黑线仓鼠的独居生活方式有关。     

Reproductive behaviour of female Siberian lemmings during the increase and peak phase of the lemming cycle

The reproduction of female Siberian lemmings in the increase and peak phases of the lemming cycle was investigated in connection with a ship-borne expedition along the Siberian arctic tundra. The cycle phase of each studied lemming population was determined using demographic analyses, i.e. current density indices (captured lemmings per 100 traps per 24 h), information on previous density (frequency of old lemming faeces and runways), and information from dendrochronological analyses revealing the most recent winters with a high intensity of willow-stem scarring caused by lemmings. The cycle phase determination was corroborated with data on the age profiles of the populations. The reproductive behaviour of female lemmings differed markedly in relation to cycle phase. In increase-phase populations, all captured females (including young and winter born) were reproducing (had embryos or were lactating), and females started to reproduce early in life, i.e. when <2 months old. By contrast, in peak-phase populations, only 6% of the young females and 63% of the winter-born ones were reproducing, and females did not start to reproduce until they were 5–6 months old. The average number of embryos per reproducing female was significantly higher in increase-phase populations than in peak-phase ones. It is concluded that the rapid population growth in lemmings during the increase phase can largely be explained by the early (young age) reproductive start and, consequently, the shorter generation time, the high proportion of females taking part in reproduction, and the large litters produced. Similarly, a delay in the start of reproduction, a lower proportion of reproducing females, and smaller litter sizes produced by peak-phase lemming populations can contribute substantially to the deceleration in the population increase and possibly lead to a decline. Received: 14 June 1999 / Accepted: 15 November 1999     

Powassan virus in Ixodes cookei and Mustelidae in New England.

Powassan virus was recovered from a pool of 3 nymphal and 1 adult female Ixodes cookei removed from a striped skunk (Mephitis mephitis) trapped in Massachusetts during 1967 and from a pool of 9 nymphal I. cookei from a long-tailed weasel (Mustela frenata) captured in Connecticut during 1978. Virus was detected in the blood of both mammals. Hemagglutination-inhibiting (HI) antibody to Powassan virus was demonstrated in 16.0% of the skunks sampled in Connecticut, and neutralizing antibody was detected in 83.3% of the skunks tested from Massachusetts. HI antibody was found in 1 of 6 long-tailed weasels from Connecticut and 1 of 6 short-tailed weasels (Mustela erminea) from Maine.     

Spatial distribution and population composition of the brown mouse lemur (Microcebus rufus) in Ranomafana National Park, Madagascar, and its implications for social organization

Through a 16-mo mark-recapture trap study, I examined aspects of spatial distribution and population composition in the brown mouse lemur, Microcebus rufus, a 42 g nocturnal strepsirhine. The study took place in the rainforest of Ranomafana National Park in southeastern Madagascar. Sherman live traps were set monthly for a variable number of nights in a quasi-grid 50 m apart. Captured individuals were marked for future identification and released at site of capture. More males than females were captured overall (102 versus 72) and at 83% of trap sites. Trap sex ratio fluctuated significantly over the course of the study. It was particularly male-biased between June and August (3.9:1), when more previously uncaptured males than females (14 versus 6) entered the trap population. Some of these males remained in the trap population. Although the average number of individuals captured was not significantly different between the first four and last four months of the study, the composition of the population changed. The female population, however, changed less: 28.9% of all females captured in the first four months of the study were recaptured in the last four months, compared to 9.7% of males. It is suggested that the pattern of appearance of new individuals and disappearance of others, both predominantly male, may indicate migratory activity. Furthermore, an average of eight individuals were captured at each trap site (approximately 70% of traps captured more than five), suggesting a high degree of spatial overlap. The average number of male and female individuals captured in each trap (5.5 males versus 2.5 females), the average number of trap sites at which males and females were captured (3.6 versus 2.4), and the average number of captures for males and females (9.8 versus 5.7) all differed significantly between the sexes.