黑线姬鼠(Apodemus agrarius)的种群繁殖参数及其地理分异特征

黑线姬鼠（Apodemus agrarius）是我国广大地区的主要害鼠之一,是余庆县农田害鼠优势种,占总鼠数的94.81%。探讨其种群繁殖参数的变动规律及其地理分异特征,对其种群数量预测预报具有重要意义。通过对1987-2005年贵州省余庆县黑线姬鼠种群繁殖参数分析结果表明：研究期间共解剖标本5497只,其中,雌鼠2698只,雄鼠2799只,黑线姬鼠在当地1-11月份均可繁殖,主要繁殖期在3-10月份,每年4-5月份和8-9月份出现2次妊娠高峰。种群总性比（♀/♂）为0.96,多年平均怀孕率为36.91%±6.79%,平均胎仔数为5.33±1.07只,平均繁殖指数为0.81±0.17,平均睾丸下降率为59.13%±7.89%。不同年龄组种群繁殖力存在显著差异,随着种群年龄的增长繁殖力不断增加,成年Ⅰ组、成年Ⅱ组、老年组是种群繁殖的主体。种群繁殖参数不同年度之间比较稳定,不同月份、不同季节之间变化差异较大,具有明显的季节变化特征。年均种群密度与年均繁殖指数呈极显著正相关,与胎仔数显著正相关,与年均怀孕率、睾丸下降率、性比相关性不显著,繁殖指数是影响黑线姬鼠种群密度的重要因子。比较全国各地黑线姬鼠种群繁殖参数的地理分异特征认为,黑线姬鼠种群繁殖参数具有明显的地理分异现象,胎仔数、生殖强度由南向北逐渐增加,具有随纬度的升高趋向增加的特征;在高纬度地区繁殖时间较短;性比与纬度、经度的变化关系密切;各繁殖参数与海拔的变化相关性不明显,可排除海拔因素的影响。     

千岛湖秋季社鼠种群年龄结构及繁殖状况初探

2007 年9 ～11 月,对千岛湖不同类型岛屿捕获的123 只社鼠的年龄结构及繁殖状况进行研究,结果表明:9 ～ 10 月为千岛湖区社鼠种群的繁殖高峰期,较同纬度其他地区早。雌鼠从亚成年组出现怀孕个体,雄鼠较雌鼠性成熟早,幼年组已出现睾丸下降个体。大、中、小型岛屿年龄结构不同,分别为稳定型、衰退型及增长型。岛屿大小能够对社鼠种群繁殖指标产生影响,大型岛屿雌鼠繁殖指数(1. 96) 与平均胎仔数(4.9 ± 0.35 只)及雄性个体睾丸下降率(50.0%)均较高,社鼠种群稳定;中型岛屿雌鼠的繁殖指数(3.45) 与平均胎仔数(5.17 ± 0.42 只)为3 种类型岛屿中最高,并且雄鼠的睾丸下降率(64.7% )也相对较高,有利于社鼠种群数量增加;小型岛屿雄鼠的睾丸下降率虽然最高(68.4% ),但雌鼠繁殖指数(0.75)与平均胎仔数(4.00 ±1.53只)均较低,且参与繁殖的主体成年组性比(10∶ 5)失调,种群易出现波动。另外,社鼠的繁殖情况与植被类型和人为干扰也有较大的关联。     

棕色田鼠种群繁殖特征及密度制约调节(英)

1992年～1994年在河南灵宝市郊黄土高源农作区春夏秋逐月捕获并解剖棕色田鼠1757只（雌性961只,雄性796只）,总性比为1．2073。全年都有繁殖鼠出现,但怀孕率、胎仔数、性比、繁殖指数有明显的季节变化,年间也有一定的差异。不同年龄组的性比、怀孕率、胎仔数、繁殖指数、睾丸下降率不同。种群密度对繁殖特征有明显的调节作用。高密度年份的棕色田鼠的性比、怀孕率和繁殖指数低于低密度年份。高密度区种群的繁殖强度受到抑制,雌鼠怀孕率、睾丸下降率低于低密度种群。     

棕色田鼠种群繁殖特征及密度制约调节

１９９２－１９９４年在河南灵宝市郊黄土高原农作区春夏秋逐月捕获并解剖棕色田鼠１７５７只,总性比为１．２０７３。全年都有繁殖鼠出现,但怀孕率、胎仔数、性比、繁殖指数有明显的季节变化,年间也有一定的差异,不同年龄组的性比、怀孕率、胎仔数、繁殖指数、睾丸下降率不同化率较为接近种群密度对繁殖特征有明显的调节作用高密度年份的棕色田鼠的性比、怀孕率和繁殖指数低于低密度年份,高密度区种群的繁殖强度受到抑制,雌鼠     

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。     

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。     

福建省莆田地区小家鼠种群繁殖的研究

1987—1989年,作者在福建省蒲田地区采集小家鼠标本1616号(雌865,雄751),解剖、观察雌雄生殖器官的特征和变化,对种群中的性比、睾丸下降率、繁殖雌鼠率、怀孕率、胎仔数、繁殖指数的季节变化和年度差异作了分析。结果表明,该地区小家鼠全年均可繁殖。雄性小家鼠体重≥10克,雌性体重≥11克时,已有75％以上达性成熟,故体重可作为划分成体的标准。种群密度对种群繁殖有明显的反馈调节作用。     

鄱阳湖区黄毛鼠(Rattus losea)繁殖生态

2015—2016年对鄱阳湖区的滨湖农田和湖滩草洲的黄毛鼠种群繁殖进行了研究。研究结果表明,其种群雌雄比为81.36%,在不同的季节、生境和年龄组之间都有一定的差别,雌雄比在夏季较低,春、秋、冬季的雌雄比都超过了50.00%,其中冬季的达到了133.33%。农田和湖滩草洲上的雌雄比也都超过了50.00%,且农田的高于湖滩草洲的。在不同的年龄组之间,雌雄比最高的为幼体组140.00%,其次为成体90.20%。所有雌鼠全年的怀孕率为45.26%,平均胎仔数为6.74只,繁殖指数为1.36。夏和秋季的怀孕率都较高,冬季未捕获到怀孕鼠,仅捕获到有怀孕经历(有宫斑)的雌鼠。从繁殖指数看,春、秋季维持高峰水平,且秋峰高于春峰。雌性黄毛鼠总的参产率为71.58%,各季节间变化呈现单峰曲线,夏季最高,其次是秋季和春季,冬季停止怀孕。随着年龄的增长,平均胎仔数有明显增加的趋势,成体组胎仔数最高,而繁殖指数也是以成体组最高,说明成体组是种群中繁殖的主体。雄性黄毛鼠的睾丸下降率全年总计为81.36%,分四季平均为79.64%,春、夏、秋季都维持在较高水平,冬季最低。下位睾丸的大小季节性差异极显著(P0.01),春季与冬季相比,有显著性差异,说明开春后,雄性黄毛鼠在生殖潜能上已有明显变化。这些特征与雌鼠的繁殖高峰基本吻合。说明黄毛鼠主要在春、夏、秋季繁殖,繁殖盛期在春、秋季。从不同的年龄组看,幼体组个体不参与繁殖,亚成体组个体开始参与繁殖,繁殖主体是成体组个体。     

不同干扰荒漠生境中子午沙鼠的繁殖及种群动态特征

子午沙鼠(Merionesmeridianus)广泛分布于我国西北部地区,是荒漠啮齿动物群落的优势鼠种。种群繁殖特征是动物生活史参数中的一个重要组成部分,是种群数量补充的重要来源,而干扰是影响繁殖特征的重要因素。本研究于2012~2014年,在位于蒙古阿拉善左旗南部典型荒漠的野外实验区,设置禁牧、开垦、过牧、轮牧4种不同干扰样地,使用铗日法对实验样地子午沙鼠相对数量及繁殖特征进行调查。4种不同干扰生境中的子午沙鼠种群数量具有显著差异,禁牧过牧轮牧开垦;雌雄性比在轮牧生境中最高,开垦生境次之,禁牧生境最低;4种干扰生境中,轮牧样地子午沙鼠雌鼠怀孕率显著高于禁牧、过牧和开垦样地;雄鼠的睾丸下降率在过牧干扰样地显著高于其他3种干扰方式样地,轮牧样地雄鼠睾丸下降率最低;雌鼠平均胎仔数在4种干扰生境间无显著性差异;轮牧干扰样地繁殖指数显著高于其他3种干扰方式样地;繁殖指数、怀孕率及睾丸下降率对密度的反馈作用最为明显,但在不同的干扰生境中其反馈特征有差异。综上,子午沙鼠在轮牧生境中各繁殖特征指数最高,繁殖能力最强,种群密度相对较高,更适合其生存,其密度制约效应表现最为明显。     

北京地区黑线姬鼠种群年龄和繁殖的研究

1982-1986年,作者在北京农业区研究黑线姬鼠种群的年龄和繁殖,共解剖标本1360号(684公, 976母)采用嗣体重划分出4个年龄组,研究睾丸重量与性成熟的关系,确定睾丸重0.5克为性成熟线。种群一年更新一次,个体年繁殖2—3胎,当年出生的鼠基本不参加繁殖,胎仔数有年度差异,1982年为6.18±0.35,1983年为5.29~0.13,1984年为5.97±0.13,1985年为5.69±0.20。     

四川荥经县赤腹松鼠体重及脏器湿重的性别与季节差异

以2015年1月至12月捕自四川荥经县的310只成体赤腹松鼠(Callosciurus erythraeus,雄鼠174只,雌鼠136只)为研究对象,分析了其体重及7种内脏器官湿重的性别和季节差异,以及妊娠对内脏器官湿重的影响。1)雌、雄鼠的体重无性别和季节差异。2)心湿重雌、雄鼠差异显著,春季雄性大于雌性,夏季相反;肝、脾、肺和肾的湿重均无性别差异。3)肝湿重夏、冬季高于春、秋季;脾湿重秋季高于冬季和春季;肺湿重春季最高,夏季最低;肾湿重冬、春季高于夏季;心湿重雄鼠秋季高于夏、冬季,雌鼠夏、秋季高于冬季;睾丸和子宫湿重都在春季最高,秋季最低。4)妊娠鼠肝、肺和肾湿重均高于未妊娠鼠。结果表明,随着季节更替赤腹松鼠的体重维持稳定,雌、雄鼠心湿重差异显著,且器官湿重表现出了一定的弹性,这可能与雌、雄鼠的繁殖状态及季节性环境的多样性变化有关。     

Age-specific reproductive performance of female polar bears (Ursus maritimus)

Age-specific patterns of maternal weight, litter size, litter weight and reproductive effort were investigated for polar bears ( Ursus maritimus ) from western Hudson Bay. Most relationships were described by quadratic equations. Maternal weight in spring and autumn increased until 17 and 15 years of age, respectively, and then declined. Age-related increases in maternal weight were thought to be associated with improving hunting skills. The relationships between age and litter size, litter weight and reproductive effort, in both the spring and autumn, increased until 14 to 16 years, followed by a decline. We speculate that age-related decreases in reproductive performance are due to undetennined processes associated with ageing that impair the accumulation of fat stores necessary for reproduction. Pregnant females lost an average of 127 kg overwinter which represented an average of 43.5% of their autumn weight. Fat stores remaining after the overwinter fast may be critical for maintaining an energy supply to cubs once they return to the sea ice where the distribution and abundance of their prey is unpredictable. We suggest that maternal condition is an important factor contributing to lifetime reproductive success in polar bears.     

Reproduction in the European hare in southern Sweden

Reproduction in the European hare Lepus europaeus Pallas populations was studied in three study areas in South Sweden during 1974–1976; two on the mainland and the third on the Island of Ven in Öresund. The monthly birth rates was calculated on the basis of the age of juvenile hares shot in autumn. The first births always occurred in February, indicating that the onset of the breeding season was governed by day length rather than by climate. Later, the reproduction rate was determined by temperature, snow cover, and precipitation. Low temperatures in spring delayed the reproduction; high temperatures in autumn favoured a prolongation of the breeding season. Low precipitation in May-July caused a decline in reproduction in July in a sandy pasture area, mainly because water amount was low in the green forage. Annual fertility, estimated on the basis of placental scars, varied between 6.8 and 8.9 young per female. There was a significant negative correlation between fertility and population density. The largest variations were recorded in one-year-old females, and on average the values were significantly higher in three-year-old females. 68% of all females examined had three litters annually; four litters were found in only 13% of all females. The mean litter size for the whole period was about 2.9 in all areas. The size of the first litter was significantly higher in females producing one or two litters than in females with three or four litters. The postnatal losses were on average 30–35% lower in the island population than in the mainland populations (73–84%), probably due to lack of predators, sparse road traffic, and inhibited juvenile dispersal.     

Breeding of African green monkeys (Cercopithecus aethiops) under indoor individually-caged conditions.

This paper reports the results of reproduction with 45 wild African green monkeys (Cercopithecus aethiops) (36 females and 9 males) during the nine years from 1981 to 1989 under indoor individually-caged conditions. In 206 cases of menstruation observed, menstrual discharge lasted for 2.5 +/- 1.2 days in cycles of 22-48 days, and the length of each menstrual cycle was 31.2 +/- 6.5 days. Females who had regular menstrual cycles were subjected to "one-to-one timed mating"; females and males were put together on a one-to-one basis daily only for a certain period of time on and after the day of ovulation. Females who had irregular menstrual cycles or had no menstruation were subjected to "every-other-day mating"; females and males were put together on a one-to-one basis every other day for at least 16 weeks. The pregnancy rate (No. of pregnant females/No. of mated females) by one-to-one timed mating was 48.9% (116/237); 2.0 mating trials were needed to obtain one case of pregnancy. On the other hand, the pregnancy rate (No. of pregnant females/No. of mating trials) by every-other-day mating was 96% (48/50). Females who delivered normally totaled 129. The mean gestation period was 165 days when males, weighing 343 g on average at birth, were delivered, and 166 days when females, weighing 318 g on average at birth, were delivered. The male and female newborns were nursed for 131 and 138 days, respectively, on average. Details are summarized in Table 3. This paper also reports 23 cases of abortion, 6 stillbirths, and 6 cases of Caesarean section, by which three live fetuses and three dead fetuses were obtained.     

高原鼠兔种群繁殖生态的研究

1985—1988年,在青海湖黑马河地区以耳标法对高原鼠兔的繁殖生态进行了研究。在繁殖群体中主要是来自上年出生的第1、2胎的鼠兔(82.85％),第3胎和老体占少数。成年雌鼠兔100％参加繁殖,通常年产3胎,有的年份可产4胎或5胎。产仔数1—8只(平均为4.52±0.12),1只雌鼠兔终生可产2—29只。妊娠期为22.2±0.13天。洞内哺乳期为11.65±0.01天。有的年份当年出生的少数雌鼠兔到36.8+3.05日龄可达到性成熟并参加繁殖,生1—2胎。雄鼠兔性成熟较晚。     

武汉三角湖浮游甲壳动物群落结构

三角湖是长江中下游地区典型的小型城市湖泊,近年来其富营养化趋势明显。2014年7月至2015年6月对湖中浮游甲壳动物群落及其影响因子进行了调查,旨在为湖泊污染防治和生态修复提供依据。在三角湖共采集浮游甲壳动物9科17属22种。浮游甲壳动物全年平均密度为(3.7±3.6)ind/L,各月密度变化范围为0.6~13.1 ind/L,夏季和秋季密度较低,密度峰值出现在2月。浮游甲壳动物全年大部分时间(5、6月除外)以桡足类及无节幼体占优势,其比例为55.2%~95.4%。浮游甲壳动物物种丰富度变化范围为6~15,平均值为10±3,夏季浮游甲壳动物物种丰富度较低。浮游甲壳动物群落Simpson指数变化范围为0.76~0.90,平均值为0.80±0.04。Pearson相关分析表明,浮游甲壳动物总密度与水深呈显著负相关(r=﹣0.636,P0.05,n=11),显示季节性的水位波动影响浮游甲壳动物密度。典范对应分析(CCA)显示,水温和透明度是影响浮游甲壳动物物种组成季节变化的主要环境因子(P0.05)。高密度的鲢(Hypophthalmichthys molitrix)、鳙(Aristichthys nobilis)放养引起的摄食压力可能是三角湖浮游甲壳动物密度较低的主要原因之一。     

臭鼩的繁殖和种群年龄结构

对浙江萧山瓜沥区农田臭鼩的研究,发现种群性比不等,存在明显的两性异型。分析了雄体的性成熟率和雌体的怀孕率及性活动率的变化规律。一年中存在两个繁殖高峰期。以齿长指数为指标．臭鼩种群可划分为4个年龄组。探讨了种群年龄结构的季节变化及其自然寿命。     

Effect of indomethacin on reproduction under laboratory and field conditions in deermice (Peromyscus maniculatus)

The purpose of this investigation was to determine the long-term effect of enterically administered indomethacin (a prostaglandin synthetase inhibitor) on reproduction in Peromyscus maniculatus (deermice) under both laboratory and field conditions. Indomethacin-coated wheat (1 mg/kg wheat) was provided to the experimental animals in the laboratory and under field conditions ad libitum. Rat chow was also provided to the animals in the laboratory. The laboratory data indicate that the number and size of the litters from the control breeding pairs were larger (number of litters=22; average number of pups/litter=4.9) than the experimental breeding pairs (number of litters=2; average number of pups/litter=2.5) over a 100-day experimental period. Field data indicate that the number of pregnant animals, the total number of animals, and mean juvenile males and females live-trapped decreased in the experimental group with respect to the control group during the experiment. The data suggest that deermice will consume indomethacin under both laboratory and field conditions, and that it effectively inhibits reproduction on a long-term basis. It is, therefore, possible that prostaglandin synthetase inhibitors may be used to control populations of rodent pests. Additionally, the data raise questions about the effect of long-term use of nonsteroidal analgesic compounds similar to indomethacin on human reproduction.     

Seasonal change and sex difference in laurate hydroxylase activity in frog liver microsomes

The content of cytochrome P-450 and the specific activity of laurate hydroxylation have been measured at monthly intervals through the year in liver microsomes of males and females of Japanese bullfrog, Rana catesbeiana. The specific activity, based on microsomal protein or cytochrome P-450 of both sexes was higher in spring (April-May) than in autumn (October-November) and the difference was statistically significant. However, in males the content of the cytochrome P-450 in the spring was almost the same level as in the autumn and it was rather lower in the spring than in the autumn in females. These suggest that the cytochrome P-450 species catalyzing laurate hydroxylation increased specifically in the spring. The specific activity (based on cytochrome P-450) in males was significantly higher than that in females in spring (April-May) or autumn (October-November).     

贵州发现毛翼管鼻蝠和华南菊头蝠及其回声定位声波特征

2017年5月分别在贵州省兴义市和安龙县用雾网采集到1只大体型雌性管鼻蝠和2只小体型雄性菊头蝠,经鉴定为毛翼管鼻蝠(Harpiocephalus harpia)和华南菊头蝠(Rhinolophus huananus),属贵州省翼手目新分布记录。所采集的毛翼管鼻蝠雌性个体可能为怀孕个体,故测量相关数据并鉴定后原地放归野外。华南菊头蝠标本保存于东北师范大学环境学院。毛翼管鼻蝠(1♀):鼻部呈短管状,全身被毛厚密而柔软,后足、翼膜和尾膜均被覆黄褐色绒毛;体重14.01 g,前臂长48.23 mm;回声定位声波为调频(FM)型,静止状态下声波峰频为(56.04±4.52)k Hz。华南菊头蝠(2♂):耳大,对耳屏相对较小;鼻叶之蹄状叶宽大,完全覆盖吻部;鞍状叶小,其高略超过其宽,近乎矩形;体毛烟褐色;2只样本体重分别为4.52 g、4.12 g,前臂长40.70 mm、40.00 mm;头骨狭长,颅全长16.35 mm、16.46 mm,颅宽8.11 mm、8.14 mm;回声定位声波属调频-恒频-调频(FM-CF-FM)型,静止状态下峰频分别为(68.48±0.08)k Hz、(67.18±0.06)k Hz。2种蝙蝠物种在贵州省为首次发现,扩大了其在国内的分布范围,丰富了生态资料,为进一步的研究和保护提供了基础资料。