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1.
笼养红斑羚生态生物学的初步观察   总被引:1,自引:0,他引:1  
This study presents the results of a demographic analysis of 20 years of birth and death records of red gorals kept at the Shanghai Zoo.The age of the first successful breeding,sex ratio at birth,seasonality of reproduction and mortality rate are presented.The females or males of red goral born in captivity can give their first birth at the age of 2 or 3 separately.The births mainly occurred from May to July and peaked in June.Ratio of females to males at birth was 2.36:1.1 The mortality rate for infants and adults were 23.1% and 11.8%,respectively while there was no sub-adult death recorded during the 20 years period.There was a definite relation between mortality rate and seasons and mainly in July.  相似文献   

2.
<正> Theory suggests that males that are larger than their competitors may have increased mating success, due to bothgreater competitive ability and increased attractiveness to females. We examined how male mating success varies with male sizein the tessellated darter Etheostoma olmstedi. Previous work has shown that large males tend to move around and breed in vacantbreeding sites, and consequently provide less care for their eggs, while smaller individuals can be allopaternal, caring for the eggsof other males as well as for their own. We studied female egg deposition in a natural breeding population using artificial breedingsites and in the laboratory, where female choice of spawning site was restricted to two breeding sites tended by two males ofdifferent sizes. In both the field and the laboratory, nests tended by larger males were more likely to receive new eggs. Additionally,the mean size of males associated with a nest was positively correlated with both the maximum coverage of eggs at the nestand the number of times new eggs were deposited. We discuss how the increased mating success of larger males, despite their decreasedparental care, may help explain allopaternal care in this species  相似文献   

3.
Knowledge of sex ratio and spatial distribution of males and females of dioecious species is both of evolutionary interest and of crucial importance for biological conservation. Eurycorymbus cavaleriei, the only species in the genus Eurycorymbus (Sapindaceae), is a dioecious tree endemic to subtropical montane forest in South China. Sex ratios were investigated in 15 natural populations for the two defined ages (young and old). Spatial distribution of males and females was further studied in six large populations occurring in different habitats (fragmented and continuous). The study revealed a slight trend of male- biased sex ratio in both ages of E. cavaleriei, but sex ratio of most populations (13 out of 15) did not display statistically significant deviation from equality. All of the four significantly male-biased populations in the young class shifted to equality or even female-biased, The Ripley's K analysis of the distribution of males with respect to females suggested that individuals of the opposite sexes were more randomly distributed rather than spatially structured. These results suggest that the male-biased sex ratio in E. cavaleriei may result from the precocity of males and habitat heterogeneity. The sex ratio and the sex spatial distribution pattern are unlikely to constitute a serious threat to the survival of the species.  相似文献   

4.
Gender and genetic strain are two prominent variants that influence drug abuse. Although certain sexrelated behavioral responses have been previously characterized in ICR mice, little is known about the effects of sex on morphine-induced behavioral responses in this outbred strain. Therefore, in this study, we investigated the sex differences of morphine-induced locomotion, anxiety-like and social behaviors in ICR mice. After morphine or saline exposure for four consecutive days(twice daily), increased locomotion, more time spent in the central area, as well as attenuated rearing and self-grooming behaviors were found in morphine-treated females in an open field; no differences were found in locomotion and the time spent in the central area between male and female controls. When interacting with the samesex individuals, female controls were engaged in more social investigation, following, body contacting and self-grooming behaviors than controls; morphine exposure reduced contacting and self-grooming behaviors in females; in contrast, these effects were not found in males. These results indicate that female ICR mice are more prosocial and are more susceptible to morphine exposure than males.  相似文献   

5.
Development, survivorship, pupal weight, oviposition, and life table parameters of the oriental tobacco budworm, Helicoverpa assulta Guenée, were evaluated in the laboratory on an artificial diet, pepper (Capsicumfrutescens L.), and tobacco (Nicotiana tobacum L.). We found that the average developmental time of immature stages was longest on tobacco (36.2 d), intermediate on pepper (34.4 d), and shortest on artificial diet (33.5 d). Immature survival from egg to pupa varied from 31% on tobacco, 43% on pepper, and 74% on artificial diet. Pupal weight ranged from 197.4 mg/pupa on tobacco, 233.1 mg/pupa on pepper and 253.4 mg/pupa on artificial diet. The average numbers of eggs laid by adults reared as larvae on the artificial diet, pepper, or tobacco were 614, 421 and 334 eggs/female, respectively. Numbers of remaining eggs in ovaries of the adult females reared as larvae on the artificial diet, pepper, or tobacco were 16, 26, and 42 eggs/female, respectively. The longevity of adult females developed from larvae reared on the three diets was not significantly different, whereas the longevity of male adults from the larvae reared on artificial diet was longer (16.8 d) than that for males reared on tobacco (13.8 d) and pepper (13.3 d). The intrinsic, finite, gross, and net rates of increase were highest for females reared as larvae on artificial diet, lowest for females emerging from larvae reared on tobacco, and intermediate for females emerging from larvae reared on pepper. Generation times and doubling time of H. assulta were shortest for larvae fed artificial diet, intermediate from larvae reared on pepper, and longest from larvae reared on tobacco. We concluded that the artificial diet was the most suitable larval diet ofH. assulta followed by pepper, and tobacco.  相似文献   

6.
Methoprene (an analogue of juvenile hormone) application and feeding on a protein diet is known to enhance male melon fly, Bactrocera cucurbitae Coquillett (Diptera: Tephritidae), mating success. In this study, we investigated the effect of these treatments on male B. cucurbitae's ability to inhibit female remating. While 14-d-old females were fed on protein diet, 6-d-old males were exposed to one of the following treatments: (i) topical application of methoprene and fed on a protein diet; (ii) no methoprene but fed on a protein diet; (iii) methoprene and sugar-fed only; and (iv) sugar-fed, 14-d-old males acted as controls. Treatments had no effect on a male's ability to depress the female remating receptivity in comparison to the control. Females mated with protein-deprived males showed higher remating receptivity than females first mated with protein-fed males. Methoprene and protein diet interaction had a positive effect on male mating success during the first and second mating of females. Significantly more females first mated with sugar-fed males remated with protein-fed males and females first mated with methoprene treated and protein-fed males were more likely to remate with similarly treated males. Females mating latency (time to start mating) was significantly shorter with protein-fed males, and mating duration was significantly longer with protein-fed males compared with protein-deprived males. These results are discussed in the context of methoprene and/or dietary protein as prerelease treatment of sterile males in area-wide control of melon fly integrating the sterile insect technique (SIT).  相似文献   

7.
The effects of powders from dry flower buds of Eugenia aromatica Baill., seeds of Piper guineense Schum and Thonn and fruits of Capsicum frutescens L. on adult behaviour, mortality and reproductive fitness of the cowpea seed beetle, Callosobruchus maculatus (Fab.) were investigated under ambient laboratory conditions. All experiments were carried out in glass Petri plates. All powders elicited aversion in adult beetles. The contact toxicity symptoms included restlessness, loss of coordination, knock down and eventual death of adult beetles. These behaviours were more pronounced with E. aromatica in which adult beetles died within 16 hours. P. guineense and C. frutescens powders did not cause 100% mortality of adult beetles, even after 24 hours. Each of the three powders significantly (P 〈 0.05) reduced the mating competition of adult males after sub-lethal exposure for one, two, and three hours, respectively. E. aromatica powder caused more reduction in male mating competition for females than any of the other two powders after each period of exposure. Receptiveness of treated females to courting males was also decreased by exposure to any of the three powders. Similarly, E. aromatica powder caused greater decreases in female receptiveness to males than any of the other two powders after each period of exposure. Exposure of either adult male or female C. maculatus to the powders for sub-lethal times of three, six and nine hours significantly reduced the fecundity of the beetles. E. aromatica powder caused the most reduction of eggs laid and also significantly reduced fertility of the eggs.  相似文献   

8.
Yan YZ  Xu YS  Chu L  He S  Chen YF 《动物学研究》2012,33(3):e25-e31
Identifying the life-history strategies of fish and their associations with the surrounding environment is the basic foundation in the conservation and sustainable utilization of fish species.We examined the age,growth,and reproduction of Sarcocheilichthys nigripinnis using 352 specimens collected monthly from May 2009 to April 2010 in the Qingyi Stream.We found the sex ratio of this study population was 0.58:1(female:male),significantly different from expected 1:1.Females and males both comprised four age groups.The annuli on the scales were formed during February and March.No obvious between-sex difference was observed in length-weight and length-scale-radius relationships.The total length in back-calculation significantly increased with age for both sexes,but did not differ significantly at each age between the two sexes.An inflection point was observed in the growth curves given by the von Bertalanffy growth function for total weight.At this inflection point,fish were 3.95 years.Both sexes reach their 50% sex maturity at age 2,when females and males were 94.7 mm and 103.0 mm total length.The temporal pattern of the gonado-somatic index corresponded to a spawning period that occurred from April through July.The non-synchronicity of egg diameter in each mature ovary during the breeding period suggested these fish may be batch spawners.The absolute fecundity increased significantly with total length and weight,whereas no significant correlation was observed between the relative fecundity and body size.  相似文献   

9.
Body size and female reproduction in the water adult females larger than 500 mm SVL and 32 adult males Ledong, Hainan under permit to our laboratory in Hainan monitor lizard (Varanus salvator) were studied. Forty-two larger than 400 mm SVL were donated by local people in in 2013 and 2014. The largest male and female measured 745 and 755 mm SVL, respectively. The mean SVL was greater in adult females than in adult males. Males had larger heads (head width) than females of the same SVL. The smallest reproductive female in our sample was 565 mm SVL. Females produced a single clutch of 17.1 (10-23) pliable-shelled eggs per breeding season stretching from mid-June and mid-September. Clutch size and clutch mass were all positively related to female SVL. However, there was no significant linear relationship between egg mass and female SVL. Larger females generally produced more eggs, and thus heavier clutches than did smaller ones. There was no significant linear relationship between relative clutch mass and female SVL. Phylogenetic generalized least squares (PGLS) analysis, accounting for phylogenetic relationships, showed that clutch size was positively correlated with mean maternal SVL in varanid lizards. PGLS analysis showed that phylogenetic relationships did not affect clutch (or/and egg) mass and the SVL although there were significant linear relationship between clutch (or/and egg) mass and mean maternal SVL. Therefore, we could draw some general conclusions about the body size and reproductive tactics in varanid lizards that larger females generally produced more eggs, larger eggs and thus heavier clutches than did smaller ones.  相似文献   

10.
The influence of female age on male mating preference and reproductive success has been studied using a promiscuous cabbage beetle, Colaphellus bowringi Baly (Coleoptera: Chrysomelidae). In a simultaneous choice test, middle-aged females had significantly greater mating success than young and old females. In single pair trials, when paired with middle-aged virgin males, middle-aged females mated faster, copulated longer, and had greater fecundity and fertility than young or old females, while the longevity of males was not significantly affected by female age. This study on C. bowringi suggests that middle-aged females are more receptive to mating, which can result in the highest male reproductive success.  相似文献   

11.
为研究贺兰山岩羊肌肉组织的营养价值,对其组成成分进行分析。结果表明:雌性岩羊与雄性岩羊肌肉组织在磷、锌、氨基酸和脂肪酸的含量方面有所不同。岩羊肌肉是蛋白质和矿物质的良好来源,尤其是钙、磷和铜。与联合国粮食农业组织(FAO)和世界卫生组织(WHO)推荐的理想蛋白质模型(EAA /TAA 比约40% )相比较,岩羊肌肉蛋白质营养价值很高(其中,雄性EAA /TAA 比为39.3% ,雌雄EAA/ TAA 比为39.2%)。通过计算氨基酸评分和氨基酸化学评分,岩羊肌肉蛋白中缬氨酸为限制性氨基酸,赖氨酸含量很高。此外,岩羊肌肉也是亚油酸和亚麻酸的良好来源。  相似文献   

12.
2003 年和2004 年的11 ~12 月,采用样线法和全事件取样法研究了贺兰山岩羊的集群特征。共观察到岩羊715 群,共计2 473只。发情前期平均群大小3.5±2.8 只(n = 241),发情期平均群大小3.4±3.2 只(n =297)。发情前期与发情期雄性群、雌性群、雌雄群、混合群及母子群大小间均无显著差异。发情前期到发情期群类型组成差异极显著,发情期雌雄群、混合群和独羊比例显著上升;雄性群、雌性群和母子群比例显著下降。发情前期到发情期,雄性岩羊在雄性群、雌雄群、混合群和独羊中的分布差异极显著,成年雌性岩羊在雌性群、雌雄群、混合群、母子群和独羊中的分布差异极显著。发情期4 个年龄等级雄性在雄性群、雌雄群、混合群和独羊中分布差异极显著,4 个年龄等级雄性岩羊都倾向分布于混合群。
  相似文献   

13.
为了解宁夏贺兰山岩羊的种群现状,2020-2021年的8月和12-1月,在宁夏贺兰山国家级自然保护区运用样线法对岩羊(Pseudois nayaur)进行种群数量调查,利用R 4.0.1中的Distance 1.0.2对样线观测数据进行分析,估测保护区内岩羊的种群数量及密度,分析其种群结构。结果显示,夏季岩羊种群数量为5176(2554-10490)只,种群密度为2.674(1.320-5.420)只/km2;冬季岩羊种群数量为15752(7294-34017)只,种群密度为8.139(3.769-17.58)只/km2;多数观测距离样线垂直距离在0-200 m之内。岩羊主要集群形式:夏季为雌幼群(52.17%);冬季为混合群(26.60%)。岩羊平均群大小:夏季为(6.261±8.023)只,冬季为(4.064±4.229)只,群大小在不同季节的差异显著(P=0.010),集群大小多集中于1-5只之间,最大为47只。夏季调查中,雄性个体占比11.27%,雌性个体占比56.74%,幼体/亚成体占比31.99%;冬季调查中,雄性个体占比29.61%,雌性个体占比50.15%,幼体/亚成体占比20.24%;夏季和冬季岩羊组成成分之间差异极显著(P<0.001)。  相似文献   

14.
贺兰山岩羊不同年龄和性别昼间时间分配的季节差异   总被引:18,自引:0,他引:18  
2003年11月-2004年10月在宁夏贺兰山国家级自然保护区苏峪口国家森林公园,在每个月的11-20日采用瞬时扫描取样法,利用SJ-1型电子事件记录器观察记录岩羊的取食、休息、运动、站立和其他行为.冬季每天的观察时间为800-1700,春、秋季为700-1800,夏季为600-2000.采用非参数估计中的2个相关样本的Wilcoxon检验、2个独立样本的Mann-Whitney U检验和K个独立样本的Kruskal-Wallis H检验对岩羊不同性别、年龄以及季节变化进行了比较.结果表明,①岩羊行为的年时间分配,取食行为最高[(63.49±7.82)%];其次是休息[(19.32±6.79)%];运动和站立较低[分别占(8.03±0.91)%和(6.66±0.57)%];其他行为所占比例最低[(2.67±0.34)%];一年中7月取食行为最低,休息最高;而在2月取食最高,运动、站立和其他行为变化不大.②春夏秋3个季节的昼间取食行为均呈现2个(清晨和黄昏)明显高峰;冬季1天中取食均达到60%以上,其他行为明显高于另外3个季节.③不同年龄年取食行为成体和亚成体>幼体;休息成体和亚成体<幼体;运动和站立幼体<成体和亚成体;亚成体的运动高于成体,而站立低于成体.④不同性别月取食行为雄性在2月最高,其余月份均低于70%;而雌性虽然也是2月最高,但从11月-次年2月均超过70%;休息行为雌雄接近;运动行为雄性高于雌性.贺兰山岩羊的昼间时间分配与许多温带有蹄类动物一样,食物数量和质量的变化以及岩羊自身不同的生长阶段和生理时期是决定其昼间时间分配的主要因素.  相似文献   

15.
樊晓丽  雷焕宗  林植华 《生态学报》2012,32(17):5574-5580
体温是影响变温动物表现的最重要生理学变量。检测了国家二级保护动物虎纹蛙的雌性亚成体、雄性亚成体、幼体和蝌蚪这4个发育阶段的选择体温和热耐受性。单因子方差分析表明,虎纹蛙选择体温、耐受低温、耐受高温和温度耐受范围的组间差异均显著,幼体的选择体温(24.13℃)显著低于雌性亚成体(28.06℃)、雄性亚成体(29.27℃)和蝌蚪(28.23℃),雌性亚成体、雄性亚成体和蝌蚪之间差异不显著;幼体的耐受低温(13.85℃)显著高于雌性亚成体(11.27℃)、雄性亚成体(10.84℃)和蝌蚪(10.74℃),雌性亚成体、雄性亚成体和蝌蚪之间差异不显著;幼体具有显著低的耐受高温(35.48℃)、蝌蚪具有显著高的耐受高温(43.31℃),雌性亚成体(39.55℃)和雄性亚成体(39.02℃)的耐受高温差异不显著;幼体(21.62℃)具有显著小的温度耐受范围、蝌蚪(32.58℃)具有显著大的温度耐受范围,雌性亚成体(28.28℃)和雄性亚成体(28.18℃)的温度耐受范围差异不显著。虎纹蛙幼体和亚成体体温和水温之间在降温速度和升温速度的相关关系均显著。用回归剩余值去除水温变化速度对体温变化的影响,双因子方差分析(降温和升温速度为重复检验设置)表明,幼体的体温变化速度显著大于亚成体,两性亚成体间差异不显著;温度变化类型(降温和升温)和两因子的交互作用对体温变化的影响不显著。基本热生态位分离和体温调节能力的发育限制是形成上述现象的最可能的原因。  相似文献   

16.
贺兰山岩羊冬季对卧息地的选择   总被引:22,自引:3,他引:19  
2003 年11~12月, 在贺兰山采用样带法对岩羊冬季卧息地的选择性进行了研究。共观察到94 个岩羊的卧息地, 结果表明岩羊对优势乔木的利用有选择性( x2 = 17.01 , df = 5 , P < 0.05) , 偏好利用灰榆占优势的卧息地, 避免选择油松和青海云杉占优势的卧息地; 对坡向选择性利用( x2= 30.69, df =2, P < 0.05) , 偏好位于阳坡的卧息地, 避免利用阴坡; 对植被类型、坡位和风向的利用无选择性。对卧息地样方与在样带中随机设置的样方进行比较, 发现卧息地具有乔木密度低、食物丰富度低、隐蔽程度高、接近水源、接近裸岩、风速低和雪覆盖浅等特征。贺兰山的岩羊经常选择岩洞作为卧息地, 占总卧息地的62.77 %。对59 个岩洞和35 个非岩洞卧息地进行比较, 表明岩洞卧息地的坡度大、隐蔽程度高、风速低、保温性好、食物丰富度低和无雪覆盖。岩羊通常选择较宽的、深度和高度适中的岩洞作为卧息地。对各种生境因子的主成分分析表明前7 个特征值的累积贡献率已经达到了80.09%, 可以较好地反映岩羊卧息地的生境特征, 第1 主成分中隐蔽级、风向、风速、距裸岩距离和雪深具有重要作用, 其余6 个主成分中优势乔木、坡向、坡位和坡度也很重要。  相似文献   

17.
The monitoring of animal populations is necessary to conserve and manage the rare or harvest species and to understand the population change over several years. We used distance sampling methods to estimate seasonal density of blue sheep in a 2,740 km2 area of Helan Mountain region by walking along 32 transect lines from winter 2003 to autumn 2005. In all, 367–780 blue sheep were observed in 91–143 groups in the surveys during the seasons. Observed mean group size ranged from 3.42 to 8.35 individuals; encounter rate, the number of groups detected per kilometre, varied from 0.19 to 0.30 during the seasons. A hazard rate key function with cosine series expansion and a half-normal key function with either cosine or simple polynomial series expansion were the best fitting models based on the lowest value of Akaike’s information criterion (AIC). Density estimates varied between 3.627 sheep per square kilometre in spring 2004 and 4.635 per square kilometre in summer 2005. There were no detectable differences in estimated density among seasons (P = 0.887). The estimated density of blue sheep was negatively correlated with the total number of deaths (P < 0.05), number of sub-adult males’ deaths (P < 0.05), number of sub-adult females’ deaths (P < 0.05), and number of male lambs’ deaths (P < 0.05). We concluded that distance sampling surveys should be used to monitor long-term population trends to provide the best quantitative estimates of blue sheep populations in the Helan Mountains region.  相似文献   

18.
唐家河自然保护区扭角羚的兽群结构及数量分布   总被引:16,自引:7,他引:9  
四川唐家河自然保护区有扭角羚480-520只。喜聚群活动,其兽群可分为家群、族群和聚集群。并随季节变化而有分群和合群现象。此外还有游离于群体之外的独羚,多为成年雄体。其兽群幼仔占17.52±6.48,亚成体占17.25±9.16%,成体占65.23±12.59%,聚集群中成体雄雌比为1:8,雌体占多数。  相似文献   

19.
The feeding habitat selection of blue sheep (Pseudois nayaur)was studied by direct observation method in the Helan Mountains,China during winter (from November to December)and spring (from April to June)from 2003 to 2004.We established 25 line transects to collect information on feeding habitats used by blue sheep.Blue sheep in the study area preferred mountain savanna forests,a habitat dominated by Ulmus glaucescens,with medium tree density (<4 individuals/400 m2),moderate tree height (4-6 m),higher shrub density (>5 individuals/100 m2),higher shrub (>1.3 m),higher food abundance (>50 g),moderate distance to human disturbance (<500 m),and mild distance to bare rock (<2 m).Such habitats characterized by 12 ecological factors were preferred as feeding areas by blue sheep during winter.Similar to habitat selection by the species during winter,blue sheep also showed a preference for mountain savanna with tree dominated by Ulmus glaucescens and medium tree density (<4 individuals/400 m2)during spring.Nevertheless,blue sheep preferred medium tree height (<6 m),moderate tree density (5-10 individuals/100 m2),medium shrub height (1.3-1.7 m),higher food abundance (>100 g),moderate altitude (<2 000 m),moderate distance to water resource (<500 m),and medium hiding cover (50%-75%)during spring.Selection of the feeding habitats by sheep showed a significant difference in vegetation type,landform feature,dominant tree,tree height,shrub density,distance to the nearest shrub,food abundance,slope direction,slope degree,distance to water resource,and hiding cover between winter and spring.Results of principal components analysis indicated that the first principal component accounted for 24.493%of the total variance among feeding habitat variance during winter,with higher loadings for vegetation type,dominant tree,tree height,distance to the nearest tree,shrub density,shrub height,altitude,distance to water resource,and distance to human disturbance.In spring,the first principal components explained 28.777%of the variance,with higher loadings for vegetation type,distance to the nearest tree,shrub height,distance to the nearest shrub,food abundance,altitude,and distance to human disturbance.  相似文献   

20.
Summary The monogamous and protandrous anemonefish,Amphiprion clarkii, utilizes only large host sea anemones as breeding sites. Under conditions of breeding site shortage, an important strategy for unmated fish may be to prepare themselves to enter quickly a breeding site from which a breeding male or female has recently disappeared. There are two types of subadults. Some juveniles become subadult males, which can change either to male or female afterwards, but others become subadult females, which can change only to female. Subadult females seem to acquire female posts more easily than subadult males. We develop an ESS model which evaluates the future reproductive success of subadult females and subadult males and test whether coexistence of subadult males and females can be interpreted as adaptive alternative tactics, using field data from two populations. The model predicts that if mortality does not differ between adult males and females the frequency for juveniles to become subadult females should be equal to the proportion of breeding post acquisition by subadult females among that by all subadults. The model also predicts that if mortality does not differ between subadult males and females, nor in adults, the frequency of subadult females among all subadults should be equal to the proportion of post acquisition. The model, with data from two study sites, suggests that alternative life-history pathways found inA. clarkii have evolved through adaptive tactics of breeding post acquisition.  相似文献   

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