拉布拉多犬的母性行为水平对幼犬胆量的影响

母性行为是动物以维持幼崽的生存及生理健康为主要目的的一种基本行为,母性行为作为重要的早期经历对动物的个体发展有深远影响。动物的行为在时间和环境中具有一致性,多个行为特征的一致性加权被称为气质特征,气质特征的差异是犬(Canis lupus familiaris)能否顺利通过培训成为导盲犬的决定性因素。其中,胆量是决定导盲犬培训成功与否的重要气质特征。本研究以中国导盲犬大连培训基地的拉布拉多种犬及幼犬为研究对象,探究母性行为水平对幼犬胆量的影响。本研究通过视频观察记录拉布拉多犬哺乳期前21 d的母性行为变量时长,对在哺乳区内、身体接触、哺乳和舔舐幼犬4项变量进行主成分分析后将7只实验犬分为母性行为高水平与低水平两组。对两组犬生产的共54只幼犬于6 ~ 8周龄时进行幼犬胆量行为测试,根据胆量行为测试的评分标准对幼犬的行为表现进行评分,统计分析母性行为高水平组与低水平组其幼犬的胆量是否存在差异。本研究结果表明,母性行为低水平组的幼犬在胆量测试中面对陌生环境、突然出现的响声刺激、突然打开的雨伞刺激以及陌生人的游戏邀请时均表现出更大的胆量。在被动测试中,母性行为低水平组幼犬的探索潜伏时长显著短于母性行为高水平组幼犬(P < 0.05),探索范围显著大于母性行为高水平组幼犬(P < 0.05),紧张程度极显著低于母性行为高水平组幼犬(P < 0.01);在金属响声测试中,母性行为低水平组幼犬的惊吓反应(P < 0.01)和紧张程度(P < 0.01)均极显著低于母性行为高水平组幼犬;在雨伞测试中,母性行为低水平组幼犬的紧张程度显著低于母性行为高水平组幼犬(P < 0.05);在玩具测试中,母性行为低水平组幼犬的玩耍兴趣显著高于母性行为高水平组幼犬(P < 0.05),紧张程度显著低于母性行为高水平组幼犬(P < 0.05);在斜坡隧道测试中,母性行为低水平组幼犬的紧张程度显著低于母性行为高水平组幼犬(P < 0.05),通过斜坡的用时短于母性行为高水平组幼犬,但经统计检验无显著差异(P > 0.05)。本研究的结论为低母性行为水平带给幼犬强度适当的早期生活压力,使幼犬面对新环境刺激时表现出更好的适应能力和较大的胆量。本研究为工作犬种犬的筛选提出新的建议：母性行为水平低的种犬对幼犬胆量的发展有更好的影响。     

圈养马麝的胆量个性及与麝香分泌和繁殖成效的关系

采用新异物刺激的方式,建立马麝惊扰反应强度指数,通过马麝惊扰后的状态量化其胆量水平,对甘肃兴隆山麝场圈养马麝交配季节和非交配季节胆量(Boldness)进行行为学研究。结合泌香量和产仔量数据,分析胆量对麝香分泌、繁殖成效的效应;同时分析了圈区环境、性别、年龄与马麝胆量之间的关系,以及交配季节与非交配季节间胆量的相关性。结果表明:圈区环境对个体胆量无显著影响(交配季节P = 0.799;非交配季节P =0.152),性别对个体胆量也无显著影响(交配季节P = 0.144;非交配季节P = 0.733),而年龄对个体胆量存在显著影响(交配季节P = 0.012;非交配季节P =0.009),个体年龄越大,胆量越大;交配季节与非交配季节之间胆量呈显著正相关(r =0.592,P < 0.001),但并无明显差异(P =0.095);雄麝泌香量与非交配季节胆量之间存在显著负相关(r = - 0.607,P = 0.016),雌麝繁殖成效与交配季节胆量之间存在显著正相关(r =0.362,P = 0.045)。圈养马麝胆量个性受年龄因素的影响,并在交配季节与非交配季节之间存在一致性,非交配季节胆量更高的雄麝泌香量趋于更少,交配季节胆量更高的雌麝产仔数趋于更多。     

The effects of early and adult social environment on zebrafish (<Emphasis Type="Italic">Danio rerio</Emphasis>) behavior

Because early social experience can have a profound effect on later mate and social choices, the availability of options and decisions made early in development can have major effects on adult behavior. Herein, we use strain differences among zebrafish, Danio rerio, as an experimental tool to test the effects of social experience on behavior. By manipulating the strain composition of groups in which the subject fish are housed at different ages, we tested (1) whether mixing with dissimilar individuals influenced subsequent behavior, (2) whether prolonged mixing during the juvenile stage had a more pronounced effect than a shorter period of mixing during adulthood and (3) whether mixing had a lasting effect after animals were resorted into groups of same strain animals. We found that social experience had a profound impact on social behavior. Both Nadia and TM1 individuals engaged in more frequent biting after having been in mixed strain groups compared to pure strain groups. This was true of groups mixed as juveniles, as well as adults, indicating that this response was not dependent on exposure during a critical developmental period. Also, TM1 fish (but not Nadia) having recently been housed in mixed-strain groups were more willing to leave the immediate vicinity of a shoal than were TM1 fish raised in pure strain groups. This change was more pronounced in groups mixed as juveniles than as adults. In addition, the observed changes persisted after mixed groups were separated into pure strain groups for a month. Other behavioral measures including Activity Level, Predator Response and Stress Recovery were unaffected by previous social experience.     

长爪沙鼠的贮食行为与其个性和代谢水平之间的关系

贮食行为是动物应对食物资源的季节性和不可预测性变化的一种适应性生存策略。在群居性贮食动物中,同胎个体常表现出不同的贮食水平,而关于贮食行为与动物的个性和代谢水平之间的关系尚缺乏研究。本文以长爪沙鼠（Meriones unguiculatus）为对象,在筛选出具有高贮食和低贮食行为特征个体的基础上,比较了两组动物的个性特征（勇敢行为和探索能力）、静止代谢率、血清甲状腺激素水平、贮食期间的运动距离和贮食后的平均每日代谢率等。结果发现：高、低贮食长爪沙鼠的数量各占49%（22/45）和47%（21/45）,两组动物之间的个性特征、静止代谢率和血清甲状腺激素均没有显著差异。在贮食期间高贮食个体的运动距离显著高于低贮食个体,且在停止贮食后,高贮食个体的平均每日代谢率显著低于低贮食个体。这些结果表明,在室内条件下,长爪沙鼠的贮食量高低与个性和静止代谢率无关,但高贮食个体会在停止贮食后降低其总能量消耗,以补偿贮食过程中的高能量代价。     

Managing boldness of wildlife: an ethological approach to reducing crop damage

Wildlife can cause serious crop damages, and factorial analyses focusing ecological aspects have been conducted to resolve this problem. However, ethological perspectives should also be considered. Individuals often show consistent biases in behaviour—so-called personality; e.g., boldness may cause to intrude into a farmland. Here, we hypothesized that boldness–shyness traits in wildlife could be managed through selective harvesting on the base of personality traits. We considered several scenarios involving the selective harvesting and fencing as means to prevent crop damage, and assessed their effects on the average boldness and population size using simulation models, assuming that bold individuals tend to enter farmlands, while shy ones prefer to stay in forests. The results showed that fencing and selective harvesting in farmlands reduced both the average boldness and crop damages, while harvesting in forests caused the increase of the both. Those results came from the selective harvesting and fencing on the base of personality traits, and indicate that not only population ecology but also an ethological approach is needed for wildlife management.     

Personality-dependent inter- and intraspecific foraging competition in the invasive round goby,Neogobius melanostomus

This study examines the impact of boldness on foraging competition of the highly invasive round goby Neogobius melanostomus Pallas 1815. Individual risk tolerance, or boldness, was measured as the time to resume movement after a simulated predation strike. Fish that resumed movement faster were categorized as “bold,” fish that took more time to resume movement were categorized as “shy” and those that fell in between these two categories were determined to have “intermediate” boldness. Competitive impacts of boldness in N. melanostomus were determined in a laboratory foraging experiment in which interspecific (juvenile Atlantic cod Gadus morhua Linnaeus 1758) and intraspecific (intermediate N. melanostomus) individuals were exposed to either bold or shy N. melanostomus competitors. G. morhua consumed fewer prey when competing with bold N. melanostomus than when competing with shy N. melanostomus, whereas intermediately bold N. melanostomus foraging was not affected by competitor boldness. Bold and shy N. melanostomus consumed similar amounts of prey, and the number of interactions between paired fish did not vary depending on the personality of N. melanostomus individuals. Therefore, intraspecific foraging competition was not found to be personality dependent. This study provides evidence that individual differences in boldness can mediate competitive interactions in N. melanostomus; nonetheless, results also show that competition is also governed by other mechanisms that require further study.     

Physiological and genetic correlates of boldness: characterising the mechanisms of behavioural variation in rainbow trout, Oncorhynchus mykiss

Bold, risk-taking animals have previously been putatively linked with a proactive stress coping style whereas it is suggested shyer, risk-averse animals exhibit a reactive coping style. The aim of this study was to investigate whether differences in the expression of bold-type behaviour were evident within and between two lines of rainbow trout, Oncorhynchus mykiss, selectively bred for a low (LR) or high (HR) endocrine response to stress, and to link boldness and stress responsiveness with the expression of related candidate genes. Boldness was determined in individual fish over two trials by measuring the latency to approach a novel object. Differences in plasma cortisol concentrations and the expression of eight novel candidate genes previously identified as being linked with divergent behaviours or stress were determined. Bold and shy individuals, approaching the object within 180 s or not approaching within 300 s respectively, were evident within each line, and this was linked with activity levels in the HR line. Post-stress plasma cortisol concentrations were significantly greater in the HR line compared with the LR line, and six of the eight tested genes were upregulated in the brains of LR fish compared with HR fish. However, no direct relationship between boldness and either stress responsiveness or gene expression was found, although clear differences in stress physiology and, for the first time, gene expression could be identified between the lines. This lack of correlation between physiological and molecular responses and behavioural variation within both lines highlights the complexity of the behavioural-physiological complex.     

Rehabilitation of research chimpanzees: stress and coping after long-term isolation

We report on the permanent retirement of chimpanzees from biomedical research and on resocialization after long-term social isolation. Our aim was to investigate to what extent behavioral and endocrine measures of stress in deprived laboratory chimpanzees can be improved by a more species-typical social life style. Personality in terms of novelty responses, social dominance after resocialization and hormonal stress susceptibility were affected by the onset of maternal separation of infant chimpanzees and duration of deprivation. Chimpanzees, who were separated from their mothers at a younger age and kept in isolation for more years appeared to be more timid personalities, less socially active, less dominant and more susceptible to stress, as compared to chimpanzees with a less severe deprivation history. However, permanent retirement from biomedical research in combination with therapeutic resocialization maximizing chimpanzees' situation control resulted in reduced fecal cortisol metabolite levels. Our results indicate that chimpanzees can recover from severe social deprivation, and may experience resocialization as less stressful than solitary housing.     

How integrated are behavioral and endocrine stress response traits? A repeated measures approach to testing the stress-coping style model

It is widely expected that physiological and behavioral stress responses will be integrated within divergent stress‐coping styles (SCS) and that these may represent opposite ends of a continuously varying reactive–proactive axis. If such a model is valid, then stress response traits should be repeatable and physiological and behavioral responses should also change in an integrated manner along a major axis of among‐individual variation. While there is some evidence of association between endocrine and behavioral stress response traits, few studies incorporate repeated observations of both. To test this model, we use a multivariate, repeated measures approach in a captive‐bred population of Xiphophorus birchmanni. We quantify among‐individual variation in behavioral stress response to an open field trial (OFT) with simulated predator attack (SPA) and measure waterborne steroid hormone levels (cortisol, 11‐ketotestosterone) before and after exposure. Under the mild stress stimulus (OFT), (multivariate) behavioral variation among individuals was consistent with a strong axis of personality (shy–bold) or coping style (reactive–proactive) variation. However, behavioral responses to a moderate stressor (SPA) were less repeatable, and robust statistical support for repeatable endocrine state over the full sampling period was limited to 11‐ketotestosterone. Although post hoc analysis suggested cortisol expression was repeatable over short time periods, qualitative relationships between behavior and glucocorticoid levels were counter to our a priori expectations. Thus, while our results clearly show among‐individual differences in behavioral and endocrine traits associated with stress response, the correlation structure between these is not consistent with a simple proactive–reactive axis of integrated stress‐coping style. Additionally, the low repeatability of cortisol suggests caution is warranted if single observations (or indeed repeat measures over short sampling periods) of glucocorticoid traits are used in ecological or evolutionary studies focussed at the individual level.     

Sequential hermaphroditism and personality in a clonal vertebrate: the mangrove killifish

Individuals are regularly documented to consistently differ in their behavioural types (BTs). For example, some individuals are bold whereas others are shy. Within the human personality literature, the big five personality dimensions are commonly documented to be sex-specific with testosterone suggested to underpin traits such as aggressiveness. In non-human animals recent research suggests sex-specific BT expression may be influenced by ecology, mating system and sexual selection. While most research on sex-specific personality has focused on dioecious species, we explore sex differences in BT expression in a sequential hermaphrodite the mangrove killifish. We replicate within 7 isogenic genotypes and investigate sex differences (hermaphrodite and secondary male) in three BTs (exploration, boldness and aggression). This approach allows us to investigate sex differences in BT expression whilst controlling for genetic variation. In this study we find that both secondary males and hermaphrodites are repeatable at the individual level yet there was no difference between the sexes in average BT scores. Furthermore, aggression scores differed between genotypes, and were repeatable at the genotype level, suggesting strong genetic control. Finally, male boldness was significantly more repeatable than hermaphrodites potentially supporting recent proposals relating to sexual selection. We document a behavioural syndrome in male fish with bolder individuals being more aggressive, this behavioural syndrome was not observed however in hermaphrodites. In contrast to a previous developmental study in this species exploration did not correlate with either aggression or boldness in either males or hermaphrodites.