首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 35 毫秒
1.
2.
Aphids harbour both an obligate bacterial symbiont, Buchnera aphidicola, and a wide range of facultative ones. Facultative symbionts can modify morphological, developmental and physiological host traits that favour their spread within aphid populations. We experimentally investigated the idea that symbionts may also modify aphid behavioural traits to enhance their transmission. Aphids exhibit many behavioural defences against enemies. Despite their benefits, these behaviours have some associated costs leading to reduction in aphid reproduction. Some aphid individuals harbour a facultative symbiont Hamiltonella defensa that provides protection against parasitoids. By analysing aphid behaviours in the presence of parasitoids, we showed that aphids infected with H. defensa exhibited reduced aggressiveness and escape reactions compared with uninfected aphids. The aphid and the symbiont have both benefited from these behavioural changes: both partners reduced the fitness decrements associated with the behavioural defences. Such symbiont-induced changes of behavioural defences may have consequences for coevolutionary processes between host organisms and their enemies.  相似文献   

3.
An attempt had been made to create five social groups from rhesus macaques with a history of early separation from their mothers, early weaning and hand feeding and, in most cases, previous housing in single cages. We investigated the exchange of affiliative behaviours after an aggressive encounter and selective attraction to the former opponent, a phenomenon previously well described in rhesus monkeys and called reconciliation. Evidence for reconciliation was only found in one of the five groups studied (corrected conciliatory tendency=13%). This group consisted of younger animals that had, at least temporarily, been living together after separation from their mothers. In the other groups studied, containing animals with a varied background, aggressive interactions were not followed by affiliative behaviours or attraction between former opponents. Our results indicate that the use of reconciliatory behaviours in adult monkeys is dependent upon social training. Lack of functional reconciliation might be one of the explanations to the severe and uncontrolled aggression previously found in groups of rhesus macaques created from animals with disturbed early socialization.  相似文献   

4.
5.
6.
半圈养条件下白唇鹿行为时间分配及活动规律的研究   总被引:10,自引:3,他引:10  
白唇鹿 (Cervus albirostris)是我国青藏高原特有种 ,在鹿类进化史上极其重要。因其药用价值很高 ,几十年来捕杀现象严重 ,数量大为减少 ,濒于灭绝 ,1 988年被列为国家一级保护动物 [13 ] 。目前白唇鹿分布在 2 9°~ 40°N,92°~ 1 0 2°E的区域内[1] 。它们主要活动于海拔 350 0~ 50 0 0 m之间的高寒半荒漠草原 ,高山草甸草原和亚高山灌丛草原 [7] 。国内对白唇鹿的研究 ,涉及到食性[7,11] 、繁殖[3~ 5] 、形态、生态地理分布[6] 等 ,而对白唇鹿非发情期行为时间分配尚无报道。 1 998年 3~ 4月我们在上海野生动物园对其进行了专题研…  相似文献   

7.
The behaviour of the tompot blenny Parablennius gattorugine was studied from a long‐term underwater photographic record from two sites on the south‐west coast of the U.K. Repeated observations of individually identifiable P. gattorugine during 112 dives revealed that male P. gattorugine may guard eggs in a particular crevice over subsequent breeding seasons, reside in the same location for up to 4 years and recover from injuries received in disputes over territory. Further observations included resident males wiping eggs with greatly expanded anal glands, adult‐type fighting between juveniles and unusual behaviour where a large male manipulated an empty mollusc shell for the attention of two smaller conspecifics.  相似文献   

8.
实蝇是全世界重要的农业害虫,其生殖行为规律对其防治方法的研究具有重要指导意义。本文在文献调研的基础上,对实蝇类昆虫求偶、交配和产卵等行为的最新研究进展进行综述。实蝇类昆虫具有非资源型交配系统,性内、性间选择共同驱动实蝇的性特征进化;同时,实蝇生殖行为受到性信息素、翅信号、物理、化学以及环境等因素的影响。此外,雌虫在交配后会为理想产卵位置发生竞争,而产卵标记信息素起着调节作用。实蝇类昆虫的诸多生殖行为研究结果已成功应用于田间防治,取得了较好的效果。  相似文献   

9.
ABSTRACT

For nurses, shift work is a necessity, required to provide 24-h continuous care for patients. Research posits that fatigue amongst shift-working nurses is associated with inadequate and poorly timed sleep and also strongly influenced by the timing, quality and quantity of food consumed. The aim of this investigation was to examine differences and similarities in the food choices and eating patterns of nurses exposed to different lengths of time in shift work, as a means of understanding how nurses can adapt their eating patterns to better manage fatigue and sleep loss. Qualitative methodology was utilised to study and capture in-depth information about nurses’ daily working lives. A case study approach allowed for the investigation of nurses with limited and extensive experience of shift work. Increased food craving, caffeine consumption and snacking behaviours during night shifts were described by both groups of nurses, as was the inability to drink enough fluids at work. Meal skipping at work, associated with high workload, was detailed more by experienced nurses. Experienced nurses described shopping and preparing home cooked meals in advance to manage food intake and associated fatigue, contrasting with patterns from inexperienced nurses. Experienced nurses recounted drinking alcohol as a way to rest and recover from shift work, unlike their less inexperienced colleagues. These findings indicate organisational and work place issues such as shift work and rostering influence the food choices and eating patterns of shift-working nurses. Experienced nurses, however, draw on a greater range of strategies around diet and eating patterns to minimise these impacts.  相似文献   

10.
Piling behaviour of laying hens often results in smothering or death due to suffocation. Mechanisms leading to piling are not yet understood though various potential factors have been suggested. In this experimental study, we predicted that the presence of a light spot, a novel object (metal foil), or a heat area within animal pens would increase animal numbers around the stimulus leading to piling behaviour. We presented the cues in a 4 × 2 Latin-square design in eight identical experimental pens including each 55 Lohmann Selected Leghorn hens. The cues were presented in two test areas per pen, at two bouts per day in the morning, consecutively for 5 days, over four periods (age: 20, 22, 24, 26 weeks). Each pen received a cue and control condition simultaneously (test areas without cue presentation) once. For a bout, each cue was presented for 35 min except for the light spot where the duration was 10 min. Birds’ responses to the cues during bout and non-bout times were video recorded and analysed for the first bout of each period. To assess the cues’ attractiveness, the number of hens during bout times was counted at predefined times within the test and control areas. To assess the cues’ effects on piling, we described piling behaviour (pile number, duration, animal numbers, trigger) in control and test areas during bout times. Furthermore, we described piling behaviour during bout times and non-bout times on the first day of the first period and fourth period. The best model explaining the number of hens included the interactions of treatment and bout time, and treatment and area. Over the bout’s time course, more hens were attracted to the light spot compared to the control condition, and more to test areas compared to control areas. In the novel object condition, more hens were drawn to the test areas compared to the control areas. Hens were not attracted to the heat area. Piling in bout times was observed twice when hens pecked at the novel object. During non-bout times, piling behaviour occurred frequently at midday and in the late morning compared to the afternoon, mostly in corners and mainly preceded by the mutual attraction of hens. Overall, hens were attracted to light spots and less so to the novel object though neither reliably induced piling behaviour. The occurrence of piling behaviour in non-bout times shows that more work is needed to understand mechanisms eliciting piling behaviour.  相似文献   

11.
Understanding how multiple mutations interact to jointly impact multiple ecologically important traits is critical for creating a robust picture of organismal fitness and the process of adaptation. However, this is complicated by both environmental heterogeneity and the complexity of genotype‐to‐phenotype relationships generated by pleiotropy and epistasis. Moreover, little is known about how pleiotropic and epistatic relationships themselves change over evolutionary time. The soil bacterium Myxococcus xanthus employs several distinct social traits across a range of environments. Here, we use an experimental lineage of M. xanthus that evolved a novel form of social motility to address how interactions between epistasis and pleiotropy evolve. Specifically, we test how mutations accumulated during selection on soft agar pleiotropically affect several other social traits (hard agar motility, predation and spore production). Relationships between changes in swarming rate in the selective environment and the four other traits varied greatly over time in both direction and magnitude, both across timescales of the entire evolutionary lineage and individual evolutionary time steps. We also tested how a previously defined epistatic interaction is pleiotropically expressed across these traits. We found that phenotypic effects of this epistatic interaction were highly correlated between soft and hard agar motility, but were uncorrelated between soft agar motility and predation, and inversely correlated between soft agar motility and spore production. Our results show that ‘epistatic pleiotropy’ varied greatly in magnitude, and often even in sign, across traits and over time, highlighting the necessity of simultaneously considering the interacting complexities of pleiotropy and epistasis when studying the process of adaptation.  相似文献   

12.
采用红外传感、减速马达和光电传感组合、压力传感、51系列单片微机控制和记忆等技术,研制一种检测动物饮食行为的仪器,用于药物和食品研制中的动物实验。经30例小鼠实验证明,效果良好,该仪器为测定动物饮食行为提供了一种全新的先进方法。  相似文献   

13.
We investigated the effect of offering supplementary dietary fibres to suckling piglets on their behaviour and performance before weaning. From 5 to 22 days of age, suckling piglets were offered a high-fibre diet (HF; 5% cellulose; n=5 litters), or a control low-fibre diet (n=5 litters). Piglets were housed with the sows in individual farrowing pens, and had access to maternal milk until weaning, at 23 days of age. Behaviours of six focal piglets per pen were scored at 6, 16 and 21 days of age. All piglets were individually weighed at 5, 15 and 20 days of age and feed intake was measured daily at the pen level. Piglets on the HF diet were more active than controls (P=0.05), and spent more time suckling or massaging the udder (P=0.01) and interacting with pen mates (P=0.008). Time spent manipulating pen mates, which may reflect re-directed foraging activity in the absence of substrate, accounted for most of the time spent interacting with pen mates (⩾73% of total time spent interacting). Dietary fibres had no effect on BW and feed intake. In conclusion, inclusion of cellulose in the supplemental diet of suckling piglets affects behaviour, with no deleterious effects on performance before weaning.  相似文献   

14.
Psychotropic medications are used regularly to manage problem behaviours among people with intellectual disabilities. This causes concern because often these medications are used out of their licensed indications in this context. The WPA Section on Psychiatry of Intellectual Disability has recently developed an evidence and consensus-based international guide for practitioners for the use of psychotropic medications for problem behaviours among adults with intellectual disabilities. This guide advises on assessment of behaviours, producing a formulation, initiation of treatment, assessment of out-come and adverse effects, follow-up arrangements, and possibility of discontinuation of treatment.  相似文献   

15.
16.
17.
《L'Anthropologie》2015,119(4):417-463
Zooarchaeological analyses were carried on new large mammal bone materials, from the Epigravettian (Late Upper Palaeolithic) site Mezhyrich (Ukraine), in the pit no 7 area associated with the mammoth bone dwelling no 1. The results exhibit a usage of the pit as a dump area of food and technical remains from mainly mammoth, hare and fox processing, and bone fuels. The information about mammoth procurement by the last Palaeolithic hunter–gatherers in Eastern Europe allows to document the hunting activities on the mammoth populations, which were probably already weakened at the end of the Pleistocene.  相似文献   

18.
1. Outbreaks of feral house mice, Mus domesticus, in Australia represent a fundamental failure of the behavioural control mechanisms of population density, as proposed in the hypothesis of self-regulation. 2. Mice have the potential to keep numbers in check via a suite of spacing behaviours; however, the self-regulation hypothesis implies that some social change occurs that permits the population to erupt. It also suggests that at different phases of an outbreak, distinct patterns of social activity are evident. 3. We compare predictions from two models encapsulating the self-regulation hypothesis as applied to feral house mice in south-eastern Australia. Each model may be distinguished by the timing of aggressiveness between mice that leads to a closed social system. We compare individual turnover, residency and territoriality in each sex and age cohort during the increase, peak and low phases of a population outbreak that peaked in 2001. 4. The activity of 438 mice was monitored via intensive mark-recapture trapping and an automated event recording system that detected the activity of 300 marked individuals at burrow entrances. 5. Our findings support the second model, which suggests that mice switch from an almost asocial structure at low densities to a territorial system as abundance increases. Adult females appear more likely than males or juveniles to make the significant social shift. The trigger for this change remains unclear and several alternative mechanisms are proposed.  相似文献   

19.
20.
<正> Natural surfaces with super hydrophobic properties often have micro or hierarchical structures.In this paper, the wettingbehaviours of a single droplet on biomimetic micro structured surfaces with different roughness parameters are investigated.Atheoretical model is proposed to study wetting transitions.The results of theoretical analysis are compared with those of experimentindicating that the proposed model can effectively predict the wetting transition.Furthermore, a numerical simulationbased on the meso scale Lattice Boltzmann Method (LBM) is performed to study dynamic contact angles, contact lines, andlocal velocity fields for the case that a droplet displays on the micro structured surface.A spherical water droplet with r_s= 15 μmfalls down to a biomimetic square-post patterned surface under the force of gravity with an initial velocity of 0.01 m·s~(-1) and aninitial vertical distance of 20 μm from droplet centre to the top of pots.In spite of a higher initial velocity, the droplet can stillstay in a Cassie state; moreover, it reaches an equilibrium state at t≈17.5 ms, when contact angle is 153.16° which is slightlylower than the prediction of Cassie-Baxter's equation which gives θ_(CB)=154.40°.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号