Effects of colony food shortage on behavioral development in honey bees

Three experiments were conducted to explore the effects of severe food shortage on the control of two important and interrelated aspects of temporal division of labor in colonies of the honey bee (Apis mellifera): the size and age distribution of a colony's foraging force. The experiments were conducted with single-cohort colonies, composed entirely of young bees, allowing us to quickly distinguish the development of new (precocious) foragers from increases in activity of bees already competent to forage. In experiment 1, colony food shortage caused an acceleration of behavioral development; a significantly greater proportion of bees from starved colonies than from fed colonies became precocious foragers, and at significantly younger ages. Temporal aspects of this starvation effect were further explored in experiment 2 by feeding colonies that we initially starved, and starving colonies that we initially fed. There was a significant decrease in the number of new foragers in starved colonies that were fed, detected 1 day after feeding. There also was a significant increase in the number of new foragers in fed colonies that were starved, but only after a 2-day lag. These results suggest that colony nutritional status does affect long-term behavioral development, rather than only modulate the activity of bees already competent to forage. In experiment 3, we uncoupled the nutritional status of a colony from that of the individual colony members. The behavior of fed individuals in starved colonies was indistinguishable from that of bees in fed colonies, but significantly different from that of bees in starved colonies, in terms of both the number and age distribution of foragers. These results demonstrate that effects of starvation on temporal polyethism are not mediated by the most obvious possible worker-nest interaction: a direct interaction with colony food stores. This is consistent with previous findings suggesting the importance of worker-worker interactions in the regulation of temporal polyethism in honey bees as well as other social insects. Received: 17 April 1997 / Accepted after revision: 26 December 1997     

长江鱼类繁殖共位群划分的初步研究

依据鱼类的繁殖习性及其早期发育阶段的适应特征,将长江中的8目17科90种鱼类划分为3个行为类型,13个繁殖共位群。其中鲤形目鱼类的86.9%属于无亲体护卫型繁殖类群,多为适应长江干流环境的漂浮性产卵类群以及适应湖泊定居的喜石性产卵类群与喜植性产卵类群。与现有的分类系统相比较,鱊亚科的全部种类仅局限于同一个繁殖共位群中,而鮈亚科的种类则分布于5个不同的繁殖共位群。对不同水系繁殖共位群的组成进行了比较。此外,讨论了不同繁殖共位群的生态适应性,及其在长江流域鱼类资源保护中的应用。
     

Household water use behavior: An integrated model

Water authorities are dealing with the challenge of ensuring that there is enough water to meet demand in the face of drought, population growth and predictions of reduced supply due to climate change. In order to develop effective household demand management programs, water managers need to understand the factors that influence household water use. Following an examination and re-analysis of current water consumption behavioral models we propose a new model for understanding household water consumption. We argue that trust plays a role in household water consumption, since people will not save water if they feel others are not minimizing their water use (inter-personal trust). Furthermore, people are less likely to save water if they do not trust the water authority (institutional trust). This paper proposes that to fully understand the factors involved in determining household water use the impact of trust on water consumption needs investigation.     

Mother-infant conflict over behavioral thermoregulation in Japanese macaques

This study evaluated the effects of time of day, ambient temperature, and relative humidity on mother-infant interactions in captive Japanese macaques (Macaca fuscata). Unlike time of day and relative humidity, temperature influenced mother-infant interactions. Even though total time spent in ventroventral contact did not change, lower temperatures were associated with greater attempts by the infants to maintain contact with their mothers and with more frequent maternal rejection. Effects of temperature on mother-infant interactions were not mediated by the effects of temperature on mothers' general activity. These results are interpreted in light of the different thermoregulatory needs of mothers and infants, and highlight a previously neglected cause for mother-infant conflict. Received: 23 June 1997 / Accepted after revision: 28 March 1998     

ACT method for safety training: An approach to improve on-site safety performance

Unsafe behavior is one of the main causes limiting the improvement of on-site safety performance. Safety training is an important means of preventing unsafe behavior. With changes in the scale of operations and employee characteristics, traditional training methods have largely failed to meet the practical demands. Therefore, to improve the effectiveness of safety training, this paper analyzes the shortcomings of the current training methods, demonstrates the potential value of accident cases for improving the training effect, and the advantages of 24Model for case analysis in safety training. Subsequently, this paper constructs a systematic training system with Accident-Cause-Training (ACT) as the training relationship chain, which runs the accident cases throughout the training process, 24Model is utilized to trace the unsafe behaviors that lead to accidents from the perspectives of organizational and individual level, and the training content is established according to the analysis results. This paper also conducts a case study to verify the operability of the ACT method, specifically, a training programme for limited space operations at a national-level oil and gas storage and transportation company is designed and implemented. Finally, by comparing the similarities and differences between the ACT method and other training methods from various perspectives, the universality and participation of the ACT method are proved, and the development trend of the ACT method is also discussed. It is believed that the proposed ACT method could enrich the types of safety training methods and provide an effective and scientific tool to enhance the safety performance of field operations.     

Behavioral Factors as Predictors of Motor Vehicle Crashes in Young Drivers

Gains in reducing mortality and morbidity from motor vehicle crashes can be achieved by understanding the behavioral factors that contribute to the elevated risk of motor vehicle-related injury and death. This study investigates the incidence, along with the effect of driver and behavioral factors, on the likelihood of motor vehicle crashes. Seventeen year old newly licensed drivers (n = 1277) in Perth, Western Australia, were recruited and followed over the first 12 months of driving. Using Cox proportional hazard analysis, driver and behavioral factors were assessed to determine whether they predicted the likelihood of a crash in the first 12 months of driving. The crash incidence rate was higher for males (1R = 4.6/10,000 driving days) than females (IR = 3.9/10,000 driving days). Multivariate analysis indicated that drivers who reported to have driven daily prior to obtaining their learners permit (L-plates) were at an increased risk of motor vehicle crash. A twofold increase in motor vehicle crash was apparent among drivers considered to be confident-adventurous drivers compared to low to moderate levels of driver confidence-adventurousness (HR = 2.04, 95% CI = 1.29-3.21). The research indicates that a driver's perception of their confidence and adventurousness in the road environment plays a part in the causal pathway leading to a motor vehicle crash. This research points to the need for preventive strategies that focus not only on knowledge and skill acquisition, but also the driver's perception in preparing young people for our roads.     

Time allocation strategies in insect parasitoids: from ultimate predictions to proximate behavioral mechanisms

As most parasitoids are time limited, they usually die before they have laid all their eggs. In such cases, optimal foraging theory predicts that female parasitoids will adopt behavioral reproductive strategies enabling them to maximize progeny production per unit of time. One key situation in which parasitoid females must optimize their time budget is related to the fact that most of their hosts are distributed in discrete patches in the environment. In this review, I first present the results of basic theoretical models predicting female wasp search duration on a patch of hosts. I then compile and analyze all studies investigating the effect of different factors on parasitoid patch time allocation and patch-leaving decision rules. Different patch-leaving mechanisms that were proposed to explain the results obtained are discussed, along with statistical methods that should be used to estimate them from experimental data. Finally, ideas for future research are presented.     

Phenotypic analysis of fetal blood leucocytes: Potential for prenatal diagnosis of immunodeficiency disorders

Recent technological advances allow the detection and quantitation of subsets of leucocytes using monoclonal antibodies. We have taken advantage of this to study the ontogeny of fetal blood leucocytes, using very small blood samples obtained at fetoscopy. By 14 weeks gestation T cells represent 35 per cent or more of fetal leucocytes and the distribution of the helper/inducer and suppressor/cytotoxic subsets is similar to that of adults. B lymphocytes before 161/2 weeks are low (4–20 per cent), but rise to a mean of 28 per cent in 17–26 week fetuses. Granulocytic cells, many of which are phenotypically immature, represent 18–34 per cent of total leucocytes. The methodology employed is very reliable and offers the opportunity for the prenatal diagnosis of some immunodeficiency disorders, since using the same reagents we have diagnosed children with severe combined immunodeficiency shortly after birth.     

Polyandry in the genus Apis, particularly Apis andreniformis

Using four polymorphic microsatellite loci, we found that four Apis andreniformis queens collected in Thailand each mated at least 10–20 times, producing an average relatedness, g _ww, of workers of 0.30 ± 0.007, and an average effective number of matings of 9.1 ± 2.2. The degrees of polyandry and intra-colonial genetic relatedness in A. andreniformis are similar to those in A. mellifera, slightly more than in A. florea, and up to 6 times less than in A. dorsata. We argue that while presently favoured hypotheses for the evolution of polyandry in monogynous social insects may adequately explain the evolution of up to five or six matings, they are inadequate to explain the extreme polyandry (10–60 matings) observed in Apis. One alternative possibility is that colony fitness is a non-additive function of the fitness of individual subfamilies. Such behavioral over-dominance may mean that queen fitness is increased by high levels of polyandry, which increase the probability of desirable combinations of worker genotypes occurring in one colony. The special attributes of honey bees which may lead to behavioral over-dominance include colony aggregation (which may increase the incidence of disease), and frequent long-distance migration. Received: 8 May 1996/Accepted after revision: 9 August 1996     

Shell choice in<Emphasis Type="Italic"> Pagurus longicarpus</Emphasis> hermit crabs: does predation threat influence shell selection behavior?

Pagurus longicarpus hermit crabs depend on empty gastropod shells for protection against predation. Hermit crabs avoid gastropod shells in which holes have been drilled by naticid gastropods, and hermit crabs forced to occupy drilled shells are more vulnerable to predation by green crabs, Carcinus maenas. In this study, we examined the effect of predator cues on P. longicarpus shell investigation behavior and shell choice. In paired laboratory shell choice trials, we examined hermit crab response to green crab chemical cues. We compared hermit crabs from two sites differing in the percentage of Littorina littorea shells with drill holes. The percentage of time hermit crabs spent occupying intact shells increased significantly in the presence of predator cues. The effect of predator cues on the amount of time hermit crabs spent investigating shells differed between individuals from the two sites. Predator effluent had a marginal effect on the proportion of hermit crabs initially choosing intact shells and within 15 min most hermit crabs in both treatments occupied intact shells due to shell switching. These results indicate that predation cues alter P. longicarpus shell choice behavior favoring intact shells, which provide greater protection. In summary, predation appears to be a key factor influencing hermit crab shell selection behavior.Communicated by T. Czeschlik