Effect of Foraging Distance on the Thermal Behaviour of Honeybees during Dancing,Walking and Trophallaxis

By means of infrared thermography and without disturbing social interactions, the correlation between thoracic temperature in honeybees, Apis mellifera carnica, upon their return to the hive and their foraging distance was investigated. Thoracic temperature while dancing and walking and during trophallactic contact with hive bees decreased with increasing flight distance. In bees foraging 0.5, 1, 1.5 and 2 molar sucrose solutions from a distance of 120 m, dancing temperature amounted to 38.4, 40.1, 40.9 and 40.6 °C, respectively; while in bees foraging from a distance of 2950 m it amounted to 36.6, 38.4, 38.6 and 39.1 °C, respectively. The rate of decrease in dancing temperature per 1000 m increase in flight distance was 0.64, 0.47, 0.81 and 0.54 °C with a 0.5, 1, 1.5 and 2 molar sucrose solution, respectively. Both at short and at long flight distances, the relationship between thoracic temperature and sucrose concentration of the food followed a non-linear curve, which flattened at concentrations higher than 1 mol/1. The experiments showed that inside the hive the foragers' level of thermoregulation depends not only on the energy (sugar) content of the food; but rather, the level of thermoregulation corresponds to the general quality of the food source, which includes both energy content and distance from the hive. Because the thermal behaviour of foragers correlates with several behavioural parameters indicating the bees' foraging tendency and their eagerness to dance, thoracic temperature seems to be a correlate of the profitability of foraging.     

Hiding Behaviour of Long-tailed Macaques (Macaca fascicularis): II. Use of Hiding Places during Aggressive Interactions

In an observational study on captive long-tailed macaques ( Macaca fascicularis ), the ability to hide was investigated in the social context of aggression. The use of five different types of hiding place during highly aggressive interactions was recorded and the choices of six different rank-sex classes were compared using an index of attractiveness of the different types of hiding place during highly aggressive interactions. There was no significant difference between the rank-sex classes in selection of the hiding places that could be connected with visibility: no specific location or type was preferred, either by the group as a whole or by any specific rank-sex class. Thus long-tailed macaques do not seem to hide shortly after aggressive interactions.     

Aggressive and Foraging Behavioral Interactions Among Ruffe

The ruffe, Gymnocephalus cernuus, is a nonindigenous percid in the Great Lakes. Ruffe are aggressive benthivores and forage over soft substrates. Laboratory studies in pools (100cm diameter, 15cm water depth) were conducted to determine whether fish density (low=2, medium=4, high=6 ruffe per pool) changed foraging and aggressive behaviors with a limited food supply of chironomid larvae. All fish densities demonstrated a hierarchy based on aggressive interactions, but ruffe were most aggressive at low and high fish densities. Time spent in foraging was lowest at the low fish density. The best forager at the low fish density was the most aggressive individual, but the second most aggressive fish at the medium and high fish density was the best forager and also the one chased most frequently. A medium fish density offered the best energetic benefits to ruffe by providing the lowest ratio of time spent in aggression to that spent foraging. Based on our results, ruffe should grow best at an intermediate density. With high ruffe densities, we would also expect disparity in size as the more aggressive fish are able to garner a disproportionate amount of the resources. Alternatively, as the Great Lakes are a fairly open system, ruffe could migrate out of one area to colonize another as populations exceed optimal densities.     

Sexual Differences in Aggressive Behaviour of the Apennine Chamois

The aggressive behaviour of female and male Apennine chamois has been compared quantitatively. As opposed to what males did, females significantly attacked each other less often; preferred to gore body regions with a low risk of lethal injury, made a greater use of direct forms of aggression; seldom interacted with the opponent before attacking and gored it more often. Front clashing and fighting were very rare in both sexes. Females live in resident kin-groups, while young males disperse and adults are solitary. To a large extent habitat separation occurs between the sexes. Sexual differences in patterns of aggressive behaviour may be related to the different gregariousness of females and males, probably influenced by resource availability in the habitats they use. Chamois sexes are nearly monomorphic, females bearing slightly less hooked horns than males. This species may have evolved strongly hooked weapons as a first step to advanced wrestling or butting type horns from the ancestral stiletto shape, as goats and sheep, as well as deer, have done.     

Aggressive Behaviour Between Gymnocharacinus Bergi (Pisces, Characidae) And Other Neotropical Fishes From A Thermal Stream In Patagonia

Gymnocharacinus bergi is a stenothermal endangered fish only found in the headwaters of a thermal stream within the temperate Somuncurá Plateau (Patagonia, Argentina). In spite of the presence of other fish species in the Valcheta Stream basin, none of these has been found at the headwaters. Temperature and salinity cannot account for the absence of extremely eurytopic Cnesterodon and Jenynsia. In addition, there is no evidence of diet overlapping or territory defence between these species and G. bergi. Therefore, we hypothesise that agonistic behaviour might be related to G. bergi's isolation. Experiments were performed in order to analyse interspecific interaction between G. bergi and individuals of the other two species. Cnesterodon decemmaculatus showed a submissive behaviour while Jenynsia multidentata was clearly aggressive. G. bergi decreased its aggressive behaviour towards C. decemmaculatus throughout the experiment. However, when placed with J. multidentata, its aggressive behaviour did not diminish. We suggest that the characteristics of the agonistic behaviour displayed by J. multidentata, opposite from those displayed by C. decemmaculatus, might account for the absence of J. multidentata in G. bergi's present habitat. With respect to C. decemmaculatus, other factors such as its low counter current swimming ability might play a major role in this phenomenon.     

Ontogeny of Aggressive Behaviour in Schools of Yellowtail, Seriola Quinqueradiata

We studied ontogenetic changes in social interactions, especially in aggressive behaviour of the migratory marine yellowtail, Seriola quinqueradiata (Carangidae), and compared these to morphological and physiological changes. No agonistic interactions were observed during the larva period until 10 mm in total length (TL), at approximately 20 days after hatching. Typical shivering behaviour with J-posture was observed during metamorphosis, when fin rays and calcification of vertebra were completed and there was an increase of tissue thyroid hormone. The onset of aggressive behaviour was just after metamorphosis to the juvenile period, and coincided with a significant increase in tissue cortisol levels. The onset of schooling behaviour was at 12 mm TL, slightly after the onset of aggressive behaviour. From observations of individual aggressive behaviour within juvenile schools, we found three categories of social rank: dominants (10-20%), intermediates (10-20%), and subordinates (60-80%). There was an inverse relationship between social rank and cortisol concentration. Otoliths of dominant fish in 8 experimental groups were labeled and the fish were returned to their groups. Six labeled dominants appeared after 1 day and three after 1 week rearing, respectively, indicating that social rank was maintained for at least 1 week (binomial distribution, p < 0.05). Dominants were larger than subordinates after 1 day rearing, whereas dominants were smaller after 1 week rearing. From long-term rearing experiments using individual otolith marking, larvae that showed the J-posture more frequently tended to become dominants after metamorphosis, indicating a positive correlation between the J-posture and aggressive behaviour. Synthesizing all results from behavioural experiments, we generated a behavioural model for the triggering mechanism of aggressive behaviour and size selection of school members.     

Aggressive Interactions and Risk of Fish Predation for Larval Damselflies

Larval damselflies frequently engage in aggressive interactions that may increase their risk of fish predation. To test this we analyzed the behavior of larval Ischnura verticalis exposed to both conspecifics and fish predators. Larvae in the presence of conspecifics oriented, struck, and swam more but crawled less compared to solitary larvae; the presence of fish reduced, or tended to reduce, all behaviors. Fish struck more at interacting larvae compared to noninteracting larvae. Increased attack rate by fish likely reflects the increase in the very active swimming behavior by larvae and suggests a conflict between antipredator behaviors. Swimming is an appropriate response to avoid predation by odonate larvae which normally ambush prey but is clearly dangerous when fast-swimming fish that cue in on movement are nearby.     

Signaling Interactions During Nodule Development

Nitrogen fixing bacteria, collectively referred to as rhizobia, are able to trigger the organogenesis of a new organ on legumes, the nodule. The morphogenetic trigger is a Rhizobium-produced lipochitin-oligosaccharide called the Nod factor, which is necessary, and in some legumes sufficient, for triggering nodule development in the absence of the bacterium. Because plant development is substantially influenced by plant hormones, it has been hypothesized that plant hormones (mainly the classical hormones abscisic acid, auxin, cytokinins, ethylene and gibberellic acid) regulate nodule development. In recent years, evidence has shown that Nod factors might act in legumes by changing the internal plant hormone balance, thereby orchestrating the nodule developmental program. In addition, many nonclassical hormonal signals have been found to play a role in nodule development, some of them similar to signals involved in animal development. These compounds include peptide hormones, nitric oxide, reactive oxygen species, jasmonic acid, salicylic acid, uridine, flavonoids and Nod factors themselves. Environmental factors, in particular nitrate, also influence nodule development by affecting the plant hormone status. This review summarizes recent findings on the involvement of classical and nonclassical signals during nodule development with the aim of illustrating the multiple interactions existing between these compounds that have made this area so complicated to analyze.     

Signal Interception and the Use of Soft Song in Aggressive Interactions

Song sparrows, like many species of songbirds, produce songs of especially low amplitude during aggressive contests. Such ‘soft songs’ have been shown to be reliable signals of intention to attack in song sparrows. Low intensity is a paradoxical feature in a highly aggressive signal, in that it seems likely to make the signal less intimidating to an opponent. A hypothesis that resolves this paradox is that use of soft songs benefits a signaler by limiting the interception of his signals by third party receivers. Here, we test this hypothesis with respect to song sparrows and two classes of third party receivers, predators and conspecific males. We tested whether selection to avoid predation is responsible for use of soft song by examining whether male song sparrows increase production of soft song in an aggressive context when they also receive signals (alarm calls) that indicate a predator is present. We found that the proportion of soft song produced by male song sparrows was actually significantly lower in the predator context than in a control context, directly contradicting the prediction. We tested whether avoiding eavesdropping by conspecific males is a benefit of soft song by removing territory owners and simulating interactions on their territories using playback from two loudspeakers. We found that intrusions by third party males were more likely in trials in which the simulated owner countered an intruder's songs using soft songs than in trials in which the simulated owner countered with loud song, again directly contradicting the hypothesis. We conclude that limiting interception by predators and conspecific males does not provide an explanation for use of soft song by song sparrows.     

Single Aggressive Interactions Increase Urinary Glucocorticoid Levels in Wild Male Chimpanzees

A basic premise in behavioural ecology is the cost-benefit arithmetic, which determines both behavioural decisions and evolutionary processes. Aggressive interactions can be costly on an energetic level, demanding increased energy or causing injuries, and on a psychological level, in the form of increased anxiety and damaged relationships between opponents. Here we used urinary glucocorticoid (uGC) levels to assess the costs of aggression in wild chimpanzees of Budongo Forest, Uganda. We collected 169 urine samples from nine adult male chimpanzees following 14 aggressive interactions (test condition) and 10 resting events (control condition). Subjects showed significantly higher uGC levels after single aggressive interactions compared to control conditions, likely for aggressors as well as victims. Higher ranking males had greater increases of uGC levels after aggression than lower ranking males. In contrast, uGC levels showed no significant change in relation to aggression length or intensity, indicating that psychological factors might have played a larger role than mere energetic expenditure. We concluded that aggressive behaviour is costly for both aggressors and victims and that costs seem poorly explained by energetic demands of the interaction. Our findings are relevant for studies of post-conflict interactions, since we provide evidence that both aggressors and victims experience a stress response to conflict.     

热污染对鱼类行为的影响

热污染,由于热(核)电站和工矿企业等热废水排入江、湖等天然水域,使水温升高而影响水生物的正常生长,甚至造成生物死亡的严重后果。由热污染引起死鱼事件,在国内外早有记述。例如1975年日本沿海的50座核电站所排放出大量的热废水,曾导致大批鱼类死亡;1978     

The Interactions of Sea Urchin Gametes During Fertilization

The interactions between sea urchin spermatozoa and ova duringfertilization usually exhibit a high degree of species specificity.Under natural conditions and reasonable gamete concentrations,most interspecific inseminations fail to yield zygotes. Macromoleculeson the external surfaces of the apposing gametes must surelybe responsible for successful gamete recognition, adhesion andfusion. Species specific recognition between surface componentsof sperm and egg could occur during at least three events comprisingthe fertilization process. The first event is the interactionof the sperm plasma membrane with the egg jelly coat. This inducesthe sperm acrosome reaction resulting in the exocytosis of the"bindin" -containing acrosome granule and also the extrusionof the acrosome process from the anterior tip of the sperm.The second event is the adhesion of the bindin-coated acrosomeprocess to glycoprotein "bindin receptors" on the external surfaceof the egg vitelline layer. The third event is the penetrationof the vitelline layer and the fusion of sperm and egg plasmamembranes. With the isolations of the component of egg jellywhich induces the acrosome reaction, sperm bindin from the acrosomevesicle and the egg surface bindin receptor from the vitellinelayer, there is hope of discovering the molecular basis of thismost interesting intercellular interaction which results inthe activation of embryonic development.     

Interactions Between Light and Plant Hormones During De-etiolation

The transition from a dark-grown (etiolated) to a light-grown (de-etiolated) morphology is marked by a number of dramatic phenotypic changes such as a significant reduction in the rate of shoot elongation, opening of the apical hook, expansion of true leaves and the development of mature chloroplasts. Many of these developmental processes are also known to be regulated by plant hormones. In this review we discuss the interactions between light and plant hormones and their role in mediating phenotypic change during de-etiolation. Clear evidence exists for a light-mediated reduction in gibberellin A, GA levels and response in pea, which is thought to be responsible, at least in part, for the reduction of shoot elongation during de-etiolation. Indirect evidence from a number of species has been used to suggest that the reduction in shoot elongation could also be mediated by a reduction in brassinosteroid (BR) levels. However, direct evidence recently obtained from pea and rice demonstrates that de-etiolation is not mediated, or even accompanied, by a reduction in BR levels. Ethylene is known to play an integral role in apical hook formation and maintenance in plants. However, the physiological significance of light-induced changes in IAA and ABA levels found in some species is not clear. Recent molecular data provide evidence of interactions between light-and IAA/CK-signalling pathways. Potential mechanisms for these interactions are discussed.     

Keratinocyte–Melanocyte Interactions During Melanosome Transfer

The epidermal–melanin unit is composed of one melanocyte and approximately 36 neighboring keratinocytes, working in synchrony to produce and distribute melanin. Melanin is synthesized in melanosomes, transferred to the dendrite tips, and translocated into keratinocytes, forming caps over the keratinocyte nuclei. The molecular and cellular mechanisms involved in melanosome transfer and the keratinocyte–melanocyte interactions required for this process are not yet completely understood. Suggested mechanisms of melanosome transfer include melanosome release and endocytosis, direct inoculation (‘injection’), keratinocyte–melanocyte membrane fusion, and phagocytosis. Studies of the keratinocyte receptor protease‐activated receptor‐2 (PAR‐2) support the phagocytosis theory. PAR‐2 controls melanosome ingestion and phagocytosis by keratinocytes and exerts a regulatory role in skin pigmentation. Modulation of PAR‐2 activity can enhance or decrease melanosome transfer and affects pigmentation only when there is keratinocyte–melanocyte contact. Moreover, PAR‐2 is induced by UV irradiation and inhibition of PAR‐2 activation results in the prevention of UVB‐induced tanning. The role of PAR‐2 in mediating UV‐induced responses remains to be elucidated.     

Keeper-Animal Interactions: Differences between the Behaviour of Zoo Animals Affect Stockmanship

Stockmanship is a term used to describe the management of animals with a good stockperson someone who does this in a in a safe, effective, and low-stress manner for both the stock-keeper and animals involved. Although impacts of unfamiliar zoo visitors on animal behaviour have been extensively studied, the impact of stockmanship i.e familiar zoo keepers is a new area of research; which could reveal significant ramifications for zoo animal behaviour and welfare. It is likely that different relationships are formed dependant on the unique keeper-animal dyad (human-animal interaction, HAI). The aims of this study were to (1) investigate if unique keeper-animal dyads were formed in zoos, (2) determine whether keepers differed in their interactions towards animals regarding their attitude, animal knowledge and experience and (3) explore what factors affect keeper-animal dyads and ultimately influence animal behaviour and welfare. Eight black rhinoceros (Diceros bicornis), eleven Chapman’s zebra (Equus burchellii), and twelve Sulawesi crested black macaques (Macaca nigra) were studied in 6 zoos across the UK and USA. Subtle cues and commands directed by keepers towards animals were identified. The animals latency to respond and the respective behavioural response (cue-response) was recorded per keeper-animal dyad (n = 93). A questionnaire was constructed following a five-point Likert Scale design to record keeper demographic information and assess the job satisfaction of keepers, their attitude towards the animals and their perceived relationship with them. There was a significant difference in the animals’ latency to appropriately respond after cues and commands from different keepers, indicating unique keeper-animal dyads were formed. Stockmanship style was also different between keepers; two main components contributed equally towards this: “attitude towards the animals” and “knowledge and experience of the animals”. In this novel study, data demonstrated unique dyads were formed between keepers and zoo animals, which influenced animal behaviour.     

Escalation of Aggressive Interactions During Staged Encounters in Halictus ligatus Say (Hymenoptera: Halictidae), with a Comparison of Circle Tube Behaviors with Other Halictine Species'

Circle tube experiments on the primitively eusocial bee, Halictus ligatus, were performed for a variety of combinations of caste and size. Push, Lunge, and Back without reverse behaviors enabled us to determine the dominant individual in most comparisons. Behavioral differences were readily detected within the first 15 min except for different-size forager–forager and same-size foundress–foundress pairs, for which 30 min of observations was required. In same-size forager–forager pairs, no differences in behaviors between individuals were detected even after 90 min. In extended observations, decreases in the frequency of the mild dominant behaviors were accompanied by a switch to the highly aggressive mandibular hold on the neck, particularly in different-size foundress–foundress and gyne–gyne pairs. Three workers were killed by their own queen as a result of this escalation of aggression. We discuss caste-based differences in the circle tube setting in terms of behaviors expected under more normal conditions and compare our data with published results from other species.