Kin and non-kin interventions in the aggressive disputes of vervet monkeys

Summary Interventions in aggressive disputes were investigated in a free-living troop of vervets (Cercopithecus aethiops sabaeus) in Barbados. Interventions on behalf of kin were more frequent than on behalf of non-kin. Both types of interventions were more likely when the intervening animal outranked the opponent; presumably because retaliation probability, and hence cost of intervening, is low against low ranking opponents. The number of interventions given on behalf of both kin and non-kin increased with the number of disputes in which they were involved. In contrast to kin interventions, the number of interventions given on behalf of non-kin was correlated with that received by non-kin, suggesting that reciprocation is a necessary component of non-kin interventions. Non-kin interventions were more likely when the recipient outranked the opponent, presumably because reciprocation probability is high. Pairs of non-kin form structured reciprocal relationships based on the proportion of interventions allocated to each other, and most non-kin interventions flowed through these relationships. Males intervened on behalf of non-kin more frequently than did females. The implications of the results for the evolution of kin and reciprocal altruism were discussed.     

生态危机的社会伦理根源

从人与自然的关系实际上是人与人之间的利益关系的论点出发,揭示了生态危机发生实质是人类为了获取自身利益的最大化,对自然资源无止境的索取和争夺而导致的;论证了生态危机发生的社会伦理根源是技术理性的扩张导致科学技术的异化、消费主义的盛行加重了对自然的消耗与污染、功利主义的漫延导致代际自然资源分配不公;提出了要缓解人与自然日趋紧张的关系,解决生态危机,不仅要依靠科技、经济手段,最根本的还是要从改变人们的社会伦理观出发,用价值理性自觉地调适技术理性的非理性倾向、改变物质主义的生活方式、摒弃发展理念的功利主义,从而调节好人与人之间的利益冲突,处理好人与自然的＂物质变换＂关系。     

Costs and benefits of home range shifts among vervet monkeys (Cercopithecus aethiops) in Amboseli National Park,Kenya

Summary A decline in the density of trees and the deterioration of the habitat of vervet monkeys (Cercopithecus aethiops) in Amboseli National Park, Kenya, have been accompanied by movement of vervet groups into unfamiliar areas. These home range shifts were documented over a period of 26 months. The largest group moved into the home ranges of neighboring groups and acquired more trees, a resource that had become more limited. The groups whose home ranges were encroached upon did not share their home ranges with the intruders, but instead moved into areas that were unoccupied and had a lower density of trees. The largest group was thus more successful than smaller groups in competition for limited resources. For all but one group, movement into new areas was directly associated with the disappearances of female and immature monkeys. Most of the disappearances were attributable to predation. These results suggest that the cost of predation in unfamiliar areas may contribute to the evolution of philopatry in vervets. However, under unstable conditions, resource competition forces these animals to disperse (in groups) despite the high risk of predation. Offprint requests to: L.A. Isbell     

Mating patterns of woolly spider monkeys,Brachyteles arachnoides: implications for female choice

Summary Woolly spider monkeys show a promiscuous, polygynous mating system in which a receptive female mates with several males, often in rapid succession. Copulation is prolonged with an average duration of 4.1±1.5 (SD) min. Coitus consists of a stationary phase with the male in intromission, followed by stercotypic behaviours of the female which appear to cue and/or accompany male climax and ejaculation. Subadult and adult males show different association patterns with individual females. Subadult males form long-term consortships with particular females while adult males appear strongly attracted to a particular female only when the is receptive. These different behavior patterns of males are viewed as age-specific mating tactics. Males in a mating aggregation show little intermale aggression for sexual access to a receptive female. Large testis size in this species suggests that much intermale competition for reproductive success may be carried out at a postcopulatory level, perhaps by sperm competition. The copulatory pattern of woolly spider monkeys may function primarily as a mechanism of female choice, aiding a female in assessing the quality of males in hei mating aggregation while helping to ensure that maximal high quality spermatozoa will be available at the proper time for fertilization.     

Identifying future scenarios and their implications for transport policy

Scenario analysis is a technique that is increasingly being used as a way of identifying future policy options and issues in the long-term. This paper discusses the role of scenario analysis in policy development in relation to future transport policy. It discusses three key stages in scenario analysis: the identification of policy targets; the development of images of the future; and the construction of policy packages.     

Current knowledge in tidal bores and their environmental,ecological and cultural impacts

A tidal bore is a series of waves propagating upstream as the tidal flow turns to rising. It forms during the spring tide conditions when the tidal range exceeds 5–6 m and the flood tide is confined to a narrow funnelled estuary with low freshwater levels. A tidal bore is associated with a massive mixing of the estuarine waters that stirs the organic matter and creates some rich fishing grounds. Its occurrence is essential to many ecological processes and the survival of unique eco-systems. The tidal bore is also an integral part of the cultural heritage in many regions: the Qiantang River bore in China, the Severn River bore in UK, the Dordogne River in France. In this contribution, the environmental, ecological and cultural impacts of tidal bores are reviewed, explained and discussed.     

Mechanisms of nonlethal predator effect on cohort size variation: ecological and evolutionary implications

Understanding the factors responsible for generating size variation in cohorts of organisms is important for predicting their population and evolutionary dynamics. We group these factors into two broad classes: those due to scaling relationships between growth and size (size-dependent factors), and those due to individual trait differences other than size (size-independent factors; e.g., morphology, behavior, etc.). We develop a framework predicting that the nonlethal presence of predators can have a strong effect on size variation, the magnitude and sign of which depend on the relative influence of both factors. We present experimental results showing that size-independent factors can strongly contribute to size variation in anuran larvae, and that the presence of a larval dragonfly predator reduced expression of these size-independent factors. Further, a review of a number of experiments shows that the effect of this predator on relative size variation of a cohort ranged from negative at low growth rates to positive at high growth rates. At high growth rates, effects of size-dependent factors predominate, and predator presence causes an increase in the scaling of growth rate with size (larger individuals respond less strongly to predator presence than small individuals). Thus predator presence led to an increase in size variation. In contrast, at low growth rates, size-independent factors were relatively more important, and predator presence reduced expression of these size-independent factors. Consequently, predator presence led to a decrease in size variation. Our results therefore indicate a further mechanism whereby nonlethal predator effects can be manifest on prey species performance. These results have strong implications for both ecological and evolutionary processes. Theoretical studies indicate that changes in cohort size variation can have profound effects on population dynamics and stability, and therefore the mere presence of a predator could have important ecological consequences. Further, changes in cohort size variation can have important evolutionary implications through changes in trait heritability.     

Kleptoparasites: a twofold cost of group living for the colonial spider, Metepeira incrassata (Araneae, Araneidae)

Several species of kleptoparasitic and araneophagic spiders (Araneae: Family Theridiidae, Subfamily Argyrodinae) are found in colonial webs of the orb-weaving spider Metepeira incrassata (Araneae, Araneidae) from Mexico, where they steal food and/or prey upon their spider hosts. Census data from natural M. incrassata colonies reveal that the incidence of these species increases with colony size. This pattern may reflect the presence of several other orb-weaving spiders, each with their own kleptoparasitic species, invading larger M. incrassata colonies. As the number of these associated spiders increases, so does the density and number of Argyrodinae species in M. incrassata colonies, suggesting that associated spiders might reduce their own kleptoparasite load by building their webs within M. incrassata colonies. This represents a twofold cost to M. incrassata, as a field enclosure experiment revealed that a primarily kleptoparasitic species (Argyrodes elevatus) may reduce prey available to their hosts, but a kleptoparasitic/araneophagic species (Neospintharus concisus) inflicts high mortality upon M. incrassata. However, the cost of kleptoparasitism and predation by these species may be offset in part for M. incrassata individuals in large colonies by certain defensive mechanisms inherent in groups, i.e., “attack-abatement” and “selfish herd” effects. We conclude that increased occurrence of kleptoparasitic and/or predatory Argyrodinae spiders is a consequence of colonial web building and is an important potential cost of group living for colonial web-building spiders.     

Social influences on body size and developmental time in the bumblebee Bombus terrestris

In many social insects, including bumblebees, the division of labor between workers relates to body size, but little is known about the factors influencing larval development and final size. We confirmed and extend the evidence that in the bumblebee Bombus terrestris the adult bee body size is positively correlated with colony age. We next performed cross-fostering experiments in which eggs were switched between incipient (before worker emergence) and later stage colonies with workers. The introduced eggs developed into adults similar in size to their unrelated nestmates and not to their same-age full sisters developing in their mother colony. Detailed observations revealed that brood tending by the queen decreases, but does not cease, in young colonies with workers. We next showed that both worker number and the queen presence influenced the final size of the developing brood, but only the queen influence was mediated by shortening developmental time. In colonies separated by a queen excluder, brood developmental time was shorter in the queenright compartment. These findings suggest that differences in body size are regulated by the brood interactions with the queen and workers, and not by factors inside the eggs that could vary along with colony development. Finally, we developed a model showing that the typical increase in worker number and the decrease in brood contact with the queen can account for the typical increase in body size. Similar self-organized social regulation of brood development may contribute to the optimization of growth and reproduction in additional social insects.     

The special role of male Cebus monkeys in predation avoidance and its effect on group composition

Summary Vigilance behavior, predator detection abilities, and responses to real and model predators were studied in two species of capuchin monkeys (Cebus albifrons and C. apella) in a Peruvian lowland rain forest. Adult males were more vigilant than adult females in both species, mainly because the males spent less time feeding and foraging and partly because they were at the periphery more often than the females. The increased vigilance of adult males is reflected in their superior performance in the detection of (model) predators. Adult and subadult males were also far more likely to approach and mob real and model predators. Adults that were outside the center of the group increased foraging activities but cut back an feeding, much of which was done in exposed tree crowns. Current theory suggests that primate groups are multi-male when a single male is unable to defend sexual access to the group of females. In these small capuchin groups, which are multimale, the enhanced safety of females and young provided by extra adult males furnishes a more plausible explanation. A comparison of the two capuchins with the ecologically similar Southeast Asian Macaca fascicularis suggests that the high predation risk outside the group may also have caused the unusual male career profile in capuchins, which have a long tenure of dominants and a very long potential lifespan. Further predictions of this hypothesis are developed.     

Ranging patterns of bottlenose dolphins living in oceanic waters: implications for population structure

Very little is known about the ecology of common bottlenose dolphins (Tursiops truncatus) living in oceanic waters. This study investigated the ranging and residence patterns of bottlenose dolphins occurring in the Azores (Portugal), the most isolated archipelago in the North Atlantic. Data were collected during standardized boat-based surveys conducted over a 6-year period in an area of approximately 5,400 km² (main study area). To investigate the extent of movements of individual animals, non-systematic surveys were also conducted outside this area. Only 44 individuals out of 966 identified were frequently sighted within and between years. The remaining individuals were either temporary migrants from within or outside the archipelago, or transients. Resident dolphins showed strong geographic fidelity to the area. Long-distance movements (of almost 300 km), consistent with foraging or exploratory trips, were observed among non-resident dolphins. Home range size was estimated for 31 individuals sighted ≥10 times. Range areas of these dolphins varied in size and location, but considerable overlap was observed in the areas used, suggesting the absence of habitat partitioning between resident and non-resident dolphins. Estimates of home range size of bottlenose dolphins in the Azores were found to be considerably larger than those previously reported for this species. It is hypothesized that dolphins living in the Azores carry out extensive movements and have large home ranges in response to the lower density and patchy distribution of prey compared to other areas. The extensive ranging behaviour and the lack of territoriality provide an opportunity for interbreeding between dolphins associated with different islands, thus preventing genetic differentiation within the population of the Azores.     

Ranging patterns of bottlenose dolphins living in oceanic waters: implications for population structure

Very little is known about the ecology of common bottlenose dolphins (Tursiops truncatus) living in oceanic waters. This study investigated the ranging and residence patterns of bottlenose dolphins occurring in the Azores (Portugal), the most isolated archipelago in the North Atlantic. Data were collected during standardized boat-based surveys conducted over a 6-year period in an area of approximately 5,400 km² (main study area). To investigate the extent of movements of individual animals, non-systematic surveys were also conducted outside this area. Only 44 individuals out of 966 identified were frequently sighted within and between years. The remaining individuals were either temporary migrants from within or outside the archipelago, or transients. Resident dolphins showed strong geographic fidelity to the area. Long-distance movements (of almost 300 km), consistent with foraging or exploratory trips, were observed among non-resident dolphins. Home range size was estimated for 31 individuals sighted ≥10 times. Range areas of these dolphins varied in size and location, but considerable overlap was observed in the areas used, suggesting the absence of habitat partitioning between resident and non-resident dolphins. Estimates of home range size of bottlenose dolphins in the Azores were found to be considerably larger than those previously reported for this species. It is hypothesized that dolphins living in the Azores carry out extensive movements and have large home ranges in response to the lower density and patchy distribution of prey compared to other areas. The extensive ranging behaviour and the lack of territoriality provide an opportunity for interbreeding between dolphins associated with different islands, thus preventing genetic differentiation within the population of the Azores.     

Informing ecological engineering through ecological network analysis,ecological modelling,and concepts of systems and engineering ecology

A shift in the basic philosophy of nature developed by Francis Bacon, Renè Descartes, and Isaac Newton, has been suggested but for the most part rejected within mainstream science. It suggests the need for viewing nature as a deeply organic and connected system of relationships that is not necessarily or readily submissive to reductive thinking and analysis. Ecosystem design within the construct of a field called ecological engineering poses fundamental questions with respect to the philosophy of nature upon which our current scientific paradigm is predominantly based. In an effort to foster development of rigorous, quantitative methods for developing insight into complex ecosystem phenomena we propose systems and engineering ecology—an integrated science comprised of principles from environ theory, ascendency theory, exergy theory, emergy theory, ecological network analysis and ecological modelling, synthesized through the formal agency of systems science. We contend that ecological engineering will be limited in its robustness apart from development of rigorous systems-based sciences that are quantitative and incorporate the complex, emergent properties of ecosystem. We justify our proposed framework on the philosophical paradox of transferring aspects of traditional engineering design into ecological engineering and on the four causes of Aristotle.     

Larvae of deep-sea fishes (Stomiatoidea) from Biscayne Bay,Florida, USA,and their ecological significance

Twenty stomiatoid fish larvae (3.1 to 21,9 mm) belonging to the genera Bathophilus, Cyclothone, and Stomias were collected in plankton nets from surface waters over depths of 3 to 4 m from Biscayne Bay, Florida, USA. The adults are mesopelagic in the open water of the Florida Current and, therefore, these larvae were presumably advected in parcels of high salinity water into the shallows of Biscayne Bay by winds, tides, or currents. The presence of these larvae suggest that sewage discharged into the Florida Current may be recycling into coastal waters as well as into Biscayne Bay.Scientific Contribution No. 1403, University of Miami, Rosenstiel School of Marine and Atmospheric Science. The support of Environmental Protection Agency Contract FW QA 18050 DIU, Water Quality Office, Division of Water Quality Research is gratefully acknowledged.     

Ecological drivers of group living in two populations of the communally rearing rodent, Octodon degus

Intraspecific variation in sociality is thought to reflect a trade-off between current fitness benefits and costs that emerge from individuals' decision to join or leave groups. Since those benefits and costs may be influenced by ecological conditions, ecological variation remains a major, ultimate cause of intraspecific variation in sociality. Intraspecific comparisons of mammalian sociality across populations facing different environmental conditions have not provided a consistent relationship between ecological variation and group-living. Thus, we studied two populations of the communally rearing rodent Octodon degus to determine how co-variation between sociality and ecology supports alternative ecological causes of group living. In particular, we examined how variables linked to predation risk, thermal conditions, burrowing costs, and food availability predicted temporal and population variation in sociality. Our study revealed population and temporal variation in total group size and group composition that covaried with population and yearly differences in ecology. In particular, predation risk and burrowing costs are supported as drivers of this social variation in degus. Thermal differences, food quantity and quality were not significant predictors of social group size. In contrast to between populations, social variation within populations was largely uncoupled from ecological differences.     

Systematic and ecological studies on Chlorophyceae of North India and their relationship with water quality

In the course of systematic and ecological studies on algal flora of fresh water environment of three different agroclimatic zone of Uttar Pradesh revealed one hundred eighty two species represented by fifty-two genera inhabiting fresh water bodies having different physico-chemical properties. In both the regions members of order Conjugales were dominant and represented by ninety nine species belonging to fourteen genera. This is followed by Chlorococcales having fifty two species represented by nineteen genera and Chaetophorales with nine species of four genera only. In the central Uttar Pradesh a positive correlation was found between hydrogen ions concentration with temperature and species diversity, while in western Uttar Pradesh a highly positive correlation was found in electrical conductivity and total dissolved solids.     

Social and ecological correlates of long-distance pant hoot calls in male chimpanzees

Long-distance calls have a variety of functions in different animal species. However, where multiple functions are proposed for a single long-distance call type, little is known about their relative importance. Chimpanzees are one species where several functions have been proposed for their long-distance call, the pant hoot. In this study, we investigated the effect of social factors, including the rank of the caller, party size, fission–fusion rates, and the presence of estrus females as well as ecological factors including the type of food consumed and travel time, on male chimpanzee (Pan troglodytes schweinfurthii) pant hooting, in order to identify the key correlates of this behavior. The wild male chimpanzees of the Kanyawara community, Uganda, produced more pant hoots on days when there were frequent changes in the male, but not female, composition of the focal’s party. This factor accounted for the largest amount of variation in pant hoot production, and we found that males were more likely to repeat a call prior to rather than after fusion with other males, suggesting that the calls facilitate fusion. Pant hoots therefore seem to play a pivotal role in regulating grouping dynamics in chimpanzees. Our study also shows that pant hooting was positively correlated with the rank of the caller, the presence of parous females in estrus, and the consumption of high-quality food, suggesting that pant hoots signal social status or social bonds when between-male competition is high. This study supports the view that pant hoots fulfill a complex social function.