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1.
The energetic state of an individual is a fundamental driver of its behavior. However, an individual in a eusocial group such as the honeybees is subject to the influence of both the individual and the colony energetic states. As these two states are normally coupled, it has led to the predominant view that behaviors, such as foraging, are dictated by the colony state acting through social regulatory mechanisms. Uncoupling the energetic state of an individual honeybee from its colony by feeding it with a non-nutritious sugar, we show that energetically stressed bees in a colony with full food stores do not consume this food to meet their energetic shortfall but instead compensate by first reducing their activity level and then by increasing their foraging rate. This suggests that foraging in eusocial groups is still partly under the regulatory control of the energetic state of the individual and supports the notion that regulatory mechanisms in solitary insects have been co-opted to drive altruistic behavior in eusocial insects. The observation that energetically stressed bees also experience higher mortality during foraging also suggests that energetic stress mediated by a variety of factors can be a common mechanism that underlies the recent observation of bees disappearing from their colonies. We also discuss how nutritional imbalance in a social insect individual can alter its behavior to influence colony life history. 相似文献
2.
Xim Cerdá Elena Angulo Raphaël Boulay Alain Lenoir 《Behavioral ecology and sociobiology》2009,63(4):551-562
In social insects, the decision to exploit a food source is made both at the individual (e.g., a worker collecting a food
item) and colony level (e.g., several workers communicating the existence of a food patch). In group recruitment, the recruiter
lays a temporary chemical trail while returning from the food source to the nest and returns to the food guiding a small group
of nestmates. We studied how food characteristics influence the decision-making process of workers changing from individual
retrieving to group recruitment in the gypsy ant Aphaenogaster senilis. We offered field colonies three types of prey: crickets (cooperatively transportable), shrimps (non-transportable), and
different quantities of sesame seeds (individually transportable). Colonies used group recruitment to collect crickets and
shrimps, as well as seeds when they were available in large piles, while small seed piles rarely led to recruitment. Foragers
were able to “measure” food characteristics (quality, quantity, transportability), deciding whether or not to recruit, accordingly.
Social integration of individual information about food emerged as a colony decision to initiate or to continue recruitment
when the food patch was rich. In addition, group recruitment allowed a fast colony response over a wide thermal range (up
to 45°C ground temperature). Therefore, by combining both advantages of social foraging (group recruitment) and thermal tolerance,
A. senilis accurately exploited different types of food sources which procured an advantage against mass-recruiting and behaviorally
dominant species such as Tapinoma nigerrimum and Lasius niger. 相似文献
3.
Development of food preferences: social learning by Belding's ground squirrels Spermophilus beldingi
Summary The mechanisms by which food selection behavior develops may constrain the evolution of optimal foraging, yet these mechanisms have received relatively little attention in recent optimal foraging studies. We used cafeteria-style feeding trials to examine the role of social learning in the development of food preferences by a generalist mammalian herbivore, Spermophilus beldingi. Naive young spent relatively little time feeding and showed no preferences among five plant species offered in their feeding trials. This random pattern persisted for one set of young during two subsequent trials in the absence of their mother. A second group of young squirrels was tested initially alone, once with their mothers, and then once more alone. These squirrels fed more than those in the control group during their final trials, and showed significant preferences among plant species. These paralleled the preferences of their mothers. These results suggest that social learning may be important in the development of feeding behavior in ground squirrels, and provide a possible mechanism for cultural differences in food preferences among populations. 相似文献
4.
Michael Hrncir Sidnei Mateus Fábio S. Nascimento 《Behavioral ecology and sociobiology》2007,61(6):975-983
An efficient exploitation of carbohydrate food sources would be beneficial for social wasp species that store nectar within
their nest. In the swarm-founding polistine wasp Polybia occidentalis, we now demonstrate that the decisions of when and where to forage are influenced by information from conspecifics. Only
when foragers had been trained to collect at artificial carbohydrate feeders did newcomers (food-source-naive individuals)
continuously arrive at these feeders during 2 h of experiment. In control tests, in which no forager had been trained, not
a single newcomer alighted at any of the offered carbohydrate food sources. This indicates that, during the foraging process,
a nest-based input provided by successful foragers must have stimulated nestmates to search for food. Once activated, the
newcomers’ choice on where to collect was strongly influenced by field-based social information. The mere visual presence
of accumulated conspecifics (wasp dummies placed on one of the feeders) attracted newcomers to the food sources. Interestingly,
however, visual enhancement was not the only decision-biasing factor at the feeding site. In an experimental series where
searching wasps had to choose between the experimental feeder at which 3 foragers continuously collected and the control feeder
with nine wasp dummies, only 40% of the wasps chose the visually enhanced feeder. This points to the existence of additional
mechanisms of local enhancement. The possibility that, in social wasps, recruitment is involved in the exploitation of carbohydrate
food sources is discussed. 相似文献
5.
Colony nutritional status modulates worker responses to foraging recruitment pheromone in the bumblebee Bombus terrestris 总被引:2,自引:1,他引:1
Mathieu Molet Lars Chittka Ralph J. Stelzer Sebastian Streit Nigel E. Raine 《Behavioral ecology and sociobiology》2008,62(12):1919-1926
Foraging activity in social insects should be regulated by colony nutritional status and food availability, such that both
the emission of, and response to, recruitment signals depend on current conditions. Using fully automatic radio-frequency
identification (RFID) technology to follow the foraging activity of tagged bumblebees (Bombus terrestris) during 16,000 foraging bouts, we tested whether the cue provided by stored food (the number of full honeypots) could modulate
the response of workers to the recruitment pheromone signal. Artificial foraging pheromones were applied to colonies with
varied levels of food reserves. The response to recruitment pheromones was stronger in colonies with low food, resulting in
more workers becoming active and more foraging bouts being performed. In addition to previous reports showing that in colonies
with low food successful foragers perform more excited runs during which they release recruitment pheromone and inactive workers
are more prone to leave the nest following nectar influx, our results indicate that evolution has shaped a third pathway that
modulates bumblebee foraging activity, thus preventing needless energy expenditure and exposure to risk when food stores are
already high. This new feedback loop is intriguing since it involves context-dependent response to a signal. It highlights
the integration of information from both forager-released pheromones (signal) and nutritional status (cue) that occurs within
individual workers before making the decision to start foraging. Our results support the emerging view that responses to pheromones
may be less hardwired than commonly acknowledged.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
6.
Adam L. Cronin 《Behavioral ecology and sociobiology》2013,67(10):1643-1651
Coordination of group actions in social organisms is often a self-organised process lacking central control. These collective behaviours are driven by mechanisms of positive feedback generated through information exchange. Understanding how different methods of communication generate positive feedback is an essential step in comprehending the functional mechanisms underlying complex systems. The Japanese small-colony ant, Myrmecina nipponica uses both pheromone trails and an apparent quorum response during consensus decisions over a new home. Both of these mechanisms have been shown to generate positive feedback and are effective means of selecting among mutually exclusive courses of action. In this study, I investigate how pheromone trails and quorum thresholds contribute to consensus decisions during house-hunting in this species through experimental manipulations of pheromone trails, colony size and environmental context. Results demonstrate that (1) providing colonies with pre-established pheromone trails increased the number of ants finding the new site and led to higher quorum thresholds and more rapid relocations, (2) experimentally halving colony size resulted in a proportional decrease in quorum thresholds and (3) colonies relocating long distances had higher quorums than those relocating short distances. Taken together, these data indicate that pheromone trails are important for recruitment and navigation during nest site selection, but that decision making is contingent on a quorum response. Such synergy between mechanisms of positive feedback may be a common means of optimising collective behaviours. 相似文献
7.
In honeybees, as in other highly eusocial species, tasks are performed by individual workers, but selection for worker task
phenotypes occurs at the colony level. We investigated the effect of colony-level selection for pollen storage levels on the
foraging behavior of individual honeybee foragers to determine (1) the relationship between genotype and phenotypic expression
of foraging traits at the individual level and (2) how genetically based variation in worker task phenotype is integrated
into colony task organization. We placed workers from lines selected at the colony level for high or low pollen stores together
with hybrid workers into a common hive environment with controlled access to resources. Workers from the selected lines showed
reciprocal variation in pollen and nectar collection. High-pollen-line foragers collected pollen preferentially, and low-
pollen-line workers collected nectar, indicating that the two tasks covary genetically. Hybrid workers were not intermediate
in phenotype, but instead showed directional dominance for nectar collection. We monitored the responses of workers from the
selected strains to changes in internal (colony) and external (resource) stimulus levels for pollen foraging to measure the
interaction between genotypic variation in foraging behavior and stimulus environment. Under low-stimulus conditions, the
foraging group was over-represented by high-pollen-line workers. However, the evenness in distribution of the focal genetic
groups increased as foraging stimuli increased. These data are consistent with a model where task choice is a consequence
of genetically based response thresholds, and where genotypic diversity allows colony flexibility by providing a range of
stimulus thresholds.
Received: 3 May 1999 / Received in revised form: 22 December 1999 / Accepted: 23 January 2000 相似文献
8.
Janette Wenrick Boughman 《Behavioral ecology and sociobiology》2006,60(6):766-777
Many studies assume that selection molds social traits and have investigated the manner in which this occurs, yet very few studies have measured the strength of selection on social traits in natural populations. In this paper, I report results of phenotypic selection analyses on two social traits – the size of social groups and the frequency of group foraging – in Phyllostomus hastatus, the greater spear-nosed bat. I found significant positive directional selection on individual group foraging frequency, but no directional selection on individuals in different-sized social groups. These results have implications for the structure of social groups, cooperative behavior among group mates, and maternal investment strategies. I argue that combining studies of natural selection on wild populations with experiments to identify the agents and mechanisms of selection can do much to increase our understanding of social evolution. 相似文献
9.
Adam R. Smith William T. Wcislo Sean O’Donnell 《Behavioral ecology and sociobiology》2007,61(7):1111-1120
Facultatively solitary and eusocial species allow for direct tests of the benefits of group living. We used the facultatively
social sweat bee Megalopta genalis to test several benefits of group living. We surveyed natural nests modified for observation in the field weekly for 5 weeks
in 2003. First, we demonstrate that social and solitary nesting are alternative behaviors, rather than different points on
one developmental trajectory. Next, we show that solitary nests suffered significantly higher rates of nest failure than did
social nests. Nest failure apparently resulted from solitary foundress mortality and subsequent brood orphanage. Social nests
had significantly higher productivity, measured as new brood cells provisioned during the study, than did solitary nests.
After accounting for nest failures, per capita productivity did not change with group size. Our results support key predictions
of Assured Fitness Return models, suggesting such indirect fitness benefits favor eusocial nesting in M. genalis. We compared field collections of natural nests to our observation nest data to show that without accounting for nest failures,
M. genalis appear to suffer a per capita productivity decrease with increasing group size. Calculating per capita productivity from
collected nests without accounting for the differential probabilities of survival across group sizes leads to an overestimate
of solitary nest productivity. 相似文献
10.
Francis Strobbe Mark A. McPeek Marjan De Block Robby Stoks 《Behavioral ecology and sociobiology》2011,65(2):241-247
Despite the importance of foraging activity for the growth/predation risk trade-off, studies that demonstrated predator-induced
survival selection on foraging activity under semi-natural conditions are relatively rare. Here, we tested for fish-induced
selection for reduced foraging activity in two larval Enallagma damselflies using a field enclosure experiment. Fish imposed considerable mortality in both damselfly species and survival
selection on foraging activity could be detected in Enallagma geminatum. We did not detect selection in Enallagma hageni, probably because this species already was not eating very much in the absence of fish compared to E. geminatum. Both species responded strongly to the presence of predators by reducing their foraging activity. The documented survival
selection on foraging activity was detected despite the already low activity levels in fish lake prey species and despite
strong predator-induced plasticity in this trait. 相似文献
11.
The benefit of group living is a fundamental question in social evolution. For sociality to evolve, each individual must gain
in terms of some fitness component by living in larger groups. However, in social insects, a decrease in per capita success in brood production has been observed in larger groups. While it has been proposed that this decrease could be outweighed
by an increase in the predictability of success, a functional basis to this hypothesis has so far never been demonstrated.
In this paper, using foraging economics as a functional proxy to colony productivity, we construct a model to explore how
number of foragers in the colony interacts with the ecology of resources to influence per capita foraging success and its
predictability. The results of the model show that there is no increase in per capita foraging success in larger colonies
under most circumstances, though there is an increase in its predictability. We then test the model with empirical data on
the foraging behavior of the primitively eusocial wasp, Ropalidia marginata. The consistency between the data and the model suggests that foraging economics could provide a robust functional basis
in explaining the relationship between colony size and productivity. 相似文献
12.
Food quality is a relevant characteristic to be transferred within eusocial insect colonies because its evaluation improves
the collective foraging efficiency. In honeybees, colony mates could directly acquire this resource characteristic during
trophallactic encounters with nectar foragers. In the present study, we focused on the gustatory responsiveness of bees that
have unloaded food from incoming foragers. The sugar sensitivity of receiver bees was assessed in the laboratory by using
the proboscis extension response paradigm. After unloading, hive bees were captured either from a colony that foraged freely
in the environmental surroundings or from a colony that foraged at an artificial feeder with a known sucrose solution. In
the first situation, the sugar sensitivity of the hive bees negatively correlated with the sugar concentration of the nectar
crops brought back by forager mates. Similarly, in the controlled situation, the highest sucrose concentration the receivers
accepted during trophallaxis corresponded to the highest thresholds to sucrose. The results indicate that first-order receivers
modify their sugar sensitivity according to the quality of the food previously transferred through trophallaxis by the incoming
foragers. In addition, trophallaxis is a mechanism capable of transferring gustatory information in honeybees. Its implications
at a social scale might involve changes in the social information as well as in nectar distribution within the colony. 相似文献
13.
Andrew M. Bouwma Kenneth J. Howard Robert L. Jeanne 《Behavioral ecology and sociobiology》2005,59(2):222-233
Behavior in eusocial insects likely reflects a long history of selection imposed by parasites and pathogens because the conditions of group living often favor the transmission of infection among nestmates. Yet, relatively few studies have quantified the effects of parasites on both the level of individual colony members and of colony success, making it difficult to assess the relative importance of different parasites to the behavioral ecology of their social insect hosts. Colonies of Polybia occidentalis, a Neotropical social wasp, are commonly infected by gregarines (Phylum Apicomplexa; Order Eugregarinida) during the wet season in Guanacaste, Costa Rica. To determine the effect of gregarine infection on individual workers in P. occidentalis, we measured foraging rates of marked wasps from colonies comprising both infected and uninfected individuals. To assess the effect of gregarines on colony success, we measured productivity and adult mortality rates in colonies with different levels of infection prevalence (proportion of adults infected). Foraging rates in marked individuals were negatively correlated with the intensity of gregarine infection. Infected colonies with high gregarine prevalence constructed nests with fewer brood cells per capita, produced less brood biomass per capita, and, surprisingly, experienced lower adult mortality rates than did uninfected or lightly infected colonies. These data strongly suggest that gregarine infection lowers foraging rates, thus reducing risk to foragers and, consequently, reducing adult mortality rates, while at the same time lowering per-capita input of materials and colony productivity. In infected colonies, queen populations were infected with a lower prevalence than were workers. Intra-colony infection prevalence decreased dramatically in the P. occidentalis population during the wet season.An erratum to this article can be found at 相似文献
14.
While there has been considerable research on the behavioral processes that underlie animals’ ability respond to shifting
rewards, it remains unclear how animals coordinate multiple processes over time. To investigate this, we compared the behavior
of honeybees (Apis mellifera) and bumblebees (Bombus impatiens), in an open-ended search task. Bees were given brief access to a high-quality food source, which then became non-rewarding.
Then, over an extended period, we examined (1) bees’ tendency to persist at the depleted site, (2) their tendency to return
to a different low-quality food source where they had been foraging previously, (3) their tendency to return to the hive,
and (4) how previous reward history influenced their tendency to shift among these options. Compared to bumblebees, honeybees
were much slower to abandon the depleted site and were much more likely to make trips to the hive while bumblebees were much
more likely to return to the familiar low-quality site. These observed species differences are interpreted in terms of evolved
individual and social differences between these species. We show evidence of well-studied behavioral processes such as extinction,
negative contrast effects, and reliance on a social group, and provide, for the first time, a picture of how these processes
interact with one another as part of a common sequential decision-making process. 相似文献
15.
Spatial movement models often base movement decision rules on traditional optimal foraging theories, including ideal free distribution (IFD) theory, more recently generalized as density-dependent habitat selection (DDHS) theory, and the marginal value theorem (MVT). Thus optimal patch departure times are predicted on the basis of the density-dependent resource level in the patch. Recently, alternatives to density as a habitat selection criterion, such as individual knowledge of the resource distribution, conspecific attraction, and site fidelity, have been recognized as important influences on movement behavior in environments with an uncertain resource distribution. For foraging processes incorporating these influences, it is not clear whether simple optimal foraging theories provide a reasonable approximation to animal behavior or whether they may be misleading. This study compares patch departure strategies predicted by DDHS theory and the MVT with evolutionarily optimal patch departure strategies for a wide range of foraging scenarios. The level of accuracy with which individuals can navigate toward local food sources is varied, and individual tendency for conspecific attraction or repulsion is optimized over a continuous spectrum. We find that DDHS theory and the MVT accurately predict the evolutionarily optimal patch departure strategy for foragers with high navigational accuracy for a wide range of resource distributions. As navigational accuracy is reduced, the patch departure strategy cannot be accurately predicted by these theories for environments with a heterogeneous resource distribution. In these situations, social forces improve foraging success and have a strong influence on optimal patch departure strategies, causing individuals to stay longer in patches than the optimal foraging theories predict. 相似文献
16.
Summary (1) When a honey bee follows recruitment dances to locate a new food source, does she sample multiple dances representing different food sources and selectively respond to the strongest dance? (2) Several initial findings suggested that foragers might indeed compare dances. First, dance information is arrayed in the hive in a way that facilitates comparison-making: dances for different flower patches are performed close together in time and space. Second, food-source quality is coded in the dances, in terms of dance length (number of circuits per dance). Third, dances to natural food sources vary in length by more than 2 orders of magnitude, indicating that the quality of natural food sources varies greatly. Fourth, foragers seeking a new food source follow several dances before exiting the hive (though only one dance is followed closely). (3) Nevertheless, a critical test for comparison-making revealed that foragers evidently do not compare dances. A colony was given two feeders that were equidistant from the hive but different in profitability. If foragers do not compare dances, then the proportion of recruits arriving at the richer feeder should match the proportion of dance circuits for the richer feeder. This is the pattern that we found in all 11 trials of the experiment. (4) We suggest that the reason foragers do not compare dances is that a colony's foraging success is greater if its foragers distribute themselves among the various food sources being advertised in the hive than if they crowd themselves on the one, best source. (5) Food-source selection by honey bee colonies is a democratic decision-making process. This study reveals that this selection process is organized to function effectively even though each member of the democracy possesses incomplete information about the available choices.
Offprint requests to: T.D. Seeley 相似文献
17.
Solitary and eusocial nests in a population of Augochlorella striata (Provancher) (Hymenoptera; Halictidae) at the northern edge of its range 总被引:2,自引:0,他引:2
Laurence Packer 《Behavioral ecology and sociobiology》1990,27(5):339-344
Summary
Augochlorella striata was studied at the northern limit of its range. The study population contained a mixture of solitary and social nest foundresses. Eusocial foundresses produced 1 or 2 workers before switching to a male biased brood. Solitary foundresses produced males first. Cells vacated by eclosed offspring were reused late in summer. A female biased brood resulted from cell reuse in both solitary and eusocial nests. Workers were slightly smaller than their mothers and were sterile although most of them mated. In comparison to published data from a Kansas population of this species, the Nova Scotia population had i) a lower proportion of multiple foundress nests, ii) a smaller worker brood and iii) a briefer period of foraging activity but iv) comparable overall nest productivity. 相似文献
18.
Bumblebees (Bombus terrestris) are attracted to those particular inflorescences where other bees are already foraging, a process known as local enhancement.
Here, we use a quantitative analysis of learning in a foraging task to illustrate that this attraction can lead bees to learn
more quickly which flower species are rewarding if they forage in the company of experienced conspecifics. This effect can
also be elicited by model bees, rather than live demonstrators. We also show that local enhancement in bumblebees most likely
reflects a general attraction to conspecifics that is not limited to a foraging context. Based on the widespread occurrence
of both local enhancement and associative learning in the invertebrates, we suggest that social influences on learning in
this group may be more common than the current literature would suggest and that invertebrates may provide a useful model
for understanding how learning processes based on social information evolve. 相似文献
19.
Deception by helpers in cooperatively breeding white-winged choughs and its experimental manipulation 总被引:3,自引:0,他引:3
Christopher R. J. Boland Robert Heinsohn Andrew Cockburn 《Behavioral ecology and sociobiology》1997,41(4):251-256
White-winged choughs (Corcorax melanorhamphos) are obligate cooperative breeders, living in groups which may contain up to 20 birds. Although breeding is dominated by
a single pair, all birds contribute to rearing young, including the provisioning of nestlings. However, some birds which have
carried food to the nest, even to the point of placing the food in the gaping mouth of a nestling, consume the food themselves
rather than provision the nestlings. Birds which fail to feed nestlings are typically young, and are only likely to fail to
deliver food when they cannot be observed by other group members. Birds which have just failed to deliver food are more likely
to engage in alternative helping behaviours such as allopreening the nestlings than are helpers which have just delivered
food in the conventional manner. Failure to deliver food is almost eliminated when foraging constraints are experimentally
reduced by supplemental feeding of the group. Collectively these observations suggest that young white-winged choughs act
deceptively by simulating helping behaviours without sacrificing food supplies.
Received: 24 January 1997 / Accepted after revision: 6 June 1997 相似文献
20.
Iain C. Field Corey J. A. Bradshaw John van den Hoff Harry R. Burton Mark A. Hindell 《Marine Biology》2007,150(6):1441-1452
Southern elephant seals are important apex predators in a highly variable and unpredictable marine environment. In the presence
of resource limitation, foraging behaviours evolve to reduce intra-specific competition increasing a species’ overall probability
of successful foraging. We examined the diet of 141 (aged 1–3 years) juvenile southern elephant seals to test the hypotheses
that differences between ages, sexes and seasons in diet structure occur. We described prey species composition for common
squid and fish species and the mean size of cephalopod prey items for these age groups. Three cephalopod species dominated
the stomach samples, Alluroteuthis antarcticus, Histioteuthis eltaninae and Slosarczykovia circumantarcticus. We found age-related differences in both species composition and size of larger prey species that probably relate to ontogenetic
changes in diving ability and haul-out behaviour and prey availability. These changes in foraging behaviour and diet are hypothesised
to reduce intra-specific food competition concomitant with the increase in foraging niche of growing juveniles. 相似文献