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1.
In most social insect species, individuals recognize and behave aggressively towards non-nestmate conspecifics to maintain
colony integrity. However, introduced populations of the invasive Argentine ant, Linepithema humile, exhibit pronounced variation in intraspecific aggression denoting diversity in nestmate recognition behavior, which possibly
shapes their social structure and the varying levels of unicoloniality observed among these populations. One approach to better
understand differential aggression behaviors towards conspecifics and recognition cue perception and response in L. humile is to examine variation in nestmate discrimination capability among genetically distinct colonies under different social
contexts. Consequently, we investigated the dynamics of queen and worker recognition in southeastern US L. humile queenless and queenright colonies by measuring rates of non-nestmate worker and queen adoption and intercolony genetic similarity.
Aggression levels between colony pairs differed and were associated with non-nestmate worker, but not queen adoption. Adoption
of queens and workers was a function of host colony origin, while colony queen number affected adoption of queens, but not
workers, with queens more readily accepted by queenless hosts. Fecundity of adopted non-nestmate queens was comparable to
that of rejected non-nestmate and host colony queens, suggesting that queen fecundity did not affect adoption decisions. Genetic
similarity between colonies ranged from 30 to 77% alleles shared, with more genetically similar colonies showing lower levels
of intraspecific aggression. Non-nestmate queens and workers that were more genetically similar to host colony workers were
more likely to be adopted. We provide the first evidence for the role of L. humile colony queen number on queen discrimination and suggest an effect of resident queens on worker conspecific acceptance thresholds.
Our findings indicate a role for genetically based cues in L. humile nestmate recognition. However, subtle discrimination capability seems to be influenced by the social context, as demonstrated
by more frequent recognition errors in queenless colonies. 相似文献
2.
Summary. Because generalist ants are aggressive towards foreign insects, the recognition of homopterans by tending ants is critical
in ant/homopteran trophobiosis. Herein we report experimental evidence indicating that Argentine ant, Linepithema humile (Mayr) (Hymenoptera: Formicidae) learn to associate the production of honeydew with the chemical characteristics of homopteran
cuticle, suppressing ant aggression and allowing the ants to tend homopterans. Although chemically-mediated associative learning
is well understood in honeybee foraging, to our knowledge, it has not been reported before in ant/homopteran trophobiosis. 相似文献
3.
Harald Wolf 《Behavioral ecology and sociobiology》2008,62(3):415-425
In the habitat of desert ants, Cataglyphis fortis, a constant wind is usually blowing during the daytime. When visiting a familiar food source, the ants steer some distance
downwind of the feeder, rather than attempting a direct approach that might miss small food sources, in particular. In the
downwind area, the ants pick up the odor plume emanating from the food and follow it upwind to the prey. This strategy saves
considerable walking distance and time. The additional path necessitated by the downwind strategy is only about 0.75 to 2 m,
depending on nest–feeder distance, while missing the food on the upwind side results in much longer search trajectories. During
the initial three to five visits to a feeding site, downwind distance and length of the approach path are shortened notably,
and the approach trajectory is straightened. Desert ants further exhibit considerable short-term flexibility in their approach.
Experienced individuals are evidently able to decide upon leaving the nest which direction to choose toward the feeder, depending
on current wind direction (that fluctuates slightly during the day). Notable changes in wind direction occur primarily overnight.
For larger nest–feeder distances, the animals adjust their approach en route to the altered wind direction during their first
foraging trip in the morning. 相似文献
4.
Social insect colonies can be expected to forage at rates that maximize colony fitness. Foraging at higher rates would increase the rate of worker production, but decrease adult survival. This trade-off has particular significance during the founding stage, when adults lost are not replaced. Prior work has shown that independent-founding wasps rear the first workers rapidly by foraging at high rates. Foraging rates decrease after those individuals pupate, presumably reducing the risk of foundress death. In the swarm-founding wasps, colony-founding units have many workers, making colony death by forager attrition less likely. Do swarm-founding wasps show similar shifts in foraging rates during the founding stage? We measured foraging rates of the swarm-founding wasp, Polybia occidentalis at four stages of colony development. At each stage, foraging rates correlated with the number of larvae present, which, in the founding stages, correlated with the number of cells in the new nest. Thus, foraging rates appear to be demand-driven, with the level of demand in the founding stage set by the size of nest that is constructed. During the founding stage, foraging rates per larva were high initially, suggesting that colonies minimize the development times of larvae early in the founding stage. Later in the stage, foraging rates decreased, which would reduce worker mortality until new workers eclose. This pattern is similar to that shown for independent-founding wasps and likely results from conflicting pressures to maximize colony growth and minimize the risk of colony death by forager attrition. 相似文献
5.
Audrey Dussutour Stamatios C. Nicolis Jean-Louis Deneubourg Vincent Fourcassié 《Behavioral ecology and sociobiology》2006,61(1):17-30
In this paper we examine the effect of crowding on the selection of a path in the mass-recruiting ant Lasius niger. In our experiment, ants had to go from their nest to a food source by crossing a diamond-shaped bridge, giving the choice between two paths. Two types of bridges were used: the first had two branches of equal length but different width while the second had two branches of different length and width. Experiments at high traffic volume always ended up with the selection of the wider branch, even if it was longer. This result shows that overcrowding on the narrow branch plays an essential role in the mechanism underlying the choice of route in ants. A mathematical model was developed to evaluate the importance of two mechanisms that could account for this result. The first is based on the difference in travel duration between the two paths. The second is based on the repulsive interactions between workers making head-on encounters. The model shows that travel duration per se is not sufficient to explain path choice. Rather, it is the interplay between trail following behaviour and repulsive interactions that allows ants to choose the path that minimizes their travel time. When choosing a path ants thus prefer to trade time against energy. Our results demonstrate that any environmental constraint that alters the dynamics of trail recruitment can lead to the emergence of adaptive foraging decisions without any explicit coding of information by the foragers at the individual level. 相似文献
6.
Robert L. McLaughlin Moira M. Ferguson David L. G. Noakes 《Behavioral ecology and sociobiology》1999,45(5):386-395
Some recently emerged brook charr (Salvelinus fontinalis) inhabiting still-water pools along the sides of streams are sedentary and eat crustaceans from the lower portion of the
water column. Others are more active and eat insects from the upper portion of the water column. We provide evidence that
this divergent foraging behavior reflects short-term divergent selection brought about by intraspecific competition in the
presence of alternative food sources. Rates of encounters and interactions between individuals were density dependent, and
encounter and interaction events were closely timed with prey capture attempts. In addition, aggressive fish made more foraging
attempts per minute than nonaggressive fish. Aggressive fish were also either inactive or very active, while nonaggressive
fish exhibited intermediate levels of activity. Growth rate potential, an important component of fitness during the early
life stages of brook charr, was assessed using tissue concentrations of RNA and found to be highest for sedentary fish and
for active fish making frequent foraging attempts, and lower for fish exhibiting intermediate levels of activity. Our findings
support contentions that individual behavior plays an important role during initial steps in the evolution of resource polymorphisms.
Received: 27 July 1998 / Accepted after revision: 16 November 1998 相似文献
7.
We studied the impact of group size on foraging behaviour and level of movement synchronisation among female herdmates of a fallow deer population in Central Italy. Both proportion of foraging events and movement synchronisation decreased with increasing group size. The proportion of foraging events was higher for animals on the edge of the group than for deer in the centre of the group; hence, there appears to be a trade-off between protection against predators and foraging interference, both of which decrease from the centre to the periphery of the group. This is the first time this type of behaviour has been recorded for wild ungulates. As expected, we also found that the movement of peripheral animals was less synchronised than that of central animals. Consequently, peripheral animals may lose contact with their herdmates and split off the group. We conclude that social inequalities may lead to conflicting requirements among group members and instability of large groups. Movement synchronisation (as a function of group size) appears to interact with habitat openness to produce variations of group size (which appear to be adaptive for individuals) as an emergent property of these aggregations. 相似文献
8.
Desert ants, Cataglyphis fortis, return to their nest by means of path integration vectors. By using the reversal of these vectors, they approach previously
visited feeding sites again. They adjust these vectors whenever outbound and inbound vector are set into conflict or when
they make use of external cues. Here, we examine the influence of repeated training on the accuracy, precision, and straightness
of outbound and inbound vectors. We trained desert ants to forage to and fro between their nest and a feeder and made sure
that they relied exclusively on their path integrator. Neither the ants’ outbound nor their inbound runs, which, in general,
are straighter than the outbound runs, become more accurate, precise, or straighter during repeated training. Hence, repeated
training does not improve the path integrator in desert ants. 相似文献
9.
Two-way selection for quantities of stored pollen resulted in the production of high and low pollen hoarding strains of honey bees (Apis mellifera L.). Strains differed in areas of stored pollen after a single generation of selection and, by the third generation, the high strain colonies stored an average 6 times more pollen than low strain colonies. Colony-level organizational components that potentially affect pollen stores were identified that varied genetically within and between these strains. Changes occurred in several of these components, in addition to changes in the selected trait. High strain colonies had a significantly higher proportion of foragers returning with loads of pollen, however, high and low strain colonies had equal total numbers of foragers Colony rates of intake of pollen and nectar were not independent. Selection resulted in an increase in the number of pollen collectors and a decrease in the number of nectar collectors in high strain colonies, while the reciprocal relationship occurred in the low strain. High and low strain colonies also demonstrated different diurnal foraging patterns as measured by the changing proportions of returning pollen foragers. High strain colonies of generation 3 contained significantly less brood than did low strain colonies, a consequence of a constraint on colony growth resulting from a fixed nest volume and large quantities of stored pollen. These components represent selectable colony-level traits on which natural selection can act and shape the social organization of honey bee coloniesCommunicated by R.F.A. Moritz 相似文献
10.
Elva J. H. Robinson Thomas O. Richardson Ana B. Sendova-Franks Ofer Feinerman Nigel R. Franks 《Behavioral ecology and sociobiology》2009,63(5):779-636
Ant colonies are factories within fortresses (Oster and Wilson 1978). They run on resources foraged from an outside world fraught with danger. On what basis do individual ants decide to leave the safety of the nest? We investigated the relative roles of social information (returning nestmates), individual experience and physiology (lipid stores/corpulence) in predicting which ants leave the nest and when. We monitored Temnothorax albipennis workers individually using passive radio-frequency identification technology, a novel procedure as applied to ants. This method allowed the matching of individual corpulence measurements to activity patterns of large numbers of individuals over several days. Social information and physiology are both good predictors of when an ant leaves the nest. Positive feedback from social information causes bouts of activity at the colony level. When certain social information is removed from the system by preventing ants returning, physiology best predicts which ants leave the nest and when. Individual experience is strongly related to physiology. A small number of lean individuals are responsible for most external trips. An individual’s nutrient status could be a useful cue in division of labour, especially when public information from other ants is unavailable. 相似文献
11.
Energy intake and expenditure on natural foraging trips were estimated for the seed-harvester ants, Pogonomyrmex maricopa and P. rugosus. During seed collection, P. maricopa foraged individually, whereas P. rugosus employed a trunk-trail foraging system. Energy gain per trip and per minute were not significantly different between species. There was also no interspecific difference in energy cost per trip, but energy cost per minute was lower for P. maricopa foragers because they spent on average 7 min longer searching for a load on each trip. Including both unsuccessful and successful foraging trips, average energy gain per trip was more than 100 times the energy cost per trip for both species. Based on this result, we suggest that time cost incurred during individual foraging trips is much more important than energy cost in terms of maximizing net resource intake over time. In addition, because energy costs are so small relative to gains, we propose that energy costs associated with foraging may be safely ignored in future tests of foraging theory with seed-harvesting ant species. 相似文献
12.
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
13.
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
14.
Alate trapping studies of a monogyne population of the fire ant Solenopsis geminata indicate that two sizes of gynes are produced. Macrogynes, which participate in late spring and summer mating flights, are larger, fattier, and more than twice as heavy as microgynes, which participate in fall mating flights. Three patterns of gyne production were observed in 51 colonies studied: 35 produced macrogynes only, 9 produced microgynes only, and 7 produced both morphs, contributing to both summer and fall mating flights. Behavioral evidence and rearing studies suggest that macrogynes found new colonies independently, whereas microgynes achieve colony queen status by infiltrating or being adopted by established colonies. Of the total number of female alates collected from the trapped colonies, 56% were microgynes. However, because of their smaller size and lower fat content, microgynes made up only one-third of the caloric investment in female alates. By measuring the thorax lengths of queens from mature colonies, we determined that at least 56% were macrogynes and 35% or more were microgynes. These results indicate that as a reproductive strategy, colony investment in microgyne production may have at least as high a payoff as investment in macrogyne production.This is publication #24 of the Fire Ant Research Team 相似文献
15.
Tropical arboreal ant mosaics: innate attraction and imprinting determine nest site selection in dominant ants 总被引:2,自引:0,他引:2
The modalities of nest site selection have, until now, been a key factor missing in the understanding of the arboreal ant
mosaic, the manipulation of which could be used to favour one ant species to the detriment of others in biological control.
We compared two dominant African arboreal ants of economic importance, Tetramorium aculeatum (Myrmicinae) and Oecophylla longinoda (Formicinae). The two species differed in terms of innate attraction to nesting site plants, their hierarchies of attractiveness
being nearly inverse. Winged females and workers were confronted with choice tests using four plant species. By using winged
females and workers originating from one of the plants to be tested, we showed the existence of a familiarisation process
which can supersede innate attraction in both species. We recorded the same effect in neonatal workers bred in the laboratory
in contact with a tested plant for 25 days after emergence, while mature workers could not be conditioned. There is, therefore,
early learning, with a sensitive period after which the influence of the environment ceases, suggesting that this is a true
imprinting process. Choice tests using neonates produced from larvae and pupae bred in the laboratory in contact with the
leaves of each tested plant permitted us to demonstrate the existence of pre-imaginal learning. Nest site selection therefore
depends on innate selective attraction and on environmental factors whose effect begins at the larval stage. There is, therefore,
the potential to “control” imprinting, allowing one ant species to be favoured to the detriment of others in monospecific
tree crop plantations.
Received: 25 May 1998 / Accepted after revision: 9 October 1998 相似文献
16.
Sophie E. F. Evison Owen L. Petchey Andrew P. Beckerman Francis L. W. Ratnieks 《Behavioral ecology and sociobiology》2008,63(2):261-267
This study investigated the relative importance of pheromone trails and visual landmarks on the ability of Lasius niger foragers to relocate a previously used food source. Colonies formed foraging trails to a 1-M sucrose feeder. Sections of
this trail were then presented back to the same colony after variable time intervals. Individual outgoing foragers were observed
to determine if they walked for 15 cm in the direction of the feeder or not. On newly established pheromone trails formed
by 500 ant passages, 77% of the foragers walked in the correct direction vs 31% for control foragers (no trail pheromone).
Pheromone trails decayed to the control levels in 20–24 h. Trails formed with fewer ant passages (125 or 30) decayed quicker.
The use of visual landmarks was investigated by using trails with outgoing foragers from the colony that established the trail,
either in the same room or in a different room, with different visual landmarks, to that used during trail establishment.
Approximately 20% more ants walked in the correct direction in the same room vs the different room. This difference decreased
to around 10% 2 h after trail establishment, indicating that the ants in the different room were learning the new visual cues
to navigate by. Our results show that visual landmarks and pheromone trails are approximately equally useful in initially
guiding L. niger foragers to food locations and that these two information sources have a complementary function. 相似文献
17.
In sexually dimorphic ungulates, males generally spend less time foraging than females, possibly because of difference in body mass or because of the energetic requirements of lactation. The relationship between body size and foraging time has received little attention at the intra-specific level, because few studies have documented activity budgets for individuals of known size. Bighorn rams are a good model to explore how body mass affects foraging time, because they range in mass from 55 to 140 kg. We examined how the foraging time of bighorn rams varied according to individual characteristics. We observed rams in a marked population and constructed time budgets during the 3 months preceding the rut. We determined ram social rank based on agonistic encounters and collected fecal samples to count lungworm larvae. Time spent foraging was negatively correlated with body mass. After accounting for age differences, larger rams spent less time foraging and more time lying than smaller rams. Among rams aged 6–12 years, dominants spent less time feeding than subordinates, while fecal output of lungworm larvae was negatively correlated with foraging time for rams of all ages. Body mass accounts for much of the individual variation in foraging time, suggesting that sexual dimorphism is important in explaining differences in feeding time between males and females.Communicated by P. Heeb 相似文献
18.
Anders Pape Møller 《Behavioral ecology and sociobiology》2007,61(8):1311-1319
Protandry reflects the earlier arrival of males than females to the site of reproduction. Such protandry is hypothesised to
arise from sex differences in costs and benefits of early arrival. I investigated temporal patterns of arrival date of male
and female barn swallows Hirundo rustica and temporal patterns of selection to test the hypothesis that sex differences in selection account for sex differences in
arrival date. Mean arrival date of male barn swallows but not of females advanced during the last 33 years, giving rise to
an increasing sex difference in arrival date. Early arrival was favoured by increasingly better survival in males, while females
showed an opposite pattern that did not reach significance, although the effect differed between sexes. Early arrival increased
fecundity in both sexes equally.The sex difference in viability selection in relation to arrival date changed from positive
to negative as the degree of protandry increased in recent years, although there was no similar significant relationship for
fecundity selection. Furthermore, sex differences in viability selection in a given year affected the degree of protandry
in the following year through differential survival of certain phenotypes over others. Finally, temporal changes in sex difference
in viability selection and protandry were related to an increase in the interval between first and second clutches, as the
duration of the breeding season increased because of climatic amelioration. These findings suggest that arrival date is under
divergent selection in the two sexes, providing a mechanism for the evolution of protandry. 相似文献
19.
Modeling and analysis of nest-site selection by honeybee swarms: the speed and accuracy trade-off 总被引:5,自引:2,他引:3
Nest-site selection in honeybees is a process of social decision making in which the scout bees in a swarm locate several
potential nest sites, evaluate them, and select the best one by means of competitive signaling. We develop a model of this
process and validate that the model possesses the key features of the bees' decision-making process, as revealed by prior
empirical studies. Next, we use the model to study the “design” of the nest-site selection process, with a focus on how certain
behavioral parameters have been tuned by natural selection to achieve a balance between speed and accuracy. First, we study
the effects of the quorum threshold and the dance decay rate. We show that evolution seems to have settled on values for these
two parameters that seek a balance between speed and accuracy of decision making by minimizing the time needed to achieve
a consensus and maximizing the probability that the best site is chosen. Second, we study the adaptive tuning of the tendency
of bees to explore for vs be recruited to a site. We show that this tendency appears to be tuned to regulate the positive
feedback process of recruitment to ensure both a reasonably rapid choice and a low probability of a poor choice. Finally we
show that the probability of choosing the best site is proportional to its quality, but that this proportionality depends
on its quality relative to other discovered sites.
相似文献
Thomas D. SeeleyEmail: |
20.
Summary. The formicine ant Paratrechina longicornis is known for its extremely opportunistic foraging behaviour. Only a single trail pheromone source, the rectum, was previously
described from this ant. Our detailed examination of this ant’s chemical communication system revealed the presence of at
least four sources of pheromones. Rectum, poison sac, and Dufour gland contain orientation components with decreasing effectiveness
and persistence (in the sequence mentioned) as well as attractants with increasing effectiveness. Furthermore, the mandibular
gland contains repellents, and a releaser of defensive behaviour. This set of various signals of different strength and persistence
allows an extraordinary degree of flexibility and efficiency in the collective behaviour of P. longicornis, especially food exploitation, and thus may contribute to this insect’s overall ecological success. 相似文献