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1.
One day is all it takes: circadian modulation of the retrieval of colour memories in honeybees 总被引:1,自引:0,他引:1
In this study, we examined how honeybees coped with successive tasks of colour discrimination with conflicting demands. Free-flying
honeybees (Apis mellifera) were trained on tasks in which they had to choose one of three colours to obtain a reward of sugar water. In acquisition,
the bees learned this task in about four trials of training. Colour memory was retained after 24-h delay in an unrewarded
retention test. Integration experiments were then conducted in which the bees had to learn two successive tasks of colour
discrimination with conflicting demands, task 1 for 20 trials and task 2 for ten trials. In task 1, one of three colours provided
sugar water while the other two provided tap water, while in task 2 a different colour provided the reward. The bees were
given unrewarded tests immediately after training on task 2 and then re-tested after 10 min, 22 h (circadian time of the start
of task 1 training), or 24 h (circadian time of the end of task 2 training). Bees strongly preferred the rewarded colour for
task 2 on immediate testing and after 10-min delay. After 22-h delay, they switched their preference to the rewarded colour
for task 1. But after 24-h delay, the bees again strongly preferred the rewarded colour for task 2. Further tests at a number
of delays between 0 and 22 h revealed a sigmoidal pattern of rise in the preference for the task 1 colour. We conclude that
circadian time modulates the retrieval of colour memories in honeybees, even when all the training took place in a single
day. 相似文献
2.
Circadian rhythmicity plays an important role for many aspects of honey bees’ lives. However, the question whether it also
affects learning and memory remained unanswered. To address this question, we studied the effect of circadian timing on olfactory
learning and memory in honey bees Apis mellifera using the olfactory conditioning of the proboscis extension reflex paradigm. Bees were differentially conditioned to odours
and tested for their odour learning at four different “Zeitgeber” time points. We show that learning behaviour is influenced
by circadian timing. Honey bees perform best in the morning compared to the other times of day. Additionally, we found influences
of the light condition bees were trained at on the olfactory learning. This circadian-mediated learning is independent from
feeding times bees were entrained to, indicating an inherited and not acquired mechanism. We hypothesise that a co-evolutionary
mechanism between the honey bee as a pollinator and plants might be the driving force for the evolution of the time-dependent
learning abilities of bees. 相似文献
3.
Individual bees often restrict their visits to only a few species out of the multitude of available plants. This flower constancy
is likely caused by limitations of memory for motor patterns, sensory stimuli, or reward levels. Here we test the implications
of sensori-motor learning and memory for flower constancy. Artificial “flowers” with two distinct “morphologies” were used,
so that in each flower type, a different motor pattern was needed to reach the nectar. As in natural flowers, these morphological
types were associated with sensory signals (blue and yellow color stimuli). Bees which learned only a single task were more
efficient in several ways than those which had learned two: they made fewer errors, had shorter flower handling times, took
shorter times to correct errors, and transitions between flowers were initially more rapid. For bees which had learned two
tasks, performance depended strongly on the training schedule: if each task was learned with blocked trials, the memory for
the second appeared to interfere with that for the first. Interference affected only the association between flower signal
and motor pattern, not the motor pattern itself. This was not the case if bees were trained for both tasks with alternating
trials. In that case, bees rapidly learned both tasks, albeit with worse saturation levels than bees which had learned only
one. Bees transferred the experience gained on one task to a second task: their initial performance on the second task was
better than their initial performance on the first. On the other hand, performance on the second task in the saturation level (in which bees no longer improve their efficiency) was worse than on the first task (negative transfer). In the saturation
phase, performance did not directly depend on switch frequency, but on whether the bee had one or two options in memory. Thus,
while bees would become proficient at two tasks more quickly if their acquisition phase included switches, such switches had
no measurable effect in the saturation phase. The implications of these findings for foraging are discussed using modern learning
theory.
Received: 4 April 1997 / Accepted after revision: 8 August 1997 相似文献
4.
Since forager honeybees change their food-unloading behavior according to nectar-source profitability, an experiment was performed in order to analyze whether food-receivers modify their within-hive tasks related to different reward conditions. We offered individual foragers two reward conditions at a rate feeder while an additional feeder offered a constant reward and was of free access to the rest of the hive. Both feeders were the only food sources exploited by the colony during the assays since a flight chamber was used. After receiving nectar, hive bees performed processing cycles that involved several behaviors and concluded when they returned to the delivery area to receive a new food sample. During these cycles, receivers mainly performed oral contacts offering food, or inspected cells, and often both. In the latter case, both behaviors occurred simultaneously and at the same distance from the hive entrance. When they performed a single task, either the occurrence of cell inspections increased or contact offerings decreased for the highest reward rate offered to the donor-forager. Receivers also begged for food more often after interacting with low-profit foragers. Thus, the profitability of the food source exploited by nectar-forager honeybees could affect receiver behaviors within the hives based on individual-to-individual interactions.Communicated by R.F.A. Moritz 相似文献
5.
Timekeeping in the honey bee colony: integration of circadian rhythms and division of labor 总被引:1,自引:0,他引:1
Darrell Moore Jennifer E. Angel Iain M. Cheeseman Susan E. Fahrbach Gene E. Robinson 《Behavioral ecology and sociobiology》1998,43(3):147-160
The daily patterns of task performance in honey bee colonies during behavioral development were studied to determine the
role of circadian rhythmicity in age-related division of labor. Although it is well known that foragers exhibit robust circadian
patterns of activity in both field and laboratory settings, we report that many in-hive tasks are not allocated according
to a daily rhythm but rather are performed 24 h per day. Around-the-clock activity at the colony level is accomplished through
the performance of some tasks by individual workers randomly with respect to time of day. Bees are initially arrhythmic with
respect to task performance but develop diel rhythmicity, by increasing the occurrence of inactivity at night, prior to becoming
foragers. There are genotypic differences for age at onset of rhythmicity and our results suggest that these differences are
correlated with genotypic variation in rate of behavioral development: genotypes of bees that progressed through the age polyethism
schedule faster also acquired behavioral rhythmicity at an earlier age. The ontogeny of circadian rhythmicity in honey bee
workers ensures that essential in-hive behaviors are performed around the clock but also allows the circadian clock to be
engaged before the onset of foraging.
Received: 6 October 1997 / Accepted after revision: 28 March 1998 相似文献
6.
We analyzed the foraging and recruitment activity of single foragers ( Apis mellifera), exploiting low reward rates of sucrose solution. Single employed foragers (test bees) were allowed to collect 2.0 m sucrose solution delivered by a rate-feeder located at 160 m from the hive for 2 h. Flow rates varied between 1.4 and 5.5 µl/min. The individual behavior of the test bees was registered both at the hive and the food source, and the social output was calculated as the number of incoming bees arriving at the feeder per hour (henceforth: arrival rate). Incoming bees were captured once they landed at the feeder and assigned to one of three categories according to their foraging experience and hive interactions with the test bee: inspector, reactivated, or inexperienced bees. Both the waggle-runs performed per hour of foraging by test bees and the social output attained, increased with the reward rate. Also the number of hive-stays and the trophallactic-offering contacts performed by test bees were positively correlated with the arrival rate. For the highest reward rates, the duration of Nasonov-gland exposure at the feeding place was higher, and the arrival of most of the incoming bees occurred shortly after the test bee landed at the feeding platform. Thus, in addition to hive-interactions, landing of incoming bees at the food source is promoted by olfactory and/or visual information provided by the test bees. The proportions of inspector, reactivated, and inexperienced bees changed depending on the reward rate offered. Therefore, not only the occurrence and intensity of the recruitment-related behaviors performed by the test bees, but also the stimulation required by each category of incoming bees, determined the social output observed. 相似文献
7.
Summary. Oviposition site selection of herbivorous insects depends primarily on host plant presence which is essential for offspring
survival. However, parasitoids can exploit host plant cues for host location. In this study, we hypothesised that herbivores
can solve this dilemma by ovipositing within high plant diversity. A diverse plant species composition might represent an
‘infochemical shelter’, as a potentially complex volatile blend can negatively affect the host location ability of parasitoids.
We examined this exemplarily for the egg-laying response of the generalist leaf beetle, Galeruca tanaceti, in relation to (1) host plant availability and (2) plant species diversity in the field. Further, we investigated the effect
of odours from mixed plant species compositions on (3) leaf beetle oviposition site selection and on (4) the orientation of
its specialised egg parasitoid, Oomyzus galerucivorus. In the field, egg clutch occurrence was positively related to the presence and quantity of two major host plants, Achillea millefolium (yarrow) and Centaurea jacea, and to the number of herbaceous plant species. In two-choice bioassays, female beetles oviposited more frequently on sites
surrounded by an odour blend from a diverse plant species composition (including yarrow) than on sites with a pure grass odour
blend. In the presence of yarrow odour and an odour blend from a diverse plant mixture (including yarrow) no difference in
the oviposition response was recorded. Experienced parasitoid females were attracted to yarrow odours, but showed no response
when yarrow odours were offered simultaneously with odours of a non-host plant. In conclusion, it could be shown in laboratory
bioassays that the parasitoid responds only to pure host plant odours but not to complex odour blends. In contrast, the herbivore
prefers to oviposit within diverse vegetation in the field and in the laboratory. However, the laboratory results also point
to a priority of host plant availability over the selection of a potential ‘infochemical shelter’ for oviposition due to high
plant diversity. 相似文献
8.
Colonies and isolated bees of the Cape honeybee, Apis mellifera capensis Esch., were observed for evidence of circadian rhythmicity under constant conditions. It was found that colonies develop free-running activity rhythms in self-selected light-dark cycles, which are slightly shorter than 24 h. The periods of the activity rhythms of individual isolated bees were longer than 24 h in self-selected light-dark and constant light, while they were shorter than 24 h in constant darkness. A greater variability in period was found in the isolated bees than in the colonies. When the rhythms of colonies and individual bees from these colonies were measured simultaneously, the activities of the isolated bees drifted with respect to that of the colonies, their period being either longer or shorter than that of their own colony. After 12 days of isolation of individual bees from their colony, all coincidence between the phases of the two rhythms was lost. We conclude that the periods of common activity and common rest of the bees within a colony result from a mutual (social) synchronization of the rhythms of the individual bees. 相似文献
9.
Workers in social groups of honeybees (Apis mellifera L.) synchronize their individual free-running circadian rhythms to an overall group rhythm. By monitoring the activity of bees by recording the oxygen consumption and intragroup temperature, it is shown that the rhythm coordination is in part achieved by temperature fluctuations as an intragroup Zeitgeber. Trophallaxis was shown to have only a minor (if any) effect on circadian rhythm synchronization. A model incorporating a feed back loop between temperature and activity can plausibly explain the observed synchronization of individual rhythms in social groups as a self-organization phenomenon.
Correspondence to: R.F.A. Moritz 相似文献
10.
Sam M. Jones Jelle S. van Zweden Christoph Grüter Cristiano Menezes Denise A. Alves Patrícia Nunes-Silva Tomer Czaczkes Vera L. Imperatriz-Fonseca Francis L. W. Ratnieks 《Behavioral ecology and sociobiology》2012,66(1):1-12
Recent research has shown that entrance guards of the stingless bee Tetragonisca angustula make less errors in distinguishing nestmates from non-nestmates than all other bee species studied to date, but how they
achieve this is unknown. We performed four experiments to investigate nestmate recognition by entrance guards in T. angustula. We first investigated the effect of colony odours on acceptance. Nestmates that acquired odour from non-nestmate workers
were 63% more likely to be rejected while the acceptance rate of non-nestmates treated with nestmate odour increased by only
7%. We further hypothesised that guards standing on the wax entrance tube might use the tube as an odour referent. However,
our findings showed that there was no difference in the acceptance of non-nestmates by guards standing on their own colony’s
entrance tube versus the non-nestmate’s entrance tube. Moreover, treatment of bees with nestmate and non-nestmate resin or
wax had a negative effect on acceptance rates of up to 65%, regardless of the origin of the wax or resin. The role of resin
as a source of recognition cues was further investigated by unidirectionally transferring resin stores between colonies. Acceptance
rates of nestmates declined by 37% for hives that donated resin, contrasting with resin donor hives where acceptance of non-nestmates
increased by 21%. Overall, our results confirm the accuracy of nestmate recognition in T. angustula and reject the hypothesis that this high level of accuracy is due to the use of the wax entrance tubes as a referent for
colony odour. Our findings also suggest that odours directly acquired from resin serve no primary function as nestmate recognition
cues. The lack of consistency among colonies plus the complex results of the third and fourth experiments highlight the need
for further research on the role of nest materials and cuticular profiles in understanding nestmate recognition in T. angustula. 相似文献
11.
A. Gumbert 《Behavioral ecology and sociobiology》2000,48(1):36-43
It is usually assumed that the choice behavior of bees for floral colors is influenced by innate preferences only for the
first flower visits prior to any experience. After visits to rewarding flowers bees learn to associate their colors with a
reward. This learning process leads to an acquired preference for the trained colors that has been believed to dominate over
previous experiences and over innate preferences. This work investigates how bumble bees (Bombus terrestris) chose among artificial flowers of different colors after they had been extensively trained to other colors. The bees chose
novel colors according to their similarity to the trained color if the trained color was similar to some of the test colors.
This was true also if trained colors and test colors were well distinguished, so their color choice reflected generalization
between colors. If the test colors were so different from the trained color that no generalization took place, choice behavior
was not affected by the trained color and reflected innate preferences. The differences in choice frequencies could not be
explained by physical properties of the test colors other than the dominant wavelength, a parameter taken to reflect hue perception.
Preferred dominant wavelengths correspond to those observed in naive bumble bees and honeybees. Thus bumble bees show innate
preferences for certain colors not only prior to color learning but also after intensive learning when choosing among very
different novel colors. Color choice among similar colors, however, is controlled by generalization from the learned color.
Received: 9 November 1999 / Received in revised form: 19 March 2000 / Accepted: 31 March 2000 相似文献
12.
The bee louse Braula coeca is a highly specialised flattened, wingless fly that spends its entire adult life on adult honeybees. It feeds by stealing food directly from bees during social feeding (trophallaxis). The Braula fly has a preference to infest the honeybee queen. The queen is the most attended individual in the colony but despite this the adult flies remain undetected by the workers. This is due to Braula possessing a cuticular hydrocarbon profile that mirrors that of their host honeybee colony, despite Diptera and Hymenoptera orders having separated over 290 million years ago. This chemical camouflage is most likely through odour acquisition from the honeybee host since even small colony-specific differences in the alkene isomer patterns present in the honeybees were also detected in the Braula’s profile. This finding further supports the idea that the honeybee recognition cues are contained within the alkene part of their hydrocarbon profile and Braula exploit this to remain undetected within an otherwise hostile colony. 相似文献
13.
The use of high-frequency acoustics has recently emerged as a viable method for mapping the areal coverage of seagrasses. Since the bubbles produced by seagrass plants are partly responsible for the observed acoustic signature, it is likely that sound transmission throughout a seagrass canopy varies on circadian cycles coinciding with photosynthetic bubble production. This study examined the propagation of high-frequency (100 kHz) sound energy through the seagrass canopies of Syringodium filiforme, Halodule wrightii and Thalassia testudinum in a shallow outdoor mesocosm. Relative changes in the received acoustic energy were recorded every hour during a 24-h period and compared to independently measured rates of oxygen production. The mean acoustic intensity of energy transmitted throughout the seagrass canopy varied by 3.5 dB for S. filiforme, 4.4 dB for T. testudinum and 4.7 dB for H. wrightii over a 24-h period. These transmission characteristics are encouraging for the future development of in situ acoustic assessments of seagrass photosynthesis. 相似文献
14.
To aid air quality model development and assess air quality forecasts, the Meteorological Development Laboratory (MDL) provided
categorical verification metrics for developmental aerosol predictions. The National Air Quality Forecasting Capability (NAQFC)
generated 48 h (of) gridded hourly developmental predictions for the lower 48 states (CONUS) domain in 12 km horizontal spacing.
The NAQFC uses the North American Mesoscale (NAM) model with EPA’s Community Multiscale Air Quality (CMAQ) model to produce
predictions of ground level aerosol concentrations. We used bilinear interpolation to calculate predicted daily maximum values
at the location of the observation sites. We compared these interpolated predicted values to the observed daily maximum to
produce 2 × 2 contingency tables, with a threshold of 40 μg/m3 during the months of March–August, 2007. The model showed some degree of skill in predicting aerosol exceedances. These results
are preliminary as the NAQFC model for aerosol prediction is in the developmental stage. A more comprehensive performance
evaluation will be accomplished in 2008, when more data become available. Our verification metrics included categorical analyses
for Fraction Correct (FC) or percent correct (FC × 100), Threat Score (TS) or Critical Success Index (CSI), Probability of
Detection (POD), and the False Alarm Rate (FAR), Mean Absolute Error (MAE) and mean algebraic error or bias, where bias is
forecast minus observation. Graphic products included weekly statistics for the CONUS displayed in the form of bar charts,
scatterplots, and graphs. In addition, we split the CONUS into six geographic regions and provided regional statistics on
a monthly basis. MDL produced spatial maps of daily 1-h maximum predicted aerosol values overlaid with the corresponding point
observations. MDL also provided spatial maps of the daily maximum of the 24-h running average. We derived the 24-h running
average from the 1-h average predicted aerosol values and observations. 相似文献
15.
Andrew M. Reynolds Jennifer L. Swain Alan D. Smith Andrew P. Martin Juliet L. Osborne 《Behavioral ecology and sociobiology》2009,64(1):115-123
The availability of food resources changes over time and space, and foraging animals are constantly faced with choices about
how to respond when a resource becomes depleted. We hypothesise that flying insects like bees discover new food sources using
an optimal Lévy flight searching strategy and odour-mediated anemotaxis, as well as visual cues. To study these searching
patterns, foraging honeybees were trained to a scented feeder which was then removed. Two new unrewarding feeders, or ‘targets’,
were then positioned up- and downwind of the original location of the training feeder. The subsequent flight patterns of the
bees were recorded over several hundred metres using harmonic radar. We show that the flight patterns constitute an optimal
Lévy flight searching strategy for the location of the training feeder, a strategy that is also optimal for the location of
alternative food sources when patchily distributed. Scented targets that were positioned upwind of the original training feeder
were investigated most with the numbers of investigations declining with increasing distance from the original feeder. Scented
targets in downwind locations were rarely investigated and unscented targets were largely ignored, despite having the same
visual appearance as the rewarding training feeder. 相似文献
16.
In the absence of predators, pollinators can often maximize their foraging success by visiting the most rewarding flowers.
However, if predators use those highly rewarding flowers to locate their prey, pollinators may benefit from changing their
foraging preferences to accept less rewarding flowers. Previous studies have shown that some predators, such as crab spiders,
indeed hunt preferentially on the most pollinator-attractive flowers. In order to determine whether predation risk can alter
pollinator preferences, we conducted laboratory experiments on the foraging behavior of bumble bees (Bombus impatiens) when predation risk was associated with a particular reward level (measured here as sugar concentration). Bees foraged in
arenas containing a choice of a high-reward and a low-reward artificial flower. On a bee’s first foraging trip, it was either
lightly squeezed with forceps, to simulate a crab spider attack, or was allowed to forage safely. The foragers’ subsequent
visits were recorded for between 1 and 4 h without any further simulated attacks. Compared to bees that foraged safely, bees
that experienced a simulated attack on a low-reward artificial flower had reduced foraging activity. However, bees attacked
on a high-reward artificial flower were more likely to visit low-reward artificial flowers on subsequent foraging trips. Forager
body size, which is thought to affect vulnerability to capture by predators, did not have an effect on response to an attack.
Predation risk can thus alter pollinator foraging behavior in ways that influence the number and reward level of flowers that
are visited. 相似文献
17.
Margaret J. Couvillon Francis L.W. Ratnieks 《Behavioral ecology and sociobiology》2008,62(7):1099-1105
In group-level recognition, discriminators use sensory information to distinguish group members and non-members. For example,
entrance guards in eusocial insect colonies discriminate nestmates from intruders by comparing their odour with a template
of the colony odour. Despite being a species-rich group of eusocial bees closely related to the honey bees, stingless bee
nestmate recognition is a relatively little-studied area. We studied Frieseomelitta varia, a common Brazilian species of stingless bee known as marmelada. By measuring the rejection rates of nestmate and non-nestmate
worker bees by guards, we were able to show that guards became significantly less accepting (from 91 to 46%) of nestmates
that had acquired odour cues from non-nestmate workers; however, guards did not become significantly more accepting (from
31 to 42%) of non-nestmates that had acquired equivalent amounts of odour cues from the guard’s nestmates. These data strongly
suggest that guards use an “undesirable–absent” system in recognition, whereby incoming conspecific workers are only accepted
if undesirable cues are absent, despite the presence of desirable cues. We suggest that an undesirable–absent system is adaptive
because robbing by conspecifics may be an important selective factor in F. varia, which would lead to selection for a non-permissive acceptance strategy by guards. 相似文献
18.
Kunde Lin 《Environmental Chemistry Letters》2009,7(4):309-312
In this study, the joint acute toxicity of tributyl phosphate (TBP) and triphenyl phosphate (TPP) was investigated using Daphnia magna as the test organism. The median lethal concentrations for TBP and TPP at 24 and 48 h were 5.48 and 0.51 mg/L, 1.17 and 0.089 mg/L,
respectively. When mixed at either equal concentration or various toxic unit ratios, TBP and TPP mixtures displayed an additive
toxicity after both 24- and 48-h exposure. This work suggests that the joint acute toxicity of TBP and TPP towards D. magna can be predicted by calculating the toxic units of mixtures. 相似文献
19.
Abi Tamim Vanak Maria Thaker Matthew E. Gompper 《Behavioral ecology and sociobiology》2009,64(2):279-287
The structure of mammalian carnivore communities is strongly influenced by both intraguild competition and predation. However, intraguild interactions involving the world’s most common carnivore, the domestic dog (Canis familiaris), have rarely been investigated. We experimentally examined the behavioural responses of a small canid, the Indian fox (Vulpes bengalensis), to the presence of dogs and dog odours. Resource competition between dogs and Indian foxes is low, so it is unclear whether foxes perceive dogs as interference competitors. To test this, we exposed foxes to neutral, live dog, and animal odour stimuli at food trays, and recorded the time spent at food trays, the amount of food eaten, and vigilance and non-vigilance behaviours. When dogs were visible, foxes continued to visit the food trays, but reduced the amount of time spent and food eaten at those trays. Foxes were more vigilant during dog trials than during neutral and odour trials and also exhibited lower levels of non-vigilance behaviour (resting and playing). In contrast, dog odours did not affect fox foraging and activity. These results show that vigilance/foraging trade-offs due to interference competition can occur between native and domestic carnivores despite low dietary overlap. These negative effects of dogs on a smaller member of the carnivore guild raise conservation concerns, especially for endangered carnivores. In many parts of the world, free-ranging dog densities are high due to human subsidies, and these subsidized predators have the potential to exacerbate the indirect effects of human presence. 相似文献
20.
Kathryn E. Gardner Robin L. Foster Sean O’Donnell 《Behavioral ecology and sociobiology》2007,61(5):783-792
Bumblebee colonies experience daily and seasonal fluctuations in ambient temperature, but proper brood development requires
a stable nest temperature. This study examined how adaptive colony responses to changing ambient temperature are achieved
through the in-nest workers’ behavioral plasticity. We studied three Bombus huntii colonies in the laboratory. In the first experiment, we manipulated ambient temperature and recorded brood cell incubation
and wing fanning by individually marked, known-age bees. The colonies maintained their nests closer to appropriate brood development
temperatures (28 to 32°C) when exposed to a range of ambient temperatures from 10.3 to 38.6°C. Incubation activity was greater
in cooler treatment conditions, whereas in the highest temperature treatment, some bees fanned and others moved off the brood.
As the ambient temperature dropped, workers increased the duration of their incubating bouts, but, except at the highest temperature,
the number of workers that incubated did not differ significantly among treatments. A subset of the bees incubated significantly
more than their nest mates, some of which never incubated. Worker body size, but not age, was a good predictor of incubation
rates, and smaller bees incubated at higher rates. In the second experiment, we removed the most actively incubating workers.
Immediately after removals, the total colony incubation effort was lower than pre-removal levels, but incubation effort rebounded
toward pre-removal levels after 24 h. The increased thermoregulatory demand after removals was met primarily by bees increasing
their rates of incubation rather than by bees switching from a different task to incubation. We conclude that some B. huntii workers specialize on nest thermoregulation, and that changes in work rates are more important than task switching in meeting
thermal challenges. 相似文献