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21.
Walter M. Farina 《Behavioral ecology and sociobiology》1996,38(1):59-64
Dancing and trophallactic behaviour of forager honey bees, Apis mellifera ligustica >Spinola, that returned from an automatic feeder with a regulated flow rate of 50% weight-to-weight sucrose solution (range:
0.76–7.65 μl/min) were studied in an observation hive. Behavioural parameters of dancing, such as probability, duration and
dance tempo, increased with the nectar flow rate, though with very different response curves among bees. For trophallaxis
(i.e. mouth-to-mouth exchange of food), the frequency of giving-contacts and the transfer rate of the nectar increased with
the nectar flow rate. After unloading, foragers often approached other nest mates and begged for food before returning to
the food source. This behaviour was less frequent at higher nectar flow rates. These results show that the profitability of
a food source in terms of nectar flow rate had a quantitative representation in the hive through quantitative changes in trophallactic
and dancing behaviour. The role of trophallaxis as a communication channel during recruitment is discussed.
Received: 14 January 1995/Accepted after revision: 14 August 1995 相似文献
22.
Walker P 《Disasters》2005,29(4):323-336
This paper reflects on the genesis of the Code of Conduct for the International Red Cross and Red Crescent Movement and Non-Governmental Organizations (NGOs) in Disaster Relief, on the tenth anniversary of its adoption. The origins, usage and future of the code are examined with respect to three debates, current at the time of its inception, namely: the debate about the core content of humanitarianism; the debate about coherence and the consensual nature of the humanitarian community; and the debate about the need for, and the ability to demonstrate, accountability. The paper concludes that although the Code of Conduct was very much a product of its time, its content remains relevant today. However, its future application hinges on the capacity of those who purport to follow it to realise true accountability, and on proving that the code, written essentially for natural disasters, is relevant to contemporary complex emergencies. 相似文献
23.
Kirkpatrick AJ Gerhardt A Dick JT Laming P Berges JA 《Environmental science and pollution research international》2006,13(4):242-250
Background Biological monitors are increasingly important in 'Biological Early Warning Systems' (BEWS) for monitoring water quality.
This study examines the freshwater amphipod Crangonyx pseudogracilis as a potential new indicator species when used in the
Multispecies Freshwater Biomonitor (MFB). The MFB is an online continuous biomonitor which uses impedance conversion to record
behavioural responses of vertebrates and invertebrates.
Methods Four experiments were undertaken to establish: (1) if the electrical field generated by the MFB affected the organisms' behaviour,
(2) if defined behaviours and their response to a gradient of ammonium chloride could be detected by the MFB, (3) if there
was variation in the behaviour of C. pseudogracilis over a diel cycle, and (4) if behaviour changed significantly in response
to a pulse of ammonium chloride.
Results and Discussion Results showed no significant effect of the MFB's current on behaviour of C. pseudogracilis. Four behaviours; swimming, walking,
grooming and inactivity, were observed and identified in the MFB. In the MFB, each behaviour changed significantly in response
to an increasing gradient of ammonium chloride exposure. The MFB also detected increases in nocturnal activity by C. pseudogracilis.
The MFB also detected a significant increase in activity after a pulse of ammonium chloride.
Conclusion The range of behaviours exhibited by Crangonyx pseudogracilis, together with its ease of culture, suggest future potential
of this species as an indicator species for the Multispecies Freshwater Biomonitor.
Recommendations and Perspective . Further testing is required over a range of toxicants and concentration gradients to establish threshold responses and the
full compliment of behaviours that could be useful in online biomonitoring. 相似文献
24.
Eva Rose Peter Nagel Daniel Haag-Wackernagel 《Behavioral ecology and sociobiology》2006,60(2):242-254
Feral pigeons are descendants of wild rock pigeons that have adapted to the urban habitat. They have partially conserved the foraging behaviour of their wild ancestors (flights to agricultural areas) but have also developed new habits. Previous studies on the foraging strategies of feral pigeons have given various results, e.g. maximum distances reached by the pigeons (measured in a straight line from the resting places) differed between 0.3–0.5 km and 18–25 km. This study focuses on the spatio-temporal activity of feral pigeons in the urban habitat. We equipped 80 free-living feral pigeons from Basel, Switzerland with GPS receivers. We found three different foraging strategies for pigeons in Basel: (1) in the streets, squares and parks near the home loft, (2) in agricultural areas surrounding the city, (3) on docks and railway lines in harbours. The maximum distance reached by a pigeon was 5.29 km. More than 32% of the pigeons remained within 0.3 km of the home lofts and only 7.5% flew distances of more than 2 km. Females covered significantly longer distances than males, preferring to fly to more abundant and predictable food sources. Temporal activity patterns showed to be influenced by sex, breeding state and season. In contrast to wild rock pigeons and to feral pigeons in other cities, pigeons in Basel showed a clear bimodal activity pattern for breeding birds only. The differences between our results and those of other studies seem to be partly method-dependent, as the GPS-technique allows to record the pigeons’ localisations continuously in contrast to other methods. Other differences might be due to different kinds of food supply in the various cities. Our study shows that feral pigeons have individual foraging strategies and are flexible enough to adapt to different urban environments.Electronic supplementary material Supplementary material is available for this article at 相似文献
25.
Summary Components of the green leaf volatile complex (Z-3-hexenyl acetate andE-2-hexenyl acetate) were shown to enhance responses of tobacco budworm,Heliothis virescens, males to the sex attractant pheromone of conspecific females in the field. The results are discussed with regard to green leaf volatiles which enhance the attractant pheromone of a cohabiting species, and serve as attractants of a parasitoid of conspecific larvae. 相似文献
26.
In signalling interactions, animals can directly address information to a specific individual. Vocal overlapping is such a
signalling strategy used in songbirds, anurans, and insects. In songbirds, numerous studies using high rates of song overlap
to simulate an escalating situation have shown that song overlapping is perceived as a threatening signal by interacting and
by listening (eavesdropping) individuals, indicating a high social relevance of song overlapping. Here we present a playback
experiment on nocturnally singing male territorial nightingales (Luscinia megarhynchos). Using three different rates of song overlap (1, 25, or 50%), we tested whether or not lower levels of song overlapping
act as a signal of aggressive intent and if birds would increase the intensity of their response with increasing level of
song overlapping. Subjects did not vary song duration in response to the different playback treatments but increasingly interrupted
their singing with increasing overlap by the three playback treatments. The effects persisted even after the playback ceased
to overlap and switched to an alternating singing mode. These results expand on previous studies by showing that song overlapping
is interpreted as an aggressive signal even when it is used at low or moderate levels. They suggest that, within the range
tested here, increasing levels of song overlapping are perceived to be increasingly aggressive. 相似文献
27.
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
28.
Crickets can autotomize a limb in order to evade predation; however, this autotomy compromises their escape speed and, therefore,
their ability to avoid subsequent predation events. We recorded two measures of predator-avoidance behaviour in field crickets
(Gryllus bimaculatus) exposed to varying levels of predation threat, with the most extreme level leading to autotomy of a limb. Our first measure
of caution was time to emergence from cover, which was affected by perceived predation treatment, with both autotomized males
and females being significantly more cautious than intact individuals. For males (but not females), the presence of a calling
conspecific encouraged earlier emergence. Our second measure of caution was alteration of male calling behaviour. Autotomized
males remained silent for significantly longer time after disturbance than intact males, but there was no difference in call
rate once they had resumed calling, suggesting that behavioural changes were not merely a result of injury response but a
controlled modification of behaviour as a result of autotomy. These data suggest that autotomy in field crickets results in
altered calling behaviour, which was not significantly altered with different acoustic environments. 相似文献
29.
Statistical inference on patch-specific survival and movement rates from marked animals 总被引:1,自引:0,他引:1
Michael J. Conroy Jon E. Anderson Stephen L. Rathbun David G. Krementz 《Environmental and Ecological Statistics》1996,3(2):99-116
Empirical estimates of patch-specific survival and movement rates are needed to parametrize spatially explicit population
models, and for inference on the effects of habitat quality and fragmentation on populations. Data from radio-marked animals,
in which both the fates and habitat locations of animals are known over time, can be used in conjunction with continuous-time
proportional hazards models to obtain inferences on survival rates. Discrete-time conditional logistic models may provide
inference on both survival and movement rates. We use Monte Carlo simulation to investigate accuracy of estimates of survival
from both approaches, and movement rates from conditional logistic regression, for two habitats. Bias was low (relative bias
< 0.04) and interval coverage accurate (close to the nominal 0.95) for estimates of habitat effect on survival based on proportional
hazards. Bias was high (
relative bias 0.60) and interval coverage poor (
= 0.26 vs. nominal 0.95) for estimates of habitat effect based on conditional logistic regression; bias was especially influenced
by heterogeneity in survival and the shape of the hazard function, whereas both bias and coverage were affected by ‘memory’
effects in movement patterns. Bias estimates of movement rate was low (
relative bias < 0.05), but interval coverage was poor (
= 0.48–0.80), possibly as a result of poor performance of a Taylor series estimate of variance. An example is provided from
a radio-telemetry study of 47 wintering American woodcock (Scolopax minor), illustrating practical difficulties in field studies to parametrize these models. We also discuss extensions of continuous-time
models to explicitly include a movement process, and further examine tradeoffs between continuous and discrete models. 相似文献
30.
David Goulson Jemma L. Cruise Kate R. Sparrow Adele J. Harris Kirsty J. Park Matthew C. Tinsley Andre S. Gilburn 《Behavioral ecology and sociobiology》2007,61(10):1523-1529
Flowers exhibit great intra-specific variation in the rewards they offer. At any one time, a significant proportion of flowers
often contain little or no reward. Hence, foraging profitably for floral rewards is problematic and any ability to discriminate
between flowers and avoid those that are less rewarding will confer great advantages. In this study, we examine discrimination
by foraging bees among flowers of nasturtium, Tropaeolum majus. Bee visitors included carpenter bees, Xylocopa violacea, which were primary nectar robbers; honeybees, Apis mellifera, which either acted as secondary nectar robbers or gathered pollen legitimately and bumblebees, Bombus hortorum, which were the only bees able to gather nectar legitimately. Many flowers were damaged by phytophagous insects. Nectar volume
was markedly lower in flowers with damaged petals (which were also likely to be older) and in flowers that had nectar-robbing
holes. We test whether bees exhibit selectivity with regards to the individual flowers, which they approach and enter, and
whether this selectivity enhances foraging efficiency. The flowers approached (within 2 cm) by A. mellifera and B. hortorum were non-random when compared to the floral population; both species selectively approached un-blemished flowers. They both
approached more yellow flowers than would be expected by chance, presumably a reflection of innate colour preferences, for
nectar standing crop did not vary according to flower colour. Bees were also more likely to accept (land on) un-blemished
flowers. A. mellifera gathering nectar exhibited selectivity with regards to the presence of robbing holes, being more likely to land on robbed
flowers (they are not able to feed on un-robbed flowers). That they frequently approached un-robbed flowers suggests that
they are not able to detect robbing holes at long-range, so that foraging efficiency may be limited by visual acuity. Nevertheless,
by using a combination of long-range and short-range selectivity, nectar-gathering A. mellifera and B. hortorum greatly increased the average reward from the flowers on which they landed (by 68% and 48%, respectively) compared to the
average standing crop in the flower population. Overall, our results demonstrate that bees use obvious floral cues (colour
and petal blemishes) at long-range, but can switch to using more subtle cues (robbing holes) at close range. They also make
many mistakes and some cues used do not correlate with floral rewards. 相似文献