共查询到20条相似文献,搜索用时 31 毫秒
1.
Matriphagous young of a subsocial spider Amaurobius ferox exhibit collective predation during their post-maternal social period. In this paper, we examine functional mechanisms of collective predation by sibling groups. Predation efficiency increased with increasing number of individuals within each group. Solitary or paired individuals were generally unable to capture a 20 mg cricket. In larger groups, more individuals participated and captured the prey more quickly. Some siblings did not take part in paralyzing prey, but later consumed it. The proportion of these profiteers within a group increased with the group size. Presented with prey of different sizes (1, 5, or 40 mg), siblings were most aggressive towards each other when predating on 5 mg prey. Prey of this size could be captured by a single individual and yet were sufficiently large for more than one individual to eat. Siblings were much less aggressive towards one another during the capture of 40 mg prey, which require the assistance of other individuals to capture. By providing the same mass of prey in different numbers of individuals (a single cricket of 40 or 40 mg of first-instar crickets), we tested the influence of cooperation on the post-maternal social period. We found no difference in the development of young during the social period nor the timing of dispersal and the body mass of dispersing individuals. We conclude that the young of this subsocial animal increased predation efficiency by cooperative hunting after the mother's death. 相似文献
2.
Bertrand Schatz Jean-Paul Lachaud Guy Beugnon 《Behavioral ecology and sociobiology》1997,40(6):337-349
According to the weight and size of their prey, Ectatomma ruidum workers can employ different recruitment systems (solitary hunting, cooperative hunting and group hunting with recruitment)
when mastering and retrieving prey items from short distances from the nest. Prey size determined the backwards entry typically
adopted by this species, while prey weight determined the predatory strategy selected. After a common initial sequence (search
for prey, detection, localization), predatory sequences varied in terms of the type of approach, the site of seizure, the
reaction after stinging and the type of transport. Nevertheless, irrespective of prey weight and size, seizure was preferentially
oriented towards the head and prey were always stung. Short-range recruitment and mass recruitment without trail laying were
elicited by a large range of heavy prey (> 2.5 times the weight of an individual worker). According to the mortality risk
associated with each prey, hunters exhibited a “prudent” stinging posture associated with an increase in the duration of the
subsequent phase of waiting for prey immobilization. The overall time of capture was positively correlated with the weight
of the prey. When collective hunting strategies were involved, E. ruidum colonies matched the number of recruited hunters to the size and weight of the prey. Compared to solitary hunting strategies,
for short food–nest distances, this graded recruitment appeared to enhance the energetic benefits derived by this species
from the use of recruitment systems: the higher the number of workers involved in the recruitment process, the greater the
energetic benefits obtained. The exhibition or absence of trail laying behavior in the recruitment responses displayed by
E. ruidum workers is discussed in relation to their involvement in scavenging or predatory behavior.
Received: 27 June 1996 / Accepted after revision: 3 March 1997 相似文献
3.
K. W. Kim 《Behavioral ecology and sociobiology》2000,48(3):182-187
This study investigates proximate factors influencing dispersal behaviour in the subsocial spider Amaurobius ferox. Dispersal of spiderlings from the natal web occurred as a progressive sigmoidal function (mean duration of dispersal period=31
days), with considerable individual variability in developmental instar and body mass within the clutch at the time of dispersal.
The spiderlings showed a significant decrease in group cohesion on the 6th day after their second moult, which corresponded
to the beginning of the dispersal period. Mutual aggressiveness appeared when the spiderlings began to show predatory behaviour
(4th day post-second moult) and increased over the course of the dispersal period. While lack of prey in the maternal nest
accelerated dispersal behaviour, the addition of prey items lengthened the dispersal period in previously non-fed clutches.
Individuals that dispersed were smaller than the remaining individuals when measured on the day 50% of the clutch had dispersed.
Timing of the appearance of the developmental characters (second moult, predation activity, agonistic behaviour against siblings,
reduction of group cohesion, dispersal) suggests that the dispersal trait might have evolved in consequence of these different
functional behaviours.
Received: 10 August 1999 / Received in revised form: 15 March 2000 / Accepted: 1 April 2000 相似文献
4.
Punzo F Preshkar C 《Journal of environmental biology / Academy of Environmental Biology, India》2002,23(4):341-345
The purpose of this study was to determine if environmental chemical cues associated with prey can affect subsequent prey choice in wolf spiderlings (Hogna carolinensis). After emergence from the egg sac, three groups of 10 spiderlings were each fed for one-week on one of three naturally-occurring prey species: group 1 fed on nymphs of the field cricket Gryllus pennsylvanicus; group 2 (house cricket, Acheta domesticus); group 3 (mole cricket, Gryllotalpa hexadactyla). They were then tested for subsequent prey preference in choice tests conducted in a plastic arena. Each spiderlings was presented simultaneously with one individual of each prey species in a randomized design. Spiderlings exhibited a significant first preference for the original diet. Thus, experience with certain foods (environmental chemical cues) encountered by newly hatched spiderlings can affect subsequent prey preference in this species. 相似文献
5.
Jonathan N. Pruitt Nicholas DiRienzo Simona Kralj-Fišer J. Chadwick Johnson Andrew Sih 《Behavioral ecology and sociobiology》2011,65(10):1987-1995
Research on consistent individual differences in behavior, or “behavioral syndromes”, continues to grow rapidly, and yet,
the aspects of behavior under consideration have remained remarkably limited. Here, we consider individual variation in consistency
of choice (termed here “choosiness”), as expressed during habitat choice. We repeatedly tested the responses of female Western
Black Widows, Latrodectus hesperus, to two cues of habitat quality: prey chemical cues and variation in web site illuminance. We estimated females’ response
by the distance they positioned themselves from (1) the source of prey chemical cues and (2) the darkest edge of our test
arena. Individuals with low variance in their responses are deemed more “choosy”, whereas individuals with high variance are
deemed less “choosy”. Generally, most females initiated web construction near the source of the prey chemical cues and tended
to place themselves in low-light conditions. However, we detected strong, repeatable differences in females’ intensity of
response, and within-individual variance of response (i.e., choosiness) was correlated across situations: females with highly
consistent responses towards cricket chemical cues also exhibited highly consistent responses towards variation in light conditions.
When deprived of food for extended periods, females were indistinguishable in their responses towards prey chemical cues,
but tended to initiate web construction in brighter lighting conditions. Food-deprived females universally exhibited higher
variance and diminished consistency in their responses (i.e., they were less choosy). Additionally, higher choosiness was
associated with greater mass loss during choice trials, suggesting choosiness is energetically costly. Our results demonstrate
that consistency of response to environmental cues is yet another element of behavior that varies among individuals and variation
in choosiness could beget speed/quality trade-offs during animal decision making. 相似文献
6.
We examined the hypothesis that a main benefit of group-living in the semifossorial rodent, Octodon degus (Rodentia: Octodontidae), is to decrease individual cost of burrow construction. We contrasted the digging behavior of groups
of three same-sex, adult-sized individuals with that of solitary degus. The behavior of singles and trios was recorded inside
a large terrarium partially filled with natural soil and under controlled conditions of food, light, and temperature. The
observation that degus in groups do not decrease their burrowing time or frequency of digging compared with solitary diggers
does not support the hypothesis that communal burrowing is a primary cause of degu sociality. On the other hand, the observation
that degus in groups removed significantly more soil per capita than solitary digging degus, and that grouped individuals
coordinated their digging – group members burrowed mostly in the same sites and formed digging chains –, suggests that social
burrowing may potentially reduce the cost of burrow construction in the long term. We suggest that such long-term benefits
will be a consequence rather than a cause of degu group-living.
Received: 9 December 1999 / Received in revised form: 2 January 2000 / Accepted: 8 February 2000 相似文献
7.
Rulon W. Clark 《Behavioral ecology and sociobiology》2005,59(2):258-261
A thorough understanding of communication requires an evaluation of both the signaler and receiver. Most analyses of prey–predator communication are incomplete because they examine only the behavior of the prey. Predators in these systems may be understudied because they are perceived as less tractable research subjects, due to their more cryptic hunting behaviors and secretive lifestyles. For example, research on interactions between rodents and rattlesnakes has focused on the behavior of rodent signalers, while responses of snakes have been virtually unexamined. Rattlesnakes are ambush predators, and capture rodents by waiting at foraging sites for long periods of time. In this study, I take advantage of the sedentary nature of this foraging strategy and use fixed videography to record natural encounters between timber rattlesnakes (Crotalus horridus) and their prey. Three different prey species were found to exhibit conspicuous visual displays to snakes, both when snakes were actively foraging, and when they were basking. After receiving displays, foraging snakes left their ambush sites and moved long distances before locating subsequent ambush sites, indicating that they responded to displays by abandoning attempts to ambush prey in the vicinity of signalers. This study represents the first quantitative analysis of the response of free-ranging snakes to signals from their prey, and elucidates a technique by which such quantitative data can be more easily obtained. 相似文献
8.
9.
Carl N. Keiser Devin K. Jones Andreas P. Modlmeier Jonathan N. Pruitt 《Behavioral ecology and sociobiology》2014,68(5):839-850
Social animals are extraordinarily diverse and ecologically abundant. In understanding the success of complex animal societies, task differentiation has been identified as a central mechanism underlying the emergence and performance of adaptive collective behaviors. In this study, we explore how individual differences in behavior and body size determine task allocation in the social spider Stegodyphus dumicola. We found that individuals with high body condition indices were less likely to participate in prey capture, and individuals’ tendency to engage in prey capture was not associated with either their behavioral traits or body size. No traits were associated with individuals’ propensity to participation in web repair, but small individuals were more likely to engage in standard web-building. We also discovered consistent, differences among colonies in their collective behavior (i.e., colony-level personality). At the colony level, within-colony variation in behavior (aggressiveness) and body size were positively associated with aggressive foraging behavior. Together, our findings reveal a subtly complex relationship between individual variation and collective behavior in this species. We close by comparing the relationship between individual variation and social organization in nine species of social spider. We conclude that intraspecific variation is a major force behind the social organization of multiple independently derived lineages of social spider. 相似文献
10.
Cooperative hunting in lions: the role of the individual 总被引:6,自引:0,他引:6
P. E. Stander 《Behavioral ecology and sociobiology》1992,29(6):445-454
Summary Individually identified lions (Panthera leo) were observed on the open, semi-arid plains in Namibia. Data from 486 coordinated group hunts were analysed to assess cooperation and individual variation in hunting tactics. Group hunts generally involved a formation whereby some lionesses (wings) circled prey while others (centres) waited for prey to move towards them. Those lionesses that occupied wing stalking roles frequently initiated an attack on the prey, while lionesses in centre roles moved relatively small distances and most often captured prey in flight from other lionesses. Each lioness in a given pride repeatedly occupied the same position in a hunting formation. Hunts where most lionesses present occupied their preferred positions had a high probability of success. Individual hunting behaviour was not inflexible, however, but varied according to different group compositions and to variations in the behaviour of other individuals present. The role of cooperative hunting and its apparent advantages within the semi-arid environment of Etosha National Park, Namibia, are discussed. 相似文献
11.
Alecia J. Carter Olivier Pays Anne W. Goldizen 《Behavioral ecology and sociobiology》2009,64(2):237-245
The mean vigilance of animals in a group often decreases as their group size increases, yet nothing is known about whether
there is individual variability in this relationship in species that change group sizes frequently, such as those that exhibit
fission–fusion social systems. We investigated variability in the relationship between group size and vigilance in the eastern
grey kangaroo (Macropus giganteus) by testing whether all individuals showed decreased vigilance with increased group size, as has been commonly assumed. We
carried out both behavioural observations of entire groups of kangaroos and focal observations of individually recognised
wild female kangaroos. As in other studies, we found a collective group-size effect on vigilance; however, individuals varied
in their vigilance patterns. The majority (57%) of the identified individual kangaroos did not show significant group-size
effects for any of the recorded measures of vigilance. The females that did not show a negative group-size effect were, on
average, more vigilant than those females that did show a group-size effect, but this difference was not significant. We propose
that some females exhibit higher levels of social vigilance than others, and that this social vigilance increases with group
size, cancelling out any group-size effect on anti-predator vigilance for those females. Our results therefore suggest that
only some prey individuals may gain anti-predator benefits by reducing their time spent scanning when in larger groups. The
large amount of variation that we found in the vigilance behaviour of individual kangaroos highlights the importance of collecting
and analysing vigilance data at the individual level, which requires individual recognition. 相似文献
12.
Lore M. Ruttan 《Behavioral ecology and sociobiology》1990,27(3):169-173
Summary
Theridion pictum (Walckenaer) is a subsocial spider, that is, the mother actively takes care of her offspring for an extended period of time after they emerge. It is demonstrated that spiderling dispersal is affected by the availability of food in the maternal web. Experimental manipulations indicate that in those webs where less food was provided, spiderlings dispersed significantly earlier and in significantly greater numbers. These results illustrate the importance of food availability as a permissive factor in the evolution of social spiders from subsocial ancestors. Food availability also affects the pattern of sex-biased philopatry and dispersal. Although both sexes are more likely to remain in the maternal web when more food is available, females are relatively more likely to do so. When less food is available, females are relatively more likely to disperse than are males. 相似文献
13.
Within populations of many species, individuals that are otherwise similar to one another in age, size or sex can differ markedly
in behaviours such as resource use, risk taking and competitive ability. There has been much research into the implications
of such variation for intraspecific interactions, yet little investigation into its role in influencing interspecific interactions
outside of a predator–prey context. In this study, we investigated the role of individual-level behavioural variation in determining
the outcomes of interactions between two ecologically similar fishes, the threespine and ninespine sticklebacks (Gasterosteus aculeatus and Pungitius pungitius). Experiment 1 asked whether individuals of both species were consistent in their expression of two behaviours: activity
in novel surroundings and latency to attack prey. For each behaviour, focal individuals were assayed twice, 10 days apart.
Performances were positively correlated between exposures, suggesting behavioural consistency within individuals, at least
over this timescale. Experiment 2 revealed not only differences in habitat use described both by species-level variation,
with ninespines spending more time in vegetated areas, but also by individual differences, with more active individuals of
both species spending more time in open water than in vegetation. Experiment 3 revealed that when heterospecific pairs competed
for prey, bolder individuals consumed a greater share, irrespective of species. These findings suggest that individual-level
variation can facilitate overlap in habitat use between heterospecifics and also determine the outcomes of resource contests
when they meet. We discuss how this might vary between populations as a function of prevailing selection pressures and suggest
approaches for testing our predictions. 相似文献
14.
A. Rus Hoelzel 《Behavioral ecology and sociobiology》1991,29(3):197-204
Summary The social dynamics of killer whales (Orcinus orca) that hunt marine mammals are apparently highly flexible, though strong individual associations do exist. The killer whales at Punta Norte offer an unusually detailed view of association patterns and foraging behaviour, and suggest a pattern of behaviour that optimizes hunting efficiency with exception only to strong associations between some individuals and the provisioning and training of offspring. The main points from this paper are as follows: First, hunting effort was concentrated where the capture rate was greatest. All pods selectively attacked the prey type for which they had the highest capture rate. The amount of southern sea lion prey captured was approximately equal to the estimated minimum energetic requirement for killer whales based on weight. Secondly, one whale in each pod did the majority of the hunting, and then provisioned the others in the pod. It was clear on numerous occasions that food was shared. A review of reported incidences of killer wales taking marine mammal prey suggests that it is common for a subset of the individuals in a pod to hunt. These results are discussed in the context of the evolution of foraging behaviour.Offprint requests to: A.R. Hoelzel at the first address 相似文献
15.
Sandra Steiger Klaus Peschke Josef K. Müller 《Behavioral ecology and sociobiology》2008,62(7):1053-1060
Nestmate recognition in eusocial insects has received a lot of attention in the last decades. Recognition in subsocial species,
in contrast, has been ignored almost completely and consequently, and little is known about proximate mechanisms of recognition
in subsocial systems. We studied one subsocial species, the biparental brood caring burying beetle Nicrophorus vespilloides, an interesting model organism for studies of recognition because of its ability to discriminate between breeding partners
and conspecific competitors. Recognition appears to be based on a chemical cue closely linked to the breeding status of individuals.
Breeding and non-breeding beetles consistently differ in their relative proportions of polyunsaturated cuticular hydrocarbons.
To investigate the function of these polyenes in the burying beetles’ recognition system, we quantified their concentration
on the cuticle during the early state of a breeding attempt and tested the response of breeding beetles in corresponding behavioural
experiments. We observed a rapid increase in the proportion of polyunsaturated hydrocarbons of both males and females after
they were provided with a carcass suitable for reproduction. Furthermore, we found that the relative amount of polyenes on
an individual’s surface was closely correlated with its chance of being accepted as breeding partner. Our results support
the idea that polyunsaturated hydrocarbons are involved in breeding partner recognition in N. vespilloides, functioning as a signal that conveys information about the individual’s breeding status. Breeding females have greater amount
of polyenes than breeding males, and females ingest more carrion during the first days on the carcass, which supports our
hypothesis that precursors for the respective polyenes are derived from ingested carrion. 相似文献
16.
Testing a stochastic version of the Beddington–DeAngelis functional response in foraging shore crabs
Current behaviour-based interference models assume that the predator population is infinitely large and that interference
is weak. While the realism of the first assumption is questionable, the second assumption conflicts with the purpose of interference
models. Here, we tested a recently developed stochastic version of the Beddington–DeAngelis functional response—which applies
to a finite predator population without assuming weak interference—against experimental data of shore crabs (Carcinus maenas) foraging on mussels (Mytilus edulis). We present an approximate maximum likelihood procedure for parameter estimation when only one focal individual is observed,
and introduce ‘correction factors’ that capture the average behaviour of the competing but unobserved individuals. We used
the method to estimate shore crab handling time, interaction time, and searching rates for prey and competitor. Especially
the searching rates were sensitive to variation in prey and competitor density. Incorporating constant parameter values in
the model and comparing observed and predicted feeding rates revealed that the predictive power of the model is high. Our
stochastic version of the Beddington–DeAngelis model better reflects reality than current interference models and is also
amenable for modelling effects of interference on predator distributions. 相似文献
17.
Disease resistance: a benefit of sociality in the dampwood termite Zootermopsis angusticollis (Isoptera: Termopsidae) 总被引:1,自引:0,他引:1
Rebeca B. Rosengaus Amy B. Maxmen Laran E. Coates James F. A. Traniello 《Behavioral ecology and sociobiology》1998,44(2):125-134
The benefit of sociality in relation to disease susceptibility was studied in the dampwood termite Zootermopsis angusticollis. Although contact with high concentrations of fungal conidia is lethal, the survivorship of nymphs exposed to spore suspensions
ranging from 6 × 106 to 2 × 108 spores/ml of the fungus Metarhizium anisopliae increased with group size. The survivorship (measured as LT50) of isolated individuals ranged from 3.0 to 4.8 days, but infected nymphs living in groups of 10 and 25 individuals survived
significantly longer (5.6–8.3 and 5.6–9.1 days, respectively). In most cases, there were no significant differences in the
survival distributions of the 10- and 25-termite groups. When nymphs were infected with concentrations of 7 × 101–7 × 104 spores/ml and allowed to interact with healthy nestmates, fungal infections were not contracted by the unexposed termites.
Moreover, infected termites benefitted from social contact with unexposed nestmates: their survival rates were significantly
higher than those of infected termites living with similarly infected nestmates. Allogrooming, which increased in frequency
during and after exposure to conidia, appeared to remove potentially infectious spores from the cuticle, thus increasing termite
survivorship. These results suggest that allogrooming plays a crucial role in the control of disease and its death hazard
in termites. The infection-reducing advantage of group living may have been significant in the evolution of social behavior
in the Isoptera.
Received: 18 March 1998 / Accepted after revision: 31 May 1998 相似文献
18.
Natural selection and the communal rearing of pups in African wild dogs (Lycaon pictus) 总被引:5,自引:0,他引:5
Summary The contributions of adult (>18 months) and yearling (10–18 months) African wild dogs (Lycaon pictus), to raising pups were quantified at eight natal dens, where pups remain for their first three months of life.Adults between 2–6 years of age did most of the hunting, and the dominant male often made the first grab at fleeing prey. Yearlings contributed to the hunting but were reluctant to tackle large prey animals. Yearlings and breeding females had prior access to food. Yearlings and adults regurgitated comparable amounts of food, but in one pack watched at a time of food shortage, the yearlings failed to regurgitate and stole food from the pups.Dominant dogs chased predators, especially spotted hyenas (Crocuta crocuta) from the area of the den more frequently than other adults or yearlings chased predators. Mothers, particularly in the first six weeks post-partum, stayed and protected the pups when the pack hunted.There is a positive, but non-significant correlation between the number of adult helpers and the number of pups raised. However, the sex ratio bias towards males at birth suggests that male helpers (which predominate) usually increase pup survivorship. The roles of direct and indirect selection in the evolution of the helping behavior are discussed. Indirect selection has probably played an important role in the unusual post-reproductive survival of males and their helping behavior.Serengeti Wildlife Research Institute contribution number 284 相似文献
19.
Elisabeth K. V. Kalko Hans-Ulrich Schnitzler Ingrid Kaipf Alan D. Grinnell 《Behavioral ecology and sociobiology》1998,42(5):305-319
We studied variability in foraging behavior of Noctilio albiventris (Chiroptera: Noctilionidae) in Costa Rica and Panamá and related it to properties of its echolocation behavior. N. albiventris searches for prey in high (>20 cm) or low (<20 cm) search flight, mostly over water. It captures insects in mid-air (aerial
captures) and from the water surface (pointed dip). We once observed an individual dragging its feet through the water (directed
random rake). In search flight, N. albiventris emits groups of echolocation signals (duration 10–11 ms) containing mixed signals with constant-frequency (CF) and frequency-modulated
(FM) components, or pure CF signals. Sometimes, mostly over land, it produces long FM signals (duration 15–21 ms). When N. albiventris approaches prey in a pointed dip or in aerial captures, pulse duration and pulse interval are reduced, the CF component is
eliminated, and a terminal phase with short FM signals (duration 2 ms) at high repetition rates (150–170 Hz) is emitted. Except
for the last pulses in the terminal phase N. albiventris avoids overlap between emitted signals and echoes returning from prey. During rakes, echolocation behavior is similar to
that in high search flight. We compare N. albiventris with its larger congener, N. leporinus, and discuss behavioral and morphological specializations that can be interpreted as preadaptations favoring the evolution
of piscivory as seen in N. leporinus. Prominent among these specializations are the CF components of the echolocation signals which allow detection and evaluation
of fluttering prey amidst clutter-echoes, high variability in foraging strategy and the associated echolocation behavior,
as well as morphological specializations such as enlarged feet for capturing prey from the water surface.
Received: 21 April 1997 / Accepted after revision: 12 January 1998 相似文献
20.
Shallow-water octopuses have been reported as major predators of motile species in benthonic marine communities, capturing
their prey by different foraging techniques. This study assessed for the first time the feeding ecology, foraging behavior,
and defensive strategy during foraging, including the use of body patterns, to construct a general octopus foraging strategy
in a shallow water-reef system. Octopus insularis was studied in situ using visual observations and video recordings. The diet included at least 55 species of crustaceans
(70%), bivalves (17.5%), and gastropods (12.5%); however, only four species accounted for half of the occurrences: the small
crabs Pitho sp. (26.8%) and Mithrax forceps (23.9%), the bivalve Lima lima (5.3%), and the gastropod Pisania pusio (4.9%). Poke and crawl were most frequent foraging behaviors observed in the video recordings. The foraging behaviors were
associated with environmental variables and octopus body size. The sequences of foraging behavior showed characteristics of
a tactile saltatory searching predator, as well as a visual opportunist. Body patterns showed a relationship with foraging
behavior, habitat variables, and octopus body size. Mottle was the most frequent pattern, especially during poke and crawl,
in shallower depths. Dorsal light–ventral blue green was more frequent during swimming at mid-water, and Blotch was the normal
pattern during web-over by large animals. The large proportion of two species of small crabs in den remains, the intense search
for food during short hunting trips, and the intense use of cryptic body patterns during foraging trips, suggest that this
species is a ‘time-minimizing’ forager instead of a ‘rate-maximizer’. 相似文献