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1.
G. W. Uetz William J. McClintock Douglas Miller Elizabeth I. Smith Kristina K. Cook 《Behavioral ecology and sociobiology》1996,38(4):253-257
Males of the brush-legged wolf spider Schizocosa ocreata (Hentz) have conspicuously decorated forelegs used in courtship and agonistic displays. Approximately one in five juvenile
males has a missing or regenerating foreleg, and regeneration of a leg lost during development usually results in the absence
of a decorative tuft on that leg. The subsequent asymmetry in this male secondary character significantly decreases success
in both courtship of females and male-male agonistic interactions. Experimental removal of tufts from one leg of previously
successful symmetric males produces similar results. As a test for concomitant behavioral effects, female spiders were shown
video images of a courting male with symmetric tufts and the same video image altered to have asymmetric tufts. Female receptivity
to the asymmetric video image was lower. In contrast to fluctuating asymmetry resulting from developmental instability, leg
tuft asymmetry in S. ocreata most likely arises from a single event during ontogeny – possibly leg loss from an aggressive or predator encounter – and
may serve as a quality indicator in female mate choice.
Received: 27 July 1995/ Accepted after revision: 19 November 1995 相似文献
2.
Gabriel?Ramos-FernándezEmail author José?L.?Mateos Octavio?Miramontes Germinal?Cocho Hernán?Larralde Bárbara?Ayala-Orozco 《Behavioral ecology and sociobiology》2004,55(3):223-230
Scale invariant patterns have been found in different biological systems, in many cases resembling what physicists have found in other, nonbiological systems. Here we describe the foraging patterns of free-ranging spider monkeys (Ateles geoffroyi) in the forest of the Yucatan Peninsula, Mexico and find that these patterns closely resemble what physicists know as Lévy walks. First, the length of a trajectorys constituent steps, or continuous moves in the same direction, is best described by a power-law distribution in which the frequency of ever larger steps decreases as a negative power function of their length. The rate of this decrease is very close to that predicted by a previous analytical Lévy walk model to be an optimal strategy to search for scarce resources distributed at random. Second, the frequency distribution of the duration of stops or waiting times also approximates to a power-law function. Finally, the mean square displacement during the monkeys first foraging trip increases more rapidly than would be expected from a random walk with constant step length, but within the range predicted for Lévy walks. In view of these results, we analyze the different exponents characterizing the trajectories described by females and males, and by monkeys on their own and when part of a subgroup. We discuss the origin of these patterns and their implications for the foraging ecology of spider monkeys.Communicated by D. Watts 相似文献
3.
Tara R. Harris 《Behavioral ecology and sociobiology》2006,61(2):317-329
In theory, between-group contest (BGC) competition for food can greatly influence female social relationships and reproductive success in primates, but few studies have investigated whether such effects occur and, if so, under what ecological conditions. There is evidence that adult male black and white colobus monkeys (Colobus guereza, “guerezas”) defend the food their mates need against other groups, suggesting that BGC competition is important in this species. Using data on feeding, ranging, vegetation patterns, and intergroup encounters between six neighboring guereza groups, I provide evidence that the highly folivorous guerezas at Kanyawara, Kibale National Park, Uganda, engaged in BGC competition over unevenly dispersed, relatively high-quality feeding areas or “core areas”. Intergroup aggression was common, and groups’ home ranges overlapped. Groups were more likely to initiate high-level aggression if they encountered another group within or near their core area, and groups that initiated and won encounters often fed in the same areas in which losing groups had fed. Guerezas fed selectively on species with contagious (clumped) distributions and concentrated their feeding efforts in areas of the forest that contained the most food (core areas). Groups could be ranked in a linear dominance hierarchy, and group rank number was inversely related to the quantity and quality of food in groups’ core areas. This study not only provides good evidence that BGC competition occurs in primates but it also reinforces the idea that folivore food resources may be worth defending. 相似文献
4.
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
5.
本文将大庆市杜蒙地区的屋舍、草甸、杨树林3个区域进行蜘蛛种类调查研究。共记述蜘蛛目9科,21属,22种,并对3个区域的分布特点进行了分析。据此,从环境保护角度提出了合理化建议。 相似文献
6.
Norberto Asensio Amanda H. Korstjens Filippo Aureli 《Behavioral ecology and sociobiology》2009,63(5):649-659
The adjustment to deal with intragroup food competition is probably the most plausible explanation of high levels of fission–fusion
dynamics. However, studies did not always support expected relations between food availability, ranging costs, and subgroup
size. We used several levels of analysis differing in the time and spatial scale in order to investigate this explanation
in spider monkeys. In our study, subgroups were larger when food availability was higher across most levels of analyses used.
We also found a fine-scale adjustment: compared to the food patch previously visited, spider monkeys traveled to larger patches
just after fusions. This was not without an immediate travel cost: the interpatch distance and travel time after a fusion
were longer than that before the fusion. This rapid adjustment shows the flexibility that fission–fusion dynamics can offer.
Spider monkeys are in large subgroups only when food conditions are favorable, as evidenced by the fact that at all the other
time-scale levels larger subgroups did not experience greater ranging costs than smaller subgroups. Our results indicate that
on the whole spider monkeys successfully minimize ranging costs by fission and fusion of subgroups. 相似文献
7.
Anne G. Oxbrough Tom Gittings John OHalloran Paul S. Giller Tom C. Kelly 《Agriculture, ecosystems & environment》2007,120(2-4):433-441
The aim of this study was to assess spider diversity among habitats that are typically used for afforestation in Ireland, and to identify habitat parameters which could potentially be used as indicators of their biodiversity value. Ground-dwelling spiders were surveyed in 24 sites across Ireland, with eight sites of each of the following habitat types: improved grassland, wet grassland and peatland. The spiders were sampled using pitfall traps which were located within the major vegetation types present in each site as well as within supplementary habitat features which may add to biodiversity value of the whole site such as hedgerows, flushes and the edges of ditches and streams.Each habitat supported distinct spider assemblages that reflect major differences in both environmental conditions and management regime. The improved grasslands had low spider species richness and low variation in assemblage structure which is probably related to the intensive management of this habitat. In this case hedgerows maybe an important aspect of the spider diversity within agricultural landscapes. The peatlands, and to a lesser extent wet grasslands, supported a diverse and specialist spider fauna, including a number of rare species; this may be due to differences in soil moisture and plant architecture. Indicators of biodiversity value identified included wet flushes in the peatlands and low grazing pressure in the wet grasslands. This study suggests that in terms of biodiversity value improved grassland is the preferable habitat for afforestation, because of the poor baseline spider diversity. However, it may be unrealistic to expect land owners to afforest their most productive agricultural land, so the management and habitat indicators identified in this study may be of use for assessing habitat quality among the wet grassland and peatlands to allow sites with lower biodiversity value to be identified. 相似文献
8.
Roman M. Wittig Catherine Crockford Robert M. Seyfarth Dorothy L. Cheney 《Behavioral ecology and sociobiology》2007,61(6):899-909
Theory predicts that females in species with matrilineal dominance hierarchies should use nepotistic support systems to maintain
their family’s rank. Female Old World monkeys, however, form alliances against other females at surprisingly low rates. Nonetheless,
in many species, females utter threat vocalizations when observing others’ disputes, suggesting that these vocalizations may
function as ‘vocal alliances’. We describe a playback experiment testing the efficacy of vocal alliances in free-ranging female
baboons. Subjects were played the same female’s threat-grunts under three separate conditions: after being threatened by the
signaller’s close relative to mimic kin support, after being threatened by a female maternally unrelated to the signaller
to mimic non-kin support, and after a friendly interaction with the signaller’s close relative as a control. Subjects responded
more strongly to the playback and avoided the signaller and her matrilineal relatives for a longer period of time in kin support
trials than in either non-kin support or no aggression trials. In contrast, there was no difference in subjects’ behaviour
between non-kin support and no aggression trials. These results corroborate observational data showing that vocal support
occurs at a higher rate than physical support in female baboons, and that kin are more likely to provide vocal support than
non-kin. We conclude that vocal support plays a similar role as physical support in the alliances of female baboons. 相似文献
9.
Spider webs as environmental indicators 总被引:1,自引:0,他引:1
Analysis of spider webs from limestone arches in New South Wales, Australia showed levels of lead and zinc to be several times higher at Jenolan Caves than reference sites at Abercrombie and Wombeyan Caves. The high concentrations at Jenolan were attributed to emissions from motor vehicles that travel through the arch. Analysis of water-soluble ions in webs from Jenolan and Abercrombie Caves showed large differences between the sites, which could be explained by differences in the geology and biology of the cave environments. Spider webs proved useful indicators of environmental chemistry and undoubtedly have applications beyond the cave environments studied here. 相似文献
10.
Knowing how far away animals can detect food has important consequences for understanding their foraging and social behaviors.
As part of a broader set of field experiments on primate foraging behavior, we set out artificial feeding platforms (90 × 90 cm
or 50 × 50 cm) throughout the home range of one group of 22 brown capuchin monkeys, at sites where they had not seen such
platforms previously. Whenever the group approached such a new platform to within 100 m, we recorded the group's direction
and speed of approach, and the identity and distance from the platform of the group member that detected the platform or came
closest to it without detecting it. We used logistic regression on these data to examine the effects of group movement speed,
platform size and height, and focal individual age and sex on the probability of detecting the platform as a function of distance.
Likelihood of detecting a platform decreased significantly at greater distances – the probability of detecting a platform
reached 0.5 at 41 m from the group's center and 25.5 m from the nearest group member. These results show that detectability
of platforms by the entire group (9 adults, 13 juveniles) was less than twice that for single group members. Detectability
at a given distance decreased severely as the group moved faster; at their fastest speed, individuals had to approach a platform
to within less than 10 m to find it. The large platforms were significantly more likely to be detected than the small ones,
suggesting that increased use of larger food patches by wild primates may not necessarily reflect foraging preferences.
Received: 20 May 1996 / Accepted after revision: 5 April 1997 相似文献