摘要:

AbstractBlue tail coloration in hatchling skinks (Eumeces fasciatusandE. laticeps) appears to be an antipredatory adaptation that distracts attention away from the body to the tail. The tail itself serves as a decoy that may be autotomized as a final defense against capture. The effectiveness of intact tails in deflecting attacks from the body was 50% against scarlet kingsnakes in the experimental conditions used. Brightness rather than hue presumably accounts for the higher attack frequency on blue than black tails in this study, but the blue color may have evolved in response to avian predation.Repeated predation without ill effects by several predators allows rejection of the hypothesis that the blue tail is aposematic for the predators tested. The hypothesis that blue tails provide stimuli inhibiting aggression or predation by adult male conspecifics is untenable forE. laticepsbecause adult males readily eat intact hatchlings. Although this study provides no statistical evidence that blue tail coloration inhibits attack by femaleE. laticepson hatchlings, the trend of predation rates on blue‐ and black‐tailed hatchlings is in the direction predicted for inhibit

ISSN:0044-3573    

DOI:10.1111/j.1439-0310.1985.tb00518.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

AbstractThe sexual behaviour of wild long‐tailed macaques (Macaca fascicularis) was studied in the Gunung Leuser National Park, Sumatra, Indonesia. All females showed some swelling of the sexual skin, but the frequency and maximum size of the swelling decreased with age. The frequency of copulations and consortships for a given female increased with increasing degree of swelling or coloration. No regular cycles could be found in the occurrence of swellings, copulations and consortships. Periods for which a female had consortships tended to be long (up to 5–6 weeks on end). These two results suggest that in the wild the predictability of the moment of ovulation is very low. The consortships were not exclusive: both the male and the female occasionally copulated with others. All females had many different male partners and, as ovulation signalling was not clear, none of these males could have any certainty about paternity of a female's offspring. Yet, the highest‐ranking males probably had the best chances to father children because they were more often involved in sexual interaction (both copulations and consortships), especially around the estimated date of conception. This does not hold for the nulliparous females who were virtually ignored by the higher‐ranking males. Consortships were occasionally actively maintained by the female, for whom a direct advantage of consorting might be an increased safety against conspecifics and predators. One advantage of mating with many different males might be a reduced risk of infa

ISSN:0044-3573    

DOI:10.1111/j.1439-0310.1985.tb00519.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

AbstractThe scalloped hammerhead,Sphyrna lewini, forms schools as highly polarized as those of the obligate schoolers,Atherinops affinis, Engraulis mordax, Scomber japonicus, andTrachurus symmetricus. On the other hand, schooling hammerheads do not maintain preferential elevations and bearings to their nearest‐neighbors and remain at larger inter‐individual distances than the facultative schoolers,Gadus morhuaandPollachius virens, and the obligate schooler,Clupea harengus. Members of hammerhead schools vary in size more than those of small bony fishes. Furthermore, aggression is very common in schools of hammerheads; most individuals are females which compete for a position at the center of the school. Larger females perform two approach‐type behaviors, Hit and Cork‐screw, within the schools and force smaller sharks to the edge as they perform two withdrawal‐type behaviors, Acceleration and Head‐shake. Males are rare and enter the schools, performing Torso‐thrust. The differences between schools of hammerheads and those of small teleosts are consistent with schooling in hammerheads functioning not to confer protection from predation, but to permit conspecifics to interact socially during the resting phase of the

ISSN:0044-3573    

DOI:10.1111/j.1439-0310.1985.tb00520.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

AbstractExperiments were conducted onMygalopsis markiBailey to determine the response of calling males to singing intruders. By increasing the density of natural aggregations of singing males we were able to observe the behavioural responses of individuals. In high density situations, males sang from lower perches in their plant and this effect was correlated with each male's proximity to other calling males. Furthermore, to examine if resident males were affected by conspecific song, a playback technique was employed using tape recordings ofM. markisong. The design of the experiment was such that when confronted with an intruder, steadily increasing the intensity of its song, resident males moved to a lower position in the plant and ceased singing.

ISSN:0044-3573    

DOI:10.1111/j.1439-0310.1985.tb00521.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

ISSN:0044-3573    

DOI:10.1111/j.1439-0310.1985.tb00522.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Book Reviewed in this article:Books: Hummel, H. E.,&T. A. Miller, eds. (1984): Techniques in pheromone research (Methoden der Pheromon‐Forschung).Laybourn‐Parry, J. (1984): A functional biology of free‐living protozoa (Biologie und Ökologie freilebender Protozoen).Bone, Q.,&N. B. Marshall (1985): Biologie der Fische (Biology of fishes).Unshelm, J., G. van Putten&K. Zeeb, eds. (1984): Proceedings of the international congress on applied ethology in farm animals.Taylor, R. J. (1984): Predation (Räuber und Beute).Barnard, C. J., ed. (1984): Producers and scroungers. Strategies of exploitation and parasitism (Produzenten und Nutznießer. Wie man auf Kosten anderer lebt).Woolfenden, G. E.,&J. W. Fitzpatrick (1984): The Florida Scrub Jay. Demography of a cooperative‐breeding bird (Der Buschblauhäher.Murie, J. O.,&G. R. Michener, eds. (1984): The biology of ground‐dwelling squirrels (Jahreszyklen, Etho‐Ökologie und Sozialverhalten von Erdhörnchen).Portmann, A. (1984): Vom Wunder des Vogellebens (The wonders of bird life).Chamisso, A. von (1819–1836): … und lassen gelten, was ich beobachtet habe. Naturwissenschaftliche Schriften mit Zeichnungen des Autors (Scientific publications with dr

ISSN:0044-3573    

DOI:10.1111/j.1439-0310.1985.tb00523.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY