摘要:

Definitions ofcastemust be based on either form or function, since the combination of both in a single definition makes the concept impossible to apply in many cases. Developmental, functional and evolutionary studies gain heuristically from a distinction between the form and the social role of a social insect, which means that the two should be treated as conceptually distinct.

ISSN:0394-9370    

DOI:10.1080/08927014.1992.9523134

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

A comparative survey of mating systems in six EuropeanAcrocephalusspecies revealed that two of the species can be classified as polygamous and four monogamous. Several correlations were then found between mating system and various aspects of behaviour, ecology and morphology. Males of polygamous species invested little or nothing in parental care, whereas males of monogamous species shared it equally with females. Males of polygamous species defended large territories in high productivity marshland ecotones rich in arthropod food. Monogamous males defended smaller territories in less productive marshland. Females of polygamous species fed their young on larger prey collected within territory near the nest. In monogamous species, smaller prey was collected from longer flights often outside territory. Polygamous species also had larger bills as an adaptation to take larger prey. Males of polygamous species had short, simple songs used in territorial defense, whereas males of monogamous species had long, complex songs for mate attraction. These correlations were then used to make predictions about the mating systems or ecology and behaviour of less well knownAcrocephalusspecies. The comparative approach is a useful tool in the continuing investigation into the evolution of polygamy. It suggests that the emancipation of males from biparental care and the constraints of food supply have both been important factors. InAcrocephaluswarblers, polygamy is best viewed as a continuum of gradual departure from monogamy in the rich but variable marshlands of Europe.

ISSN:0394-9370    

DOI:10.1080/08927014.1992.9523135

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The mating behaviour ofDytiscus alaskanuswas studied in the laboratory using frame-by-frame analysis of time-lapse video tape. Matings proceed with little precopulatory courtship and consist of eight patterns: mounting, lateral shake, swimming, copulation, plug visible, probing, female breathe, and female swim. Although matings last nearly 8 hr, copulation usually takes place within the first 4 min and is marked by the passage of a spermatophore. Matings performed in the fall result in the formation of an external mating plug. The rest of the mating is devoted to probing of the plug by the male. After matings in the spring, no external plug is formed. The prolonged postcopulatory period may be a form of guarding that has different functions depending on season.

ISSN:0394-9370    

DOI:10.1080/08927014.1992.9523136

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

This laboratory study investigated the costs, in terms of energy or time, of grouping as a function of group size. I manipulated group size by randomly assembling small and medium sized pumpkinseed sunfish (Lepomis gibbosus) into groups of various sizes. Agonistic interactions within groups were highly non-random. Consequently, linear dominance hierarchies often could not be inferred due to too many dominance relationships not being expressed at all. The interaction frequencyper groupper hour increased, whereas the interaction frequencyper individualper hour (agonistic index) decreased with group size; the agonistic activity of the most dominant individual within each group did not change with group size. A null model predicting that the agonistic index should increase in proportion to the number of potential dyadic relationships in any given group could be rejected. Instead, the data supported an alternative hypothesis derived from the theory of economic defensibility of a resource (here, a feeding space conferring food with a certain probability) in that the per capita frequency of agonistic interactions decreased with increasing intruder pressure (i.e. group size). Based only on the assessment of the probability of being engaged in a fight, potential subordinates should hence prefer larger groups (a type of intra-group dilution effect), while potential dominants should have no group size preferences other than solitary lifestyles.

ISSN:0394-9370    

DOI:10.1080/08927014.1992.9523137

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

In this study we addressed five questions concerning kin recognition and shoaling in threespine sticklebackGasterosteus aculeatusfry. Our results were: (1) fry distinguished between similar-aged sibs and non-sibs when tested at 18, 30 and 45 days of age, (2) fry reared with maternal half-sibs distinguished sibs from half-sibs; fry reared with paternal half-sibs did not discriminate between paternal half-sibs and either sibs or non-sibs, (3) the ability to discriminate sibs from non-sibs did not require experience, but the strength of the shoaling preference was modified by events early in life, (4) fry spent more time near kin when a predator was present and (5) fry did not distinguish between non-sib conspecifics and heterospecifics.

ISSN:0394-9370    

DOI:10.1080/08927014.1992.9523138

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

We analysed nursing and suckling behaviour in the mouflon (Ovis orientalis musimon) in a captive herd. The suckling frequency, average duration and success rate were found to decrease with lamb age, particularly during the first few weeks. After an initial increase, the frequency of unsuccessful suckle attempts remained virtually constant at significantly high levels for 2 months, after which it decreased until the end of the observation period. Suckling actions towards strange mothers were small in number and unsuccessful in every case. After the 2nd week, suckling was always terminated by the mother.

ISSN:0394-9370    

DOI:10.1080/08927014.1992.9523139

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The effects of reduced activity in the amphipodGammarus jossarumon the foraging behaviour of naive and experienced cyprinid fish,Vimba elongata, were tested experimentally. Prey mobility reduced latencies. Generally, latencies declined with increasing experience of the fish.Vimbasnapped at prey and inconspicuous particles at a higher frequency when prey were mobile than when they where immobile. The frequency of snaps increased with experience. These results conform to predictions from the search rate hypothesis.

ISSN:0394-9370    

DOI:10.1080/08927014.1992.9523140

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Wonderful life: the Burgess shale and the nature of history. By Stephen Jay Gould. ISBN 0-90-174271-4, 1990, 347 pp., hardback, price £ 14.95 net in UK only.

ISSN:0394-9370    

DOI:10.1080/08927014.1992.9523141

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Created from animals: the moral implications of Darwinism. By James Rachels. ISBN 0-19-217775-3, 1990, 245 pp., price £ 17.50 in UK.

ISSN:0394-9370    

DOI:10.1080/08927014.1992.9523142

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

ISSN:0394-9370    

DOI:10.1080/08927014.1992.9523133

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor