摘要:

Implantation failure in newly inseminated females induced by food deprivation for 48 hr beginning at 10.00 hr on day 4post coitumwas prevented by the presence of the stud male. However, a «familiar» male which had cohabitaded with the female for 7 days or more before pairing with the stud male did not show this protective effect. By contrast, a «familiar» male which had cohabitated with the female for 24 hr during the pericopulatory period provided protection to implantation in food-deprived females, comparable to that given by stud males. The results suggest that exposure to a male, whether the stud male or any other conspecific male, during and immediately after coitus enables the female to memorise the male-originating olfactory cues. This olfactory «memory» induces a luteotrophic effect in the female on re-exposure to the same male after mating. This accounts for the protective effect of the stud male and the «familiar» male on implantation in food-deprived females. The findings also provide additional support to the view that the newly inseminated female mouse is capable of individual identification of males through olfactory cues perceived during the pericopulatory period.

ISSN:0394-9370    

DOI:10.1080/08927014.1992.9523124

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

An examination has been made of factors triggering attack behaviour in adultCephalota circumdata leonschaeferi(Cassola), living in the coastal strip of the Orbetello Lagoon Nature Reserve. Coloured dummies (blue, white, brown, black, red, and green) of various sizes (3.8, 7.5, 15 and 30 mm) have been used to evaluate the rôle of the following stimuli: movement, size and colour. Attacks recorded with experiments carried out in absence of movement (3.83%) were markedly fewer than those in presence (57.26%) of movement. The size of bait most frequently attacked by Tiger beetles was the 7.5-mm long one (corresponding to 1/2 the size of the adultCephalota). The largest bait (30 mm) was significantly less stimulating than the other three sizes. Red was the colour that most stimulated attack and white the least. Brown and black gave results more similar to those of red, whereas green and blue frequently displayed a significantly less stimulatory effect.

ISSN:0394-9370    

DOI:10.1080/08927014.1992.9523125

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Nests of a paper waspPolistes stigmain south India were initiated mostly on plants, either on the underside of leaves (47%) or on the stems of woody grasses, leafstalks and twigs (53%) in woody areas, at a mean height of 2.5 m. Sixty-one (93.8%) of 65 colonies were founded by single females. This is in strong contrast to the large proportion (>80%) of multiple-female founding reported so far in neotropicalPolistes. Twenty-three (88.5%) of 26 colonies did not survive the pre-emergence stage. Eight (88.9%) of nine post-emergence colonies (five natural and four transplanted colonies) were attacked by hornets (Vespaspp.) and abandoned.

ISSN:0394-9370    

DOI:10.1080/08927014.1992.9523126

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Regional integumentary loss is a predator escape strategy employed by representatives of at least 10 genera of gekkonid lizards in several evolutionary lineages. It involves the loss of patches of the skin and is dependent on the bilayering of the dermis and the inherent weakness of the outer layers of the skin. Such loss engenders problems of radiation exposure, osmoregulation and immunological integrity. The vast majority of geckos exhibiting the trait live on islands. The subjugation mode employed by island predators, such as primates and snakes, may be a significant factor in driving selection for integumentary loss. Skin weakness may be expected to evolve when the chief predators use grasping or pinning in the early stages of subjugation, rather than an initial killing bite or strike. Skin-loss is a phenomenon similar to caudal autotomy, but differs primarily in that it is effective only with respect to some types of predators and only as a last line of defense, after predator contact with the prey body has been made.

ISSN:0394-9370    

DOI:10.1080/08927014.1992.9523127

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

InCataglyphis ibericaant societies, social carrying of workers from one nest to another of the polycalic colony is a common phenomenon mostly performed by a group of workers, the transporters. They are old workers (with completely resorbed ovaries and low fat body content), included among the most active individuals of the colony, and specialized in adult transport. Behaviourally they occupy an intermediate position between interior and exterior workers, since they perform, together with adult transport, some activities characteristic of those two groups of workers. Notwithstanding, their characterization as an independent group varies greatly between periods and colonies.

ISSN:0394-9370    

DOI:10.1080/08927014.1992.9523128

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

According to current theory young passerine migrants on their first migration are equipped with a genetic programme of duration and direction of migration which enables them to reach their winter quarters independently of adults. The question was investigated whether in birds prevented from gathering migratory experience the genetically determined directional information is expressed only during the first autumn migratory season or whether it is retained as an endogenous directional preference at least throughout the 2nd year of life.

ISSN:0394-9370    

DOI:10.1080/08927014.1992.9523129

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

It has been proposed that in some queenless ponerine ants, includingOphthalmopone berthoudi, oviposition is triggered by mating, and that virgin workers are functionally sterile only because they are uninseminated. This mechanism would be unique amongst ants. By isolating newly eclosed virgin workers ofO. berthoudifrom mated workers, it was shown that they are in fact capable of laying eggs without mating. Virgin workers in intact colonies appear to be inhibited by a pheromone produced by their reproductively-active nestmates, as in other ants.

ISSN:0394-9370    

DOI:10.1080/08927014.1992.9523130

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Homing pigeons were made temporarily anosmic and released from four locations to examine the importance of atmospheric odors for their navigational performance in northwest Ohio, USA. From each location, the navigational performance of the anosmic pigeons was poorer compared to controls either with respect to vanishing bearings, homing time or homing success. Although the effect of anosmia varied between release sites, the results are consistent with a large body of existing evidence emphasizing a critical role for olfaction in homing pigeon navigation.

ISSN:0394-9370    

DOI:10.1080/08927014.1992.9523131

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The Observer: software for behavioural research, version 2.0. Base Package for the IBM PC, PS/2 and compatible computers; Support Package for the TRS-80 Model 100, Tandy 102 and Olivetti M10 portable computers; Support Package for Psion Organiser hand-held computers; Support Package for the Epson PX-8 portable computer.

ISSN:0394-9370    

DOI:10.1080/08927014.1992.9523132

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

ISSN:0394-9370    

DOI:10.1080/08927014.1992.9523123

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor