摘要:

The main results achieved by research work on pigeon olfactory navigation are reviewed and discussed, taking into account different interpretations and a recent critical review by K. SCHMIDT-KOENIG. Crucial experiments demonstrating that anosmic birds are heavily impaired in homing from unfamiliar sites have been reported by different authors from different laboratories. In addition, initial orientation is disturbed by anosmia over unfamiliar areas; the claim that, in some environmental and training conditions, pigeons develop a non-olfactory navigational mechanism could not be confirmed in the most recent experiments. The experiments performed a) by preventing birds from smelling during the outward journey and/or at the release site, b) by transporting the birds by a circuitous way, and c) by allowing birds to perceive atmospheric odours at a site different from that of release, all yielded results which form a coherent picture as to how pigeons use local odours to fix their position with respect to home.

ISSN:0394-9370    

DOI:10.1080/08927014.1989.9525511

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Data on the nesting behaviour ofTachysphex albocinctus(Lucas),T. consociusKohl, andT. tarsinus(Lepeletier) are presented. T. alhocinctus uses immature mantids as prey, and their males exhibit territorial behaviour;T. consociusandT. tarsinusprey on nymphal acridids.

ISSN:0394-9370    

DOI:10.1080/08927014.1989.9525512

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Individual performances in sun orientation ofTalitrus saltator(Montagu) were analysed in order to test phenotypic variability within the progeny of pairs of sandhoppers from a natural population. Most individuals in each family tested were individually oriented, although not all in the expected direction towards the sea. Thus the «scattered» behaviour shown by some of the families arises from different individual decisions and not from general «lack of decision». In a comparison between the orientation of expert adults and inexpert young, the latter tended to show higher deviation values. The importance of genetic heterogeneity and its interplay with phenotypic plasticity in the adaptation of sandhoppers is discussed.

ISSN:0394-9370    

DOI:10.1080/08927014.1989.9525513

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

This paper concerns the olfactory reaction of female domestic cats (Felis catusL.), distributed in four different groups on the basis of their reproductive state (pregnant, with kittens, in oestrous, in anoestrous), to sprayed urine from a strange, unrelated male cat.

ISSN:0394-9370    

DOI:10.1080/08927014.1989.9525514

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Factors affecting Brown hare (Lepus europaeus) density were studied in protected areas of northern Italy with the aim of evaluating the influence of vegetation type on the distribution of animals in arable farmland. Drive censuses were used on sample plots to assess autumn and spring hare densities. Correlations and multiple regression analysis showed that ploughed fields in spring, and maize and rice crops in autumn have a negative effect on density, while the grass edges and meadows in spring, and poplar groves and wheat in autumn, have a positive effect. Lucerne crops, in which farming practices induce a high death rate of leverets, reduce density. The effect of natural vegetation is not clear. Landscape diversity, which in the study areas depends on certain unfavourable crops, is inversely correlated with autumn density.

ISSN:0394-9370    

DOI:10.1080/08927014.1989.9525515

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

In a dwarf mongoose family group, guarding is performed almost exclusively by subordinate males. The amount of time this social category invests in vigilance varies with group size. When too few guards are present, although mean vigilance time/guard increases, the vigilance systems becomes inefficient and gaps occur between guards. The effectivity of vigilance is high, 9 3% of incipient raptor attacks being aborted by the guard giving warning beforehand. For ground predators, vigilance efficiency is 100% when guards are present. For dwarf mongoose family groups, predation mortality is shown to be the major cause of reduced reproductive success. The number of young surviving is positively correlated with group size. Group size is shown to be a function of the efficiency of group protection mechanisms such as vigilance and group attack of ground predators. Maximal fitness gains at the level of the individual are attained at a group size lower than the observed mean group size. This finding is related to the concept of differing optimal group sizes for dominant and subordinate animals. The trend towards larger group sizes than necessary for optimal fitness is considered a means of reducing costs to subordinate animals involved in group protective roles.

ISSN:0394-9370    

DOI:10.1080/08927014.1989.9525516

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The effect of being located inuterobetween two females (0M), a male and a female (1M) or two males (2M) was assessed on subsequent infanticidal behaviour (i.e. the killing of alien pups) in primiparous female outbred Swiss and inbred BALB/c and C57BL/10 mice. Strain of subject had a significant effect on infanticide, with Swiss females showing a higher incidence than subjects of the other strains. Intrauterine location also had a significant effect on this behaviour with 2M females showing most infanticide, 0M female least and 1M females being intermediate in this respect. It seems likely that the intrauterine effects are caused by exposure to transplacental androgen from male siblings. Genotype might influence the capacity of animals to respond to hormonal influences in early life. The possible implications of this phenomenon on the reproductive ecology of house mice are examined.

ISSN:0394-9370    

DOI:10.1080/08927014.1989.9525517

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Data collected from 13 fallow deer populations indicate that although population density is an important correlate of lek breeding in this species, environmental heterogeneity can also be a decisive factor promoting lekking even in the absence of high densities.

ISSN:0394-9370    

DOI:10.1080/08927014.1989.9525518

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

ISSN:0394-9370    

DOI:10.1080/08927014.1989.9525510

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor