摘要:

The hypothesis that the evolutionary origin of novel behavior patterns may be imprecision in the execution of existing patterns is examined using data from spider web construction behavior. Several aspects of orb construction behavior are both extremely invariable intraspecifically, and highly conserved evolutionarily. The behavior of spiders in the genusWendilgarda, which build highly modified, simplified webs derived from orbs, is exceptional in being highly variable both within and between species. Reduced intensity of selection for behavioral stereotypy combined with behavioral imprecision may explain the high intraspecific and intra-individual variability inWendilgarda. This increased variation may in turn explain the unusual interspecific diversity of web designs in this genus.

ISSN:0394-9370    

DOI:10.1080/08927014.2000.9522797

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

Genetic parentage was determined by DNA-fingerprinting with multilocus probes and microsatellite PCR in threeAcrocephalusspecies with different mating systems: the socially monogamous marsh warbler (A. palustris), the polygynous great reed warbler (A. arundinaceus) and the promiscuous aquatic warbler (A. paludicola). The amount of extra-pair paternity (EPP)/multiple paternity (MP) was then related to ecological parameters (increasing productivity) and parental care (decreasing male participation) ofAcrocephalusspecies.

ISSN:0394-9370    

DOI:10.1080/08927014.2000.9522798

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

Cloacal microparasites such as viruses, bacteria and fungi are expected to condition choice of sexual partner, as they can not only affect the expression of secondary sexual traits used in courtship, but they could be also directly transmitted to partners through copulation. We investigated the distribution of three cloacal microparasites (the bacteriumChlamydia psittaciand the yeastsCandida albicansandKloeckeriasp.) among males and females of the sexually plumage dichromaticMalurus cyaneusandSericornis frontalis, and the plumage monochromaticManorina melanophrys.

ISSN:0394-9370    

DOI:10.1080/08927014.2000.9522799

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

Pair formation in the lesser wax moth,Achroia grisella(Lepidoptera Pyralidae), is accomplished via male-produced pulses (100 µsec) of ultrasound (100 kHz) attractive to females.A. grisellaare sensitive to a wide range of ultrasonic frequencies, enabling them to hear the echolocation signals of both aerialhawking and substrate-gleaning bats. Both flying and running moths exhibit defensive behaviors, dropping to the ground and cessation of locomotion, respectively, in response to simulated bat echolocations. We determined that femaleA. griselladiscriminate the mating signals of advertising males from bat echolocations on the basis of the faster pulse rates (> 60 sec−1) of mating signals. Terrestrial defensive behavior is elicited by a slow rate of lengthy (≥ 1 msec) pulses, features of most searching phase bat echolocations.

ISSN:0394-9370    

DOI:10.1080/08927014.2000.9522800

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

Endocrine and immune parameters, namely glucocorticoid receptors (GcR) and IFN-γ production in peripheral blood mononuclear cells (PBMC), and corticosterone in plasma, were studied in groups of four male rabbits observed in seminatural conditions in relation to agonistic behaviour and to seasonal variations. These parameters were selected on the basis of the findings that the presence of GcR in PBMC gives an indication of the in vivo biological effects of glucocorticoids and that PBMC cytokine production and plasma corticosterone are related to social behaviour. The frequency of active and passive behaviours was used to rank the animals. Seasonal variations were present for agonistic behaviours (Attack, Follow, Chase) and for plasma corticosterone, which were significantly higher in winter. IFN-γ production in PBMC was increased after social interactions in both seasons, while plasma corticosterone was increased only in winter. GcR capacity in PBMC was decreased after social interactions. The results indicate that social and physical environmental factors are correlated with immune-endocrine functions.

ISSN:0394-9370    

DOI:10.1080/08927014.2000.9522801

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

In some passerine species, 1st-year males are clearly distinguishable from adults; they have a different, typically dull, plumage. At least 15 explanations of the delayed plumage maturation of 1st-year males have been proposed. In the present study, we investigate if there is a similar widespread phenomenon regarding song, i.e. if males of some species have a distinct song in their first breeding season (delayed song maturation). A comparative analysis of 137 West Palearctic passerines showed that detailed data on how the song changes with age in breeding males is available for only a few species. Moreover, it is difficult to assess whether the song features continue to change considerably year after year or if, as we suggest, the main difference is between 1st-year vs 2-years and older males. We found that species with a suggested delay in song maturation were mostly those with delayed plumage maturation; a preliminary comparison suggests that these species have greater longevity. We also discuss the evolutionary significance of delayed song and plumage maturation and we suggest some possible directions for future research on these phenomenona.

ISSN:0394-9370    

DOI:10.1080/08927014.2000.9522802

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

In hymenopteran societies, workers are not always sterile, and may produce parthenogenetically either males (arrhenotoky) or females (thelytoky). Thelytoky however is exceptional, and has been recorded in only four ant species. Here we provide evidence for worker thelytoky in an additional species, the harvesting antMessor capitatus(Latreille) (Hymenoptera Formicidae Myrmicinae). Two orphaned colonies produced a large amount of worker offspring during 10 months in the laboratory. Dissections showed that reproduction was performed by workers and not by mated worker-like individuals (ergatoids). In some parasitoid wasps, parthenogenetic reproduction is caused by the maternally transmitted bacteriumWolbachia. Using a PCR-based assay we showed thatWolbachiacan not be involved in parthenogenesis induction in this species. Finally, we point out reasons for the lowWolbachiasusceptibility of parthenogenetic ant species.

ISSN:0394-9370    

DOI:10.1080/08927014.2000.9522803

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

The role of decyl butyrate (the main component of the secretion of Dufour's gland in newly-mated queens) during host-colony usurpation was investigated in the European amazon antPolyergus rufescens. The effect of this ester on the behaviour of workers of the common host speciesFormica cuniculariawas analysed. We used a laboratory aggression test during which workers of the speciesCamponotus ligniperda, masked with synthetic decyl butyrate, were introduced into colony fragments ofF. cunicularia. The results showed that this compound drastically lowers the degree of overt aggression against the introduced ants, and we suggest that it acts as an appeasement allomone. Moreover, pieces of filter-paper soaked with decyl butyrate were more attractive than pieces of paper treated with solvent. The results are discussed in relation to a chemical strategy that likely allows an easier invasion and usurpation of host colonies by queens of this obligatory slave-making ant.

ISSN:0394-9370    

DOI:10.1080/08927014.2000.9522804

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

Are non-indigenous species “ecological malignancies”?Man did not weave the web of life, he is merely a strand in it. Whatever he does to the web, he does to himself. (Chief Seattle, 1852)

ISSN:0394-9370    

DOI:10.1080/08927014.2000.9522805

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor