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José P. Veiga 《Behavioral ecology and sociobiology》1996,39(5):345-352
In many bird species the cryptic winter plumage is due to the presence of light feather tips that conceal conspicuous colorations.
The gradual abrasion of these tips that makes sexual traits visible has been interpreted as a strategy to improve mating success
(here referred as the permanent exhibition hypothesis). However, under some circumstances, the maintenance of a full plumage
that facultatively enables the bird to exhibit or cover aggression-inducing traits has proved to be advantageous (the coverable
badge hypothesis). In a population of house sparrows where black throat patches (here called badges) are used in intrasexual
competition, the degree of abrasion of dull feather tips that conceal bright colour early in the breeding season correlated
neither with badge size nor with traits indicating morphology and body condition. These results are only in accordance with
predictions of the coverable badge hypothesis. In 1992 experimental clipping of badge feather tips, which forced permanent
exposure of badges, negatively affected birds with the largest badges in terms of nest acquisition, but an opposite trend
was indicated for birds with the smallest badges. In 1993, when more novel birds in the study area were competing for nesting
sites than in 1992, only badge size, but not the experimental manipulation, affected nesting success. These results suggest
that the loss of the ability to conceal badges was disadvantageous, and more so if most competing individuals had already
been resident in the colony in previous years and the larger their badges were. There is a striking contrast between the results
reported for this study population, where badges mainly signal fighting ability, and those reported for another house sparrow
population, where badges are mainly used in mate choice. In this last population, tip abrasion is advantageous for dominant
individuals showing the largest badges. This suggests that the trade-off between conserving versus wearing off the feathers
that conceal ornaments could have different optimal resolutions depending on the relative importance of inter and intrasexual
selection on indicator traits.
Received: 29 September 1995/Accepted after revision: 14 July 1996 相似文献
2.
Lorin A. Neuman-Lee Gareth R. Hopkins Edmund D. Brodie Jr. Susannah S. French 《Journal of environmental science and health. Part. B》2013,48(6):442-448
This study examined the effects of sub-lethal exposure of the ubiquitous pesticide malathion on the behavior of the model orthopteran species, the house cricket (Acheta domesticus). Increasing concentrations of malathion caused male crickets to increase periods of non-directional movement, such as twitching and grooming, directional movement, and to seek out shelter less. These are all behavioral alterations that may increase the cricket's chances of being preyed upon, and thus have the potential for serious ecological consequences through trophic transfer. This study also revealed that female crickets appeared to be less affected by malathion than their male conspecifics, indicating a potential sex-bias in both susceptibility and possible predator attack. 相似文献
3.
There is evidence to suggest that males of various species can respond to the threat of sperm competition by varying the
amount of sperm transferred during copulation. We tested this in two species of cricket, Acheta domesticus and Gryllodes supplicans (Orthoptera: Gryllidae) by varying the apparent threat of intermale competition experimentally. The results showed that males
of both species increased the amount of sperm transferred as apparent competition increased and that male A. domesticus transferred more sperm when encountering larger females. The results also showed that male G. supplicans produced a larger spermatophylax when a larger ampulla was transferred, a relationship consistent with a sperm protection
function.
Received: 5 May 1995/Accepted after revision: 27 January 1996 相似文献
4.
P. J. Cordero S. C. Griffith J. M. Aparicio D. T. Parkin 《Behavioral ecology and sociobiology》2000,48(5):353-357
Recent evidence has revealed an apparently high degree of control by female birds over the physiological aspects of their
reproduction and offspring sex allocation, consistent with adaptive hypotheses of sex allocation and differential investment
in their offspring. In the house sparrow, we investigated possible mechanisms that may be used by females to enhance the fitness
returns from a reproductive effort. Using molecular techniques, we demonstrate that house sparrow eggs containing male embryos
are significantly larger than those containing female embryos. We also found that male embryos were laid randomly with respect
to laying order. We speculate that this sexual dimorphism of eggs is adaptive, because male house sparrows show greater variance
in condition-dependent reproductive success than females. More important, the result provides further evidence of the ability
of females to detect or control ovulation of either male or female ova and to differentially invest in one sex over the other.
Received: 19 January 2000 / Revised: 29 June 2000 / Accepted 20 July 2000 相似文献
5.
Justyna Maliszewska Bartosz Piechowicz Gabriela Maciąga Lech Zaręba Sonia Marcinkowska 《Journal of environmental science and health. Part. B》2018,53(7):441-446
Many factors may affect pesticide effectiveness against pests. One of the factors that should be considered is circadian rhythmicity. In this study, we evaluated daily variations in pyrethroid susceptibility in the house cricket, Acheta domesticus L. Crickets were exposed to a standard dose of ß-cyfluthrin at different times of a day, and pesticide residue levels were evaluated using gas chromatography. Results demonstrate that the time of pyrethroid disappearance is correlated with the circadian clock, with the highest decomposition rate at night. Furthermore, crickets also showed the highest resistance to the insecticide at night, expressed as a high survival rate. Moreover, ß-cyfluthrin induced significant changes in thermal preferences of intoxicated crickets. This is the first report showing that pyrethroid residue levels in the crickets' body depend on its circadian clock. 相似文献
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