Extra-pair paternity is common in socially monogamous passerines; however, despite considerable research attention, consistent
differences in fitness between within-pair offspring (WPO) and extra-pair offspring (EPO) have not been demonstrated. Recent
evidence indicates that differences between maternal half-siblings may depend on environmental conditions, but it is unclear
whether the influence of paternal genetic contribution should be most apparent under comparatively poor or favourable conditions.
We compared phenotypic characteristics of WPO and EPO in 30 mixed-paternity broods of the tree swallow (Tachycineta bicolor) in relation to experimentally increased nest temperature (n = 13 heated nests; 17 control nests) and natural abundance of haematophagous parasites (Protocalliphora spp.). This allowed us to test the hypothesis that genetic benefits of extra-pair mating are environment dependent. EPO grew
their ninth primary feathers faster than WPO regardless of nest temperature or parasite load and had significantly longer
ninth primary feathers at fledging when parasite abundance was low, and when they were positioned early in the hatching sequence
relative to WPO. In contrast, WPO under similar conditions did not differ from EPO in any phenotypic trait measured. These
results indicate that the fitness benefits of extra-pair mating are likely to be context dependent, and that genetic effects
on some phenotypic traits may be more apparent when conditions are relatively favourable. 相似文献
Objective: Drivers’ behaviors such as violations and errors have been demonstrated to predict crash involvement among young Omani drivers. However, there is a dearth of studies linking risky driving behaviors to the personality of young drivers. The aim of the present study was to assess such traits within a sample of young Omani drivers (as measured through the behavioral inhibition system [BIS] and the behavioral activation system [BAS]) and determine links with aberrant driving behaviors and self-reported crash involvement.
Methods: A cross-sectional study was conducted at the Sultan Qaboos University that targeted all licensed Omani's undergraduate students. A total of 529 randomly selected students completed the self-reported questionnaire that included an assessment of driving behaviors (e.g., Driver Behaviour Questionnaire, DBQ) as well as the BIS/BAS measures.
Results: A total of 237 participants (44.8%) reported involvement in at least one crash since being licensed. Young drivers with lower BIS–Anxiety scores and higher BAS–Fun Seeking tendencies as well as male drivers were more likely to report driving violations. Statistically significant gender differences were observed on all BIS and BAS subscales (except for BAS–Fun) and the DBQ subscales, because males reported higher trait scores. Though personality traits were related to aberrant driving behaviors at the bivariate level, the constructs were not predictive of engaging in violations or errors. Furthermore, consistent with previous research, a supplementary multivariate logistic regression analysis revealed that only driving experience was predictive of crash involvement.
Conclusions: The findings highlight that though personality traits influence self-reported driving styles (and differ between the genders), the relationship with crash involvement is not as clear. This article further outlines the key findings of the study in regards to understanding core psychological constructs that increase crash risk. 相似文献
With the UN‐led celebration of the International Year of Youth from August 2010 to August 2011 there has been a renewed interest in young people and the vital role they can play in important issues, such as disaster risk reduction (DRR). This study aims to examine the potential of science clubs as a vehicle for youth participation in DRR in the Philippines. A questionnaire survey was conducted to obtain quantitative and qualitative data. A total of 658 science club members from different provinces of the Philippines participated in the survey. The result of the survey is used to explain how the major barriers to youth participation in DRR can be overcome. Through science clubs, the youth can become a link between their school, home and community and can contribute to spreading knowledge about disaster prevention, preparedness and response learned inside and outside the classroom. 相似文献
Although mate guarding as prevention of extra-pair copulation is common among birds, evidence for aggressive behaviour involving
physical contact related to mate guarding in passerines is scarce and cases of the presence of one partner directly influencing
the aggressiveness of the other are lacking. We investigated the intra-specific territorial behaviour of male meadow pipits
(Anthus pratensis; Passeriformes: Motacillidae) at the beginning of the breeding season by placing a pipit model accompanied by an intra-specific
song playback in the territory of socially paired males and compared the responses of males whose mates were physically present
during trials with those whose females were out of sight. The level of aggression of males was significantly higher in the
presence of the female; half of the males in this group physically attacked the model (the most intense and risky aggressive
behaviour). Physical attacks did not occur among males whose female was absent during the trial; response to the playback
by most of these males was only weak. This pattern may be related to the prevention of extra-pair copulation; if the risks
involved in the conflict are outweighed by potential loss of paternity, such aggressive mate guarding may pay off. The apparently
overlooked effect on the territorial behaviour of a partner’s passive physical presence during conflict should be further
evaluated because it may be important for the design and interpretation of results of behavioural experiments. 相似文献
This study investigates social monogamy in the Australian sleepy lizard, Tiliqua rugosa. At a 70-ha site near Mount Mary, South Australia, we radio tracked 55 adult female and 39 adult male lizards during their
spring activity periods. Each lizard was observed in 1–5 years. Females were observed with a single male partner on an average
of 10.8 days per year, although in 17.3% of cases, females were observed on 2 or fewer days with a male. The most intense
pairing period each year was 15 September–15 November when females were with male partners on an average of 36% of observation
days. Partnerships lasted an average of 43.3 days each year. After mating in early November, the pairs separated. Observations
of females pairing with other males were rare. Most males (82%) were also consistently monogamous, although 7 were observed
pairing with 2 females within one season. To investigate paternity, we allowed 21 gravid females to give birth to 42 offspring
in the laboratory. We determined genotypes at five polymorphic microsatellite DNA loci for the females, their male partners
and their offspring. Four litters (19%) and 6 of the offspring from those litters (14.3%) showed evidence of extra-pair fertilization
(EPF). Although the sample sizes are small, females of polygynous males were more likely to experience EPF.
Received: 22 February 1998 / Accepted after revision: 23 May 1998 相似文献
Extensive behavioural and pedigree data on a colour-marked population of Florida scrub-jays (Aphelocoma coerulescens) suggested that this cooperatively breeding species is monogamous, with extremely rare exceptions in which males have two
mates. We used multi-locus DNA fingerprinting to test these observations by determining genetic parentage. Despite restricted
dispersal and high relatedness between behavioural parents and non-breeding members of the group, DNA fingerprints provided
sufficient variability to determine parentage unambiguously in almost all cases. We found no evidence of extra-pair fertilisation
of females or egg dumping, and confirmed a suspected case of polygyny in which a mother and daughter laid and incubated in
the same nest. Our results confirm that detailed behavioural data allow accurate assignment of genetic parentage in this species.
In Florida scrub-jays, large territory size may limit opportunities for cuckoldry, and persistent intense competition for
limited breeding space may lead to low variance in the quality of established male breeders. These factors would reduce both
the opportunity for, and benefits of engaging in extra-pair fertilisations. Delayed dispersal and cooperative breeding in
this species have not evolved as avenues for direct reproduction by unpaired individuals.
Received: 25 May 1998 / Accepted after revision: 26 June 1998 相似文献
Ornamental traits are thought to evolve because they give individuals an advantage in securing multiple mates. Thus, the presence
of ornamentation among males in many monogamous bird species presents something of a conundrum. Under certain conditions,
extra-pair paternity can increase the variance in reproductive success among males, thus increasing the potential for sexual
selection to act. We addressed this possibility in the mountain bluebird (Sialia currucoides), a socially monogamous songbird in which males possess brilliant ultraviolet (UV)-blue plumage. Specifically, we asked whether
a male’s success at siring offspring within his own nest and within the nests of other males was related to his coloration.
In pairwise comparisons, males that sired extra-pair offspring were not more colorful than the males that they cuckolded.
However, males that sired at least one extra-pair offspring were, on average, brighter and more UV-blue than males that did
not sire extra-pair offspring. Brighter, more UV-blue males sired more offspring both with their own mate and tended to sire
more offspring with extra-pair mates and thus sired more offspring overall. Our results support the hypothesis that the brilliant
UV-blue ornamental plumage of male mountain bluebirds evolved at least in part because it provides males with an advantage
in fertilizing the eggs of multiple females. 相似文献