Objectives: Studies from different parts of the world have indicated that the impact of road traffic incidents disproportionally affects young adults. Few known studies have been forthcoming from Arabian Gulf countries. Within Oman, a high proportion of the population is under the age of 20. Coupled with the drastic increase in motorization in recent years, there is a need to understand the state of road safety among young people in Oman. The current research aimed to explore the prevalence and characteristics of road traffic injuries among young drivers aged 17–25 years.
Methods: Crash data from 2009 to 2011 were extracted from the Directorate General of Traffic, Royal Oman Police (ROP) database in Oman. The data were analyzed to explore the impact of road crashes on young people (17–25 years), the characteristics of young driver crashes, and how these differ from older drivers and to identify key predictors of fatalities in young driver crashes.
Results: Overall, young people were overrepresented in injuries and fatalities within the sample time period. Though it is true that many young people in crashes were driving at the time, it was also evident that young people were often victims in a crash caused by someone else. Thus, to reduce the impact of road crashes on young people, there is a need to generally address road safety within Oman. When young drivers were involved in crashes they were predominantly male. The types of crashes these drivers have can be broadly attributed to risk taking and inexperience. Speeding and nighttime driving were the key risk factors for fatalities.
Conclusion: The results highlight the need to address young driver safety in Oman. From these findings, the introduction of a graduated driver licensing system with nighttime driving restrictions could significantly improve young driver safety. 相似文献
Sex allocation theory predicts that if variance in reproductive success differs between the sexes, females who are able to
produce high-quality young should bias offspring sex ratio towards the sex with the higher potential reproductive success.
We tested the hypothesis that high-quality (i.e., heavy) female eastern kingbirds (Tyrannus tyrannus) that bred early in the breeding season would produce male-biased clutches. A significant opportunity for sexual selection
also exists in this socially monogamous but cryptically polygamous species, and we predicted that successful extra-pair (EP)
sires would be associated with an excess of male offspring. Although population brood sex ratio did not differ from parity,
it increased significantly with female body mass and declined with female breeding date, but was independent of the morphology
and display (song) behavior (correlates of reproductive success) of social males and EP sires. Male offspring were significantly
heavier than female offspring at fledging. Moreover, the probability that male offspring were resighted in subsequent years
declined with breeding date, and was greater in replacement clutches, but lower when clutch size was large. Probability of
resighting female offspring varied annually, but was independent of all other variables. Given that variance in reproductive
success of male kingbirds is much greater than that of females, and that male offspring are more expensive to produce and
have a higher probability of recruitment if fledged early in the season, our results support predictions of sex allocation
theory: high-quality (heavy) females breeding when conditions were optimal for male recruitment produced an excess of sons. 相似文献
Extra-pair fertilizations are common in many socially monogamous species, and paternity studies have indicated that females
may use male vocal performance and plumage ornaments as cues to assess male quality. Female off-territory forays may represent
a key component of female choice and male extra-pair mating success, and female foray behaviour is expected to be strongly
influenced by indictors of male quality. In this study, we examined how male song and ornamentation affect how often females
left their territories, which males they visited and extra-pair paternity in a socially monogamous passerine, the hooded warbler
(Wilsonia citrina). We radiotracked 17 females during the fertile period and quantified male vocal performance (song output and rate) and plumage
characteristics (size of the black melanin hood and colour of the black hood, yellow cheeks and breast areas). We obtained
blood samples and determined paternity at 35 nests including those of 14 females that we radiotracked. Eleven (65%) of the
17 females forayed off-territory, whilst fertile and female foray rate was positively correlated with the number of extra-pair
young in the nest. Females that left their territories more frequently were paired with males that sang at a low rate. In
addition, extra-pair mates had higher song rates than the social mates they cuckolded (5.3 songs/min vs. 4.4 songs/min). Female
off-territory forays or extra-pair paternity were not significantly related to male plumage characteristics. Our results indicate
that a high song rate influences both the foray behaviour of a male’s social mate and the likelihood that he will sire extra-pair
offspring with neighbouring females. 相似文献
Sperm competition (the competition among the sperm of different males for fertilization of the eggs of a female) has been
suggested to be an important component of sexual selection, but no general assessment has been made of this proposition. We
used a meta-analytic approach to assess the extensive literature on paternity (the proportion of offspring in a focal nest
sired by an attending male) in birds based on allozyme and molecular techniques. The relative variance in male mating success
was on average increased by a factor of 4.6 over the variance in apparent male success. Males with more extravagant secondary
sexual characters had higher paternity in their own nests than less adorned males. There was a weak effect of male age being
positively associated with paternity in own nests. Male body size measured as the length of wing and tarsus was weakly positively
associated with paternity in own nests. Male survival prospect was positively associated with paternity in own nests. Polygynous
males generally had decreased paternity of their broods compared to monogamous males. Paternity of the resident male decreased
with increasing population density and breeding asynchrony. The intensity of paternity guards such as within-pair copulation
rate and mate guarding were not significantly related to extra-pair paternity. Sperm competition was thus an important component
of sexual selection by increasing the variance in male mating success, and by being associated with the expression of secondary
sexual characters, in particular in dense and asynchronously breeding populations of birds.
Received: 12 February 1998 / Accepted after revision: 31 May 1998 相似文献
Empirical and theoretical studies have only recently begun to examine how females use complex multi-component displays when
selecting mates. Superb fairy-wrens are well suited to the study of female choice because females have control over extra-group
paternity and cuckold their mates at high rates, while males possess a variety of sexually selected traits. Available evidence
suggests that females base their extra-group mate choice on the timing of male moult into breeding plumage or the onset of
display. However, males continue to perform elaborate displays throughout the season, and direct most displays to females
during their fertile period. We therefore conducted focal observations on fertile females to quantify the frequency of male
display and used microsatellite genotyping to compare the role of display rate during the breeding season and the timing of
male moult on female mate choice. We show that the addition of data on male display rate does not improve our ability to predict
which males obtain extra-group paternity. The timing of male moult into breeding plumage remains the only predictor of male
extra-group reproductive success. Nevertheless, we found that males displayed more to females that were unable to select extra-group
mates on the basis of the timing of moult or the onset of display. This raises the possibility that there are circumstances
when females use display rate to discriminate between potential extra-group sires. Overall this study supports the theoretical
prediction that females are more likely to base their mate choice on reliable indicators of male quality such as fixed morphological
traits and displays of endurance, in this case an early moult into breeding plumage and the performance of an elaborate display
during the winter, than a flexible behavioural trait such as display rate during the breeding season.
Received: 26 January 2000 / Revised: 1 August 2000 / Accepted: 26 August 2000 相似文献
We examined correlates of extra-pair fertilization (EPF) success in the hooded warbler (Wilsonia citrina), a species where females pursue extra-pair matings. The good genes hypothesis predicts that females choose extra-pair mates
with morphological or behavioral traits that reflect differences in male genetic quality. EPFs were common, as 35.3% (42/119)
of broods contained extra-pair young (EPY) and 26.7% (95/356) of nestlings were the result of EPFs. There was a strong skew
in male EPF success which increased the variance in annual male mating success 2–3 fold. However, male morphology did not
predict EPF success, as extra-pair males were not older or larger than the males they cuckolded. Likewise, there were no significant
correlations between the proportion of extra-pair young in a brood and male size or age. The good genes hypothesis predicts
that high-quality males will be consistently preferred as genetic mates, but the number of young sired by a male with his
social mate was not consistent from one year to the next. There was a significant negative correlation between female age
and proportion of EPY produced, which could result if older females obtain higher-quality social mates. We found no strong
evidence that females choose extra-pair mates for good genes, but females may use behavioral rather than morphological cues
to assess relative male quality.
Received: 31 May 1996 / Accepted after revision: 17 October 1996 相似文献
The response of males to reduced paternity has important consequences for the evolution and maintenance of a mixed reproductive strategy. Paternity is predicted to affect directly the level of male parental care in some cases but not in others. The response of males to reduced paternity will be influenced by their ability to assess their paternity, the predictability of cuckoldry and the costs and benefits of parental care. Although male house martins (Delichon urbica) provide among the highest levels of male parental care known in passerines (incubation, brooding and feeding nestlings), there was no evidence that cuckolded males substantially reduced their level of parental care, and, as a result, all young fledged successfully. Thus, extra-pair fertilizations enhanced the reproductive success of some males because they were able to parasitize the parental care of cuckolded males. We discuss several conditions which may favor extensive male parental care even when the male's paternity is very low. 相似文献