940 research outputs found

    Volume of the cloacal protuberance as an indication of reproductive state in male Blue Tits <i>Cyanistes caeruleus</i>

    Get PDF
    In male passerines, the accumulation of sperm in the sperm reserves causes the cloaca to become enlarged, forming the cloacal protuberance (CP). In Blue Tits, the timing of breeding differs considerably between pairs. Hence, when catching a male during the breeding season it may be unclear whether he is in a reproductively active state (i.e. producing sperm). Here, we show in captive Blue Tits Cyanistes caeruleus that CP volume is increased in males in a reproductively active state when compared to the same males in a reproductively inactive state. However, there was some overlap in CP volume when comparing the values in reproductively active and non-active states. Measurements of CP volume at a single time point, therefore, do not allow the researcher to reliably determine an individual's reproductive status.

    Polygyny and extra-pair paternity enhance the opportunity for sexual selection in blue tits

    Get PDF
    Polygyny and extra-pair paternity are generally thought to enhance sexual selection. However, the extent to which these phenomena increase variance in male reproductive success will depend on the covariance between success at these two strategies. We analysed these patterns over four breeding seasons in facultatively polygynous blue tits Cyanistes caeruleus. We found that both polygyny and extra-pair paternity increased variance in male reproductive success and that standardised variance in annual number of genetic fledglings was 2.6 times higher than standardised variance in apparent success when assuming strict monogamy. Nevertheless, male success at securing within-pair paternity was unrelated to success at gaining extra-pair paternity and, when considering the positive effect of age on extra-pair success and attracting a second female, polygynous males were no more likely to sire extra-pair fledglings. Overall, polygynous males fledged more genetic offspring than monogamous males, but first-year polygynous males lost a greater share of within-pair paternity. A literature review suggests that this adverse effect of polygyny on within-pair paternity is frequent among birds, inconsistent with the prediction that females engage in extra-pair copulation with successful males to obtain good genes. Furthermore, a male's share of paternity was repeatable between years, and among females of polygynous males within years, such that a compatibility function of extra-pair copulations was likewise unsupported. Instead, we suggest that the observed patterns are most consistent with a fertility insurance role for extra-pair copulations, which does not exclude the greater opportunity for sexual selection through differential ability of males to gain paternity

    Declining extra-pair paternity with laying order associated with initial incubation behavior, but independent of final clutch size in the blue tit

    Get PDF
    Although functional explanations for female engagement in extra-pair copulation have been studied extensively in birds, little is known about how extra-pair paternity is linked to other fundamental aspects of avian reproduction. However, recent studies indicate that the occurrence of extra-pair offspring may generally decline with laying order, possibly because stimulation by eggs induces incubation, which may suppress female motivation to acquire extra-pair paternity. Here we tested whether experimental inhibition of incubation during the laying phase, induced by the temporary removal of eggs, resulted in increased extra-pair paternity, in concert with a later cessation of laying, in blue tits (Cyanistes caeruleus). As expected, experimental females showed a more gradual increase in nocturnal incubation duration over the laying phase and produced larger clutches than controls. Moreover, incubation duration on the night after the first egg was laid predicted how extra-pair paternity declined with laying order, with less incubation being associated with more extra-pair offspring among the earliest eggs in the clutch. However, incubation duration on this first night was unrelated to our experimental treatment and independent of final clutch size. Consequently, the observed decline in extra-pair paternity with laying order was unaffected by our manipulation and larger clutches included proportionally fewer extra-pair offspring. We suggest that female physiological state prior to laying, associated with incubation at the onset of laying, determines motivation to acquire extra-pair paternity independent of final clutch size. This decline in proportion of extra-pair offspring with clutch size may be a general pattern within bird species.</p

    The effect of behind-the-scenes encounters and interactive presentations on the welfare of captive servals (Leptailurus serval)

    Get PDF
    The serval (Leptailurus serval) is a small African felid that is well represented in zoos and often serves as an animal ambassador in encounter programs with zoo visitors. The impact on serval welfare in relation to such programs has not been investigated to date, and the aim of this study was to assess short-term welfare effects of varying levels of visitor interaction in two captive servals. Weekly blocks of four different treatments were imposed three times on each animal over 12 weeks, and the treatments involved (1) Presentations (serval undertaking a routine training session in a designated presentation space, typically attracting high visitor numbers), (2) Behind-the-scenes (BTS, a close encounter allowing a small group of visitors to interact closely with the cat in its enclosure), (3) Presentations and BTS combined, and (4) No visitor interaction. Serval activity budgets as well as behavioural diversity were created from behaviours observed from Close Circuit Television (CCTV) footage during four daily recording sessions per animal over three consecutive days per treatment, using instantaneous scan sampling every 60 s. Individual faecal samples were collected daily to monitor changes in faecal glucocorticoid metabolite (FGM) concentration. Results indicate that the mean number of scans with stereotypic pacing was significantly reduced (p = 0.01) during Treatments 1 and 3, when cats participated in presentations only, or the two activities combined. Conversely, a significant reduction in behavioural diversity (p 0.05). Given the reduction in stereotypic pacing, these findings suggest that involvement in an encounter program appears to exert an overall positive short-term welfare effect on the individual servals in this study. Although a reduction in behavioural diversity was not considered a negative welfare effect in the short term, potential long-term negative welfare effects resulting from a more frequent encounter program could not be ruled out in the present study

    Different understandings of quality education across the globe: a special issue on the guiding theme of the BAICE 2016 Conference Editorial : Editorial, Compare: A Journal of Comparative and International Education

    Get PDF
    While the concept of ‘quality education’ has been widely debated, there is by no means a universal definition in the literature (e.g. Harvey and Williams 2010; Mishra 2007; Tam 2001). Different approaches and conceptualisations reveal the context-based nature of quality as a value judgement. In the education field in particular, its vagueness is further compounded by the difficulty in measuring education performance: learning outcomes are reflected in transformations of individuals in terms of their knowledge, characteristics and behaviour (Tsinidou, Gerogiannis, and Fitsilis 2010), and these outcomes are defined and understood in ways that are highly contextualised (Tikly 2011; Walker 2006). The critical role of context in the construction of quality education is a central theme in this special issue

    Using an Electronic Monitoring System to Link Offspring Provisioning and Foraging Behavior of a Wild Passerine

    Full text link
    Although the costs of parental care are at the foundations of optimal-parental-investment theory, our understanding of the nature of the underlying costs is limited by the difficulty of measuring variation in foraging effort. We simultaneously measured parental provisioning and foraging behavior in a free-living population of Zebra Finches (Taeniopygia guttata) using an electronic monitoring system. We fitted 145 adults with a passive transponder tag and remotely recorded their visits to nest boxes and feeders continuously over a 2-month period. After validating the accuracy of this monitoring system, we studied how provisioning and foraging activities varied through time (day and breeding cycle) and influenced the benefits (food received by the offspring) and costs (interclutch interval) of parental care. The provisioning rates of wild Zebra Finches were surprisingly low, with an average of only one visit per hour throughout the day. This was significantly lower than those reported for this model species in captivity and for most other passerines in the wild. Nest visitation rate only partially explained the amount of food received by the young, with parental foraging activity, including the minimum distance covered on foraging trips, being better predictors. Parents that sustained higher foraging activity and covered more distance during the first breeding attempt took longer to renest. These results demonstrate that in some species matching foraging activity with offspring provisioning may provide a better estimate of the true investment that individuals commit to a reproductive attempt

    Gay male athletes’ coming-out stories on Outsports.com

    Get PDF
    For two decades, Outsports.com – the world’s first website dedicated to the LGBT+ community’s experiences in sport – has provided sexual minority athletes with the opportunity to share their stories. In this research, we examine the published coming-out narratives of 60 out gay male athletes across a variety of different sports. Our analysis indicates that, prior to coming-out, many of these athletes felt the need to adopt an identity predicated on masculine stereotypes, thus distancing themselves from homosexuality. Upon coming-out to teammates, however, most of these athletes experienced acceptance and inclusivity which, in turn, led to improved health and wellbeing. Additionally, we document the changing nature of homosexually themed language on these men’s sports teams. Finally, we recognize the importance of mediums such as Outsports in providing athletes across the world the opportunity to share their coming-out stories. Accordingly, this research advances a body of evidence documenting sport’s growing inclusivity for the LGBT+ community
    corecore