Nestling barn owls assess short-term variation in the amount of vocally competing siblings
نویسندگان
چکیده
منابع مشابه
Barn owl (Tyto alba) siblings vocally negotiate resources.
Current theory proposes that nestlings beg to signal hunger level to parents honestly, or that siblings compete by escalating begging to attract the attention of parents. Although begging is assumed to be directed at parents, barn owl (Tyto alba) nestlings vocalize in the presence but also in the absence of the parents. Applying the theory of asymmetrical contests we experimentally tested three...
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از گذشته تا کنون، تحقیقات بسیاری صورت گرفته است که همگی به گونه ای بر مثمر ثمر بودن استفاده از استراتژی های یادگیری لغت در یک زبان بیگانه اذعان داشته اند. این تحقیق به بررسی تاثیر دو روش مختلف آموزش واژگان انگلیسی (کلیدی و بافتی) بر تلفظ و دانش لغوی فراگیران ایرانی زیر متوسط زبان انگلیسی و بر ماندگاری آن در حافظه می پردازد. به این منظور، تعداد شصت نفر از زبان آموزان ایرانی هشت تا چهارده ساله با...
15 صفحه اولShort- and Long-term Fitness Correlates of Rearing Conditions in Barn Owls Tyto Alba
In birds, the quality of rearing conditions is a major determinant of nestling body condition, nestling survival and recruitment probability (Martin 1987). When food becomes short, sibling competition increases (Mock & Parker 1997), growth is depressed (Smith et al. 1989), and chicks are more vulnerable to environmental stress factors (Hoffmann & Merila 1999). Although the effect of rearing con...
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Barn owl (Tyto alba) siblings preen and offer food items to one another, behaviours that can be considered prosocial because they benefit a conspecific by relieving distress or need. In experimental broods, we analysed whether such behaviours were reciprocated, preferentially exchanged between specific phenotypes, performed to avoid harassment and food theft or signals of hierarchy status. Thre...
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Vernier acuity thresholds were obtained psychophysically in three adult barn owls with vertical bars and sinusoidal gratings. A minimal displacement threshold of 0.58 arcmin was observed with the bar stimulus under binocular viewing conditions. The mean binocular bar threshold was 2.51 arcmin. Bar thresholds were lower than grating thresholds. Monocular thresholds, obtained in one bird only, we...
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ژورنال
عنوان ژورنال: Animal Cognition
سال: 2013
ISSN: 1435-9448,1435-9456
DOI: 10.1007/s10071-013-0634-y