Patterns of Growth in Nestling Indian Barn-Owls
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چکیده
منابع مشابه
Reciprocal preening and food sharing in colour-polymorphic nestling barn owls.
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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Studying the geographic variation of phenotypic traits can provide key information about the potential adaptive function of alternative phenotypes. Gloger’s rule posits that animals should be darkvs. light-colored in warm and humid vs. cold and dry habitats, respectively. The rule is based on the assumption that melanin pigments and/or dark coloration confer selective advantages in warm and hum...
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BACKGROUND Barn owls integrate spatial information across frequency channels to localize sounds in space. METHODOLOGY/PRINCIPAL FINDINGS We presented barn owls with synchronous sounds that contained different bands of frequencies (3-5 kHz and 7-9 kHz) from different locations in space. When the owls were confronted with the conflicting localization cues from two synchronous sounds of equal le...
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ژورنال
عنوان ژورنال: The Condor
سال: 2002
ISSN: 0010-5422,1938-5129
DOI: 10.1093/condor/104.4.885