DOI: 10.5061/dryad.768vg
title: Data from: Decoding colouration of begging traits by the experimental addition of the appetite enhancer cyproheptadine hydrochloride in magpie (Pica pica) nestlings

description: The colouration of some traits in nestlings of altricial birds may
 influence parental food allocation as it may reflect physical condition or
 hunger. There is increasing evidence of the relationship between
 colouration of begging traits and nestling performance. However, evidence
 of the influence of hunger level on nestling colouration is scarce, mainly
 because of difficulty of distinguishing between the effects of physical
 condition and hunger levels. Here, we used the appetite stimulant
 cyproheptadine hydrochloride to increase the sensation of hunger of magpie
 (Pica pica) nestlings for eight days and assessed the effect on the
 colouration of rictal flanges, mouth and body skin. We found that
 nestlings administered with cyproheptadine had flanges more conspicuous
 (chromatic visual contrast), more UV coloured and less yellow coloured
 than their control nestmates. Conversely, mouths of experimental nestlings
 were more yellow coloured and less UV coloured than controls. Our
 pharmacological experiment affected the strength of the relationship
 between body mass and some colour components of body skin (chromatic and
 achromatic visual contrasts, UV–chroma and Yellow–chroma) and of rictal
 flanges (chromatic visual contrasts, UV–chroma and yellow–chroma), but not
 for mouth colouration. These results taken together suggest that the
 effect of the cyproheptadine on nestling colourations is probably mediated
 by an increase in hunger levels of nestlings for rictal flanges and body
 skin colourations, and by an increase in physical condition in the case of
 mouth coloration.
description: Reflectance of mouth,
 rictal flange and body skin at the beginning of the treatment with
 cyproheptadineSpectral reflectance
 (300nm to 700nm) of three begging-related traits of magpie nestlings:
 mouth (gape or palate), rictal flange and body skin at the beginning of
 the treatment with cyproheptadine (nestlings 2–4 days old). Values are
 means obtained from three replicates and corrected by a triangular
 smoothing (i.e. a floating mean with weights within a distance of
 10nm).Before_experimemt_reflectance_300_700nm.txtReflectance of mouth, rictal flange and body skin at the end of the treatment with cyproheptadineSpectral reflectance (300nm to 700nm) of three begging-related traits of magpie nestlings: mouth (gape or palate), rictal flange and body skin at the end of the treatment with cyproheptadine (nestlings 10–12 days old). Values are means obtained from three replicates and corrected by a triangular smoothing (i.e. a floating mean with weights within a distance of 10nm).After_experimemt_reflectance_300_700nm.txtIrradiance inside 10 active magpie nestsIrradiance measurements were performed in 10 active magpie nests between March and April of 2009, and between 09:00am and 11:00am in a magpie population in Guadix (Spain). It was done by placing the probe above the nest cup and pointing vertically toward the dome. Values are means per each nest from three replicates.Irradiance_inside_nests_300_700nm_moles_means.txtNestling weights and colour measurements for the three begging-related traits before and after the treatment with cyproheptadinedata_set_Martin-Galvez_and_Soler_2016.xlsx