Banca de DEFESA: Mariana de Carvalho

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : Mariana de Carvalho
DATE: 31/08/2022
TIME: 09:00
LOCAL: a definir
TITLE:

Breeding strategies, signaling of individual quality and seasonal movements of Sicalis citrina pelzeln, 1870.

KEY WORDS:

Animal behavior, Body condition, Carotenoids, Coloring, Immune health, Lutein, Natural history, Ornaments, Reproduction, Sexual dimorphism, Thaupidae.

PAGES: 120
BIG AREA: Ciências Biológicas
AREA: Ecologia
SUMMARY:

Birds have a high diversity of plumage coloration, and most species exhibit sexual dichromatism. An individual´s color can convey information about their quality or health. Among the types of colors present in birds, those based on carotenoid pigments have usually been shown to be indicative of individual quality. However, these signals do not always truly reflect quality. The stripe-tailed yellow finch Sicalis citrina Pelzeln 1870 is a sexually dichromatic passerine that presents coloration derived from carotenoid pigments, thus an interesting model for investigation of (i) variation in the color of individuals within the visual system of birds; and (ii) expression of the quality of individuals through their coloring. In addition, despite being an abundant species, little is known about its reproductive behavior and seasonal movement, although anecdotally, it is considered a migratory bird. This thesis is divided into three chapters that seek to advance the objectives mentioned above, as well as to contribute to the natural history information about this bird. Chapter I describes the coloration of females and males, identifies the occurrence of delayed plumage maturation in males, and describes previously undocumented facets of the reproductive behavior of the stripe-tailed yellow finch. Females and males have high reflectance in the ultraviolet spectrum on the head and ventral region, the main parts of the body used for social signaling. The delay in plumage maturation in males is part of the reproductive strategy of the stripe-tailed yellow finch, but there are significant differences, indistinguishable to human eyes, between the coloration of the sexes. Chapter II tests hypotheses associated with the phenotypic expression (color) and individual quality of females and males. The color of females depends on their body condition, i.e. those in better condition have a brown hue. The quality of males is not associated with a colorful plumage. Males access different food items that improve their color (C3 and C4 grains) or their immune system (protein), which suggests that they may choose to invest in ornamentation or health. Finally, chapter III identifies the type of seasonal movement of the stripe-tailed yellow finch. Differently from what is presented in the literature, it is a nomadic species. In an integrated way, the results of this thesis contribute to information about the coloration of a Neotropical Thraupid, tests hypotheses about the allocation of resources for the production of color and about signals that may express individual quality, and in addition, contribute to natural history information about this species.

BANKING MEMBERS:
Externo à Instituição - ANDRÉ DE CAMARGO GUARALDO
Externo à Instituição - FABIO JOSE VIANA COSTA
Interno - 1460864 - FELIPE MALHEIROS GAWRYSZEWSKI
Presidente - 1122677 - REGINA HELENA FERRAZ MACEDO
Interna - 1194783 - ROSANA TIDON