Banca de DEFESA: Emanuel Messias Lima da Silva

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : Emanuel Messias Lima da Silva
DATE: 11/03/2024
TIME: 09:00
LOCAL: Auditório 03 do Instituto de Biologia - IB
TITLE:

"Habitat use and diet of Saffron finch (Sicalis flaveola Linnaeus, 1766) and its relationship with ornamental plumage coloration".

KEY WORDS:

Carotenoids, Foraging ability, Plumage ornametantion, Saffron Finch, Sicalis flaveola, Stable isotope, Temporal Variation of Resources.

PAGES: 85
BIG AREA: Ciências Biológicas
AREA: Ecologia
SUMMARY:

A ornamental coloring of plumage based carotenoids receives notable attention because carotenoid pigments are acquired through diet. This has raised the idea that carotenoid-based ornamentation acts as a reliable signal of foraging ability, nutritional status, and health, as carotenoids can also be used in maintaining physiological processes. It is important to consider that age and sex classes, which often exhibit gradual differences in plumage coloration, may reflect differences in foraging. Here, we use the stable isotope ratios of carbon (δ13C) and nitrogen (δ15N) to investigate how the diet varies among individuals of the Saffron Finch (Sicalis flaveola Linnaeus, 1766) of different age and sex classes based on foraging ability throughout the year, and how the diet of yellow males correlates with plumage expression. A total of 195 individuals were sampled in seven field campaigns between January 2017 and March 2018. We classified individuals based on plumage color: yellow females (i.e., adult females with yellow plumage), yellow males (i.e., adult males with yellow plumage), and brown individuals (i.e., juveniles and sub-adults of both sexes with brown plumage). Blood and different feathers were collected for δ13C and δ15N analysis. Colorimetric variables of male ornamental feathers, specifically forehead and chest, were measured to relate to the diet. In our results, brown individuals had low δ 15N values in October 2017 compared to other months and in relation to yellow males, who accessed high trophic level resources. The mean difference in isotopic values between feathers and blood was low, reflecting similar values among color classes for each feather and among color classes for each feather. We observed that yellow males had a higher dietary diversity and greater niche overlap compared to yellow females and brown individuals, suggesting greater intraindividual variation in diet. The carotenoids deposited in the ornamentation of the forehead and chest of yellow males come from contrasting acquisition pathways. The r hue of the forehead feathers was inversely correlated with δ15N, indicating that carotenoids come from high trophic level sources. The yellower hue of chest feathers was inversely correlated with δ13C and positively correlated with δ15N, suggesting that carotenoids come from basal, low trophic level sources.

COMMITTEE MEMBERS:
Externo à Instituição - LUCIANO NICOLÁS NAKA - UFPE
Presidente - 1803800 - GABRIELA BIELEFELD NARDOTTO
Interno - ***.440.331-** - PEDRO DINIZ ALVES - UnB