Banca de QUALIFICAÇÃO: MARCELO CAMARA RODRIGUES

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : MARCELO CAMARA RODRIGUES
DATE: 27/08/2021
TIME: 08:00
LOCAL: Google Meets
TITLE:

Reproductive biology, habitat use and social structure in Cyanocorax cyanopogon

KEY WORDS:

Seasonality; Occupancy models; Animal social networks; Corvidae; Caatinga

PAGES: 30
BIG AREA: Ciências Biológicas
AREA: Ecologia
SUMMARY:

Although costly, group living is widely distributed in nature. Among birds, crows and jays (Corvidae) stand out for their cognitive ability and for forming social groups that provide better performance in caring for offspring. Cyanocorax cyanopogon (white-naped jay) are endemic to Brazil and occur mainly in Caatinga and Cerrado, two biomes with strong seasonal component, switching between periods of low and high productivity. To understand the strategies used by these birds to live in these biomes: 1) we will verify if they adjust their reproduction to the availability of resources in the environment; 2) we will analyze if the environmental characteristics and the availability of resources interfere with their occurrence in an area of Caatinga; and 3) we will describe the social structure of the groups of individuals that use the area of FLONA-Açu. With our nest records we verified that the development of the nestlings lasts about 4 months, from the construction of the nest until the nestlings have acquired adult plumage. Putting our breeding records together with those available on Wikiaves and comparing with the rainfall data from WorldClim, we found that most records anticipate the month with the highest rainfall. We also found that this trend is stronger in the Cerrado than in the Caatinga. We compared 128 models generated from our global model with 7 environmental variables. Of the total, 5 models were the most representative. The most relevant parameters for occupancy were: season, distance from headquarters and NDVI. In this model the occupancy estimate for the rainy period was almost half of what was observed in the dry period. Occupancy also varied positively as a function of NDVI and negatively as a function of distance from headquarters, both with greater effect in the rainy season. We captured and ringed 89 individuals at the headquarters of the Açu National Forest. However, between January and the end of July 2021, we found again only 42 of them. In them were nestlings and some adults. The consistent resighting of a few individuals together is a strong indication that they maintain a family group formation within the study area. More consistent and systematic monitoring of the groups, along with genetic analyses of relatedness will help test this hypothesis. Considering the occurrence of reproductive records throughout the year and the higher estimate of occupancy in the dry season, we hypothesize that C. cyanopogon utilize resources available in suburban and cultivated areas to ensure their reproductive success in less productive periods. Added to this, nest helpers may contribute substantially to the costly task of caring for offspring in the harsh conditions of the Caatinga.     

BANKING MEMBERS:
Externa à Instituição - ANGELICA MARIA KAZUE UEJIMA - UFPE
Externo ao Programa - 1476621 - DANIEL MARQUES DE ALMEIDA PESSOA
Presidente - 1439088 - MAURO PICHORIM