Banca de DEFESA: LUCIENE MARQUI CORRÊA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : LUCIENE MARQUI CORRÊA
DATE: 24/04/2024
TIME: 10:00
LOCAL: on-line
TITLE:

Fidelity, behavior, group size and population composition of guiana dolphin, Sotalia guianensis (Cetacea:Delphinidae) in Sepetiba Bay - RJ, what has changed in a decade?

KEY WORDS:

Cetacean, group structure, conservation

PAGES: 54
BIG AREA: Ciências Biológicas
AREA: Zoologia
SUBÁREA: Zoologia Aplicada
SUMMARY:

The considerable increase in anthropogenic activities in Sepetiba Bay has been promoting
the exposure of numerous long-term threats to the guiana dolphin population, leading to
significant ecological changes, categorizing it as a future concern in the conservation of
the resident population. The present study aimed to investigate possible behavioral
changes, including fidelity and the structure of groups of guiana dolphin in Sepetiba Bay
– RJ in the last decade. Data were collected in two different sampling periods in Sepetiba
Bay-RJ: 1. Past, including the periods (2006-2007), and 2. Present, including the periods
(2017-2019). The photo-identification technique was used in the study to analyze the
pattern of fidelity of individuals between periods, also observing the number of groups of
guiana dolphins in each behavioral state, investigating possible seasonal variations.
Furthermore, the composition of the group and the correlation between immature
individuals and adults were evaluated, considering the presence/absence of puppies. The
Mann-Whitney U and Chi-square tests were applied to assess whether the size and
behavior of the groups differed between periods. To investigate seasonal variations in
group size between Past and Present, the Kruskal-Wallis non-parametric test was
performed during all seasons. The results showed that in relation to fidelity, only 2.02%
of individuals from the past period were recaptured in the present period, indicating that
these individuals had been using the region for more than a decade. Additionally, a 71.3%
reduction in average group sizes was observed, varying between seasons, and an almost
80% reduction in the number of feeding groups. Then, a greater number of puppies were
recorded per group observed in the past period, with a frequency four times higher
compared to the present period. Therefore, the discrepancy in relation to group size, as
well as fidelity and the decline in the number of offspring per group, may be a reflection
of both the reduced population size due to the morbillivirus and the highly degraded
nature of the habitat, considering the period spent with lower human activity compared
to the present period.

COMMITTEE MEMBERS:
Externo à Instituição - GABRIEL ALVES MELO SANTOS - UERJ
Externo à Instituição - ISRAEL DE SÁ MACIEL - UERJ
Interno - 2143107 - LEONARDO MITRANO NEVES
Interno - 1341945 - RAFAEL DE ALMEIDA TUBINO
Externo à Instituição - RODRIGO HIPÓLITO TARDIN OLIVEIRA - UFRJ