Banca de QUALIFICAÇÃO: RAIANE VITAL DA PAZ

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : RAIANE VITAL DA PAZ
DATE: 30/04/2026
TIME: 09:00
LOCAL: Híbrida - https://meet.google.com/eic-sesj-vfz
TITLE:

Soundscape: bioacoustic approaches in bird communities along an urban–forest gradient

KEY WORDS:

Acoustic adaptation; Acoustic indices; Acoustic niche; Noise pollution; Urbanization

PAGES: 94
BIG AREA: Ciências Biológicas
AREA: Ecologia
SUBÁREA: Ecologia Aplicada
SUMMARY:

Acoustic communication is vital for many organisms, playing a fundamental role in information exchange. However, increasing noise pollution has impaired this communication, reducing the range and effectiveness of acoustic signal transmission. Therefore, it is essential to investigate the impact of urbanization on the acoustic ecology of birds in the Atlantic Forest along urban–forest gradients. This study is divided into three chapters: (i) to evaluate the relationship between six acoustic indices and the level of urbanization along an urban–forest gradient in northeastern Brazil; (ii) to investigate how nocturnal birds use and structure the acoustic space in order to understand the mechanisms that organize their interactions and enable their coexistence, based on the acoustic niche hypothesis (ANH); and (iii) to assess whether vegetation structure influences the vocalization patterns of nocturnal birds, based on the acoustic adaptation hypothesis (AAH). Data were collected in three types of environments: forest, intermediate areas, and urban squares. Eight sampling points, at least 500 m apart, were randomly established within forest and intermediate fragments. Species were recorded using autonomous recorders, positioned at 1.50 m above ground and active for three consecutive days. To understand how the landscape affects the acoustic parameters of birds, microhabitat variables were measured within a 5 m radius around each recording point, including canopy openness, understory density, tree density, tree height, and trunk circumference. At broader spatial scales (10, 100, and 1000 ha), data on bare ground cover, forest cover, and urban cover were collected. Vocalizations were annotated using spectrograms in Raven Pro 2.0 software. From these recordings, temporal and spectral parameters were extracted (call duration, minimum and maximum frequencies, peak frequency, number of notes, and bandwidth), and vocal activity was quantified over time. In the first chapter, acoustic indices did not show a consistent relationship with the level of urbanization. The acoustic richness index (AR) distinguished forest and intermediate fragments but failed to consistently separate urban squares. Vegetation structure influenced index responses, with mean trunk circumference positively associated with ADI and negatively associated with ACI, while BIO and NDSI showed higher values in more urbanized areas, although NDSI did not differ significantly across the gradient. These results indicate that acoustic indices respond to urbanization in complex ways, likely reflecting the combined influence of biophonic and anthropogenic sounds.The second chapter analyzes acoustic niche overlap among nocturnal species by comparing temporal and spectral vocalization parameters across forest fragments. The results showed that the organization of acoustic space in nocturnal bird communities is mediated by different combinations of temporal and spectral segregation, varying among species pairs but maintaining consistent patterns at the community level. While some species exhibited high multidimensional overlap, others showed separation in frequency or time, revealing multiple strategies of acoustic niche partitioning. In the third chapter, we investigate whether landscape structure influences the vocalization patterns of nocturnal birds, considering how environmental characteristics may shape sound propagation and signal structure, based on the acoustic adaptation hypothesis. We expect species to exhibit different spectral parameters across fragments, given that each environment has distinct structural characteristics. Additionally, we expect species to produce lower-frequency vocalizations in more structurally closed environments, which may favor sound transmission. Overall, this study expands our understanding of how landscape structure influences soundscapes and avian communication, while also providing insights into the mechanisms that enable vocal coexistence in species-rich communities. Finally, it highlights the importance of integrated, multi-scale approaches for the management of threatened ecosystems.

COMMITTEE MEMBERS:
Externo à Instituição - GABRIEL LIMA MEDINA ROSA
Interno - 1718346 - EDUARDO MARTINS VENTICINQUE
Presidente - 1439088 - MAURO PICHORIM