Biology subjects

Peres, C. A.

Publications and source records attributed to Peres, C. A..

4 recordsLinked to original sources

bioRxiv2023

Extending species-area relationships into the realm of ecoacoustics: The soundscape-area relationship

The rise in species richness with area is one of the best-studied patterns in ecology. Yet, little is known about the spatial scaling of alternate dimensions of diversity. Here, we provide empirical evidence for a relationship between the richness of acoustic traits emanating from the landscape, or soundscape richness, and the island area, which we term the Soundscape Area Relationship (SSAR). We show a positive relationship between the gamma soundscape richness and island area, with slope and R2-values of comparable magnitude to those reported in the literature. This relationship breaks down at the smallest spatial scales, indicating a small-island effect. Moreover, we demonstrate a positive spatial scaling of the plot-scale alpha soundscape richness, but not the beta soundscape turnover, suggesting disproportionate effects are an important underlying mechanism. We conclude that the scaling of biodiversity can be extended to the realm of ecoacoustics, implying soundscape metrics are sensitive to fundamental ecological patterns and useful to disentangle the complex mechanisms that drive them.

ecology↗

bioRxiv2022

A framework for the quantification of soundscape diversity using Hill numbers

O_LISoundscape studies are increasingly common to capture landscape-scale ecological patterns. Yet, several aspects of soundscape diversity quantification remain unexplored. Although some processes influencing acoustic niche usage may operate in the 24h domain, most acoustic indices only capture the diversity of sounds co-occurring in sound files at a specific time of day. Moreover, many indices do not consider the relationship between the spectral and temporal traits of sounds simultaneously. To provide novel insights into landscape-scale patterns of acoustic niche usage at broader temporal scales, we present a workflow to quantify soundscape diversity through the lens of functional ecology. C_LIO_LIOur workflow quantifies the functional diversity of sound in the 24-hour acoustic trait space. We put forward an entity, the Operational Sound Unit (OSU), which groups sounds by their shared functional properties. Using OSUs as our unit of diversity measurement, and building on the framework of Hill numbers, we propose three metrics that capture different aspects of acoustic trait space usage: (i) soundscape richness; (ii) soundscape diversity; (iii) soundscape evenness. We demonstrate the use of these metrics by (a) simulating soundscapes to assess if the indices possess a set of desirable behaviours; and (b) quantifying the soundscape richness and evenness along a gradient in species richness to illustrate how these metrics can be used to shed unique insights into patterns of acoustic niche usage. C_LIO_LIWe demonstrate that: (a) the indices outlined herein have desirable behaviours; and (b) the soundscape richness and evenness are positively correlated with the richness of soniferous species. This suggests that the acoustic niche space is more filled where taxonomic richness is higher. Moreover, species-poor acoustic communities have a higher proportion of rare sounds and use the acoustic space less effectively. As the correlation between the soundscape and taxonomic richness is strong (>0.8) and holds at low sampling intensities, soundscape richness could serve as a proxy for taxonomic richness. C_LIO_LIQuantifying the soundscape diversity through the lens of functional ecology using the analytical framework of Hill numbers generates novel insights into acoustic niche usage at a landscape scale and provides a useful proxy for taxonomic richness measurement. C_LI

ecology↗

bioRxiv2021

Impending anthropogenic threats and protected area prioritization for the largest Neotropical apex predator in its Amazonian stronghold

Jaguars (Panthera onca) exert critical top-down control over large vertebrates across the Neotropics and have been declining due to multiple threats. Based on geospatial layers, we extracted socio-environmental variables for 447 protected areas across the Brazilian Amazon to identify protected areas that merit short-term high-priority efforts to maximize jaguar persistence. Data were analyzed using descriptive statistics, structural equations and regression modeling. Our results reveal that areas containing the largest jaguar densities and estimated population sizes are precisely those confronting most anthropogenic threats. We reveal that jaguars in the worlds largest tropical forest biome are threatened by deforestation associated with anthropogenic fires, and subsequent establishment of pastures. We provide a shortlist of protected areas that should be prioritized for short-term jaguar conservation. The future predicament of jaguar populations can only be ensured if protected areas can be proofed against downgrading and downsizing geopolitical pressures and external anthropogenic threats.

ecology↗

bioRxiv2021

Extensive aquatic subsidies lead to territorial breakdown and high density of an apex predator

Energetic subsidies between terrestrial and aquatic ecosystems can strongly influence food webs and population dynamics. Our objective was to study how aquatic subsidies affected jaguar (Panthera onca) diet, sociality, and population density in a seasonally flooded protected area in the Brazilian Pantanal. The diet (n = 138 scats) was dominated by fish (46%) and aquatic reptiles (55%), representing the first jaguar population known to feed extensively on fish and to minimally consume mammals (11%). These aquatic subsidies supported the highest jaguar population density estimate to date (12.4 per 100 km2) derived from camera traps (8,065 trap nights) and GPS collars (n = 13). Contrary to their mostly solitary behavior elsewhere, we documented social interactions previously unobserved between same-sex adults including cooperative fishing, co-traveling, and play. Our research demonstrates that aquatic subsidies seen in omnivores can be highly influential to obligate carnivores leading to high population density and altered social structure.

ecology↗