Avian extinctions induced by the oldest Amazonian hydropower mega dam: evidence from museum collections and sighting data spanning 172 years

Abstract

Hydroelectric dams represent an emergent threat to lowland tropical forest biodiversity. Despite the large number of operational, under-construction, and planned hydroelectric dams, their long-term effects on biodiversity loss are still poorly documented. Here, we investigate avian extinctions resulting from the Tucuruí Hydroelectric Reservoir (THR), the oldest Amazonian mega dam, which impounded the Tocantins River in 1984. Our avian inventory—based on several sampling methods (mist-netting, point-counts, boat census and qualitative surveys) during 280 days of fieldwork from 2005 to 2007—was combined with an exhaustive search of museum vouchers and digital online databases of citizen science from the lower Tocantins River to identify long-term trends in species persistence and extinction in the THR influence area. The regional avifauna was comprised of 479 species, 404 of which were recorded during our fieldwork. Based on recent and historical records spanning 172 years, we found evidence for likely extinctions at THR influence area for 53 (11.06%) species that have remained entirely unreported since 1984. We were further able to estimate extinction probabilities for 20 species; 15 species were considered to be extinct, including Psophia interjecta and Pyrilia vulturina that are red-listed by IUCN. Our study serves as a baseline for avifaunal monitoring in the THR influence area and shows that degree of habitat specialization is a key factor in determining species extinctions caused by nonrandom habitat loss from either inundation or deforestation. Avian species extinctions will most likely continue across the area affected by the reservoir as a direct impact of alluvial forest loss and ongoing habitat degradation of upland forests.

Foraging guild modulates insectivorous bat responses to habitat loss and insular fragmentation in peninsular Malaysia

“…A number of studies have demonstrated that habitat loss and insular fragmentation cause species local extinctions across lowland tropical forests (Gibson et al, 2013; Moore et al, 2022; Palmeirim et al, 2022; Pinto Henriques et al, 2021). Here, we contribute to fill an important knowledge gap by accordingly demonstrating overall negative bats response to disturbance across an insular fragmented landscape in Southeast Asia.…”

Comparative Phylogeography of Birds Across the Tocantins–Araguaia Interfluve Reveals a New Biogeographic Suture in the Amazon Far East

“…To detect broad patterns of avian taxa replacement across the TAI and neighboring interfluves (BAE and XAE) and select the taxa to be sampled in this study, we mapped localities and assessed subspecific taxonomies of specimens from these areas deposited at the Fernando C. Novaes Ornithological Collection at the Museu Paraense Emílio Goeldi (hereafter MPEG), as well as those obtained from the literature. For the BAE, the following references were considered: Roma (1996), Vasconcelos et al (2007), Novaes and Lima (2009), Portes et al (2011), Oren and Roma (2012), Lees et al (2012), Henriques et al (2021) and the Wikiaves portal. 1 For the XAE, the following references were consulted: Graves and Zusi (1990), Aleixo et al (2000), Oliveira ) was considered.…”