ANALYSIS OF MERCURY AND LEAD IN BIRDS OF PREY FROM GOLD-MINING AREAS OF THE PERUVIAN AMAZON

This study was conducted to determine levels of lead and mercury in the raptors of the South-eastern Peruvian Amazon. The study took place within the Los Amigos Conservation Concession in Madre de Dios, Peru. Eighty-six raptors from among sixteen species were captured with Bal-Chatri traps. From each individual, feather samples were obtained for mercury analysis and blood was taken for lead analysis. Each raptor was then released without incident or injury. Mercury amalgamation for gold extraction is widely used by small-scale, transient mining operations, which are numerous along the rivers and creeks in the tropical forests and other locations in Latin America. These mining operations have a high waste output of mercury into the water and the air. Mercury which is not bound to gold is dumped into the waste water which returns to the river; and mercury which is bound to gold is later burned off to purify the gold. Once elemental mercury is released into the environment, it cannot be cleaned up. It persists for decades, even centuries after the mining has ceased. Predatory birds are useful for representing the contamination of the ecosystem at levels higher than mammalian bioindicators. The use of feathers to evaluate exposure of birds to heavy metals like mercury is a common method of analysis. During this investigation, a combination of tail and breast feathers were analyzed from each individual sampled. It was determined that 81 of the raptors sampled had elevated mercury levels, with many at or above the level known to cause reproductive symptoms in other species. No toxic reference values exist for any of the species sampled. Further study is required to determine if these levels represent a significant threat to raptors. Blood samples were analyzed for lead concentrations. Lead levels were consistant with or slightly above background levels, with the exception of one individual. This individual appeared healthy and normal upon capture, although his lead levels were consistant with those known to cause symptoms in other species. Probable causes for this individual\u27s elevated blood lead level include having survived being shot with lead shot, ot having consumed a prey item which had been shot with lead shot. The results of this study will provide insight as to the threat to raptors from mercury and lead from gold mining activity. The results will be reviewed by Peruvian agencies responsible for ecosystem monitoring. This study, among others, may lead to the control of mercury use for gold mining in the Amazon

Multiple lines of evidence suggest the persistence of the Ivory‐billed Woodpecker (Campephilus principalis) in Louisiana

Abstract The history of the decline of the Ivory‐billed Woodpecker is long and complex, but the status of the species since 1944, when the last widely accepted sighting in continental North America occurred, is particularly controversial. Reports of Ivory‐billed Woodpeckers have continued, but none has reached the threshold of quality for general acceptance by ornithologists or the birdwatching public. In 2021, the U.S. Fish and Wildlife Service opened for public comment a proposal to declare the species extinct. Here, we present evidence suggesting the presence of the Ivory‐billed Woodpecker at our study site, based on a variety of data collected over a 10‐year search period, 2012–2022. These data are drawn from visual observations, ~70,000 h of recordings by 80–100 acoustic recording units, ~472,550 camera‐hours by as many as 34 trail cameras, and ~1089 h of video drawn from ~3265 drone flights. Using multiple lines of evidence, the data suggest intermittent but repeated presence of multiple individual birds with field marks and behaviors consistent with those of Ivory‐billed Woodpeckers. Data indicate repeated reuse of foraging sites and core habitat. Our findings, and the inferences drawn from them, suggest that not all is lost for the Ivory‐billed Woodpecker, and that it is clearly premature for the species to be declared extinct

Mercury in Neotropical birds: a synthesis and prospectus on 13 years of exposure data.

Environmental mercury (Hg) contamination of the global tropics outpaces our understanding of its consequences for biodiversity. Knowledge gaps of pollution exposure could obscure conservation threats in the Neotropics: a region that supports over half of the worlds species, but faces ongoing land-use change and Hg emission via artisanal and small-scale gold mining (ASGM). Due to their global distribution and sensitivity to pollution, birds provide a valuable opportunity as bioindicators to assess how accelerating Hg emissions impact an ecosystems ability to support biodiversity, and ultimately, global health. We present the largest database on Neotropical bird Hg concentrations (n = 2316) and establish exposure baselines for 322 bird species spanning nine countries across Central America, South America, and the West Indies. Patterns of avian Hg exposure in the Neotropics broadly align with those in temperate regions: consistent bioaccumulation across functional groups and high spatiotemporal variation. Bird species occupying higher trophic positions and aquatic habitats exhibited elevated Hg concentrations that have been previously associated with reductions in reproductive success. Notably, bird Hg concentrations were over four times higher at sites impacted by ASGM activities and differed by season for certain trophic niches. We developed this synthesis via a collaborative research network, the Tropical Research for Avian Conservation and Ecotoxicology (TRACE) Initiative, which exemplifies inclusive, equitable, and international data-sharing. While our findings signal an urgent need to assess sampling biases, mechanisms, and consequences of Hg exposure to tropical avian communities, the TRACE Initiative provides a meaningful framework to achieve such goals. Ultimately, our collective efforts support and inform local, scientific, and government entities, including Parties of the United Nations Minamata Convention on Mercury, as we continue working together to understand how Hg pollution impacts biodiversity conservation, ecosystem function, and public health in the tropics