Garbage Dump Use, Mortality, and Microplastic Exposure of Raptors in Ushuaia, Tierra Del Fuego Province, Southern Argentina

Abstract

Organic waste in garbage dumps serves as an easily obtained food subsidy for many species globally, with a variety of both positive and negative effects on animals' reproductive and health parameters. However, in some regions, such as southern Patagonia, this phenomenon remains unstudied. In Ushuaia, Tierra del Fuego province, Argentina, seven species of facultative and obligate scavenging raptors have been recorded using the garbage dump. During November 2018 to September 2019, we assessed seasonal garbage dump use by facultative and obligate scavenging raptors in Ushuaia, Argentina, and recorded abundance, mortality events, and microplastic ingestion. We observed up to 225 raptors of five species foraging in the deposit zone of the garbage dump, with a fourfold overall increase in early winter compared to the other seasons. We recorded 17 dead raptors of three species, and we identified shooting, entanglement, plastic ingestion, and electrocution as the causes of mortality. Even in samples collected from control birds not associated with the garbage dump, 80–90% of the excreta samples contained microplastics. We suggest that raptors at the Ushuaia garbage dump may serve as sentinel species for environmental monitoring programs, which can facilitate evidence-based conservation management.