Wildfires blazed in the Pantanal Wetland from January to November 2020, wreaking havoc on the world’s largest tropical wetland. Walfrido Moraes Tomas, Ronaldo Morato, and fellow researchers estimated the wildfire animal fatalities by counting carcasses in burned areas. In the early aftermath of the fire, the experts sampled corpses at intervals along tracts of the marsh (a total of 114.43 kilometers).
The researchers discovered 302 carcasses and were able to identify the species in the majority of cases, despite their poor state. The experts estimated the total number of animal deaths by multiplying their figures for small vertebrates (those weighing less than 2kg) and medium-to-large vertebrates (those weighing more than 2kg).
From January to November 2020, the authors estimate that between 13,206,700 and 18,811,300 small vertebrates were killed across the 39,030 km2 charred area of the Pantanal wetlands. Small lizards, birds, and rodents were among the small vertebrates that suffered fatalities.
The scientists also calculated that between 691,090 and 1,196,570 medium-to-large creatures, including ungulates and primates, perished instantly during the Brazilian wildfires. Overall, the study estimates that a total of 16,952,000 vertebrates were lost in the fires.
According to the study authors, some species known to have been killed by the fires, including jaguars, pumas, and tapirs, were likely overlooked in their survey. They also point out that their estimate does not take into account the whole impact of the flames, which would have resulted in animal mortality as a result of habitat destruction.
The researchers concluded that their study demonstrates the devastating impact of wildfires in the Pantanal wetlands in 2020, as well as the need of preventing similar calamities.
“Our estimates indicate that at least 16.952 million vertebrates were killed immediately by the fires in the Pantanal, demonstrating the impact of such an event in wet savanna ecosystems,” wrote the study authors.
“The Pantanal case also reminds us that the cumulative impact of widespread burning would be catastrophic, as fire recurrence may lead to the impoverishment of ecosystems and the disruption of their functioning.”
“To overcome this unsustainable scenario, it is necessary to establish proper biomass fuel management to avoid cumulative impacts caused by fire over biodiversity and ecosystem services.”
The study is published in the journal Scientific Reports.