Fauna such as ocelots, tortoises, peccaries, armadillos, and various species of birds died intoxicated by carbon monoxide, said local veterinarian Jerjes Suarez.
The conservation area is located within the indigenous municipality of Charagua.
Authorities reported that almost 600,000 hectares had been burned. Nine municipalities, including Charagua, have declared a state of emergency.
73% of the department is at extreme risk of forest fires due to high temperatures, strong winds, and drought.