
Monitoring of Otter Populations in 2024
Throughout 2024, our team conducted population monitoring of giant otters in two distinct areas of the Pantanal, one in the Brazilian Cerrado (in partnership with Naturatins), and another in the Amazon (in partnership with Instituto Mamirauá). This effort aimed to understand population dynamics and the impacts of environmental and human factors on the species. The monitored areas included Porto Jofre in the northern Pantanal, Rio Negro in the southern Pantanal, Cantão State Park in Tocantins, and the Amanã Reserve in the Amazon.
Across the study areas, we identified approximately 126 giant otters in 2024. In the Pantanal, we monitored around 190 km of rivers, recording a total of 82 individuals, including 23 pups and 59 adults (9 of which were solitary), organized into 13 social groups. Since 2019, when the Giant Otter Project began these population monitoring efforts, a total of 461 individuals have been cataloged in our image database. These data are essential for understanding population composition, species behavior, and the impacts of environmental and human factors across different habitats.
In the Porto Jofre region, we observed a high number of predation events of giant otters by jaguars, including the loss of one dominant adult female,, and 6 out of the 14 pups identified in the area. These events have drawn our attention and highlight the need to understand the factors that may be causing these changes in the area.
Long-term monitoring is crucial for understanding how giant otters respond to a variety of environmental factors, such as wildfires, which affected many regions of the Pantanal this year, prolonged drought periods, boat traffic, and other human activities. These variables can directly impact the survival, reproduction, and individual migration patterns.
With the results of the monitoring conducted, we were able to record important data on birth and mortality rates in giant otter populations, as well as observations on individual migrations within the monitored areas. The information gathered is also contributing to the development of several scientific research projects aimed at deepening our knowledge of the species and its behavior, as well as its relationship with the local ecosystem.
Additionally, we collected biological samples and behavioral data, which are essential for monitoring the health of the populations and understanding the species’ conservation needs. The results of these studies are fundamental for planning long-term conservation strategies and implementing more efficient actions to ensure that this species continues to play its vital role in the ecosystems where it occurs.