A feather hydrogen (δ2H) isoscape for Brazil

Area of Science:

• Stable isotope ecology
• Biogeochemistry
• Avian ecology

Background:

• Isoscapes, or spatial isotope patterns, are crucial for tracing animal origins in ecological and forensic studies.
• Hydrogen stable isotopes (δ2H) in animal tissues reflect geographic origins.
• Developing regional isoscapes is essential for accurate ecological investigations.

Purpose of the Study:

• To develop the first feather hydrogen isotope (δ2Hf) isoscape for Brazil.
• To model the spatial distribution of δ2Hf values across Brazil.
• To provide a tool for ecological and biogeochemical research in the region.

Main Methods:

• Utilized 192 feather samples from the Thraupidae family across Brazil.
• Employed a Random Forest (RF) model to predict δ2Hf values.
• Incorporated environmental variables such as precipitation and solar radiation as predictors.

Main Results:

• δ2Hf values varied significantly across Brazilian biomes, with higher values in Caatinga and lower values in Amazon and Pantanal.
• The RF model identified key environmental drivers influencing feather δ2H, including precipitation and solar radiation.
• Modeled δ2Hf values ranged from -85.7 to -13.6‰.

Conclusions:

• The developed δ2Hf isoscape is a valuable resource for understanding spatial variation in hydrogen isotopes in Brazil.
• The isoscape can aid in ecological and biogeochemical studies, despite limitations in predictive power in tropical regions.
• Further research with expanded sample data and improved standards is encouraged to enhance isoscape precision.