The primary determinant of a species' range is environmental factors such as climate, habitat availability, and resource accessibility. These factors determine where a species can survive, reproduce, and thrive. Biotic interactions, including competition and predation, also play a role in limiting or expanding a species' range. Additionally, abiotic factors like temperature, humidity, and soil composition can significantly influence distribution patterns. Understanding these determinants is essential for conservation efforts and predicting how species may respond to environmental changes.