Primary environmental factors affecting species distribution include climate, habitat availability, and food resources. Climate influences temperature and precipitation patterns, shaping the types of ecosystems that can thrive in an area. Habitat availability ensures that species have the appropriate environments for nesting, feeding, and reproduction. Additionally, the distribution of food resources affects population dynamics, as species depend on these for survival. Other factors like competition, predation, and human activities such as urbanization can further influence how, where, and why species inhabit particular regions.