The primary determinant of an organism’s ecological niche is its adaptations to the environment, including its role in resource utilization and interactions with other species. Factors such as habitat preferences, dietary needs, and reproductive strategies dictate how an organism fits into an ecosystem. Additionally, abiotic factors like temperature, moisture, and competition for resources also shape an organism's niche. Understanding these determinants is crucial for assessing how environmental changes might impact species survival and ecosystem dynamics, informing conservation strategies.