Two male elk fighting over a female is not an example of abiotic and biotic factors in an ecosystem. Biotic factors are factors which are living such as plants and animals and abiotic factors are non-living organisms such as rocks, minerals, and even temperature and the wind. Therefore, flowers opening at night is an example of a biotic factor changing (the flower) to the abiotic factor (the sunlight). This patter fits for the other answers as well because bears and butterflies moving due to winter is a relationship between a biotic and an abiotic factor in the environment.
