How are niches influenced by competition?
composition can force a population to develop a new niche.
A well-studied example is the Finches of the Galapagos islands.
It is believed that a single population of finches immigrated to the isolated islands. There were no other birds on the newly formed volcanic islands. There were multiple niches available. Different populations of finches carved out different niches.
It is estimated that there are now 13 different subspecies of these finches on the islands. Some of the finches are large beaked ground finches able to eat large seeds. There are also medium and small beaked ground finches. There are finches that eat cactus. Competition on the semi-desert islands forced the finches to find new niches and ways of surviving.