how can two or more species of finch co-exist without much competition in the same habitat
Niche differentiation
When species use different resources , this can help them to coexist . For example , some lizard species appear to coexist because they consume insects of differing sizes . Alternatively , species can coexist on the same resources if each species is limited by different resources , or differently able to capture resources . For example , different types of phytoplankton can coexist when different species are differently limited by nitrogen , phosphorus , silicon , and light . In the Galapagos Islands , finches with small beaks are more able to consume small seeds , and finches with large beaks are more able to consume large seeds . If a species ' density declines , then the food it most depends on will become more abundant ( since there are so few individuals to consume it ) . As a result , the remaining individuals will experience less competition for food . 
When species use different resources , this can help them to coexist . For example , some lizard species appear to coexist because they consume insects of differing sizes . Alternatively , species can coexist on the same resources if each species is limited by different resources , or differently able to capture resources . For example , different types of phytoplankton can coexist when different species are differently limited by nitrogen , phosphorus , silicon , and light . In the Galapagos Islands , finches with small beaks are more able to consume small seeds , and finches with large beaks are more able to consume large seeds . If a species ' density declines , then the food it most depends on will become more abundant ( since there are so few individuals to consume it ) . As a result , the remaining individuals will experience less competition for food .
When species use different resources, this can help them to coexist. For example, in the Galapagos Islands, finches with small beaks are more able to consume small seeds, and finches with large beaks are more able to consume large seeds.
When species use different resources , this can help them to coexist . In the Galapagos Islands , finches with small beaks are more able to consume small seeds , and finches with large beaks are more able to consume large seeds .