Such changes based on the unique environmental pressures of species living on islands comes under the heading of Foster's Rule: https://en.wikipedia.org/wiki/F

Such changes based on the unique environmental pressures of species living on islands comes under the heading of Foster's Rule: https://en.wikipedia.org/wiki/Foster%27s_rule https://en.wikipedia.org/wiki/Foster%27s_rule Interestingly, species will both grow or shrink, depending on their initial niche before becoming an island population, as well as local resource availability.