If you’ve ever wondered how so many similar species can share the same niche, resource partitioning may be the answer. Learn how partitioning resources allows organisms to specialize and outcompete their rivals.
What Is Resource Partitioning in Biology?
Have you ever bought one of those timed entry tickets to a museum show or special event? Have you ever shared a bunk bed with a sibling or a roommate? In each case, you were sharing a limited resource.
In the case of timed tickets, you were sharing space and time, which was a limited resource because so many people wanted to experience the same thing at once. In the case of bunk beds, the limited resource may have been floor space in a small bedroom or dorm room.When species divide a niche to avoid competition for resources, it is called resource partitioning. The timed entry tickets or bunk beds are similar to the way other species share food supplies or space in the wild. Animals and plants may evolve to reproduce at different times of the year, feed at different times of the day or night, or use a different part of a forest or different depths of a lake.
Scientists disagree on how resource partitioning should be viewed, however. Some believe that having a special adaptation, such as a habit of eating at night, or an extra-long tongue that can reach the biggest termites in a termite mound, is part of the definition of resource partitioning. Some would say partitioning is partitioning regardless of how it became that way.
Not all competition in nature is alike. Competition between species is called interspecific competition. An example of that would be two species of hummingbirds in a tropical rainforest, each using flower nectar as their main source of food. But, individuals of the same species can compete with each other also.
That is intraspecific competition. Two tigers defining and defending their territories would be a good example of how individuals of the same species compete. Both the hummingbirds and the tigers are partitioning the resource they are competing for.
Examples of Resource Partitioning
Resource partitioning helps to explain how so many species of animals and plants can live in places like tropical rain forests. Many species have very specific ways they use a resource; so while it seems like many would be directly competing for the same things, they are often adapted for a very narrow piece of the resource pie.On the island of Puerto Rico, two species of Anolis lizards compete for food or insects. Anolis evermanni and Anolis gundlachi both share the forest and the insects, but one species, gundlachi, hangs out within a couple meters of the ground, and the evermanni generally feeds in the branches above two meters.
But there are also examples of resource partitioning where species aren’t so tightly packed. In Colorado, scientists found that bees have an interesting way of dividing up the flowers they use. Flowers vary in their shapes and corolla lengths. It turns out that the different bee species also vary in the length of their proboscis. Not all bee species can use the same flowers.
So, the bees are competing for flowers in general, but they have avoided direct competition because they are not actually sharing the same flowers.Also in Colorado, coyotes and swift foxes have partitioned the prey resource. You might think that two small predators sharing the same habitat would constantly compete for the same food supply, but they each have a specialty.
Swift foxes specialize in eating insects and small rodents. Coyotes specialize in eating rabbits and deer. This makes all the difference when two species are trying to share the same role in a competitive environment.
When species divide a niche to avoid competition for resources, it is called resource partitioning. Sometimes the competition is between species, called interspecific competition, and sometimes it’s between individuals of the same species, or intraspecific competition. Resources might be shared by reproducing at different times of the year, using different levels of a forest, feeding at different times or in different ways. Whether it is Anolis lizards partitioning their forest habitat by feeding at different levels or bees in Colorado whose mouth parts fit only certain flowers, resource partitioning lets more creatures share a niche.
After this science lesson, you should be able to:
- Explain what resource partitioning is in terms of biology
- Distinguish between interspecific competition and intraspecific competition
- Recognize examples of resource partitioning