Primates Aren’t Just ‘Monkeying Around’
By Quinn Banning-Arndt, Broadreach HQ
WHAT ROLE DO PRIMATES PLAY IN A TROPICAL FOREST?
The evolution of all ecosystems is shaped and influenced by the existing flora and fauna. In tropical forests, these intricate relationships between plants and animals have resulted in evolutionary changes in plant structure and have created unique roles for the primates residing in these ecosystems.
Primates’ predation on leaves, roots and seeds has caused many plants to adapt and develop a variety of defense mechanisms. Many tropical forest plants produce toxins within their leaves, which discourages animals from consuming them. These toxins can result in illness or even death. While toxins can prevent leaf consumption, seeds are another large component of the primates’ diet. Many plant seeds have developed a hard outer coating which is designed to either discourage consumption all together or to protect the seeds, allowing them to pass through the primate’s intestinal tract unharmed.
While primates can negatively impact plants in these ways, they have also developed some mutually beneficial interactions. Some flowering plants have evolved specific mechanisms to attract animals. Primates have become a big factor in the dispersion of pollen. They are attracted to the flower’s nectar and in the process of collecting the nectar, the primate becomes covered in the plant’s pollen. They then disperse the pollen as they visit other flowers and plants, helping the pollination to reach across a much larger area.
Primates also help in seed dispersal for trees. As mentioned above, many plants have developed a hard, protective coating on their seeds. This protects the seed as it passes through the primate who is traveling away from the “parent plant.” When seeds fall directly at the base of the tree, the likelihood that they will be able to mature into trees themselves is low. When primates consume fruit or seeds, they either spit the seed out away from the tree or it passes through the digestive system to be “deposited” a sizable distance from the parent tree. Dispersal via digestive tract travel is a great solution for those plants who have developed seeds with hard outer coatings. However, some seeds have soft coatings which can be harmed as they pass through the primate’s stomach. For these plants, the likelihood of seed survival and germination is higher if they are spat out during consumption and not subjected to the acids in the digestive tract.
As these roles as pollinators and seeds dispersers grow, the primates’ impact on forest regeneration increases. This is an important contribution that primates make to their ecosystem. Forests, both tropical and other, are the “life-support systems” for terrestrial organisms on Earth. Conservationists have recently changed their views of forests to better express the impact they have on our world as a whole and to acknowledge the many “services” they provide.
One of the greatest contributions forests make to the world is in regards to water systems. Healthy forests help to purify water, regulate surface flow, help in nutrient cycling within an ecosystem, and help to control erosion. Without forests, either through deforestation or natural ecosystem death, there would be an enormous void which no other ecosystem could fill. Without the assistance of primates in regenerating trees and vegetation, these forests would not be able to perform their crucial role.
Primates, and their environmental interactions, provide a shaping force within their ecosystem. The many roles primates fill not only impact their lives and those around them, but also cause a ripple that can impact ecosystems and weather without them ever knowing.
If you’re interested in learning more about primates in their natural habitats, check out our Costa Rica & Panama Primate Studies program.