When two separate species cross paths and interact with each other this phenomenon is known as polyspecific association. This is rare and often involves species of similar stature and food preference. The situations where the interactions occur must provide a benefit for at least one of the two species. These polyspecific associations can last from less than an hour to months! Most of the time both species experience higher levels of protection from predators due to their larger numbers. These cooperative survival missions that the allying species go on are reflective of the small habitat area that they must share if they want to occupy.
In the main textbook Strier elaborates on polyspecific associations taking place between saddle-back tamarins (Saguinus fuscicollis) and moustached tamarins (Saguinus mystax). These two species live in Brazil, Peru, and other South American rainforests. The smaller saddle-back tamarin has a multicolored saddle on it’s back, which is where it derives its name. The moustached tamarin has fall colors all over it: black, brown, orange as well as a lifestyle defining bright white moustache.
In the Amazon they have reached a permanent polyspecific association. The moustached tamarin is physically much larger, this plays a role in how the two monkeys interact. By being around each other more often, these groups of tamarins can better foresee predator attacks. The two live in the same niche habitat, and forage together nearly everyday. The saddlebacks live in the understory, 4 meters or less of the ground; while the moustached tamarins frolic in the lower to mid canopy levels- 4 to 15 meters above ground. In this way during foraging parties they can both coexist peacefully without rubbing elbows. The moustached tamarins may be unaware in the ways that they are aiding their cousins below, by dropping insects and foodstuffs that the grateful saddle-backs readily consume. This shows that over time saddle-backs have realized that following their cousins to consume is very advantageous for them. It seems that saddle-backs are behind a number of shortcuts to food through exploiting their primate cousins, the next one I’ll delve into involves brush ins with marmosets.
In the Primate Ethnographies text book Steve Ferrari divulges the polyspecific associations that occur between saddle-back tamarins and a rare species of marmoset (Mico rondoni). Marmosets are very talented at creating gouge holes in gum trees so that they can consume the sap as food. One day Ferrari saw a group of saddle-backs beeline for a gum tree that they had found to be pockmarked by marmosets earlier, probably the day before. The sap moves slowly, and only creates food sources about once a day, so the food supply is limited but also refills daily. Marmosets have adapted special teeth to gain the ability to create this pathway to the fruit of the gum tree. Somehow the saddle-backs realized this, Ferrari saw them swarming the tree consuming lots of gum very quickly. Then he observed marmosets (much smaller animals than the tamarins) come back towards the pockmarked gum tree, as this happened the tamarins departed. Ferrari said that he heard whimpering sighs coming from the marmosets, as they had been cheated out of the food that they created by the conniving tamarins. The gum was a fall-back food for the tamarins- who must have needed it because of a fruit shortage.
Ferrari said that he thought of this situation as an undeclared competition war, and that it could potentially affect the wellbeing of the marmosets in that region. This represents a case where the unaware marmosets lost benefits from polyspecific association while the saddle-backs gained. In my understanding the saddle-back tamarins have become very good at utilizing other primates talents, they could be the executives of their niches.
Strier, Karen B. Primate Behavioral Ecology. Boston: Allyn and Bacon, 2000. Print.
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