Estación Biológica Cocha Cashu
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Interactions of peccaries and tapirs on plants, including seed predation, dispersal, and the impact of tramping

Principal Investigator: Harald Beck, PhD

Department of Biological Sciences, Towson University
Towson, MD 21252 USA
Office: Smith 249

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Harald Beck

One of my research focuses on animal-plant interactions and how those affect the population dynamics and species richness of tree seedlings in the Amazon. For instance, the dramatic impacts of peccaries on the forest dynamics become apparent to anyone who has watched a 100-strong herd of these animals thundering through the understory and thereby trampling and uprooting many seedlings. One obvious question is how are seedling growth, survival, and diversity affected by movement and foraging behaviors of large mammals such as peccaries? To test this and other hypotheses, in 2004 I established several long-term exclosure experiments in Cocha Cashu and Los Amigos.
Within the pristine and well protected setting of Manu National Park, results from this study may not only provide "baseline data" on animal-plant interactions and their ecological ramifications but also allow comparisons with forests where overhunting has driven large mammals to extinction and new generations of trees are maturing without the seed predation, dispersal, soil disturbance, and physical damage.

“Large-mammal exclosure (2 x 5 m) in Cocha Cashu established in 2004”

Another research project is to test if peccaries function as Eecosystem Engineers by physically modifying and creating new habitats for other species. Peccaries create and maintain wallows, terrestrial water bodies that range from 1 to over 80 square meters. Wallows are the only permanent water body in the dry season. Thereby they may be crucial foraging and breeding habitat for numerous animal taxa. Since 2004 I have been quantifying the animal community in over 55 wallows, and compared those to other ephemeral pools that filled after rain.
Preliminary results demonstrate that wallows have a higher species diverse and unique amphibian community compared to other water bodies. For example, during the dry season over 12 different frog species utilize wallows as habitat and foraging ground. In addition, six frog species used wallows as breeding habitat. Other taxa found in wallow include many invertebrates, turtles, snakes, and even nine different fish species!
These data support the notion that peccaries do function as ecosystem engineers and maintain species diversity. The question is how are species that utilize or depend on wallows affected in forests were peccaries are extinct?

“A typical peccary wallow during the dry season, notice the trampled area surrounding the wallow”

If you are interested in working with my on these or other projects or do a master thesis feel free to send me an e-mail at