Nutrition and foraging strategies of the black howler monkey (Alouatta pigra) in Palenque National Park, Mexico

Black howler monkeys (Alouatta pigra) in Palenque National Park, Mexico, do not appear to be energy-limited despite their leaf-heavy diet. Contrary to common assumptions, these primates meet their estimated energy requirements and surpass protein needs, consuming an average of 0.58 MJ of overall energy per metabolic body mass per day and 8.2 g of protein daily. The study, conducted over a 10-month period with two groups (N=16 individuals), combined dietary pattern data, food consumption rates, and published nutritional content to estimate energy and nutrient intake. Surprisingly, resting time was not correlated with diet composition or energy intake, suggesting that the howlers' feeding ecology may be more similar to fruit-eating atelines than previously thought. This challenges long-held assumptions about their behavior and foraging strategies.

Amato, K. R., & Garber, P. A. (2014). Nutrition and foraging strategies of the black howler monkey (Alouatta pigra) in Palenque National Park, Mexico. American Journal of Primatology, 76(8), 774–787. Portico. https://doi.org/10.1002/ajp.22268