Howler Photo by princessangel
Milton's Study on and Island in the Panama Canal
Recharging the Batteries
The howler diet limits their activity and, indeed, dominates it. On average, howlers spend over 60% of their day resting and traveled mainly to locate or monitor food sources (
Trichromatic primates, which include humans as well as Alouatta, have three specialized cones for color vision (Fleagle 1999, pp. 25-26). In a study of the red howler, in the rainforest of
Washing it all down? Not for the Howler.
Howlers generally obtain water from their food (Carpenter 1934; Milton 1980; Kinzey 1997; Gilbert and Stouffer 1989), leaves and fruit can contain up to 95% water by weight or from arboreal sources following a rain where the monkeys lick their fingers after wetting them in the runoff (Carpenter 1934). Rarely, howlers have been observed coming to drink at standing ground water sources (Gilbert and Stouffer 1989; Carpenter 1934), but in a very cautious manner. The observation by Gilbert and Stouffer was that the monkeys left the trees one at a time to drink with a male, probably the alpha, standing watch. They hypothesized that the dry conditions of that year imposed a water stress that inhibited growth of new leaves, forcing the howlers to obtain water from other sources.