Red howler (Alouatta seniculus)
Primate Factsheets: Red howler (Alouatta seniculus)
Fruit availability in red howler habitat is often very seasonal and as a
result, its relative importance in the diet varies throughout the year and
between study sites. Thus, at some times during the year, the species can be
described as predominantly folivorous while at other times they are
predominantly frugivorous (for an example see Simmen et al. 2001). In Colombia
at Tinigua National Park, red howler diet varies with food availability, but the
two main staples are fruits and leaves which range between 10-49% and 43-76%
of the diet respectively throughout the year. In the fruit scarcity period at
the end of the wet season at this location, between September and November,
leaves form a greater percentage of the diet than fruits. Seeds (2-8%),
flowers (3-6%) and other foods (1-2%) make up the rest of the diet over the
course of the year. Also at Tinigua, fruit abundance goes up during the
beginning of the wet season (March-May) and during the dry season
(December-February) (Stevenson et al. 2000). In Peru at the Pacaya-Samiria
National Reserve, fruit availability is similar to that at Tinigua except for a
general scarcity in the dry season. At this study site, feeding time was
divided into fruit (72%), leaves (25%) and flowers (3%) and leaves are eaten
year-round (Soini 1986). Red howler monkeys do not need to drink water and thus
can live in areas away from natural water (Crockett 1998b). Red howlers have
also been known to eat soil at natural saltlicks and to eat termite nest
material, doing so every two or three days (Izawa & Lozano 1990a). In
addition, a solitary male howler was observed catching and consuming green
iguanas in French Guiana; however this is the only recorded example of predatory
behavior in the species and may be unique to this one individual (de Thoisy
& Parc 1999).
Photo: Roy Fontaine
Red howlers, a
diurnal
species, show differences in daily activities between
the dry and wet seasons. In Venezuela during the dry season, activities on a
daily basis consisted of sleeping (37.9%), snoozing (24.0), feeding (19.8%) and
locomotion (18.4%). During the rainy season, percentages of daily activities
changed to sleeping (43.2%), snoozing (18.2%), feeding (23.8%), and locomotion
(14.8%) (Braza et al. 1981). Elsewhere, activity rates are similar, with over
half of the time spent resting with feeding and traveling making up the rest of
the activities for the day (Schön Ybarra 1984; Neves & Rylands 1991).
The predominance of resting activity in the red howler has been proposed to be
the result of their highly folivorous diet and the difficulties associated with
leaf digestion (Gaulin & Gaulin 1982). In the rainy season, more time is
spent feeding than in the dry season and less time is spent resting (Sekulic
1982c). Daily during the dry season, there are two main feeding bouts--one
intense bout in the morning and one in the afternoon, a pattern followed in the
Andes as well (Sekulic 1982c; Gaulin & Gaulin 1982). In addition, there can
be up to three or four smaller feeding bouts throughout the day. A general
pattern follows of more fruit being eaten in the earlier hours of the day and
more leaves later in the day (Gaulin & Gaulin 1982). Daily activities,
especially feeding, often start before the sun rises but stop before nightfall
(Soini 1986). Red howlers spend the night in the canopy, huddled in groups
(Soini 1986).
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