Saimiri macrodon Elliot 1907
Creators: name: Russell A. Mittermeier
name: Anthony B. Rylands
name: Don E. Wilson
Publisher: name: Lynx Edicions
Year: 2013
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Mammalia
Primates
Cebidae
Saimiri
Saimiri macrodon

description: 3.
Ecuadorian Squirrel Monkey
Saimiri macrodon
French: Saimiri d’'Equateur / German: Ecuador-Totenkopfaffe / Spanish: Mono ardilla ecuatoriano
Taxonomy. Saimiri macrodon Elliot, 1907,
Rio Copataza, upper Rio Pastaza, Pastaza, Ecuador.
R. Thorington, Jr. considered S. macrodon a junior synonym of S. sciureus. In a paper published in 1976, J. Hernandez-Camacho and R. Cooper recognized S. sciureus caquetensis, named by J. A. Allen in 1916, from the Rio Caqueta. It was considered to be a junior synonym of S. sciureus macrodon by P. Hershkovitz and C. P. Groves. S. macrodon 1s chromosomally distinct, with six pairs of acrocentric chromosomes. S. macrodon intergrades with S. boliviensis peruviensis in the basins of the rios Tapiche and Blanco, and natural hybrids of S. macrodon x S. b. peruviensis have been recorded from Pucallpa, Peru, and the Rio Ucayali, in the Tapiche Basin. Monotypic.
Distribution. W Brazilian Amazon (W from the rios Japura and Jurua), extending W in S Colombia (up to the Rio Apaporis), to E Ecuador (W to the Andes), and to N & E Peru, S to the Rio Abujao, (N of the Rio Maranon as far as the mouth of the Rio Huallaga where it also extends S of the Maranon along the left (W) bank of the Rio Huallaga to about 9° S, and E of the Rio Ucayali).
Descriptive notes. Head—body 25-32 cm, tail 34—44 cm; weight 835-1380 g (males) and 590-1150 g (females). The Ecuadorian Squirrel Monkey is very similar to the Guianan Squirrel Monkey (S. sciureus), but the back is darker. The general color including the crown and dorsal surface of the tail is a grayish olivaceous, washed with orange. Flanks and inside of the legs and arms and ventral surface of the tail are paler. Feet and hands are deep yellowy orange. Ventral surfaces are pale yellowish white. The muzzle is black with white around the eyes and on the cheeks and throat extending to the upper chest. Ears are white, slightly furred (not tufted), and pointed. The tail pencil is black on the dorsal surface. White arches above the eyes are of the “Gothic arch” type.
Habitat. Humid tropical and subtropical forest at 200-1200 m above sea level. At least in Ecuador, they are more common at elevations of 500 m or less. Ecuadorian Squirrel Monkeys prefer dense vegetation and lianas of seasonally inundated forests, and they are able to adapt to secondary and disturbed forest. They are reported to be scarce or absent from terra firma lowland and hillside forest far from rivers of lakes.
Food and Feeding. There is no specific information available for this species, but its diet is likely composed of small animals and fruits, including infructescences of Cecropia (Urticaceae), figs (Ficus, Moraceae), Euterpe palms (Arecaceae), and Campomanesia (Myrtaceae).
Breeding. There is no information available for this species.
Activity patterns. There is no information available for this species.
Movements, Home range and Social organization. One group of Ecuadorian Squirrel Monkeys counted at the Quebradon Ayo, a small clear-water tributary of the Rio Caqueta in Colombia, had 18 individuals. The area has nutrient poor soils, low productivity, and low primate densities. Surveys of Ecuadorian Squirrel Monkeys there indicated densities of 0-6 groups/km* and 11-3 ind/km?®. They have been recorded in groups of 40-50 individuals and, like other squirrel monkeys, associate with groups of capuchins (Sapajus and Cebus).
Status and Conservation. CITES Appendix II. Classified as Least Concern on The IUCN Red List (as S. sciureus macrodon). The Ecuadorian Squirrel Monkey is widespread and generally common throughoutits distribution where there is suitable habitat. In some areas in Peru, it raids cornfields and banana plantations and is considered a pest. It occurs in Amacayacu, Cahuinari, and La Paya national natural parks in Colombia; Yasuni National Park, Cayambe-Coca, and Cofan-Bermejo ecological reserves, and Cuyabeno Wildlife Reserve in Ecuador; and ACR Comunal Tamshiyacu Tahuayo in Peru.
Bibliography. Aquino & Encarnacion (1994b), Allen (1916), Carretero-Pinzén et al. (2009), Defler (2003b), Hernandez-Camacho & Cooper (1976), Hershkovitz (1984), Lavergne et al. (2009), Schneider, Harada et al. (1993), Silva et al. (1992), Tirira (2007).
description: Published as part of Russell A. Mittermeier, Anthony B. Rylands & Don E. Wilson, 2013, Cebidae, pp. 348-413 in Handbook of the Mammals of the World – Volume 3 Primates, Barcelona :Lynx Edicions on page 393, DOI: 10.5281/zenodo.6628559