ABSTRACT
Spider monkeys are large arboreal New World primates, about 9 to 10 kg in weight, usually classified in four species of the genus Ateles, although taxonomy is in flux. As a genus, spider monkeys are presently distributed from southern Mexico to the upper Amazon. Spider monkeys do not travel consistently in cohesive units, but associate in flexible “parties” of variable and frequently changing size and composition. This chapter presents the study in Tikal used strip census methods. The basic technique is simply walking slowly along trails, recording for every contact with monkeys: number and age-sex composition of individuals sighted and the perpendicular distance from the animals when detected to the census route. Strip censusing with calculation of strip width is more accurate than simple hunches about efficiency of detection which have characterized a number of primate surveys where observers arrived at a width of 100 m.
