Epsilon Archive for Student Projects

Abstract

The red-tailed monkey (Cercopithecus ascanius) is a small, alert and active animal inhabiting forests with dense vegetation and as such hard to observe in its natural habitat. The principal aim of this study was to scrutinize whether the methods, previously used in a behavioural study of the blue monkey (Cercopithecus mitis) can be applied in studies of the red-tailed monkey’s behaviour as well. Additionally, habitat preference and foraging behaviour of the red-tailed monkey were examined. The study was carried out between the 16th and the 22nd of March 2009 in the Sabaringo forest, located on the western border of the Masai Mara National Reserve. Non-lactating and lactating females with their offspring were observed. Because we could not recognise individual animals a focal animal was selected by the proximity to the observer and overall visibility. During this time a total of 66 hours of data was collected of which 54 hours were for adult females and 12 hours for offspring. Recordings of foraging, postural, locomotor and social behaviours were made on foot, employing the interval sampling method. No statistical analyses have been made in this descriptive study. Overall, the monkeys showed clear preference for the tree habitat. Non-lactating females spent a considerable part of their time on the ground but lactating females almost never went there which was most likely a form of an antipredatory behaviour. Sitting was the most common postural behaviour regardless of habitat type whilst lying almost never occurred. Standing but especially moving behaviours were higher in occurrence when the monkeys were on the ground presumably because this open habitat required them to be more alert and vigilant. The performance of “Other behaviour”, which was mainly comprised of playing and grooming, was not tremendous. Foraging behaviour occurred in all habitats but most commonly on the ground. A large proportion of the time spent on the ground was dedicated to foraging on fallen fruit but also on leaves which the monkeys picked from low tree branches and saplings. There was a more even distribution between the preferences for leaves and fruits when the monkeys were on trees whilst leaves were favoured in the vine habitat. During the foraging time spent on man-made objects the monkeys were feeding predominantly on “Other food” which included trash, grass and unidentified food. Curiously, we did not record any cases of feeding on arthropod prey despite the fact that the other studies reported this to be an important part of the red-tailed monkey’s diet. The methods used in this study proved viable for observations of the red-tailed monkey’s behaviour.