HABITAT QUALITY AND AVAILABILITY OF THE WESTERN CEYLON SLENDER LORIS, Loris tardigradus IN THE KOTTAWA ARBORETUM

S.N. GAMAGE, D. WEERAKOON, A. GUNAWARDENA

Abstract


The red slender loris, Loris tardigradus is one of the three primate species endemic to Sri Lanka. Currently there are two recognized subspecies of the red slender loris, L. t. tardigradus and L. t. nycticeboides. Of these L. t. tardigradus (Western Ceylon slender loris) inhabits rainforests in the southwestern region of the island while L. t. nycticeboides (Ceylon mountain slender loris) is restricted to the montan zone. Kottawa Arboretum harbors one of the few remaining L. t. tardigradus populations in the country. This study was conducted to determine the population density, habitat selection criteria and to assess the habitat availability of L. t. tardigradus in the Kottawa Arboretum. Using the line transect method, 34 sightings were made over a period of 21 months. Based on these observations the density of Western Ceylon slender loris in the Kottawa Arboretum and habitat selection criteria were ascertained. The calculated density of L. t. tardigradus in the Kottawa Arboretum is 41-animals/ km2. The average height of trees preferred by L. t. tardigradus is 13.97 m ± 6.02. Most of the time lorises were observed at a height range of 3.5-15 m above the ground level. Average height from the ground level where L. t. tardigradus were observed to occupy the tree was 8.64 m ± 5.00. Of the 50 tree species recorded in the Kottawa Arboretum, L. t. tardigradus was found to utilize only 16 species.


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