Morphological And Ecological Variation In Otopteropus cartilagonodus Kock, 1969 (Mammalia, Chiroptera, Pteropodidae) From Luzon, Philippines

Abstract

(Uploaded by Plazi for the Bat Literature Project) Morphological variation in twenty-four characters of the skull, eight wing bones, and five characters of external morphology, as well as ecological data, are examined in the pteropodid bat, Otopteropus cartilagonodus, heretofore only known from six specimens. This study examines O. cartilagonodus from three populations: Zambales Mountains {n = 38), Mount Isarog (n = 46), and Isabela Province {n = 1). In the Zambales population, marked sexual dimorphism was found in five cranial characters associated with the feeding apparatus, as well as in overall length. Only two characters differed between sexes in the Mount Isarog population. The Zambales and Mount Isarog populations differed significantly in 21 out of 37 mensural characters, as well as in reproductive timing and embryonic development. From the segregation of sexes along an elevational gradient in the Zambales population, it is hypothesized that bats of this population may reduce intersexual competition by displaying distinct trophic and habitat preferences. This pattern of altitudinal segregation was not as marked in the Mount Isarog population. The structured, geographically and morphologically cohesive populations of O. cartilagonodus represent an ideal organism for elucidation of zoogeographic relationships among the different regions of the island of Luzon.