Vertical stratification of dung beetles in young secondary forests of Singapore

• Main Authors: Abdul Rahman, Ita Liana, Yap, Sean, Goh, Thary Gazi, Toh, Kai Xin, Yee, Qian Qi Hillary, Puniamoorthy, Nalini
• Format: Article
• Published: Wiley 2021
• Subjects: Q Science (General)
• Online Access: http://eprints.um.edu.my/28494/
• Institution: Universiti Malaya

In tropical rain forests where resources are present at different spatial scales, niche partitioning could affect biodiversity. For instance, insects inhabiting the arboreal strata often differ drastically from those in the ground strata. In this study, we investigated the vertical distribution of dung beetles in young secondary forests of Singapore by comparing their biodiversity from both ground and canopy traps. In total, we sampled 2242 individuals from four genera. Species composition significantly differed between canopy and ground traps, with Onthophagus cf. crassicollis, Onthophagus cf. deliensis, Onthophagus cf. leusermontis, and Onthophagus cf. babirussa contributing most differences. We report the presence of Onthophagus. cf. deliensis-an abundant, widespread arboreal specialist. Species richness and diversity were significantly lower in canopy traps, indicative of ephemeral dung present. When comparing Shannon diversity differences between stratum, temperature and humidity did not have significant effects. Morphological analyses suggested that arboreal dung beetles are smaller with greater wing loading, exposed eye ratio and leg size, which improve flight, vision, and dung manipulation. This study is a first step toward documenting vertical stratification of dung beetles in young secondary forests of Singapore; detecting morphological differences between ground and arboreal specialists, that are likely adaptations to divergent niches.