Spatio‐temporal patterns in the abundance of active terrestrial leeches in a Malaysian rainforest

Abstract

AbstractTerrestrial leeches can be useful tools for wildlife assessment. However, limited information is available on their fundamental ecology, such as temporal activity patterns and habitat preferences in tropical rainforests. Therefore, this study aimed to reveal the temporal (diel and seasonal) and spatial patterns of active leech abundance and identify abiotic and biotic factors (abundance of potential hosts) involved in shaping the abundance patterns at Endau Rompin National Park (ERNP) in southern peninsular Malaysia. We conducted surveys on the relative abundance of active brown leeches (Haemadipsa sp.) at 99 sampling points repeatedly over 18 months, and installed camera traps to quantify the relative abundance of wildlife and humans at 24 of the sampling points. Although no consistent diel and seasonal patterns were observed in leech relative abundance, the abundance showed a strong positive correlation with air humidity at the sampling time. Similarly, the spatial pattern of leech relative abundance was positively correlated with air humidity and proximity to the nearest river at the sampling sites. The mean relative abundance of active leeches was 2–3 times higher on trails than off trails. However, there was no significant correlation between relative abundance of leeches and that of wildlife and humans on trails. Therefore, leech abundance was largely determined by air humidity rather than host abundance, suggesting the difficulty of its use as an indicator of wildlife abundance at fine spatial scales. Instead, utilizing the sensitivity of leeches to drier environments, terrestrial leeches could be useful as an indicator of intact tropical rainforests.Abstract in Malay is available with online material.