Frugivory of Yellow-eared Bulbul (Pycnonotus penicillatus) and Seasonal Variation of Fruiting Phenology in Tropical Montane Cloud Forests of Horton Plains National Park, Sri Lanka

Abstract

This study was conducted on a frugivorous bird species, Yellow-eared Bulbul (Pycnonotus penicillatus) which is an endemic and threatened species, at Horton Plains National Park (HPNP), from September 2015 to November 2017. Direct methods as focal animal sampling and faecal analysis were used to identify food items of P. penicillatus. Feeding plants were identified using field guides. To find out the fruit phenology, ten individuals per plant species were tagged. Fruit cover was estimated in the each tagged tree. According to the present findings, P. penicillatus mainly consumed, 16 species of feeding plants belonging to eleven families. Among them six endemic, eight native and one introduced species were observed. P. penicillatus consumed Rubus ellipticus as their major fruit source. There were seeds of nine plant species were identified by faecal analysis. Maximum ripen fruit cover was recorded from Solanum mauritianum in the northeast monsoon season, first inter-monsoon season and second intermonsoon season. However, in the southwest monsoon season highest ripen fruit cover was recorded from Berberis ceylanica. There was a correlation between number of feeding attempts and ripen fruit cover, of Symplocos bractealis, S. mauritianum and Strobilanthes viscosa. Moreover, there was a correlation between number of feeding attempts and number of trees in fruiting, of Elaeocarpus coreaceus, Passiflora tripartita, Eugenia mabaeoides and S. viscosa. The present study has revealed importance of the floral community to the P. penicillatus. Therefore, it is important to recommend monitoring protocols about the seasonal variations of fruiting phenology in and around HPNP, which are harbouring a large variety of feeding plants of the threatened birds species such as P. penicillatus for conservational purposes.