Avian frugivory and seed dispersal in Amorphophallus paeoniifolius and Alocasia odora

Abstract

Frugivores and seed dispersers are important in maintaining biodiversity and ecosystems. Yet, these agents receive less attention, in particular from ubiquitous or garden-cultivated species like Amorphophallus paeoniifolius and Alocasia odora. Despite extensive ecological studies carried out across the distribution regions of both species in tropical and subtropical, the only known disperser of A. paeoniifolius is the bird-of-paradise that was reported from Papua New Guinea. Meanwhile, there are reports of Pycnonotus and Eudynamys being the dispersers for both wild and cultivated Amorphophallus in India. Despite this, the frugivores and dispersal agents for both A. paeoniifolius and A. odora, in general, are not known and may be different in other parts of the world. In this study, I set up camera traps at five sites (two for A. paeoniifolius and three for A. odora) between 2017 and 2019 at the Xishuangbanna Tropical Botanical Garden to observe the frugivores and dispersal agents for these two ubiquitous cultivated aroid species. Apart from morphological observations on the infructescence of A. paeoniifolius and A. odora, the size of berries were measured and number of seeds per berry were counted. Six frugivores (Pycnonotus aurigaster, Copsychus saularis, Alophoixus pallidus, Niltiva davidi, Orthotomus sutorius, and Pycnonotus jocosus) were identified as potential dispersal agents, attracted to the colourful, succulent, and smaller (< 2 cm) berries. Pycnonotus aurigaster visited both A. odora and A. paeniifolius. The latter four frugivores visited A. paeniifolius, whereas P. jocosus visited only A. odora. All frugivores demonstrate endozoochory, and consumed the entire berries without showing any peculiar behaviour patterns. The berries are red-yellowish on ripening, with an average size of 1.63 cm ± 0.23 cm × 0.88 cm ± 0.19 (L × W) for A. paeniifolius, and 1.04 ± 0.09 cm × 0.67 ± 0.09 cm for A. odora. This study provides insight into how frugivores may depend on and connect to their regions of distribution as well as the distributions of plant taxa. Similar studies could be comparatively expanded into different distribution localities of A. paeoniifolius and A. odora for a wider understanding of their relationship linkage to the dispersal agents.