Seed Dispersal of Vitex Glabrata and Prunus Ceylanica by Civets (Viverridae) in Pakke Tiger Reserve, North-East India: Spatial Patterns and Post-Dispersal Seed Fates

Abstract

Civets are considered potentially important seed dispersers in tropical forests of Asia, but relatively little is known about spatial patterns of dispersal and post-dispersal fates of civet-dispersed seeds. We explored these aspects of civet seed dispersal for two tree species Vitex glabrata (Lamiaceae), also known as smooth chaste tree and Prunus ceylanica (Rosaceae), in Pakke Tiger Reserve, a tropical forest reserve in northeast India. Pakke has five known species of viverrids: small Indian civet (Viverricula indica), large Indian civet (Viverra zibetha), common palm civet (Paradoxurus hermaphroditus), masked palm civet (Paguma larvata) and the binturong (Arctictis binturong). For both tree species, civets as a group dispersed seeds (100% of scats that we found) within 50 meters from fruiting trees and deposited seeds onto multiple substrates including tree branches, forest floor, and fallen logs. However, the distribution of seeds among substrates differed for the two tree species: while most seeds of V. glabrata (> 90%) were deposited onto canopy branches and fallen logs, the majority of P. ceylanica seeds (> 70%) were deposited on the forest floor. For both tree species, seeds deposited on logs experienced higher seed predation than seeds on the forest floor, especially when local seed densities (number of seeds in 1m 2 area around the scat and in the scat) were high. Further, seed viability of P. ceylanica was significantly lower on logs (~35%) than on the forest floor (~65%). For both tree species, civets neither dispersed seeds far from fruiting trees nor to sites where seeds experienced either low predation or high survival, suggesting that while civets were legitimate dispersers, they were not especially effective.

Defaunation of large-bodied frugivores reduces carbon storage in a tropical forest of Southeast Asia

“…This assumption may affect the scenario of primate extirpation as described in the later subsection, but not in the scenario of all LBF extirpation. However, we assume that their effect is negligible in our simulations, because they rarely feed on typical primate fruits such as Nephelium melliferum in our plot (unpublished data) and frequently disperse seeds out of old-growth forest into disturbed areas 49,51,52 .…”

Animal‐mediated seed dispersal in India: Implications for conservation of India’s biodiversity

“…In contrast, Chakravarthy and Ratnam (2015) found that while civets did disperse the seeds of Vitex glabrata and Prunus ceylanica , they carried them within 50 m of the parent trees and deposited them on multiple substrates. However, seeds deposited on fallen logs experienced higher predation and had lower seed viability than those on the forest floor (Chakravarthy & Ratnam, 2015).…”

“…as is evidenced by the germination of seedlings of these species in civet feces across different years and sites (Mudappa et al, 2010). In contrast, Chakravarthy and Ratnam (2015) found that while civets did disperse the seeds of Vitex glabrata and Prunus ceylanica, they carried them within 50 m of the parent trees and deposited them on multiple substrates.…”

Forest seed dispersal by carnivores in temperate forests and dry tropical forests

“…Seed dispersal by carnivores influences the recruitment of various plant species in temperate forests (Koike et al, 2008) and tropical forests (Chakravarthy & Ratnam, 2015;Zhou et al, 2008), that is, the seeds dispersed by these types of mammals often lead to the establishment of plants (Howe & Miriti, 2000). However, data on dispersal by carnivores in other ecosystems such as temperate forests (TF) and dry tropical forests (DTF) are scarce (Godínez-Alvarez et al, 2007).…”