Secondary seed dispersal by dung beetles in an Amazonian forest fragment of Colombia: influence of dung type and edge effect

Abstract

Seeds of many plant species are secondarily dispersed by dung beetles, but the outcome of this interaction is highly context-specific. Little is known about how certain anthropogenic disturbances affect this plant-animal interaction. The aims of this study were to assess the effect of dung type on secondary dispersal by dung beetles in a forest fragment, and to determine whether this interaction is affected by edge effects. Using pitfall traps, we captured dung beetles attracted to dung of 2 frugivorous mammals: woolly monkeys and howler monkeys. We found differences between both dung beetle assemblages, but these differences were not consistent in time. Using seeds surrounded by both dung types, we carried out a field experiment using seeds of 2 plant species. We found that the probability of secondary dispersal by dung beetles was higher for seeds placed in woolly monkey dung. Finally, we carried out a field experiment using plastic beads as seed mimics to assess edge effects. We found that secondary seed dispersal by dung beetles was negatively affected by edges. The disruption of plant-animal interactions along anthropogenic forest edges could have long-term negative effects on forest dynamics by affecting processes of regeneration.

Dung Beetle Community and Functions along a Habitat-Disturbance Gradient in the Amazon: A Rapid Assessment of Ecological Functions Associated to Biodiversity

“…These results clearly demonstrate the relevance of empirically estimating the amount of ecological functions rather than deducing it from community attributes, as has already been pointed out by previous studies [26], [52]. Furthermore, among the functional variables, dung removal was the least sensitive to habitat disturbance.…”

Herbivore dung as food for dung beetles: elementary coprology for entomologists

“…Losey & Vaughan, ; Nichols et al , ; Beynon et al , ); germination and/or secondary dispersal of seeds owing to dung relocation by beetles (e.g. D'hondt et al , ; Santos‐Heredia et al , ; Midgley et al , ); dung beetle behaviour associated with provisioning/relocation of food for the larvae (e.g. Halffter & Edmonds, ; Klemperer, ; Dacke, ; Dacke et al , ); dung preferences (e.g.…”

Spatial and temporal effects on seed dispersal and seed predation of Musa acuminata in southern Yunnan, China

“…Fedriani and Manzaneda (2005) also found that seeds located in sheltered microsites experience higher removal by seed predators compared with seeds in open microsites. Therefore, spatial patterns of seed predation and plant-animal interactions are not only affected by rodent population densities, but also by other factors, such as habitat type (Calvĩno-Cancela & Martín-Herrero 2009), the degree of disturbance or habitat degradation (Cole 2009), seed availability and habitat physiognomy (Díaz 1992), predator's preferences (Vanhoenacker et al 2009), habitat preferences of predators (Manson & Stiles 1998) or edge effects (Notman et al 1996;Santos-Heredia et al 2011). Furthermore, the high seed predation number in the wild banana stands might reduce competition between seed -1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 lings and parent plants, according to the escape hypothesis of Janzen-Connell (Janzen 1970;Connell 1971).…”