Behavioral and Social Structure Effects on Seed Dispersal Curves of a Forest‐Interior Bulbul (Pycnonotidae) in a Tropical Evergreen Forest

Abstract

Movement patterns of animals can vary dramatically as a function of their reproductive cycle or social structure; however, little is known about how changes in the social structure of dispersers affect patterns of seed dispersal. We examined the movement patterns of the forest-dwelling and cooperatively breeding Puff-throated Bulbul (Alophoixus pallidus) in relation to different stages of their reproductive cycle, time of day, and group size, to determine potential impacts on the shape and scale of dispersal curves generated using a combination of gut passage time and displacement distance data. There were significant differences in dispersal distances depending on group size, season (breeding, non-breeding), incubation (vs. other times of the year), and time of the day. The estimated median seed dispersal distance was 28 m. The median dispersal distances produced by birds in larger groups were longer than those of smaller groups (29 m vs. 25 m). During the breeding season, median dispersal distances were longer than during the non-breeding season (31 m vs. 25 m), but the median dispersal distances were significantly shorter during incubation than during outside incubation (24 m vs. 28 m). The median dispersal distance produced in the early morning (30 m) was also longer than that of other times of the day (23 m late morning, 28 m early afternoon, and 26 m late afternoon). This study suggests that various aspects of an animal's behavior are likely to have significant effects on seed shadows and that this may vary significantly even among individuals of the same species.Abstract in Thai is available in the online version of this article.

Spatial patterns of local species richness reveal importance of frugivores for tropical forest diversity

“…Khao Yai National Park still contains a high diversity of largely frugivorous arboreal mammal and bird species, including gibbons ( Hylobates lar and Hylobates pileatus ), macaques ( Macaca leonina ), civets (five species), bears ( Ursus thibetana , Helarctos malayanus ), hornbills (four species) and other smaller frugivorous birds such as barbets, orioles, pigeons, mynas and bulbuls (Lynam, Round, & Brockelman, ). Gibbons (Brockelman et al., ; McConkey & Brockelman, ; McConkey, Brockelman, Saralamba, & Nathalang, ; Whittington & Treesucon, ), macaques (Albert, Hambuckers, et al., ), deer (Brodie, Helmy, Brockelman, & Maron, ; Chanthorn & Brockelman, ), bears (Ngoprasert, Steinmetz, Reed, Savini, & Gale, ), hornbills (Kitamura et al., , ) and smaller birds (Khamcha et al., ; Sankamethawee, Pierce, Gale, & Hardesty, ) are all potentially important seed dispersers in the Mo Singto area of Khao Yai Park. The most probable seed dispersers of tree species in the Mo Singto plot are shown in Table based on extensive observations of Kitamura et al.…”

“…Gibbons McConkey & Brockelman, 2011;McConkey, Brockelman, Saralamba, & Nathalang, 2015;Whittington & Treesucon, 1991), macaques , deer (Brodie, Helmy, Brockelman, & Maron, 2009;Chanthorn & Brockelman, 2008), bears (Ngoprasert, Steinmetz, Reed, Savini, & Gale, 2011), hornbills (Kitamura et al, 2002(Kitamura et al, , 2004 and smaller birds (Khamcha et al, 2014;Sankamethawee, Pierce, Gale, & Hardesty, 2011) are all potentially important seed dispersers in the Mo Singto area of Khao Yai Park. The most probable seed dispersers of tree species in the Mo Singto plot are shown in Table S1 based on extensive observations of Kitamura et al (2002) and Brockelman et al (2017).…”

Body-size dependent foraging strategies in the Christmas Island flying-fox: implications for seed and pollen dispersal within a threatened island ecosystem

“…Over evolutionary timeframes, dispersal patterns determine both gene flow between populations and the frequency with which a species experiences new selection regimes that facilitate evolution in novel environments [ 73 ]. Among plants that are dispersed by animals, gene-flow through seed dispersal and pollination are affected by various characteristics of a dispersers’ biology such as population density, food availability, and behavior [ 43 , 46 ]. Despite the recognized importance of the dispersal services provided by animals, the processes that influence seed and pollen dispersal are not fully understood.…”

Seed Size Variation of Trees and Lianas in a Tropical Forest of Southeast Asia: Allometry, Phylogeny, and Seed Trait - Plant Functional Trait Relationships

“…Some species that we were unable to classify were assigned to an unknown dispersal mode group (see Supplementary Table 3 ). To avoid problems of high variation of body size among frugivores in each tree species, we determined the mean body size of all animal fruit consumers from the body mass data of Kitamura et al (2002) and Khamcha et al (2014) ( Supplementary Table 1 ). Intuitively, given that one fruit species is equally favored by two frugivores, we assumed the frugivore with larger body size consumes more fruit than the smaller one.…”