Reliability of macaques as seed dispersers

Sengupta, Asmita; Gazagne, Eva; Albert-Daviaud, Aurélie; Tsuji, Yamato; Radhakrishna, S.

doi:10.1002/ajp.23115

Cited by 6 publications

(7 citation statements)

References 62 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Our results are in agreement with the finding that seeds with MCD > 3 mm were predated [ 44 ]. Although large seeds were damaged at a high rate in our study, the encrustation of berries from genuine fruits may have a positive influence on intact seed ingestion by monkeys, and previous research has identified the genus Macaca as a reliable seed disperser [ 45 ]. Our findings could point to the possibility of Tibetan macaques dispersing seeds with an MCD of less than 3 mm.…”

Section: Discussionmentioning

confidence: 72%

The Influence of Seed Characteristics on Seed Dispersal Early Stages by Tibetan Macaques

Qian

2022

Animals

View full text Add to dashboard Cite

There are numerous ecological and evolutionary implications for the ability of frugivores to predate on fruits and consume or disperse their seeds. Tibetan macaques, which are considered important seed predators, typically feed on fruits or seeds. However, systematic research into whether they have a seed dispersal function is still lacking. Endozoochory allows seeds to disperse over greater distances by allowing them to remain in the animal’s digestive tract. Consumption of fruit may not imply effective seed dispersal, and the physical characteristics of seeds (e.g., size, weight, specific gravity, etc.) may influence the dispersal phase’s outcome. We conducted feeding experiments with three captive Tibetan macaques (Macaca thibetana) and nine plant seeds to determine the influence of seed characteristics on Tibetan macaques’ early stages of seed dispersal. The results revealed that the percentage of seed destruction (PSD) after ingestion was 81.45% (range: 15.67–100%), with the PSD varying between plant species. Among the three passage time parameters, the transit time (TT) (mean: 18.8 h and range: 4–24 h) and the time of seed last appearance (TLA) (mean: 100.4 h and range: 48–168 h) differed significantly between seed species, whereas the mean retention time (MRT) (mean: 47.0 h and range: 32–70.3 h) did not. In terms of model selection, PSD was influenced by seed size, weight, volume, and specific gravity; TT was influenced by seed-to-shell investment rate, weight, volume, and specific gravity; and TLA was influenced only by seed size. These findings imply that seeds with a smaller size, specific gravity, volume, and greater weight pass more easily through the monkeys’ digestive tracts. Particularly, seeds with a mean cubic diameter (MCD) of <3 mm had a higher rate of expulsion, larger volume, and weight seeds pass faster, while smaller remained longer. Tibetan macaques, as potential seed dispersers, require specific passage time and passage rates of small or medium-sized seeds. Larger and heavier seeds may be more reliant on endozoochory. Tibetan macaques have the ability to disperse seeds over long distances, allowing for gene flow within the plant community.

show abstract

Section: Discussionmentioning

confidence: 72%

The Influence of Seed Characteristics on Seed Dispersal Early Stages by Tibetan Macaques

Qian

2022

Animals

View full text Add to dashboard Cite

show abstract

“…(Preference indices) = ratio of number of feeding scans for the consumed species to the total number of feeding scans/ratio of number of stems for the consumed species of the total number of stems into the botanical plots. Preference indices >1 indicate a preference for a fruit family [50]; -= no data; Processing methods: W = swallow, S = spit out. Grey shaded rows present the species used for the simulations of a species seed shadow using the mechanistic Model of Seed Tranfert (MOST).…”

Section: Discussionmentioning

confidence: 99%

“…Additionally, we estimated seed shadow of a subset of three trees and one liana species, with medium and large seeds, to illustrate species specific variability (i.e., seasonal distribution and availability, plant traits, seed treatments). We selected these four plant species among the most consumed within macaques' diet or with the highest preference indices (based on the species relative consumption over the species relative availability, following Sengupta et al [50]) and either abundant or rare across macaques' home range.…”

Section: Ranging Movement Patterns and Seasonalitymentioning

confidence: 99%

Seed Shadows of Northern Pigtailed Macaques within a Degraded Forest Fragment, Thailand

Gazagne

Pitance

Savini

et al. 2020

Forests

Self Cite

View full text Add to dashboard Cite

Research Highlights: Frugivores able to disperse large seeds over large distances are indispensable for seedling recruitment, colonization and regeneration of tropical forests. Understanding their effectiveness as seed dispersal agents in degraded habitat is becoming a pressing issue because of escalating anthropogenic disturbance. Although of paramount importance in the matter, animal behaviour’s influence on seed shadows (i.e., seed deposition pattern of a plant population) is difficult to evaluate by direct observations. Background and Objectives: We illustrated a modeling approach of seed shadows incorporating field-collected data on a troop of northern pigtailed macaques (Macaca leonina) inhabiting a degraded forest fragment in Thailand, by implementing a mechanistic model of seed deposition with random components. Materials and Methods: We parameterized the mechanistic model of seed deposition with macaque feeding behavior (i.e., consumed fruit species, seed treatments), gut and cheek pouch retention time, location of feeding and sleeping sites, monthly photoperiod and movement patterns based on monthly native fruit availability using Hidden Markov models (HMM). Results: We found that northern pigtailed macaques dispersed at least 5.5% of the seeds into plantation forests, with a majority of medium- to large-seeded species across large distances (mean > 500 m, maximum range of 2300 m), promoting genetic mixing and colonization of plantation forests. Additionally, the macaques produced complementary seed shadows, with a sparse distribution of seeds spat out locally (mean >50 m, maximum range of 870 m) that probably ensures seedling recruitment of the immediate plant populations. Conclusions: Macaques’ large dispersal distance reliability is often underestimated and overlooked; however, their behavioral flexibility places them among the last remaining dispersers of large seeds in disturbed habitats. Our study shows that this taxon is likely to maintain significant seed dispersal services and promote forest regeneration in degraded forest fragments.

show abstract

“…While the term stomatochory was used as far back as the 1980s (van der Pijl, 1982), it has rarely been used in the seed dispersal literature until the last decade when it was applied to seed dispersal by parrots (Blanco et al., 2015; Tella et al., 2015). Despite an increasing number of studies documenting stomatochoric dispersal (Aziz et al., 2021; Baños‐Villalba et al., 2017; Blanco et al., 2019; McConkey & Brockelman, 2011; Sengupta et al., 2020), these studies remain largely species‐focused (rather than incorporated in community studies) and stomatochory is rarely considered a legitimate dispersal mode in comparison to endozoochory.…”

Section: Introductionmentioning

confidence: 99%

“…However, many seed disperser communities harbour abundant populations of non‐endozoochoric dispersers as well, who also consume fruits for the pulp, or even the seeds. Individually, these animals might not always disperse seeds as often and as far, but they can be frequent dispersers of viable seeds (Baños‐Villalba et al., 2017; Gómez et al., 2019; Ong et al., 2022; Sengupta et al., 2020). Furthermore, germination tests often show that the removal of pulp can have a stronger positive effect than seed scarification so that non‐endozoochoric dispersers can also enhance seed germination (Fedriani et al., 2012).…”

Section: Introductionmentioning

confidence: 99%

Seed dispersal by frugivores without seed swallowing: Evaluating the contributions of stomatochoric seed dispersers

McConkey,

Sushma,

Sengupta

2024

Functional Ecology

Self Cite

View full text Add to dashboard Cite

The process of seed dispersal that underpins ecosystem maintenance is performed by diverse arrays of fruit‐eating animals. However, seed dispersal studies are primarily focused on a subset of these animal communities that disperse seeds by endozoochory. Stomatochory (seed dispersal in which seeds are carried externally and are not swallowed) is rarely considered to be effective, despite an increasing number of taxa‐focused studies that indicate otherwise. We collated the available information on stomatochory to provide a quantitative overview of the dispersal mechanism, including plant types and fruit traits dispersed, dispersal distances and germination potential for all available taxa. We compared seed sizes dispersed, dispersal distances and germination potential with corresponding data on endozoochory for bats and primates. We also identified the main taxa dispersing seeds by stomatochory and assessed what factors influenced the distances that they carried seeds to. Stomatochoric dispersers can displace large quantities of seeds, including large seeds and those of large fruits, and over short to long distances (>1 km). Compared with similar‐sized endozoochoric dispersers, they can disperse larger seeds, but over shorter distances, on average. Similar to endozoochory, seed handling by stomatochory also improves the germination potential of dispersed seeds. Dispersal distances achieved by stomatochory were influenced by body mass, daily path length, seed width, fruit type and seed handling techniques. Five main taxonomic groups of stomatochoric dispersers were identified: bats, parrots, squirrels, corvids and Old World monkeys (cercopithecines). Parrots perform dispersal services for the largest fruits and over the longest distances. However, given the lack of research on stomatochory, it is likely other taxa are also important stomatochoric dispersers but have not been identified yet. More research attention must be directed towards seed dispersal services that are not provided by endozoochory. Many stomatochoric dispersers are common animals within communities and could be playing dominant seed dispersal roles, even without swallowing seeds. Community‐wide studies should incorporate all seed dispersal interactions, rather than focusing solely on endozoochory. This will ensure a more robust understanding of community‐wide patterns. Read the free Plain Language Summary for this article on the Journal blog.

show abstract

Reliability of macaques as seed dispersers

Cited by 6 publications

References 62 publications

The Influence of Seed Characteristics on Seed Dispersal Early Stages by Tibetan Macaques

The Influence of Seed Characteristics on Seed Dispersal Early Stages by Tibetan Macaques

Seed Shadows of Northern Pigtailed Macaques within a Degraded Forest Fragment, Thailand

Seed dispersal by frugivores without seed swallowing: Evaluating the contributions of stomatochoric seed dispersers

Contact Info

Product

Resources

About