scholarly journals Faecal analysis of frugivorous birds and seed dispersal in conifer plantations

2009 ◽  
Vol 58 (2) ◽  
pp. 187-191 ◽  
Author(s):  
Ryoko Hirata ◽  
Kunihiko Hata ◽  
Koichi Sone
Keyword(s):  
Seed Dispersal ◽  
Frugivorous Birds ◽  
Faecal Analysis ◽  
Conifer Plantations

scholarly journals Do Coarser Gap Mosaics in Conifer Plantations Induce More Seed Dispersal by Birds? Temporal Changes during 12 Years after Gap Creation

Forests ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 918
Author(s):  
Tsubasa Takano ◽  
Yohsuke Kominami ◽  
Hiromi Mizunaga
Keyword(s):  
Seed Dispersal ◽  
Species Composition ◽  
Winter Season ◽  
Temporal Changes ◽  
Canopy Gaps ◽  
Vegetation Development ◽  
Frugivorous Birds ◽  
Α Diversity ◽  
Conifer Plantations ◽  
Gap Creation

The creation of canopy gaps is thought to be an efficient silvicultural operation to diversify species composition of monoculture conifer plantations; however, the shortage of regeneration materials in overclosed plantations is one of the concerns related to this operation. Seed dispersal by frugivorous birds may play an important role in inducing the spread of native broad-leaved trees in canopy gaps in plantations in the warm temperate zone of central Japan because bird-dispersed woody species are abundant in this area. We monitored the dynamics of the abundance and species composition of bird-dispersed seeds over 12 years after gap creation in the canopy of a Japanese cypress (Chamaecyparis obtusa (Siebold et Zucc.) Endl.) plantation. We also studied the effects of gap-mosaic patterns (from many small gaps to fewer large gaps) on dispersal. We used a hierarchical Bayesian zero-inflated Poisson model to analyze the factors affecting seed dispersal by frugivorous birds. Seed dispersal by birds increased with gap age except for just after gap creation. Dispersal in coarser gap mosaics was more abundant than that in finer gap mosaics. The species diversity of dispersed seeds in each seed trap (α-diversity) and plot (γ-diversity) showed similar trends in terms of temporal changes and differences between plots related to seed dispersal abundance; β-diversity did not. These trends might have been caused by shrub-vegetation development after gap creation. The effects of shrub vegetation were classified into the attraction by fruits borne within the vegetation, as well as other effects related to vegetation, such as functions of perch availability and insect presence as a food source. The presence of bird-dispersed seeds was strongly promoted by vegetation in all seasons, but only marginally by the presence of fruit-bearing vegetation. However, fruits attracted seed dispersal by frugivorous birds in the winter season. Our results suggest that both vegetation development and fruiting are important for promoting seed dispersal by frugivorous birds, and those effects are different in different seasons according to vegetation conditions and shifting food resources.

Fruits foraging patterns and seed dispersal effect of frugivorous birds on Hippophae rhamnoides sinensis

2006 ◽  
Vol 1 (3) ◽  
pp. 318-322 ◽  
Author(s):  
Xianwen Lu ◽  
Kun Sun ◽  
Ruijun Ma ◽  
Hui Zhang ◽  
Xue Su ◽  
...  
Keyword(s):  
Seed Dispersal ◽  
Hippophae Rhamnoides ◽  
Frugivorous Birds ◽  
Foraging Patterns ◽  
Hippophaë Rhamnoides

Seed dispersal effectiveness by frugivorous birds: Identifying functional equivalent species in bird assemblages

2019 ◽  
Vol 12 (3) ◽  
pp. 103-108
Author(s):  
Facundo Xavier Palacio
Keyword(s):  
Seed Dispersal ◽  
Statistical Significance ◽  
Bird Species ◽  
Kernel Functions ◽  
Bird Conservation ◽  
Frugivorous Birds ◽  
Seed Dispersal Effectiveness ◽  
Bird Assemblages ◽  
Functional Equivalent ◽  
Dispersal Effectiveness

Seed dispersal by birds is a pivotal ecosystem function worldwide; yet, the rapid and ongoing global biodiversity loss poses a major threat to this essential ecosystem service. Seed dispersal effectiveness (SDE) is a key outcome of the interaction, represented by the product of seed dispersal quantity (number of seed dispersed) and quality (probability of recruitment of dispersed seeds). Therefore, identifying functional equivalent species in terms of SDE should become a key issue for bird conservation, since the effects of local extinctions on seed dispersal services may be weakened by remaining equivalent species. However, a method to quantitatively identify functional equivalent species in frugivorous bird assemblages is still lacking. To estimate SDE overlap between seed dispersers and assess whether two species may be functionally equivalent, I apply a novel nonparametric niche overlap index based on kernel functions and null models to test its statistical significance. For each bird species, I account for intraspecific variation in seed dispersal effectiveness to obtain a distribution of seed dispersal effectiveness values, an often neglected source of variation in seed dispersal assemblages. Non-significant differences in seed dispersal effectiveness overlap support the hypothesis that two species are functional equivalent, thus playing similar functional roles. The model proposed is applicable to any other quantity or quality component and is independent from the method or sampling design used to quantify SDE. The identification of functional equivalent species in seed dispersal assemblages adds to the theoretical framework of seed dispersal effectiveness and offers new insights into the ecology of the seed dispersal service provided by birds.

scholarly journals Seed Dispersal by Frugivores and Germination Success of the Invasive Alien Shrub Pyracantha Angustifolia in the Eastern Free State Province, South Africa

2021 ◽  
Author(s):  
Lehlohonolo Donald Adams ◽  
Grant D. Martin ◽  
Colleen T. Downs ◽  
Vincent Ralph Clark ◽  
Vuyisile Thabethe ◽  
...  
Keyword(s):  
Seed Dispersal ◽  
Bird Species ◽  
Camera Traps ◽  
Free State ◽  
Fruit Pulp ◽  
Frugivorous Birds ◽  
Alien Plant ◽  
Free State Province ◽  
Germination Success ◽  
Eastern Free State

Abstract Invasive alien plants can use animal-plant interactions to increase their invasiveness. This study investigated the role of frugivorous birds in seed dispersal and germination of the alien plant Pyracantha angustifolia (Rosaceae) in South African high elevation grasslands. We monitored which bird species fed on the fruit of the invasive P. angustifolia in some farms in the Eastern Free State Province using camera-traps and direct surveillance. Nine bird species visited P. angustifolia shrubs to perch or feed on fruits, but only one bird (Speckled Mousebird) fed on the fruits during timed observations. To assess the effect of ingestion by avian frugivores on P. angustifolia germination, P. angustifolia fruits were fed to captive Cape White-eyes (Zosterops virens), Dark-capped Bulbuls (Pycnonotus tricolor), Purple-crested Turacos (Gallirex porphyreolophus), Red-winged Starlings (Onychognathus morio) and Speckled Mousebirds (Colius striatus). Seeds collected from bird excreta, whole fruits, and depulped fruits were grown under greenhouse conditions and germination rates recorded. All captive bird species, except for Cape White-eyes, ingested the seeds; Cape White-eyes only fed on fruit pulp that they had manually removed. Bird species with relatively larger body mass had longer seed retention times compared with the smaller bird species. Germination success of both depulped and ingested P. angustifolia seeds was high (> 80%) and that of whole fruits low (7%). Ingestion by the four avian frugivore species did not affect germination rate and success; instead, the birds facilitate the spread and germination of seeds by removing the fruit pulp and spreading the seed away from the parent shrubs.

Seed-dispersing bird assemblages in riparian environments of a partially urbanized river basin, Southeastern Brazil

2020 ◽  
Author(s):  
B. F. Lessi ◽  
M. G. Reis ◽  
C. Z. Fieker ◽  
M. M. Dias
Keyword(s):  
Ecosystem Services ◽  
Seed Dispersal ◽  
Bird Species ◽  
Dry Season ◽  
Ecosystem Dynamics ◽  
Southeastern Brazil ◽  
Wet Season ◽  
Frugivorous Birds ◽  
Entire Area ◽  
Number Of Individuals

Abstract Birds play a key role in ecosystem dynamics, including urban and rural areas, bringing environmental quality improvements and ecological stability. Species contribute directly to natural regeneration of vegetation and succession processes, by offering ecosystem services as seed dispersal, an important role in human-modified areas. We studied the assemblages of fruit-eating birds in riparian environments of Monjolinho basin, central São Paulo state, southeastern Brazil. Birds were recorded in 41 points distributed in riparian ecosystems alongside waterbodies, in landscapes with five types of surrounding matrices: urban, periurban, farmland, and native vegetation. We described how assemblages are structured aiming to evaluate the possible influence of seasonality and landscape type. We recorded 39 bird species that can play a role as seed-dispersers, 32 in wet season and 32 in dry season. There were no significant differences in the diversity and dominance of species between seasons considering the entire area, indicating stability of basic assemblage structure. However, total number of individuals of all species recorded in different landscapes were influenced by seasonality. Also, the composition and abundance of species significantly changed between seasons, leading to a high dissimilarity with almost 50% of the species contributing with almost 90% of the observed variation. A higher taxonomic diversity and distinctness pointed to a wider array of possible seed dispersal services in natural areas, while the lowest values of indexes were found in human-modified areas. The higher number of non-related bird species during dry season contrasted with the higher number of individuals during wet season, indicating that there is more possible ecosystem services offered by frugivorous birds in driest period of the year, while in the rainy period the carrying capacity of the riparian environments was increased.

Two-phase seed dispersal: linking the effects of frugivorous birds and seed-caching rodents

Oecologia ◽  
2005 ◽  
Vol 145 (2) ◽  
pp. 281-286 ◽  
Author(s):  
Stephen B. Vander Wall ◽  
Kellie M. Kuhn ◽  
Jennifer R. Gworek
Keyword(s):  
Seed Dispersal ◽  
Two Phase ◽  
Frugivorous Birds ◽  
Seed Caching

scholarly journals Stability and generalization in seed dispersal networks: a case study of frugivorous fish in Neotropical wetlands

2016 ◽  
Vol 283 (1837) ◽  
pp. 20161267 ◽  
Author(s):  
Sandra Bibiana Correa ◽  
Joisiane K. Arujo ◽  
Jerry Penha ◽  
Catia Nunes da Cunha ◽  
Karen E. Bobier ◽  
...  
Keyword(s):  
Seed Dispersal ◽  
Plant Species ◽  
Binary Data ◽  
Species Loss ◽  
Small Species ◽  
Network Stability ◽  
Frugivorous Birds ◽  
Neotropical Wetlands ◽  
Using Data

When species within guilds perform similar ecological roles, functional redundancy can buffer ecosystems against species loss. Using data on the frequency of interactions between fish and fruit, we assessed whether co-occurring frugivores provide redundant seed dispersal services in three species-rich Neotropical wetlands. Our study revealed that frugivorous fishes have generalized diets; however, large-bodied fishes had greater seed dispersal breadth than small species, in some cases, providing seed dispersal services not achieved by smaller fish species. As overfishing disproportionately affects big fishes, the extirpation of these species could cause larger secondary extinctions of plant species than the loss of small specialist frugivores. To evaluate the consequences of frugivore specialization for network stability, we extracted data from 39 published seed dispersal networks of frugivorous birds, mammals and fish (our networks) across ecosystems. Our analysis of interaction frequencies revealed low frugivore specialization and lower nestedness than analyses based on binary data (presence–absence of interactions). In that case, ecosystems may be resilient to loss of any given frugivore. However, robustness to frugivore extinction declines with specialization, such that networks composed primarily of specialist frugivores are highly susceptible to the loss of generalists. In contrast with analyses of binary data, recently developed algorithms capable of modelling interaction strengths provide opportunities to enhance our understanding of complex ecological networks by accounting for heterogeneity of frugivore–fruit interactions.

The effect of gut processing on the quality of mistletoe seed dispersal

2007 ◽  
Vol 23 (3) ◽  
pp. 377-380 ◽  
Author(s):  
Lizanne Roxburgh
Keyword(s):  
Seed Dispersal ◽  
Frugivorous Birds ◽  
The Future ◽  
Future Reproduction ◽  
Number Of Visits ◽  
Fruiting Plant ◽  
Number Of Seeds ◽  
Disperser Effectiveness

Disperser effectiveness is the contribution that a disperser makes to the future reproduction of a plant (Schupp 1993), and it has two components: quality and quantity of dispersal. Quantity of dispersal is a function of the number of visits that a disperser makes to a fruiting plant and the number of seeds that are dispersed during each visit. Quality of dispersal is a function of the treatment that a seed receives from its disperser and the site that the seed is finally deposited in. The quality of seed dispersal of the mistletoe Phragmanthera dschallensis (Engl.) M.G. Gilbert (Loranthaceae) by frugivorous birds was examined in this study.

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