Trophic Organization of Understory Birds in a Malaysian Dipterocarp Forest

Abstract Single-sample studies suggested that understory flowers and fruits and their avian consumers are scarce in the Malaysian rain forest as compared with African and Central American rain forests. Results from my longer-term studies at Pasoh Forest Reserve (Negeri Sembilan, Peninsular Malaysia) established that flowers and fruits were consistently rare as food for birds. A comparison of two forest types at Pasoh revealed the effect of lower food availability on avian trophic organization. Food resources (e.g. flowers, fruits, arthropods) were less abundant in the regenerating than in the virgin forest, and bird species richness and individual abundance were also lower in the regenerating forest understory. However, the two forests did not differ significantly in the relative importance of the various foraging guilds, suggesting that similar types of resources were present in similar proportions. None of the birds sampled in the Malaysian rain-forest understory was a specialized consumer of understory flowers or fruit, whereas birds feeding mainly on foliage-dwelling arthropods were abundant and were represented by many species. This trophic organization is contrary to that reported for rain forests in other tropical regions but may simply reflect an allocation of harvestable productivity that is different rather than lower.

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Fig-eating by birds in a Malaysian lowland rain forest

Journal of Tropical Ecology ◽

10.1017/s0266467400003850 ◽

1989 ◽

Vol 5 (4) ◽

pp. 401-412 ◽

Cited By ~ 54

Author(s):

Frank Lambert

Keyword(s):

Rain Forest ◽

Bird Species ◽

Peninsular Malaysia ◽

Forest Site ◽

Lowland Forest ◽

Lowland Rain Forest

ABSTRACTSixty bird species ate the figs of 29 Ficus taxa at a lowland forest site in Peninsular Malaysia. Although most bird-eaten figs were brightly coloured, four Ficus species produced dull-coloured ripe fruits. Whilst there was tremendous overlap in the sizes of figs eaten by different bird species, data presented show that the fig resource was partitioned by birds. Large birds were commoner visitors to large-fruited Ficus, but small birds tended to eat small figs. Within two avian genera, the Treron pigeons and Megalaima barbets, there was distinct partitioning of figs consumed according to fig size.

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Ecological Role of a Tree (Gmelina Arborea) Plantation in Guatemala: An Assessment of an Alternative Land use for Tropical Avian Conservation

The Auk ◽

10.1093/auk/124.1.316 ◽

2007 ◽

Vol 124 (1) ◽

pp. 316-330 ◽

Cited By ~ 1

Author(s):

James A. Rotenberg

Keyword(s):

Species Richness ◽

Bird Species ◽

Positive Association ◽

Management Plan ◽

Forest Fragments ◽

Land Uses ◽

Gmelina Arborea ◽

Bird Species Richness ◽

Tropical Regions ◽

Grazed Pasture

AbstractEstablished parks and nature reserves may be inadequate to preserve long-term biotic diversity, especially in tropical regions of Latin America where anthropogenic disturbance and land-conversion is an ongoing problem. Demand for economically productive land uses, such as cattle pastures or monoculture plantations, is one of the greatest threats to habitat and wildlife preservation. As a result, conservation biologists have turned to examining attributes of nonprotected lands to determine which land uses both support wildlife and make economic sense. I examined bird use of a plantation of Gmelina arborea (“white teak” or “melina” trees; hereafter “plantation”) in Guatemala to assess its suitability as bird habitat. Gmelina arborea is grown mainly for wood and paper pulp. Several compositionally different habitats were identified, based on the amount of natural vegetation grown within and among the plantation trees, forming a heterogeneous landscape. I detected 195 bird species from 45 families within this plantation-dominated landscape, and 144 species in plantation habitats combined. I observed a positive association between increased vegetative complexity and bird species richness; moreover, bird species richness attained levels statistically indistinguishable from those found in nearby forest fragments. Mixed plantation habitat containing 19–31% natural vegetative coverage supported bird communities that equaled or surpassed levels of species richness found by other researchers in shaded coffee (Coffea spp.) plantations. However, pure stands of G. arborea supported richness levels equal to those of grazed pasture; diversity levels associated with both these land uses were close to those reported for sun coffee plantations. Clearly, native vegetation played a significant role in enhancing bird species richness in the plantation habitat, and amounts of relative cover similar to or exceeding those in the plantation I studied should be considered in any management plan for G. arborea in Central America.Rol Ecológico de Plantaciones de Árboles de Gmelina arborea en Guatemala: Una Evaluación de un Uso Alternativo del Suelo para la Conservación de las Aves Tropicales

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Effectiveness of protected areas in conserving tropical forest birds

Nature Communications ◽

10.1038/s41467-020-18230-0 ◽

2020 ◽

Vol 11 (1) ◽

Author(s):

Victor Cazalis ◽

Karine Princé ◽

Jean-Baptiste Mihoub ◽

Joseph Kelly ◽

Stuart H. M. Butchart ◽

...

Keyword(s):

Tropical Forest ◽

Protected Areas ◽

Bird Species ◽

Terrestrial Ecosystems ◽

Forest Birds ◽

Bird Diversity ◽

Bird Species Richness ◽

Tropical Regions ◽

Positive Effects ◽

Near Threatened

Abstract Protected areas (PAs) are the cornerstones of global biodiversity conservation efforts, but to fulfil this role they must be effective at conserving the ecosystems and species that occur within their boundaries. Adequate monitoring datasets that allow comparing biodiversity between protected and unprotected sites are lacking in tropical regions. Here we use the largest citizen science biodiversity dataset – eBird – to quantify the extent to which protected areas in eight tropical forest biodiversity hotspots are effective at retaining bird diversity. We find generally positive effects of protection on the diversity of bird species that are forest-dependent, endemic to the hotspots, or threatened or Near Threatened, but not on overall bird species richness. Furthermore, we show that in most of the hotspots examined this benefit is driven by protected areas preventing both forest loss and degradation. Our results provide evidence that, on average, protected areas contribute measurably to conserving bird species in some of the world’s most diverse and threatened terrestrial ecosystems.

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Functional evenness of bird communities varies along the elevational gradient in Europe: Conservation implications

10.32942/osf.io/sx9n8 ◽

2019 ◽

Author(s):

Federico Morelli ◽

Yanina

Keyword(s):

Species Richness ◽

Elevation Gradient ◽

Bird Species ◽

Elevational Gradient ◽

Negative Association ◽

Bird Communities ◽

Breeding Bird ◽

Bird Species Richness ◽

Large Spatial Scale ◽

Functional Evenness

ContextThe negative association between elevation and species richness is a well-recognized pattern in macro-ecology. ObjectivesThe aim of this study was to investigate changes in functional evenness of breeding bird communities along an elevation gradient in Europe. MethodsUsing the bird data from the EBCC Atlas of European Breeding Birds we estimated an index of functional evenness which can be assumed as a measure of the potential resilience of communities.ResultsOur findings confirm the existence of a negative association between elevation and bird species richness in all European eco regions. However, we also explored a novel aspect of this relationship, important for conservation: Our findings provide evidence at large spatial scale of a negative association between the functional evenness (potential community resilience) and elevation, independent of the eco region. We also found that the Natura2000 protected areas covers the territory most in need of protection, those characterized by bird communities with low potential resilience, in hilly and mountainous areas.ConclusionsThese results draw attention to European areas occupied by bird communities characterized by a potential lower capacity to respond to strong ecological changes, and, therefore, potentially more exposed to risks for conservation.

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Ants accelerate litter decomposition in a Costa Rican lowland tropical rain forest

Journal of Tropical Ecology ◽

10.1017/s0266467412000375 ◽

2012 ◽

Vol 28 (5) ◽

pp. 437-443 ◽

Cited By ~ 15

Author(s):

Terrence P. McGlynn ◽

Evan K. Poirson

Keyword(s):

Mass Loss ◽

Leaf Litter ◽

Litter Decomposition ◽

Rain Forest ◽

Costa Rican ◽

Tropical Rain Forests ◽

Rain Forests ◽

Food Web Structure ◽

Litter Bags ◽

Lowland Rain Forest

Abstract:The decomposition of leaf litter is governed, in part, by litter invertebrates. In tropical rain forests, ants are dominant predators in the leaf litter and may alter litter decomposition through the action of a top-down control of food web structure. The role of ants in litter decomposition was investigated in a Costa Rican lowland rain forest with two experiments. In a mesocosm experiment, we manipulated ant presence in 50 ambient leaf-litter mesocosms. In a litterbag gradient experiment, Cecropia obtusifolia litter was used to measure decomposition rate constants across gradients in nutrients, ant density and richness, with 27 separate litterbag treatments for total arthropod exclusion or partial arthropod exclusion. After 2 mo, mass loss in mesocosms containing ants was 30.9%, significantly greater than the 23.5% mass loss in mesocosms without ants. In the litter bags with all arthropods excluded, decomposition was best accounted by the carbon: phosphorus content of soil (r2 = 0.41). In litter bags permitting smaller arthropods but excluding ants, decomposition was best explained by the local biomass of ants in the vicinity of the litter bags (r2 = 0.50). Once the microarthropod prey of ants are permitted to enter litterbags, the biomass of ants near the litterbags overtakes soil chemistry as the regulator of decomposition. In concert, these results support a working hypothesis that litter-dwelling ants are responsible for accelerating litter decomposition in lowland tropical rain forests.

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Community characteristics of forest understory birds along an elevational gradient in the Horn of Africa: A multi-year baseline

The Condor ◽

10.1093/ornithapp/duab009 ◽

2021 ◽

Author(s):

Kyle D Kittelberger ◽

Montague H C Neate-Clegg ◽

Evan R Buechley ◽

Çağan Hakkı Şekercioğlu

Keyword(s):

Species Richness ◽

Species Turnover ◽

Survival Rates ◽

Elevational Gradient ◽

Forest Understory ◽

Bird Abundance ◽

Tropical Mountains ◽

Demographic Rates ◽

Understory Birds ◽

Over Time

Abstract Tropical mountains are global hotspots for birdlife. However, there is a dearth of baseline avifaunal data along elevational gradients, particularly in Africa, limiting our ability to observe and assess changes over time in tropical montane avian communities. In this study, we undertook a multi-year assessment of understory birds along a 1,750 m elevational gradient (1,430–3,186 m) in an Afrotropical moist evergreen montane forest within Ethiopia’s Bale Mountains. Analyzing 6 years of systematic bird-banding data from 5 sites, we describe the patterns of species richness, abundance, community composition, and demographic rates over space and time. We found bimodal patterns in observed and estimated species richness across the elevational gradient (peaking at 1,430 and 2,388 m), although no sites reached asymptotic species richness throughout the study. Species turnover was high across the gradient, though forested sites at mid-elevations resembled each other in species composition. We found significant variation across sites in bird abundance in some of the dietary and habitat guilds. However, we did not find any significant trends in species richness or guild abundances over time. For the majority of analyzed species, capture rates did not change over time and there were no changes in species’ mean elevations. Population growth rates, recruitment rates, and apparent survival rates averaged 1.02, 0.52, and 0.51 respectively, and there were no elevational patterns in demographic rates. This study establishes a multi-year baseline for Afrotropical birds along an elevational gradient in an under-studied international biodiversity hotspot. These data will be critical in assessing the long-term responses of tropical montane birdlife to climate change and habitat degradation.

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Patterns of bird species richness explained by annual variation in remotely sensed Dynamic Habitat Indices

Ecological Indicators ◽

10.1016/j.ecolind.2021.107774 ◽

2021 ◽

Vol 127 ◽

pp. 107774

Author(s):

Martina L. Hobi ◽

Laura S. Farwell ◽

Maxim Dubinin ◽

Dmitrij Kolesov ◽

Anna M. Pidgeon ◽

...

Keyword(s):

Species Richness ◽

Annual Variation ◽

Bird Species ◽

Remotely Sensed ◽

Bird Species Richness ◽

Dynamic Habitat

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Can clearcuts increase bird species richness in managed forests?

Journal of Forest Science ◽

10.17221/787-jfs ◽

2008 ◽

Vol 54 (No. 4) ◽

pp. 189-193

Author(s):

M. Żmihorski

Keyword(s):

Species Richness ◽

Bird Species ◽

Bird Communities ◽

Cumulative Number ◽

Managed Forests ◽

Managed Forest ◽

Bird Species Richness ◽

Forest Interior ◽

Transect Counts ◽

The Difference

Clearcuts are one of the results of forest management. The aim of this study was to assess the effect of clearcuts on bird communities in a managed forest in Western Poland. I applied the method of point transect counts. 20 points were located near clearcuts (less than 100 m from the nearest clearcut) and 25 points in the forest interior. In total, 36 bird species were recorded. On average, I found 9.20 bird species at points located near clearcuts and 6.72 species at points situated in the forest interior, and the difference was significant. The cumulative number of bird species for a given number of sampling points in the vicinity of clearcuts was higher than in the forest interior. The obtained results indicate that in managed, even-aged forests the generation of clearcuts can lead to an increase in local bird species richness.

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Evaluating the role of contracting and expanding rainforest in initiating cycles of speciation across the Isthmus of Panama

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2012.0706 ◽

2012 ◽

Vol 279 (1742) ◽

pp. 3520-3526 ◽

Cited By ~ 37

Author(s):

Brian Tilston Smith ◽

Amei Amei ◽

John Klicka

Keyword(s):

Bird Species ◽

Tropical Regions ◽

Isthmus Of Panama ◽

Species Pairs ◽

The Matrix ◽

High Species Richness ◽

The Rich ◽

The Tropics ◽

The Impact

Climatic and geological changes across time are presumed to have shaped the rich biodiversity of tropical regions. However, the impact climatic drying and subsequent tropical rainforest contraction had on speciation has been controversial because of inconsistent palaeoecological and genetic data. Despite the strong interest in examining the role of climatic change on speciation in the Neotropics there has been few comparative studies, particularly, those that include non-rainforest taxa. We used bird species that inhabit humid or dry habitats that dispersed across the Panamanian Isthmus to characterize temporal and spatial patterns of speciation across this barrier. Here, we show that these two assemblages of birds exhibit temporally different speciation time patterns that supports multiple cycles of speciation. Evidence for these cycles is further corroborated by the finding that both assemblages consist of ‘young’ and ‘old’ species, despite dry habitat species pairs being geographically more distant than pairs of humid habitat species. The matrix of humid and dry habitats in the tropics not only allows for the maintenance of high species richness, but additionally this study suggests that these environments may have promoted speciation. We conclude that differentially expanding and contracting distributions of dry and humid habitats was probably an important contributor to speciation in the tropics.

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