Pest-removal services provided by birds on subsistence farms in south-eastern Nigeria

To what extent birds provide the ecosystem service of pest control in subsistence farms, and how this service might depend on retained natural habitats near farmlands is unexplored in West Africa. To fill this knowledge gap, we placed plasticine mimics of insect pests on experimentally grown crops on the Mambilla Plateau, South Eastern Nigeria. We recorded bird attacks on the mimics and the proportion of mimics removed by birds. We also determined the influence of distance of crops from forest fragments on both attack and removal rates. We placed 90 potted plants of groundnut (Arachis hypogea) and bambara nut (Vigna subterranea) along 15 transects running 4.5 km from forest edge into open grassland. Each plant had six of the 540 mimics in total placed on their leaves. We inspected the potted plants weekly for 12 weeks to record (i) the presence of bird beak marks on mimics, and (ii) the number of missing mimics. Once a week we collected all the mimics from the plants and counted the number of assumed beak marks. After counting we replaced the mimics on the plants, mark free. We found a strong positive correlation between the abundance of insectivorous birds and the mean number of missing mimics and/or bird attack marks on mimics. However, this positive effect of insectivorous bird abundance on prey mimic attack/removal became less strong the farther they were from a forest fragment. We found increased predation rates and abundance of insectivorous birds closer to forest fragments. Our data suggest that pest predation may be a key ecosystem service provided by insectivorous birds on Nigerian farmlands. Farmlands that are closer to forest fragments may experience a higher rate of pest control by insectivorous birds than those further away, suggesting that retaining forest fragments in the landscape may enhance pest control services in sub-Saharan subsistence farms.

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Landscape drivers and effectiveness of pest control by insectivorous birds in a landscape-dominant woody crop

10.1101/2020.03.07.981845 ◽

2020 ◽

Author(s):

Carlos Martínez-Núñez ◽

Pedro J. Rey ◽

Antonio J. Manzaneda ◽

Daniel García ◽

Rubén Tarifa ◽

...

Keyword(s):

Pest Control ◽

Ecosystem Service ◽

Field Experiments ◽

Landscape Heterogeneity ◽

List Type ◽

Insectivorous Birds ◽

Landscape Complexity ◽

Pest Damage ◽

Woody Crop ◽

Plasticine Models

AbstractAvian-mediated pest control is a significant ecosystem service with important economic implications. However, there is an overall paucity of experimental information about how landscape simplification affect its current level. Information on pest control by birds is missing in some permanent agroecosystems of worldwide importance, like olive orchards, that dominate vast areas in the Mediterranean region.We assess the effectiveness of insectivorous birds for controlling the two main pest insects in olive orchards and explore the effects of landscape complexity and distance to semi-natural patches on avian insectivore abundance and pest control. For this, we combine bird surveys with field experiments (branch exclusions and pest plasticine models) at the regional scale.Landscape heterogeneity increased the abundance and richness of insectivorous birds, which were also more abundant and diverse in semi-natural patches, compared to the farm olive matrix. Experiments evidenced that pest control by birds (measured as attack rates to plasticine models and pest damage) in the studied olive orchards is negligible, while pests were overall abundant and pest damage was high on most farms. This raises alarms about the status of avian pest control in this agroecosystem.Although landscape heterogeneity increased the abundance/richness of insectivorous birds, and favored some forest species, insectivorous bird abundance seems diluted in relation to prey availability in all landscapes. Thus, pest control by birds seems currently unsuccessful in olive orchards. Our results might be evidencing the loss of an ecosystem service due to a generalized massive decline of common and forest insectivorous birds.Key messageOlive orchards dominate extensive areas causing important landscape simplification.Insectivorous birds are more abundant in semi-natural patches within olive farms.Field experiments show a low impact of birds on olive pests and damage.Avian-mediated pest biocontrol seems diluted by limited suitable habitat for birds.Agri-environmental measures should focus on increasing landscape complexity.

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Proportion of Grassland at Landscape Scale Drives Natural Pest Control Services in Agricultural Landscapes

Frontiers in Ecology and Evolution ◽

10.3389/fevo.2021.607023 ◽

2021 ◽

Vol 9 ◽

Author(s):

Thomas Perrot ◽

Adrien Rusch ◽

Camille Coux ◽

Sabrina Gaba ◽

Vincent Bretagnolle

Keyword(s):

Pest Control ◽

Crop Yields ◽

Spatial Arrangement ◽

Agricultural Landscapes ◽

Dispersal Ability ◽

Forest Fragments ◽

Natural Habitats ◽

Arable Fields ◽

Cereal Fields ◽

Natural Pest Control

Managing regulating ecosystem services delivered by biodiversity in farmland is a way to maintain crop yields while reducing the use of agrochemicals. Because semi-natural habitats provide shelter and food for pest enemies, a higher proportion of semi-natural habitats in the landscape or their proximity to crops may enhance pest control in arable fields. However, the ways in which the spatial arrangement of these habitats affects the delivery of this beneficial ecosystem service to crops remains poorly known. Here, we investigated the relative effects of the amount of grassland in the landscape versus the distance to the nearest grassland on the predation rates of weed seeds and aphids into 52 cereal fields. We found that both seed and aphid predation levels increased with the proportion of grassland in a 500 m radius buffer while the distance to the nearest grassland displayed no effect. We show that increasing from 0 to 50% the proportion of grasslands in a 500 m radius, respectively, increased seed and aphid predation by 38 and 20%. In addition to the strong effect of the proportion of grassland, we found that seed predation increased with the proportion of forest fragments while aphid predation increased with the proportion of organic farming in the landscape. Overall, our results reveal that natural pest control in cereal crops is not related to the distance to the nearest grassland, suggesting that natural enemies are not limited by their dispersal ability. Our study indicates that maintaining key semi-natural habitats, such as grasslands, is needed to ensure natural pest control and support food production in agricultural landscapes.

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Variegated tropical landscapes conserve diverse dung beetle communities

PeerJ ◽

10.7717/peerj.3125 ◽

2017 ◽

Vol 5 ◽

pp. e3125 ◽

Cited By ~ 12

Author(s):

Cristiane Costa ◽

Victor Hugo F. Oliveira ◽

Rafaella Maciel ◽

Wallace Beiroz ◽

Vanesca Korasaki ◽

...

Keyword(s):

Species Richness ◽

Community Structure ◽

Canopy Cover ◽

Dung Beetle ◽

Dung Beetles ◽

Forest Fragments ◽

Forest Fragment ◽

Natural Habitats ◽

Vegetation Heterogeneity ◽

Tropical Landscapes

BackgroundConserving biodiversity in tropical landscapes is a major challenge to scientists and conservationists. Current rates of deforestation, fragmentation, and land use intensification are producing variegated landscapes with undetermined values for the conservation of biological communities and ecosystem functioning. Here, we investigate the importance of tropical variegated landscapes to biodiversity conservation, using dung beetle as focal taxa.MethodsThe study was carried out in 12 variegated landscapes where dung beetles were sampled using six pitfall traps, 30 m apart from each other, along a transect in each studied landscape use and cover classes—LUCC (forest fragment and corridor, coffee plantation, and pasture). We baited each pitfall trap with 30 g of human feces and left open for a 48 h period. We also measured three environmental variables reflecting structural differences among the studied classes: canopy cover, local vegetation heterogeneity and soil sand content.ResultsWe collected 52 species and 2,695 individuals of dung beetles. We observed significant differences in the mean species richness, abundance and biomass among classes, with forest fragments presenting the highest values, forest corridors and coffee plantations presenting intermediate values, and pastures the lowest values. Regarding community structure, we also found significant differences among classes. Canopy cover was the only variable explaining variation in dung beetle species richness, abundance, biomass, and community structure. The relative importance of spatial turnover was greater than nestedness-resultant component in all studied landscapes.DiscussionThis study evaluated the ecological patterns of dung beetle communities in variegated tropical landscapes highlighting the importance of these landscapes for conservation of tropical biodiversity. However, we encourage variegation for the management of landscapes that have already been fragmented or as a complementary initiative of current conservation practices (e.g., protection of natural habitats and establishment of reserves).

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Small mammal glucocorticoid concentrations vary with forest fragment size, trap type, and mammal taxa in the Interior Atlantic Forest

Scientific Reports ◽

10.1038/s41598-021-81073-2 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Sarah A. Boyle ◽

Noé U. de la Sancha ◽

Pastor Pérez ◽

David Kabelik

Keyword(s):

Atlantic Forest ◽

Small Mammals ◽

Acute Stress ◽

Physiological Stress ◽

Fragment Size ◽

Hair Shaft ◽

Forest Fragments ◽

Forest Fragment ◽

Trapping Methods ◽

Free Ranging

AbstractSpecies that live in degraded habitats often show signs of physiological stress. Glucocorticoid hormones (e.g., corticosterone and cortisol) are often assessed as a proxy of the extent of physiological stress an animal has experienced. Our goal was to quantify glucocorticoids in free-ranging small mammals in fragments of Interior Atlantic Forest. We extracted glucocorticoids from fur samples of 106 small mammals (rodent genera Akodon and Oligoryzomys, and marsupial genera Gracilinanus and Marmosa) from six forest fragments (2–1200 ha) in the Reserva Natural Tapytá, Caazapá Department, Paraguay. To our knowledge, this is the first publication of corticosterone and cortisol levels for three of the four sampled genera (Akodon, Oligoryzomys, and Marmosa) in this forest system. We discovered three notable results. First, as predicted, glucocorticoid levels were higher in individuals living withing small forest fragments. Second, animals captured live using restraint trapping methods (Sherman traps) had higher glucocorticoid levels than those animals captured using kill traps (Victor traps), suggesting that hair glucocorticoid measures can reflect acute stress levels in addition to long-term glucocorticoid incorporation. These acute levels are likely due to urinary steroids diffusing into the hair shaft. This finding raises a concern about the use of certain trapping techniques in association with fur hormone analysis. Finally, as expected, we also detected genus-specific differences in glucocorticoid levels, as well as cortisol/corticosterone ratios.

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Distribution of Atta (Hymenoptera - Formicidae) in "terra-firme" rain forest of Central Amazonia: density, species composition and preliminary results on effects of forest fragmentation

Acta Amazonica ◽

10.1590/1809-43921988183315 ◽

1988 ◽

Vol 18 (3-4) ◽

pp. 309-315 ◽

Cited By ~ 14

Author(s):

Heraldo Luís de Vasconcelos

Keyword(s):

Species Composition ◽

Rain Forest ◽

Abundant Species ◽

Forest Fragments ◽

Forest Fragment ◽

Terra Firme ◽

Atta Sexdens ◽

Conservation Areas ◽

Continuous Forest ◽

Leaf Cutting

One hundred and fourteen hectares of a "terra-fiirme" rain forest 70 km north of Manaus, Amazonas, Brazil, were surveyed for leaf-cutting ant colonies (Atta spp). One half of this area was in isolated forest fragments (surrounded by pastures or second growth) of two sizes: 1 and 10 ha. The other half was in non-isolated fragments (connected to a large parch of forest) of the same sizes. Only two species occured in this forest: Atta sexdens sexdens L. and A. cepfhalotes L. The first was the most abundant species with a mean density of 0.35 colonies per ha. The mean density of A. cephalotes colonies was 0.03 per ha. The density of colonies was not significantly different between the isolated fragments and the continuous forest. Furthermore, the species composition did not change with isolation. However, pre-isolation data and long term monitoring are necessary to conclude that the isolation of a forest fragment has no effect upon Atta colonies. The non-uniform spatial distribution of Atta colonics within the "terra-firme" forest must be taken into account when selecting conservation areas in the Amazon, in order to preserve this important group of ants together with their native habitat.

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Distribution of the community of frugivorous birds along a successional gradient in a tropical dry forest in south-western Mexico

Journal of Tropical Ecology ◽

10.1017/s0266467414000601 ◽

2014 ◽

Vol 31 (1) ◽

pp. 57-68 ◽

Cited By ~ 10

Author(s):

R. Carlos Almazán-Núñez ◽

María del Coro Arizmendi ◽

Luis E. Eguiarte ◽

Pablo Corcuera

Keyword(s):

Tropical Dry Forest ◽

Dry Season ◽

Dry Forest ◽

Forest Fragments ◽

Dry Forests ◽

Bird Abundance ◽

Frugivorous Birds ◽

Seed Predators ◽

Western Mexico ◽

Successional Forests

Abstract:Few reports have described the relationship between the distribution of frugivorous birds and vegetation successional changes in dry forests. We assessed the abundance and behaviour of frugivorous birds in early, intermediate and mature dry forests in the Balsas river basin, Guerrero, Mexico. We selected nine dry-forest fragments, three fragments per stage, in these three stages of succession. We analysed the vegetation, estimated bird abundances in 10-min count periods, and recorded the way birds process fruits in circular plots (11–15 plots per fragment, 123 plots in total). Birds were classified as seed predators (15% of all individuals in this study), pulp consumers (15%) or legitimate dispersers (70%). Bird abundance was higher in mature forests in the dry season, while abundance and richness of legitimate dispersers and seed predators were positively related to vegetation complexity. Mature forests have a high vegetation complexity and a high cover ofBurseraspecies that produce fruit during the dry season. During the rains, abundance was higher in early-successional sites when the zoochorous plants produced fruit. Legitimate disperser migrants (i.e.Tyrannus vociferans, Myiarchus cinerascensandM. tyrannulus) were widespread, helping the establishment of zoochorous trees such asBurseraspp. in early-successional forests.

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The Participation by Cuckoos in Mixed-Species Flocks of Insectivorous Birds in South-Eastern Australia

Emu - Austral Ornithology ◽

10.1071/mu9860249b ◽

1986 ◽

Vol 86 (4) ◽

pp. 249-253 ◽

Cited By ~ 3

Author(s):

H.L. Bell ◽

H.A. Ford

Keyword(s):

Insectivorous Birds ◽

Mixed Species ◽

South Eastern ◽

Eastern Australia ◽

Mixed Species Flocks ◽

Species Flocks ◽

South Eastern Australia

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Do differences in food web structure between organic and conventional farms affect the ecosystem service of pest control?

Ecology Letters ◽

10.1111/j.1461-0248.2008.01279.x ◽

2009 ◽

Vol 12 (3) ◽

pp. 229-238 ◽

Cited By ~ 147

Author(s):

Sarina Macfadyen ◽

Rachel Gibson ◽

Andrew Polaszek ◽

Rebecca J. Morris ◽

Paul G. Craze ◽

...

Keyword(s):

Food Web ◽

Pest Control ◽

Ecosystem Service ◽

Food Web Structure ◽

Web Structure ◽

Conventional Farms

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ESTRUTURA, DIVERSIDADE E HETEROGENEIDADE DO ESTRATO REGENERANTE EM UM FRAGMENTO FLORESTAL URBANO APÓS 10 ANOS DE SUCESSÃO FLORESTAL

FLORESTA ◽

10.5380/rf.v45i3.34533 ◽

2015 ◽

Vol 45 (3) ◽

pp. 535 ◽

Cited By ~ 1

Author(s):

Raphaela Vilela Eiras e Paiva ◽

José Hugo Campos Ribeiro ◽

Fabricio Alvim Carvalho

Keyword(s):

Multivariate Analysis ◽

Species Diversity ◽

Urban Forest ◽

Shannon Index ◽

Forest Fragments ◽

Ecological Groups ◽

Small Fragment ◽

Forest Fragment ◽

Semideciduous Forest ◽

Dalbergia Nigra

Este estudo visou avaliar a composição florística, a fitossociologia e a diversidade de espécies do estrato regenerante arbóreo de um pequeno fragmento (0,5 ha) de Floresta Estacional Semidecidual, após 10 anos de abandono, no perímetro urbano do município de Juiz de Fora, MG, Brasil. Os indivíduos da regeneração arbórea (altura ≥ 1 m e DAP < 5 cm) foram amostrados em 25 parcelas aleatórias de 5 x 5 m. Foram amostrados 1224 indivíduos pertencentes a 40 espécies. Houve uma forte predominância (> 90%) de espécies de estágios sucessionais iniciais (pioneiras e secundárias iniciais). Como reflexo da forte dominância ecológica observada, exercida principalmente pela elevada densidade das espécies Dalbergia nigra e Siparuna guianensis, o valor do índice de diversidade de espécies de Shannon (H’ = 2,38) foi muito inferior aos valores encontrados para fragmentos florestais maduros. Mesmo sendo um fragmento pequeno, isolado e em estágio inicial de sucessão secundária, análises multivariadas (agrupamento e DCA) evidenciaram a formação de grupos florísticos e uma forte diferenciação no arranjo das espécies, evidenciando a heterogeneidade típica de florestas tropicais. Embora apresente uma baixa diversidade, esse fragmento urbano tem funções ecológicas e sociais importantes para a região, que carece de áreas verdes para a conservação da flora nativa.AbstractStructure, diversity and heterogeneity of regeneration stratum in an urban forest fragment after 10 years of forest succession. This research aimed to evaluate the floristic composition, phytosociology and species diversity of the regenerating woody stratum of a small fragment (0.5 ha) of Semideciduous Forest, after 10 years of abandonment, in the municipality of Juiz de Fora, MG, Brazil. All woody individuals (height ≥ 1 m dbh <5 cm) were sampled at 25 random plots of 5 x 5 m. We sampled 1224 individuals belonging to 40 species. There was a strong predominance (> 90%) of species of early successional stages (pioneer and early secondary). Reflecting the strong observed ecological dominance, exercised primarily by the high density of the species Dalbergia nigra and Siparuna guianensis, species diversity value (Shannon index H '= 2.38) was much lower than the values found for mature forest fragments in this region. Although a small fragment, isolated and in early stages of secondary succession, the multivariate analysis (cluster and DCA) revealed the formation of distinct floristic groups and a strong differentiation in the arrangement of the species, showing the tropical forests typical heterogeneity. Although it has a low diversity, this urban fragment has ecological and social importance to the region, that present lack of green areas to conserve the native flora.Keywords: Phytosociology; multivariate analysis; gradient analysis; ecological groups.

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