scholarly journals Long-term declines in bird populations in tropical agricultural countryside

2019 ◽  
Vol 116 (20) ◽  
pp. 9903-9912 ◽  
Author(s):  
Çağan H. Şekercioğlu ◽  
Chase D. Mendenhall ◽  
Federico Oviedo-Brenes ◽  
Joshua J. Horns ◽  
Paul R. Ehrlich ◽  
...  
Keyword(s):  
Protected Areas ◽  
Bird Species ◽  
Agricultural Landscapes ◽  
Tree Cover ◽  
Conservation Value ◽  
Coffee Plantations ◽  
Forest Bird ◽  
Bird Populations ◽  
Capture Rates

Tropical agriculture is a major driver of biodiversity loss, yet it can provide conservation opportunities, especially where protected areas are inadequate. To investigate the long-term biodiversity capacity of agricultural countryside, we quantified bird population trends in Costa Rica by mist netting 57,255 birds of 265 species between 1999 and 2010 in sun coffee plantations, riparian corridors, secondary forests, forest fragments, and primary forest reserves. More bird populations (69) were declining than were stable (39) or increasing (4). Declines were common in resident, insectivorous, and more specialized species. There was no relationship between the species richness of a habitat and its conservation value. High-value forest bird communities were characterized by their distinct species composition and habitat and dietary functional signatures. While 49% of bird species preferred forest to coffee, 39% preferred coffee to forest and 12% used both habitats, indicating that coffee plantations have some conservation value. Coffee plantations, although lacking most of the forest specialists, hosted 185 bird species, had the highest capture rates, and supported increasing numbers of some forest species. Coffee plantations with higher tree cover (7% vs. 13%) had more species with increasing capture rates, twice as many forest specialists, and half as many nonforest species. Costa Rican countryside habitats, especially those with greater tree cover, host many bird species and are critical for connecting bird populations in forest remnants. Diversified agricultural landscapes can enhance the biodiversity capacity of tropical countryside, but, for the long-term persistence of all forest bird species, large (>1,000 ha) protected areas are essential.

scholarly journals Low effect on open-farmland birds of young afforestations in heterogeneous Mediterranean croplands

2014 ◽  
Author(s):  
Juan S. Sánchez-Oliver ◽  
José M. Rey Benayas ◽  
Luis M. L.M. Carrascal
Keyword(s):  
Species Richness ◽  
Bird Species ◽  
Agricultural Landscapes ◽  
Tree Plantations ◽  
Conservation Value ◽  
Farmland Birds ◽  
Negative Effects ◽  
Bird Species Richness ◽  
Positive Effects ◽  
The One

Afforestation programs such as the one promoted by the EU Common Agricultural Policy have spread tree plantations on former cropland. These afforestations attract generalist forest and ubiquitous species but may cause severe damage to open habitat species, especially birds of high conservation value. We investigated the effects of young (< 20 yr) tree plantations dominated by pine P. halepensis on bird communities inhabiting the adjacent open farmland habitat in central Spain. We hypothesize that pine plantations with larger surface, and areas at shorter distances from plantations, would result in lower bird species richness and conservation value of open farmland birds. Regression models controlling for the influence of land use types around plantations revealed significant positive effects of distance to pine plantation edge on community species richness in winter, and negative effects on an index of conservation concern (SPEC) during the breeding season. However, plantation area did not have any effect on species richness or community conservation value. Our results indicate that pine afforestation of Mediterranean cropland in heterogeneous agricultural landscapes has an overall low detrimental effect on bird species that are characteristic of open farmland habitat.

scholarly journals Farmland biodiversity: wildflower-sown islands within arable fields and grassy field margins both promote spider diversity

2021 ◽  
Author(s):  
Tamara Rischen ◽  
Katharina Geisbüsch ◽  
Daniel Ruppert ◽  
Klaus Fischer
Keyword(s):  
Agricultural Landscape ◽  
Agricultural Landscapes ◽  
Added Value ◽  
Conservation Strategies ◽  
Small Scale ◽  
Conservation Value ◽  
Field Margins ◽  
Farmland Biodiversity ◽  
Power Pole

Abstract Agricultural intensification and the concomitant landscape homogenization is leading to a worldwide decline in farmland biodiversity. Non-crop habitats in agroecosystems may counteract the loss of arthropods such as spiders and thus contribute to sustainable agriculture. However, the effectiveness of field margins and set-aside wildflower-sown patches in maintaining spider diversity is not well understood. Here, we investigated the effects of three different non-crop habitats, namely field margins, set-aside wildflower-sown patches under power poles (‘power pole islands’), and grassland fallows on spider diversity as compared to wheat fields in an agricultural landscape in western Germany. Using pitfall trapping and suction sampling, we show that species richness and overall conservation value were higher in non-crop habitats than in wheat fields. Interestingly, field margins and power pole islands differed from long-term grassland fallows only in conservation value, which was significantly higher in grassland fallows. Species assemblages differed considerably between grassland fallows, field margins and power pole islands, and wheat fields, documenting the added value of using different conservation strategies. Implications for insect conservation Small-scale non-crop habitats adjacent to wheat fields were surprisingly effective in promoting spider diversity in an agricultural landscape, with field margins and power pole islands being equally effective. To maximize overall diversity in agricultural landscapes, we propose a combination of larger long-term fallows and smaller non-crop habitats such as field margins or set-aside wildflower-sown patches.

Evaluating the long-term effectiveness of terrestrial protected areas: a 40-year look at forest bird diversity

2019 ◽  
Vol 28 (4) ◽  
pp. 811-826 ◽  
Author(s):  
Jeffrey A. Brown ◽  
Julie L. Lockwood ◽  
Julian D. Avery ◽  
J. Curtis Burkhalter ◽  
Kevin Aagaard ◽  
...  
Keyword(s):  
Protected Areas ◽  
Bird Diversity ◽  
Forest Bird

scholarly journals Increased nesting success of Hawaii Elepaio in response to the removal of invasive black rats

The Condor ◽  
2019 ◽  
Vol 121 (2) ◽  
Author(s):  
Paul C Banko ◽  
Kelly A Jaenecke ◽  
Robert W Peck ◽  
Kevin W Brinck
Keyword(s):  
Forest Restoration ◽  
Nest Success ◽  
Rattus Rattus ◽  
Bird Species ◽  
Oceanic Islands ◽  
Nesting Success ◽  
Native Forest ◽  
Forest Bird ◽  
Bird Populations ◽  
Black Rats

Abstract In Hawaii and other oceanic islands with few native land mammals, black rats (Rattus rattus) are among the most damaging invasive vertebrate species to native forest bird populations and habitats, due to their arboreal behavior and generalist foraging habits and habitat use. We evaluated the nesting response of Hawaii Elepaio (Chasiempis sandwichensis; Monarchidae), a generalist insectivore, to the removal of black rats using rodenticide in a before-after-control-impact study in high- and low-elevation mesic montane habitat recovering from long-term damage from introduced ungulates and weeds. We monitored nesting success and rat abundance during 2015–2016 before applying rodenticide bait in 2017 to remove rats from two 700 × 700 m treatment plots that were paired with 2 nontreatment plots of the same size. Rat abundance was reduced by 90% during treatment, with combined variables treatment and elevation best explaining the change using GLM methods and AIC model selection. The daily survival rate (DSR) of nests (n = 191) was greater on treated plots after rodenticide application (mean ± SE = 0.980 ± 0.004 treatment; 0.964 ± 0.004 nontreatment), modeled nest success increased from 29% to 50%, and apparent nest success (number of successful nests per total nests) increased from 37% to 52%. The most informative model for predicting DSR included the effect of treatment. Predation by rats was documented at 3 of 16 nests using video surveillance, and we observed additional evidence of rat predation during in-person nest monitoring. Rats targeted adults on the nest and sometimes removed intact eggs, leaving little trace of their activity. Our results demonstrate that reducing rat predation can immediately improve the nesting success of even a common bird species in habitat with a long history of forest restoration. Sustained predator control may be critical to accelerating the recovery of native forest bird communities.

scholarly journals Monitoring Breeding Bird Populations in Grand Teton National Park: 1995-1997

1997 ◽  
Vol 21 ◽  
pp. 13-25
Author(s):  
Martin Cody ◽  
Stephen Cain
Keyword(s):  
Breeding Season ◽  
National Park ◽  
Management Strategies ◽  
Bird Species ◽  
Breeding Habitat ◽  
Breeding Bird ◽  
Grand Teton National Park ◽  
Bird Populations ◽  
The Impact

In summer 1997 our NPS-funded project # CA-1460-5-0010, covering a 3-y period from summer 1995 through summer 1997, was completed. The immediate goals of the project were to instigate a system for monitoring the densities of breeding bird species, by establishment of flxed sites as a basis for a long term monitoring plan and of census protocols that can detect changes of breeding species and their densities over successive years. The monitoring scheme is conducted largely within Grand Teton National Park (GTNP), but covers habitats and an avifauna representative of the Greater Yellowstone Ecosystem (GYE) and the central-northern Rocky Mountains in general. The project emphasizes the need for long­term and on-going studies on breeding bird species and densities and their importance as a tool for evaluating the impact of both local and distant influences on breeding bird populations. For residents, species that remain all year in or near the breeding habitat, local effects include those operating on-site during the non-breeding season as well as during the breeding season. For migrant species, those that breed on-site but leave to spend the non-breeding season in other locations, often distant and usually of quite different habitat composition, there are both on-site influences on breeding population densities, such as inter-year changes in vegetation structure and productivity, and off-site or distant influences, including factors that affect over-wintering success in the non­breeding habitat and others that influence a successful transit between wintering and breeding grounds. The assessment of long-term trends in bird densities may be used as a form of bioassay of the state of the local environments. Information from such studies can provide region-wide indicators that, given a sufficiently comprehensive data base, can segregate local from distant influences on populations. Such indicators can be incorporated into management strategies to aid in determining which local strategies may be necessary (and feasible) to help maintain the biota.

scholarly journals Breeding Bird Communities in a Naturally Fragemented Forest Ecosystem in Grand Teton National Park

1998 ◽  
Vol 22 ◽  
pp. 37-37
Author(s):  
Gregory Schrott
Keyword(s):  
Habitat Fragmentation ◽  
National Park ◽  
Bird Species ◽  
Bird Communities ◽  
Western North America ◽  
Breeding Bird ◽  
Grand Teton National Park ◽  
Bird Populations ◽  
Natural Processes

This project examined the bird species breeding in the morainal forests on the valley floor in Grand Teton National Park. These forests are very patchily distributed and range in size from less than 1 hectare to over 700 hectares, allowing for a unique opportunity to study the responses of the local bird species to a forest system that has been fragmented for centuries through natural processes. This information can be useful for predicting the potential long-term impacts of human-caused forest fragmentation on bird populations in western North America. Until quite recently very little was known of the tolerances of western forest bird species to habitat fragmentation and this project could represent an important step towards understanding their needs in this regard.

scholarly journals The dynamics of avicultural markets

2001 ◽  
Vol 28 (1) ◽  
pp. 76-85 ◽  
Author(s):  
Jennifer M. Robinson
Keyword(s):  
Captive Breeding ◽  
Bird Species ◽  
Decision Makers ◽  
Trade Restrictions ◽  
Model Simulations ◽  
Species Introductions ◽  
Bird Populations ◽  
Potential Source ◽  
The World

Trade restrictions stemming from the Convention on International Trade in Endangered Species (CITES) have created a situation in which rare and attractive bird species command high prices on international pet markets. Most of these species are of tropical or subtropical origin, and many are amenable to captive breeding. Hence, the possibility of exporting birds under CITES provisions for the export of captive-raised animals is under debate in many countries around the world. If export bans are replaced by systems of export permits, the economics of avicultural markets will govern the magnitude, timing, and nature of the impacts of the bird trade. Avicultural economics, however, is little studied, and the long-term economic viabilities of exotic pet markets are poorly understood. In order to elucidate these, a dynamic model of an avicultural market was constructed, based on descriptive information. Model simulations showed that the high prices commanded by sought-after bird species tended to bring about oversupply and rapid price decline. Short-lived, fecund species produced a rapid, sharp pulse of oversupply; longer-lived species produced more persistent but less acute conditions of oversupply. The present high prices for protected bird species may be regarded as a potential source of windfall profits, or as a factor that might be manipulated to discourage the poaching and smuggling of wild birds. If export-oriented aviculture is considered as a component of strategies for diversification of agriculture and promotion of sustainable development, it is important that decision-makers factor in the likelihood of significant declines in bird prices and that they consider the risk of accidental species introductions that is inherent in holding large exotic-bird populations.

Variations in pest bird density in Argentinean agroecosystems in relation to land use and/or cover, vegetation productivity and climate

2018 ◽  
Vol 45 (8) ◽  
pp. 668 ◽  
Author(s):  
Noelia C. Calamari ◽  
Sonia B. Canavelli ◽  
Alexis Cerezo ◽  
Sebastián Dardanelli ◽  
Jaime N. Bernardos ◽  
...  
Keyword(s):  
Land Use ◽  
Population Distribution ◽  
Bird Species ◽  
Crop Damage ◽  
Vegetation Productivity ◽  
Monk Parakeet ◽  
Bird Populations ◽  
Myiopsitta Monachus ◽  
Bird Density

Context Changes in environmental conditions may influence bird populations, including pest bird species, and their distribution. In Argentina, particularly in the Pampas region, agricultural expansion has resulted in important changes in agroecosystems, with impacts on bird species. Aims This study analysed the relationship between pest bird densities and the environmental variables associated with land use and/or cover, vegetation productivity and climate. The study focused on the most important pest bird species to grain crops in Argentina and Uruguay: the eared dove (Zenaida auriculata) and the monk parakeet (Myiopsitta monachus). Methods An area in Central Argentina was divided into three agro-productive regions, one predominantly agricultural and two with mixed production activities: agricultural rangeland and agricultural forested rangeland. Bird populations were sampled on a yearly basis between 2003 and 2011 in point-transects located along secondary roads (47 routes in total). Linear mixed models and a multi-model inference approach were used to compare the effects of individual predictive variables on bird densities. Key results Mean estimated density for the eared dove was 0.39 individuals per ha (±0.02), almost three times the density of the monk parakeet (0.10 individuals per ha±0.02). The spatial distribution of changes in density of the eared dove and monk parakeet showed irregular patterns across the study area. Density of eared dove was directly related to cover of native and exotic woodlots and inversely related to cover of fallow and weedy fields, and to temperature and rainfall. Monk parakeet density, in turn, was directly related to cover of woodlots. Conclusions The density of eared doves and monk parakeets changed mostly in relation to land use and/or cover and, to a lesser extent, to climatic conditions. Information of pest bird populations in a long-term period allowed us to understand spatial patterns in bird population distribution and to identify the main environmental factors explaining them. Implications The consideration of land use and/or cover, vegetation productivity and climate variables at regional scale, measured during a long-term period, would be critical for anticipating population increases and, possibly, increases in crop damage.

scholarly journals Beyond pattern to process: current themes and future directions for the conservation of woodland birds through restoration plantings

2018 ◽  
Vol 45 (6) ◽  
pp. 473 ◽  
Author(s):  
Donna J. Belder ◽  
Jennifer C. Pierson ◽  
Karen Ikin ◽  
David B. Lindenmayer
Keyword(s):  
Habitat Loss ◽  
Resource Availability ◽  
Bird Species ◽  
Agricultural Landscapes ◽  
Conservation Strategies ◽  
Future Research ◽  
Knowledge Gaps ◽  
Woodland Birds ◽  
Conservation Concern

Habitat loss as a result of land conversion for agriculture is a leading cause of global biodiversity loss and altered ecosystem processes. Restoration plantings are an increasingly common strategy to address habitat loss in fragmented agricultural landscapes. However, the capacity of restoration plantings to support reproducing populations of native plants and animals is rarely measured or monitored. This review focuses on avifaunal response to revegetation in Australian temperate woodlands, one of the world’s most heavily altered biomes. Woodland birds are a species assemblage of conservation concern, but only limited research to date has gone beyond pattern data and occupancy trends to examine whether they persist and breed in restoration plantings. Moreover, habitat quality and resource availability, including food, nesting sites and adequate protection from predation, remain largely unquantified. Several studies have found that some bird species, including species of conservation concern, will preferentially occupy restoration plantings relative to remnant woodland patches. However, detailed empirical research to verify long-term population growth, colonisation and extinction dynamics is lacking. If restoration plantings are preferentially occupied but fail to provide sufficient quality habitat for woodland birds to form breeding populations, they may act as ecological traps, exacerbating population declines. Monitoring breeding success and site fidelity are under-utilised pathways to understanding which, if any, bird species are being supported by restoration plantings in the long term. There has been limited research on these topics internationally, and almost none in Australian temperate woodland systems. Key knowledge gaps centre on provision of food resources, formation of optimal foraging patterns, nest-predation levels and the prevalence of primary predators, the role of brood parasitism, and the effects of patch size and isolation on resource availability and population dynamics in a restoration context. To ensure that restoration plantings benefit woodland birds and are cost-effective as conservation strategies, the knowledge gaps identified by this review should be investigated as priorities in future research.

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