46 research outputs found
Supporting Farmer Adoption of Sustainable Bird Management Strategies
Pest birds cause substantial and costly damage to crops. Managing birds is complex because (1) they are highly mobile, (2) they habituate quickly to many deterrents, (3) some species provide benefits to farmers by deterring and consuming pest insects, rodents, and other birds, and (4) birds are highly valued by many people. Thus, farmers have many issues to consider when developing bird management strategies. Here I discuss recent work indicating that farmer adoption of sustainable agricultural practices is more likely when practices are effective, clear guidelines for implementation are available, implementation is relatively easy, and when practices are linked, in farmersâ minds and logistically, with other farm management practices. This manuscript draws together information about these factors for common bird management tactics to aid in the development of sustainable bird management strategies by farmers and the development of education programs for farmers by extension personnel and researchers. Such strategies will necessarily involve combinations of tactics, following the framework of Integrated Pest Management
Falcons using orchard nest boxes reduce fruit-eating bird abundances and provide economic benefits for a fruit-growing region
1. Suppression of pest species via a native predator is a regulating ecosystem service that has the potential to limit crop damage and produce economic benefits. American kestrels Falco sparverius are widespread, highly mobile, generalist predators that hunt in human-dominated habitats and have the potential to provide previously undocumented ecosystem services in agricultural landscapes.
2. We hypothesized that kestrel activity associated with nest boxes and artificial perches acts to increase perceived predation risk that, in combination with direct predation, can reduce fruit-eating bird abundances in orchards. We used counts and observations of fruit-eating birds from fixed-width transect surveys to investigate variation in bird abundances and to estimate sweet cherry loss in cherry orchards with and without active kestrel boxes. We also conducted a benefitâcost analysis of nest box installation and used regional economic modelling to estimate macroeconomic impacts of increased sweet cherry production in Michigan, an important US fruit production region.
3. Fruit-eating bird counts were significantly lower at orchards with active kestrel boxes. Although kestrels used the perches in young orchard blocks and may benefit from them, the presence of perches did not have a significant effect on bird counts.
4. Benefitâcost ratios for kestrel nest boxes indicated that for every dollar spent on nest boxes, 357 of sweet cherries would be saved from fruit-eating birds. Regional economic modelling predicted that increased sweet cherry production from reduced bird damage would result in 46â50 jobs created and 2.4 million in increased income for the state of Michigan over a 5-year period.
5. Synthesis and applications. Kestrel nest boxes in sweet cherry orchards provide a highly cost-effective ecosystem service with potential reverberating benefits for a regional economy. Box occupancy rates will undoubtedly vary across landscapes and regions. However, costs to install and maintain boxes are small and, even if box occupancy rates are low, boxes can direct kestrel activity to particular places in agricultural landscapes where they can deter pest birds. Thus, the potential benefits for fruit crops greatly outweigh the costs of this pest management strategy
Bird consumption of sweet and tart cherries
Identifying species responsible for crop damage is an important first step in developing management strategies. Previous studies have surveyed bird species flying through cherry orchards but have not documented which species were consuming cherries. We conducted traditional surveys and behavioral observations in orchards of sweet cherries (Prunus avium) and tart cherries (Prunus cerasus) in Michigan during 2010 to compare results from the 2 techniques. American robins (Turdus migratorius) were detected most frequently during sweet cherry surveys, while behavioral observations showed that cedar waxwings (Bombycilla cedrorum) consumed more sweet cherries than did robins. Chipping sparrows (Spizella passerina) were the most commonly detected species during tart cherry surveys, while observations showed that American robins and common grackles (Quiscalus quiscula) consumed the most tart cherries. Although observational work is more labor-intensive than surveys, observations are more likely to provide accurate information on the relative importance of fruit-consuming species
Measuring Bird Damage to Three Fruit Crops: A Comparison of Grower and Field Estimates
Birds are common pests in fruit orchards. They frequently consume and damage fruit resulting in decreased yields for growers. The true extent of damage is difficult to measure. Producer surveys are often implemented to estimate damage, but the accuracy of these estimates is uncertain. We compared damage estimates obtained through field studies with estimates from a producer survey for three fruit crops: wine grapes, sweet cherries, and âHoneycrispâ apples. We also analyzed relationships between use of various damage management methods and levels of bird damage. We found wine grape and sweet cherry growers accurately assessed bird damage, while âHoneycrispâ apple growers may overestimate damage. Growing region appears to be an important damage predictor for wine grape and sweet cherry crops. Significant relationships between management methods and damage were positive, suggesting growers only use these methods when bird damage is substantial
Proportions of bird damage in tree fruits are higher in low-fruit-abundance contexts
Frugivorous birds impose significant costs on tree fruit growers through direct consumption of fruit and grower efforts to manage birds.We documented factors that influenced tree fruit bird damage from 2012 through 2014 with a coordinated field study in Michigan, New York, and Washington. For sweet cherries, percent bird damage was higher in 2012 compared to 2013 and 2014, in Michigan and New York compared toWashington, and in blocks with more edges adjacent to non-sweet cherry land-cover types. These patterns appeared to be associated with fruit abundance patterns; 2012 was a particularly lowyield year for tree fruits in Michigan and New York and percent bird damage was high. In addition, percent bird damage to sweet and tart cherries in Michigan was higher in landscapes with low to moderate forest cover compared to higher forest cover landscapes. \u27Honeycrisp\u27 apple blocks under utility wires were marginally more likely to have greater bird damage compared to blocks without wires. We recommend growers prepare bird management plans that consider the spatial distribution of fruit and non-fruit areas of the farm. Growers should generally expect to invest more in bird management in low-yield years, in blocks isolated from other blocks of the same crop, and in blocks where trees can provide entry to the crop for frugivorous birds
Bird and bat predation services in tropical forests and agroforestry landscapes
Understanding distribution patterns and multitrophic interactions is critical for managing batĂą and birdĂą mediated ecosystem services such as the suppression of pest and nonĂą pest arthropods. Despite the ecological and economic importance of bats and birds in tropical forests, agroforestry systems, and agricultural systems mixed with natural forest, a systematic review of their impact is still missing. A growing number of bird and bat exclosure experiments has improved our knowledge allowing new conclusions regarding their roles in food webs and associated ecosystem services. Here, we review the distribution patterns of insectivorous birds and bats, their local and landscape drivers, and their effects on trophic cascades in tropical ecosystems. We report that for birds but not bats community composition and relative importance of functional groups changes conspicuously from forests to habitats including both agricultural areas and forests, here termed Ăą forestĂą agriĂą habitats, with reduced representation of insectivores in the latter. In contrast to previous theory regarding trophic cascade strength, we find that birds and bats reduce the density and biomass of arthropods in the tropics with effect sizes similar to those in temperate and boreal communities. The relative importance of birds versus bats in regulating pest abundances varies with season, geography and management. Birds and bats may even suppress tropical arthropod outbreaks, although positive effects on plant growth are not always reported. As both bats and birds are major agents of pest suppression, a better understanding of the local and landscape factors driving the variability of their impact is needed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134094/1/brv12211_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134094/2/brv12211.pd
Hyper-IgG4 disease: report and characterisation of a new disease
BACKGROUND: We highlight a chronic inflammatory disease we call 'hyper-IgG4 disease', which has many synonyms depending on the organ involved, the country of origin and the year of the report. It is characterized histologically by a lymphoplasmacytic inflammation with IgG4-positive cells and exuberant fibrosis, which leaves dense fibrosis on resolution. A typical example is idiopathic retroperitoneal fibrosis, but the initial report in 2001 was of sclerosing pancreatitis. METHODS: We report an index case with fever and severe systemic disease. We have also reviewed the histology of 11 further patients with idiopathic retroperitoneal fibrosis for evidence of IgG4-expressing plasma cells, and examined a wide range of other inflammatory conditions and fibrotic diseases as organ-specific controls. We have reviewed the published literature for disease associations with idiopathic, systemic fibrosing conditions and the synonyms: pseudotumour, myofibroblastic tumour, plasma cell granuloma, systemic fibrosis, xanthofibrogranulomatosis, and multifocal fibrosclerosis. RESULTS: Histology from all 12 patients showed, to varying degrees, fibrosis, intense inflammatory cell infiltration with lymphocytes, plasma cells, scattered neutrophils, and sometimes eosinophilic aggregates, with venulitis and obliterative arteritis. The majority of lymphocytes were T cells that expressed CD8 and CD4, with scattered B-cell-rich small lymphoid follicles. In all cases, there was a significant increase in IgG4-positive plasma cells compared with controls. In two cases, biopsies before and after steroid treatment were available, and only scattered plasma cells were seen after treatment, none of them expressing IgG4. Review of the literature shows that although pathology commonly appears confined to one organ, patients can have systemic symptoms and fever. In the active period, there is an acute phase response with a high serum concentration of IgG, and during this phase, there is a rapid clinical response to glucocorticoid steroid treatment. CONCLUSION: We believe that hyper-IgG4 disease is an important condition to recognise, as the diagnosis can be readily verified and the outcome with treatment is very good
Bird Management in Fruit Crops: How We Make Progress
Fruit producers have identified bird damage as a critical issue that has received limited attention from researchers. A USDA study estimated that birds cost producers in 7 states tens of millions of dollars through fruit loss and management efforts. Despite these costs, research has been uncoordinated and piecemeal, leaving producers with few, well-tested management options. We describe several objectives to strive for in order to achieve the goal of providing producers with region-specific, cost-effective, and environmentally sustainable bird management strategies. These objectives include 1) quantifying economic consequences of bird damage for producers, consumers, and regional economies, and determining costs and benefits of various management techniques; 2) identifying amounts of damage attributable to specific bird species across crops and regions; 3) determining how bird damage varies within and across spatial scales (orchard, landscape, region); 4) evaluating consumer responses to management strategies and potential effects on marketing; 5) integrating economic, biological, and consumer information, i.e. using a systems approach, to determine the management strategies that should be tested; and 6) testing management strategies for efficacy with replicated, well-controlled experimental designs. By focusing on these objectives and coordinating activities among researchers and extension personnel from different regions of the country and from different disciplines, we will maximize efficiency in addressing this issue on a national scale while providing individual producers with region-specific information to guide their bird management efforts. Communication among researchers, extension personnel, and producers will be critical to minimize the costs of bird damage
Falcons using orchard nest boxes reduce fruit-eating bird abundances and provide economic benefits for a fruit-growing region
1. Suppression of pest species via a native predator is a regulating ecosystem service that has the potential to limit crop damage and produce economic benefits. American kestrels Falco sparverius are widespread, highly mobile, generalist predators that hunt in human-dominated habitats and have the potential to provide previously undocumented ecosystem services in agricultural landscapes.
2. We hypothesized that kestrel activity associated with nest boxes and artificial perches acts to increase perceived predation risk that, in combination with direct predation, can reduce fruit-eating bird abundances in orchards. We used counts and observations of fruit-eating birds from fixed-width transect surveys to investigate variation in bird abundances and to estimate sweet cherry loss in cherry orchards with and without active kestrel boxes. We also conducted a benefitâcost analysis of nest box installation and used regional economic modelling to estimate macroeconomic impacts of increased sweet cherry production in Michigan, an important US fruit production region.
3. Fruit-eating bird counts were significantly lower at orchards with active kestrel boxes. Although kestrels used the perches in young orchard blocks and may benefit from them, the presence of perches did not have a significant effect on bird counts.
4. Benefitâcost ratios for kestrel nest boxes indicated that for every dollar spent on nest boxes, 357 of sweet cherries would be saved from fruit-eating birds. Regional economic modelling predicted that increased sweet cherry production from reduced bird damage would result in 46â50 jobs created and 2.4 million in increased income for the state of Michigan over a 5-year period.
5. Synthesis and applications. Kestrel nest boxes in sweet cherry orchards provide a highly cost-effective ecosystem service with potential reverberating benefits for a regional economy. Box occupancy rates will undoubtedly vary across landscapes and regions. However, costs to install and maintain boxes are small and, even if box occupancy rates are low, boxes can direct kestrel activity to particular places in agricultural landscapes where they can deter pest birds. Thus, the potential benefits for fruit crops greatly outweigh the costs of this pest management strategy
Bird Pollinator Visitation is Equivalent in Island and Plantation Planting Designs in Tropical Forest Restoration Sites
sustainabilit