Bird Abundance and Nesting Success in Iowa CRP Fields: The Importance of Vegetation Structure and Composition

1996 ◽  
Vol 135 (1) ◽  
pp. 153 ◽  
Author(s):  
Matthew P. Patterson ◽  
L. B. Best
Keyword(s):  
Vegetation Structure ◽  
Nesting Success ◽  
Bird Abundance

scholarly journals Bird diversity and abundance on two different shade coffee plantations in Guatemala

1998 ◽  
Vol 8 (3) ◽  
pp. 297-308 ◽  
Author(s):  
Lorena Calvo ◽  
John Blake
Keyword(s):  
Vegetation Structure ◽  
Management Practices ◽  
Bird Diversity ◽  
Bird Abundance ◽  
Shade Coffee ◽  
Coffee Plantations ◽  
Bird Populations ◽  
Migrant Birds ◽  
Abundance And Diversity ◽  
Fertilizer Regimes

SummaryMany studies have examined differences in bird communities between shade and sun coffee plantations but less is known about how different management practices within shade coffee plantations affect bird populations. This study compares diversity and abundance of resident and migrant birds in two shade coffee plantations located in Palajunoj, Quetzaltenango, Guatemala, that differ in their farming practices (e.g. pruning schedules and fertilizer regimes) and, consequently, in vegetation structure. One plantation represents a traditional, polyculture shade system whereas the second represents a more modernized, monoculture shade system. Both plantations supported many resident and migrant birds. Bird abundance and diversity were significantly greater during both wet and dry seasons on the traditional farm, due largely to the vegetation structure resulting from the different management practices. All plantations typically classified as ‘shade coffee’ are not equivalent, much of their conservation value coming from the more diverse and structurally complex traditional polycultures rather than from the newer, monocultural systems. Coffee production techniques that affect the structural and floristic diversity of the vegetation (e.g. pruning, application of chemicals) have important consequences for birds.

scholarly journals Increased songbird nest depredation due to invasive Aleppo pine (Pinus halepensis) encroachment in Mediterranean shrubland

2019 ◽  
Author(s):  
Asaf Ben-David ◽  
Hila Shamoon ◽  
Ido Izhaki ◽  
Roni Efronny ◽  
Roi Maor ◽  
...  
Keyword(s):  
Vegetation Structure ◽  
Nest Predation ◽  
Pinus Halepensis ◽  
Indirect Evidence ◽  
Nesting Success ◽  
Aleppo Pine ◽  
Occurrence Rate ◽  
Mediterranean Shrublands ◽  
Mediterranean Shrubland ◽  
Nest Depredation

Abstract Background In recent decates, a decrease of passerine densities was documented in Mediterenean shrublands. At the same time, a widspread encroachment of Aleppo pines (Pinus halepensis) to Mediterranean shrubland occurred. Such changes in vegetation structure may effect passerine predator assemblage and densities, and in turn impact passerine densities. Depredation during the nesting season is an important factor to influence passerine population size. Understanding the effects of changes in vegetation structure (pine encroachment) on passerine nesting success is the main objective of this study. We do so by assesing the effects of Aleppo pine encroachment on Sardinian warbler (Sylvia melanocephala) nest depredation in Mediterranean shrublands. Methods We examined direct and indirect predation pressures throught a gradients of pine density, using four methods: (1) placing dummy nests; (2) acoustic monitoring of mobbing events; (3) direct observations on nest predation using cameras; and (4) observation of Eurasian jay (Garrulus glandarius) behaviour as indirect evidence of predation risk. Results We found that Aleppo pine encroachment to Mediterranean shrublands increased nest predation by Eurasian jays. Nest predation was highest in with median encroaching pine. These areas are suitable for warblers, but had high occurrence rate of Eurasian jays. Conclusions Invasive pines directly increase activity of avian predators in shrubland habitats which impacted shrubland songbird nesting success. These findings are supported by multiple methodologies, illustrating different predation pressures along a gradient of pine densities in natural shrublands. Management of Aleppo pine seedlings and removal of unwanted trees in natural shrubland might mitigate arrival and expansion of native-invasive predators and decrease the predation pressure on passerine nests.

scholarly journals Increased songbird nest depredation due to Aleppo pine (Pinus halepensis) encroachment in Mediterranean shrubland

BMC Ecology ◽  
2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Asaf Ben-David ◽  
Hila Shamon ◽  
Ido Izhaki ◽  
Ronny Efronny ◽  
Roi Maor ◽  
...  
Keyword(s):  
Vegetation Structure ◽  
Nest Predation ◽  
Pinus Halepensis ◽  
Indirect Evidence ◽  
Nesting Success ◽  
Aleppo Pine ◽  
Occurrence Rate ◽  
Mediterranean Shrublands ◽  
Mediterranean Shrubland ◽  
Nest Depredation

Abstract Background In recent decades, a decrease of passerine densities was documented in Mediterranean shrublands. At the same time, a widespread encroachment of Aleppo pines (Pinus halepensis) to Mediterranean shrubland occurred. Such changes in vegetation structure may affect passerine predator assemblage and densities, and in turn impact passerine densities. Depredation during the nesting season is an important factor to influence passerine population size. Understanding the effects of changes in vegetation structure (pine encroachment) on passerine nesting success is the main objective of this study. We do so by assessing the effects of Aleppo pine encroachment on Sardinian warbler (Sylvia melanocephala) nest depredation in Mediterranean shrublands. We examined direct and indirect predation pressures through a gradients of pine density, using four methods: (1) placing dummy nests; (2) acoustic monitoring of mobbing events; (3) direct observations on nest predation using cameras; and (4) observation of Eurasian jay (Garrulus glandarius) behaviour as indirect evidence of predation risk. Results We found that Aleppo pine encroachment to Mediterranean shrublands increased nest predation by Eurasian jays. Nest predation was highest in mixed shrubland and pines. These areas are suitable for warblers but had high occurrence rate of Eurasian jays. Conclusions Encroaching pines directly increase activity of Eurasian jays in shrubland habitats, which reduced the nesting success of Sardinian warblers. These findings are supported by multiple methodologies, illustrating different predation pressures along a gradient of pine densities in natural shrublands. Management of Aleppo pine seedlings and removal of unwanted trees in natural shrubland might mitigate arrival and expansion of predators and decrease the predation pressure on passerine nests.

Winter habitat selection by a montane forest bird assemblage: the effects of solar radiation

2001 ◽  
Vol 79 (2) ◽  
pp. 279-284 ◽  
Author(s):  
Daniel L Huertas ◽  
José A Díaz
Keyword(s):  
Solar Radiation ◽  
Vegetation Structure ◽  
Prey Availability ◽  
Bird Species ◽  
Principal Component ◽  
Interspecific Variation ◽  
Montane Forest ◽  
Bird Abundance ◽  
Winter Habitat ◽  
Movement Rates

A relationship between sunlight and bird abundance in cold climates may seem intuitive and perhaps obvious. However, there is, surprisingly, little or no evidence to support it. We investigated the effects of solar radiation on the winter abundance of insectivorous birds inhabiting a Mediterranean montane forest with a high frequency of cold, cloudless days. We censused birds by ear in 20 different forest tracts in which we simultaneously quantified a number of variables related to the availability of solar radiation, vegetation structure, arthropod abundance, and altitude. All variables related to solar radiation were reduced to a single principal component that attained high scores for south-facing transects, where many tree trunks received direct sunlight for a long period daily. The abundance of all bird species was positively related to the scores of transects on this component after the effects of vegetation structure, altitude, and prey availability were controlled for. Solar radiation was the main predictor of overall abundance and species richness of bird assemblages. Body mass and diet (insectivorous vs. mixed) explained 94.6% of interspecific variation in the strength of the relationship between solar radiation and bird abundance. We hypothesize that selecting forest sectors with a higher availability of sunlit patches allows birds to improve their winter survival by reducing the metabolic costs of thermoregulation, decreasing movement rates, and (or) increasing the time spent motionless in safe locations.

Riparian edge effects on boreal balsam fir bird communities

1995 ◽  
Vol 25 (4) ◽  
pp. 555-566 ◽  
Author(s):  
Pierre Larue ◽  
Louis Bélanger ◽  
Jean Huot
Keyword(s):  
Edge Effect ◽  
Vegetation Structure ◽  
Riparian Forest ◽  
Close Association ◽  
Bird Communities ◽  
Riparian Forests ◽  
Balsam Fir ◽  
Bird Abundance ◽  
Vegetation Diversity ◽  
Bird Richness

Riparian forests are often identified as prime habitat for wildlife because of the presence of particular plant communities and edges creating a highly developed and diversified vegetation structure. However, in the northeastern boreal forests of Canada, where narrow land–water ecotones with abrupt edges are quite common, the relative habitat value of riparian forests remains to be demonstrated. We compared bird communities of eight pairs of riparian and nonriparian plots, similar in vegetation structure and composition, to verify the relative value for breeding birds of typical coniferous riparian forest stands of the southern boreal region of eastern Quebec. Bird abundance (P = 0.02), richness (P = 0.03), and diversity (P = 0.02) were significantly higher in the riparian stands, where the spatial sequence of three distinct habitats (a balsam fir (Abiesbalsamea (L.) Mill.)–northern white cedar (Thujaoccidentalis L.) forest, a narrow alder (Alnusrugosa (Du Roi) Spreng.) - grass wetland, and water) created high horizontal vegetation diversity. In riparian stands median bird richness and density were, respectively, 23.5 species and 437.5 territories/km2 compared with 19.0 species and 348.2 territories/km2 for interior stands. Nine species were observed exclusively in riparian plots. In addition to the species usually found in the studied nonriparian forests, the riparian plots were used by species typically related to the water edge such as the Northern Waterthrush (Seiurusnoveboracensis Gmelin) and Rusty Blackbird (Euphaguscarolinus Miiller) as well as species associated with the shrub and grass wetland such as the American Robin (Turdusmigratorius L.), the Veery (Catharusfuscescens Stephens), and the Common Yellowthroat (Geothlypistrichas L.). The shrub-foraging guild showed higher abundance in riparian stands. The tree-foraging and tree-bole foraging guilds, however, were comparable in both groups of stands. In this study, the natural conditions prevailing along he riparian sites appeared mostly positive for the breeding-bird community; it created what is perceived as being an "edge effect." The edge effect can be defined, in this case, as being the additional density and number of species induced by the added horizontal vegetation diversity created by the close association of three extremely different ecosystems: a forest stand, an aquatic ecosystem, and a narrow but distinct shrub-grass wetland. This also confirms the necessity of distinguishing natural edges that are permanent features of the landscape from induced edges created by human activity.

scholarly journals Increased songbird nest depredation due to Aleppo pine (Pinus halepensis) encroachment in Mediterranean shrubland

2019 ◽  
Author(s):  
Asaf Ben-David ◽  
Hila Shamon ◽  
Ido Izhaki ◽  
Roni Efronny ◽  
Roi Maor ◽  
...  
Keyword(s):  
Vegetation Structure ◽  
Nest Predation ◽  
Pinus Halepensis ◽  
Indirect Evidence ◽  
Nesting Success ◽  
Aleppo Pine ◽  
Occurrence Rate ◽  
Mediterranean Shrublands ◽  
Mediterranean Shrubland ◽  
Nest Depredation

Abstract Background In recent decades, a decrease of passerine densities was documented in Mediterranean shrublands. At the same time, a widespread encroachment of Aleppo pines ( Pinus halepensis ) to Mediterranean shrubland occurred. Such changes in vegetation structure may affect passerine predator assemblage and densities, and in turn impact passerine densities. Depredation during the nesting season is an important factor to influence passerine population size. Understanding the effects of changes in vegetation structure (pine encroachment) on passerine nesting success is the main objective of this study. We do so by assessing the effects of Aleppo pine encroachment on Sardinian warbler ( Sylvia melanocephala ) nest depredation in Mediterranean shrublands. We examined direct and indirect predation pressures through a gradients of pine density, using four methods: (1) placing dummy nests; (2) acoustic monitoring of mobbing events; (3) direct observations on nest predation using cameras; and (4) observation of Eurasian jay ( Garrulus glandarius ) behaviour as indirect evidence of predation risk. Results We found that Aleppo pine encroachment to Mediterranean shrublands increased nest predation by Eurasian jays. Nest predation was highest in mixed shrubland and pines. These areas are suitable for warblers but had high occurrence rate of Eurasian jays. Conclusions Encroaching pines directly increase activity of Eurasian jays in shrubland habitats, which reduced the nesting success of Sardinian warblers. These findings are supported by multiple methodologies, illustrating different predation pressures along a gradient of pine densities in natural shrublands. Management of Aleppo pine seedlings and removal of unwanted trees in natural shrubland might mitigate arrival and expansion of predators and decrease the predation pressure on passerine nests.

scholarly journals Increased songbird nest depredation due to Aleppo pine (Pinus halepensis) encroachment in Mediterranean shrubland

2019 ◽  
Author(s):  
Asaf Ben-David ◽  
Hila Shamoon ◽  
Ido Izhaki ◽  
Roni Efronny ◽  
Roi Maor ◽  
...  
Keyword(s):  
Vegetation Structure ◽  
Nest Predation ◽  
Pinus Halepensis ◽  
Indirect Evidence ◽  
Nesting Success ◽  
Aleppo Pine ◽  
Occurrence Rate ◽  
Mediterranean Shrublands ◽  
Mediterranean Shrubland ◽  
Nest Depredation

Abstract Background In recent decades, a decrease of passerine densities was documented in Mediterranean shrublands. At the same time, a widespread encroachment of Aleppo pines ( Pinus halepensis ) to Mediterranean shrubland occurred. Such changes in vegetation structure may affect passerine predator assemblage and densities, and in turn impact passerine densities. Depredation during the nesting season is an important factor to influence passerine population size. Understanding the effects of changes in vegetation structure (pine encroachment) on passerine nesting success is the main objective of this study. We do so by assessing the effects of Aleppo pine encroachment on Sardinian warbler ( Sylvia melanocephala ) nest depredation in Mediterranean shrublands. Methods We examined direct and indirect predation pressures through a gradients of pine density, using four methods: (1) placing dummy nests; (2) acoustic monitoring of mobbing events; (3) direct observations on nest predation using cameras; and (4) observation of Eurasian jay ( Garrulus glandarius ) behaviour as indirect evidence of predation risk. Results We found that Aleppo pine encroachment to Mediterranean shrublands increased nest predation by Eurasian jays. Nest predation was highest in mixed shrubland and pines. These areas are suitable for warblers but had high occurrence rate of Eurasian jays. Conclusions Encroaching pines directly increase activity of Eurasian jays in shrubland habitats, which reduced the nesting success of Sardinian warblers. These findings are supported by multiple methodologies, illustrating different predation pressures along a gradient of pine densities in natural shrublands. Management of Aleppo pine seedlings and removal of unwanted trees in natural shrubland might mitigate arrival and expansion of predators and decrease the predation pressure on passerine nests.

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