scholarly journals Sociality and Foraging Behavior of the Cerulean Warbler in Venezuelan Shade-Coffee Plantations

The Condor ◽  
2000 ◽  
Vol 102 (4) ◽  
pp. 958-962 ◽  
Author(s):  
Jason Jones ◽  
Paolo Ramoni Perazzi ◽  
Erin H. Carruthers ◽  
Raleigh J. Robertson
Keyword(s):  
Foraging Behavior ◽  
Territory Size ◽  
Flock Size ◽  
Adult Males ◽  
Shade Coffee ◽  
Coffee Plantations ◽  
Dendroica Cerulea ◽  
Cerulean Warbler ◽  
Mixed Species Flocks ◽  
Cerulean Warblers

Abstract We examined the use of Venezuelan shade-coffee plantations by the Cerulean Warbler (Dendroica cerulea) and other Neotropical migrants. Cerulean Warblers were commonly observed as pairs in mixed-species flocks. Average (± SE) flock size was 13 ± 2 species with 22 ± 3 individuals. Average flock territory size was 2.5 ± 0.2 ha. No differences were detected in foraging behavior (maneuvers, location, or success) among adult males, adult females, and immature birds. Adult males were often observed visiting flowers of canopy trees. The results of this study indicate that shade coffee plantations may provide suitable wintering habitat for Cerulean Warblers although comparisons with other habitats are needed.

Cerulean Warbler (Dendroica Cerulea) Microhabitat and Landscape-Level Habitat Characteristics in Southern West Virginia

The Auk ◽  
2005 ◽  
Vol 122 (2) ◽  
pp. 497-508 ◽  
Author(s):  
Cathy A. Weakland ◽  
Petra Bohall Wood
Keyword(s):  
West Virginia ◽  
Forest Fragmentation ◽  
Microhabitat Use ◽  
Dendroica Cerulea ◽  
Cerulean Warbler ◽  
Open Canopy ◽  
Territory Density ◽  
Cerulean Warblers ◽  
Mountaintop Mining ◽  
Spot Mapping

AbstractThe Cerulean Warbler (Dendroica cerulea) is a species of conservation concern in eastern North America, where declines in its population have been documented over the past several decades. A high proportion of the population occurs in forested areas of southern West Virginia, where it may be threatened by loss and degradation of forested habitat from mountaintop mining and valley fill (MTMVF). We examined, from a landscape perspective, the effects of forest fragmentation (in particular, effects of fragment size and response to edges) on Cerulean Warblers, using territory mapping techniques and geographic information system (GIS) technology in portions of four counties in southwestern West Virginia. We quantified landscape characteristics from digitized aerial photographs and measured microhabitat characteristics on spot-mapping plots. Territory density of Cerulean Warblers was 4.6 territories per 10 ha in intact forest and 0.7 territories per 10 ha in fragmented forest. The best habitat model included both landscape and microhabitat variables and indicated that territory density increased with increasing snag density, percentage of canopy cover >6–12 m and >24 m in height, and distance from mine edge. Models for predicting microhabitat use at the territory level were weak, indicating that microhabitat characteristics of territories were similar to habitat available on spot-mapping plots. The species did not appear to avoid internal edges, such as natural canopy gaps and open-canopy or partially open-canopy roads. Territory placement on ridges was greater than expected, and in bottomlands (ravines) and midslopes less than expected, given availability. Fifty percent of all territories were on ridges. Preference for ridges suggests that MTMVF may have a greater effect on Cerulean Warbler populations than other sources of forest fragmentation, given that ridges are removed in MTMVF. Our data indicate that Cerulean Warblers are negatively affected by mountaintop mining from loss of forested habitat, particularly ridgetops, and from degradation of remaining forests, as evidenced by lower territory density in fragmented forests and lower territory density closer to mine edges.

scholarly journals Phenotypic Clumping Decreases With Flock Richness in Mixed-Species Bird Flocks

2021 ◽  
Vol 8 ◽  
Author(s):  
Priti Bangal ◽  
Hari Sridhar ◽  
Kartik Shanker
Keyword(s):  
Body Size ◽  
Foraging Behavior ◽  
Group Size ◽  
Positive Interactions ◽  
Flock Size ◽  
Mixed Species ◽  
Taxonomic Relatedness ◽  
Western Ghats Of India ◽  
Mixed Species Flocks ◽  
Species Flocks

Animals that live in groups may experience positive interactions such as cooperative behavior or negative interactions such as competition from group members depending on group size and similarity between individuals. The effect of group size and phenotypic and ecological similarity on group assembly has not been well-studied. Mixed-species flocks are important subsets of bird communities worldwide. We examined associations within these in relation to flock size, to understand rules of flock assembly, in the Western Ghats of India. We examined the relationship between phenotypic clumping and flock richness using four variables—body size, foraging behavior, foraging height and taxonomic relatedness. Using a null model approach, we found that small flocks were more phenotypically clumped for body size than expected by chance; however, phenotypic clumping decreased as flocks increased in size and approached expected phenotypic variation in large flocks. This pattern was not as clear for foraging height and foraging behavior. We then examined a dataset of 55 flock matrices from 24 sites across the world. We found that sites with smaller flocks had higher values of phenotypic clumping for body size and sites with larger flocks were less phenotypically clumped. This relationship was weakly negative for foraging behavior and not statistically significant for taxonomic relatedness. Unlike most single-species groups, participants in mixed-species flocks appear to be able to separate on different axes of trait similarity. They can gain benefits from similarity on one axis while mitigating competition by dissimilarity on others. Consistent with our results, we speculate that flock assembly was deterministic up to a certain point with participants being similar in body size, but larger flocks tended to approach random phenotypic assemblages of species.

Geographic variation in prevalence and parasitemia of Haemoproteus paruli in the cerulean warbler (Dendroica cerulea)

2005 ◽  
Vol 83 (4) ◽  
pp. 626-629 ◽  
Author(s):  
Christine E Gibb ◽  
Jason Jones ◽  
M Kate Girvan ◽  
Jennifer J Barg ◽  
Raleigh J Robertson
Keyword(s):  
Geographic Variation ◽  
Body Condition ◽  
Significant Relationship ◽  
Regional Differences ◽  
Age Classes ◽  
Dendroica Cerulea ◽  
Cerulean Warbler ◽  
Host Parasite Interactions ◽  
Cerulean Warblers ◽  
Host Parasite

Although host–parasite interactions can affect the ecology and distribution of species, virtually nothing is known about range-wide variation in haematozoan levels in North American birds. We investigated haematozoan prevalence and parasitemia in 112 adult male cerulean warblers (Dendroica cerulea (Wilson, 1810)) in six populations throughout this species' breeding range. Thirty-six birds were infected with Haemoproteus paruli at low parasitemia (mean ± 1 SE, 6.18 ± 1.27 parasites/2000 erythrocytes). Prevalence did not differ between age classes, and there was no significant relationship between parasitism and body condition. However, prevalence and parasitemia were significantly higher in southern populations and further study is required to elucidate factors underlying regional differences in cerulean warbler haematozoan levels.

scholarly journals Territory and Nest-Site Selection of Cerulean Warblers in Eastern Ontario

The Auk ◽  
2001 ◽  
Vol 118 (3) ◽  
pp. 727-735 ◽  
Author(s):  
Jason Jones ◽  
Raleigh J. Robertson
Keyword(s):  
Site Selection ◽  
Nest Site ◽  
Deciduous Forest ◽  
Spatial Scales ◽  
Nest Site Selection ◽  
Population Characteristics ◽  
Dendroica Cerulea ◽  
Large Trees ◽  
Eastern Ontario ◽  
Cerulean Warblers

Abstract We examined habitat selection by breeding Cerulean Warblers (Dendroica cerulea) at three spatial scales in eastern Ontario over three years (1997–1999). Territories were characterized by well-spaced large trees, with high canopies and dense foliage cover at heights between 12–18 m. Nesting habitat additionally was characterized by dense foliage cover above 18 m. The results of our nest-patch (0.04 ha circle around nest) and nest-site (0.01 ha circle) analyses indicate that male Cerulean Warblers may take active roles in nest-site selection when selecting territories. We conclude from our nest-patch and nest-site selection analyses that territories likely contain multiple nest patches and sites and that male Cerulean Warblers may defend areas with multiple nest patches or sites, which may attract females to settle with them. Whether or not Cerulean Warbler females use nest-site availability as a mate- or territory-choice cue remains unknown. We also tested the validity of a commonly made assumption that a random sampling of habitat by researchers is representative of the habitat actually available to birds and found that, in our study area, the assumption was invalid. Taken together, our results point toward the need to maintain sizeable stands of mature, deciduous forest to ensure the persistence of Cerulean Warblers in eastern Ontario. Population characteristics such as lower minimum area requirements and a resilience to habitat disturbance may make that an easier job in eastern Ontario than elsewhere in this species' breeding range.

WITHIN-TERRITORY HABITAT USE AND MICROHABITAT SELECTION BY MALE CERULEAN WARBLERS (DENDROICA CERULEA)

The Auk ◽  
2006 ◽  
Vol 123 (3) ◽  
pp. 795 ◽  
Author(s):  
Jennifer J. Barg ◽  
Deviah M. Aiama ◽  
Jason Jones ◽  
Raleigh J. Robertson
Keyword(s):  
Habitat Use ◽  
Microhabitat Selection ◽  
Dendroica Cerulea ◽  
Cerulean Warblers

Song Rates, Mating Status, and Territory Size of Cerulean Warblers in Missouri Ozark Riparian Forest

2009 ◽  
Vol 121 (2) ◽  
pp. 283-289 ◽  
Author(s):  
Mark B. Robbins ◽  
Árpád S. Nyári ◽  
Monica Papeş ◽  
Brett W. Benz
Keyword(s):  
Riparian Forest ◽  
Territory Size ◽  
Mating Status ◽  
Cerulean Warblers

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.

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