scholarly journals An East-West Comparison of Migration in North American Wood Warblers

The Condor ◽  
2005 ◽  
Vol 107 (2) ◽  
pp. 197-211 ◽  
Author(s):  
Jeffrey F. Kelly ◽  
Richard L. Hutto
Keyword(s):  
Riparian Vegetation ◽  
Large Scale ◽  
Ecological Systems ◽  
Migration Routes ◽  
Stopover Ecology ◽  
Wood Warblers ◽  
Songbird Migration ◽  
Published Research ◽  
Migration Systems ◽  
East West

Abstract That western and eastern songbird migration routes are distinct ecological systems has been proposed for over 100 years. Nonetheless, this distinction has not been widely recognized nor have there been any comparative studies that quantitatively evaluate the differences and similarities between western and eastern songbird migration systems. We drew from previously published research on wood warblers to highlight patterns in stopover ecology that suggest fundamental differences between western and eastern migrants. In particular, we compared biogeography, evolutionary relationships, and stopover ecology of wood warblers from western and eastern North America and found: (1) multiple lines of evidence that indicate western wood warblers are geographically isolated from eastern conspecifics or congeners throughout the annual cycle, (2) eastern and western wood warbler taxa are distinct evolutionary units, (3) migrant wood warblers captured in the Southwest tended to carry lower fat loads and be comprised of more after-hatch-year birds than is typical of eastern migrants, (4) frugivory is unknown in wood warblers endemic to the Northwest or Southwest and (5) relative to other regions and seasons, riparian vegetation is heavily used by western wood warblers in the spring. We think that further examination and synthesis of these differences would yield a more mechanistic understanding of Nearctic-Neotropical avian migration. On this basis, we elaborate our view that (1) an improved understanding of western songbird migration ought to be a high priority for science, conservation, and education, and (2) large-scale coordinated research efforts would be the most effective strategy for advancing our knowledge of passerine migration in the West. Una Comparación Este-Oeste de la Migración de las Reinitas de Bosque (Parulidae) de Norte América Resumen. Por más de 100 años se ha propuesto que las rutas de migración de aves paseriformes del este y del oeste son sistemas ecológicos diferentes. Sin embargo, esta distinción no ha sido reconocida ampliamente, ni se han realizado estudios comparativos que evalúen cuantitativamente las diferencias y similitudes entre los sistemas de migración del este y del oeste. Revisamos estudios previamente publicados sobre aves de bosque de la familia Parulidae (Reinitas) para destacar los patrones ecológicos de las paradas migratorias que sugieran diferencias fundamentales entre las aves paseriformes migratorias el este y del oeste. Particularmente, comparamos la biogeografía, las relaciones evolutivas y la ecología de las paradas migratorias de las Reinitas del este y del oeste de Norteamérica y encontramos: (1) múltiples líneas de evidencia que indican que las Reinitas del oeste se encuentran geográficamente aisladas de sus coespecíficos o cogenéricos del este durante todo el ciclo anual, (2) los taxa del este y del oeste son unidades evolutivas independientes, (3) las Reinitas migratorias capturadas en el suroeste tendieron a presentar menores cargas de grasa y una mayor proporción de aves eclosionadas durante el año, que lo es típicamente observado para las aves migratorias del este, (4) la frugivoría no se conoce en las Reinitas endémicas del noroeste o sudoeste y (5) en relación a otras regiones o estaciones, la vegetación riparia es usada intensamente durante la primavera por las Reinitas del oeste. Creemos que estudios adicionales y una síntesis de estas diferencias podrían producir un mejor entendimiento mecanístico de la migración Neártico-Neotropical de aves. Basados en esto, sugerimos que (1) un mejor entendimiento de la migración de aves paserinas del oeste debería tener alta prioridad para la ciencia, conservación y educación y (2) que los esfuerzos de investigación coordinados a gran escala serían la estrategia más efectiva para progresar en nuestro conocimiento sobre la migración de las aves paserinas en el oeste.

scholarly journals Converging migration routes of Eurasian hobbies Falco subbuteo crossing the African equatorial rain forest

2008 ◽  
Vol 276 (1657) ◽  
pp. 727-733 ◽  
Author(s):  
Roine Strandberg ◽  
Raymond H.G Klaassen ◽  
Mikael Hake ◽  
Patrik Olofsson ◽  
Thomas Alerstam
Keyword(s):  
Southern Africa ◽  
Rain Forest ◽  
Large Scale ◽  
Bird Migration ◽  
Satellite Telemetry ◽  
Flight Distance ◽  
Migration Routes ◽  
Restricted Area ◽  
Migration Systems

Autumn migration of adult Eurasian hobbies Falco subbuteo from Europe to southern Africa was recorded by satellite telemetry and observed routes were compared with randomly simulated routes. Two non-random features of observed routes were revealed: (i) shifts to more westerly longitudes than straight paths to destinations and (ii) strong route convergence towards a restricted area close to the equator (1° S, 15° E). The birds migrated south or southwest to approximately 10° N, where they changed to south-easterly courses. The maximal spread between routes at 10° N (2134 km) rapidly decreased to a minimum (67 km) close to the equator. We found a striking relationship between the route convergence and the distribution of continuous rainforest, suggesting that hobbies minimize flight distance across the forest, concentrating in a corridor where habitat may be more suitable for travelling and foraging. With rainforest forming a possible ecological barrier, many migrants may cross the equator either at 15° E, similar to the hobbies, or at 30–40° E, east of the rainforest where large-scale migration is well documented. Much remains to be understood about the role of the rainforest for the evolution and future of the trans-equatorial Palaearctic-African bird migration systems.

scholarly journals Evaluation of Long-Distance Orientation in Birds on the Basis of Migration Routes Recorded by Radar and Satellite Tracking

2001 ◽  
Vol 54 (3) ◽  
pp. 393-403 ◽  
Author(s):  
Thomas Alerstam
Keyword(s):  
Large Scale ◽  
Satellite Tracking ◽  
Polar Regions ◽  
High Latitudes ◽  
Migration Routes ◽  
Long Distance ◽  
Sun Compass ◽  
Branta Bernicla ◽  
Migrating Birds ◽  
East West

Predicted flight trajectories differ depending on which orientation cues are used by migrating birds. Results from radar and satellite tracking of migrating birds can be used to test which of the predicted trajectories shows the best fit with observed flight routes, supporting the use of the associated orientation mechanism. Radar studies of bird migration at the Northeast Passage and the Northwest Passage support the occurrence of migration along sun compass routes in these polar regions. In contrast, satellite tracking of Brent geese (Branta bernicla) migrating from Iceland across Greenland and from Northwest Europe to Siberia show routes that conform most closely with geographic loxodromes, but which are also profoundly influenced by large-scale topography. These evaluations are discussed in relation to the adaptive values of different routes in different parts of the world. Sun compass routes are favourable mainly for east-west migration at high latitudes. For east-west migration at mid and high latitudes magnetic loxodromes are more favourable than geographic loxodromes in certain regions while the reverse holds in other regions. The geometry of migration routes, as recorded by radar and satellite tracking, may be important for understanding the evolution of the complexity of birds' orientation systems, and for providing clues about the orientation mechanisms guiding the birds on their global journeys.

scholarly journals Geolocators reveal migration routes, stopover sites, and nonbreeding dispersion in a population of Cerulean Warblers

2020 ◽  
Vol 7 (1) ◽  
pp. 19-26
Author(s):  
Clayton D Delancey ◽  
Kamal Islam ◽  
Gunnar R Kramer ◽  
Garrett J MacDonald ◽  
Alexander R Sharp ◽  
...  
Keyword(s):  
Gulf Of Mexico ◽  
Spring Migration ◽  
Autumn Migration ◽  
Migration Routes ◽  
Neotropical Migrant ◽  
Wood Warblers ◽  
Before And After ◽  
The Caribbean ◽  
Declining Species ◽  
Cerulean Warblers

AbstractCerulean Warblers (Setophaga cerulea) are among the fastest declining Nearctic-Neotropical migrant wood-warblers (Parulidae) in North America. Despite ongoing conservation efforts, little is known about their non-breeding distribution. In June 2016-2018, we deployed geolocators (n = 30) on adult male Cerulean Warblers in Indiana, USA, to track annual movements of individuals. Recovered geolocators (n = 4) showed that Cerulean Warblers occurred broadly throughout northern South America. Autumn migration lasted 44-71 days (n = 4), whereas spring migration lasted 37-41 days (n = 3). The average migration distance was 5268 km. During autumn migration, Cerulean Warblers made 1-4 stopovers (i.e., ≥2 days; n = 4) and 1-2 stopovers during spring migration (n = 3). When crossing the Gulf of Mexico during autumn migration, two birds stopped over after crossing, but not beforehand. Two others navigated through the Caribbean rather than crossing the Gulf of Mexico. During spring migration, one individual stopped after crossing, one individual stopped before crossing, and one individual stopped before and after crossing the Gulf of Mexico. No birds migrated through the Caribbean Islands during spring migration. These results represent novel information describing annual movements of individual Cerulean Warblers and will inform conservation efforts for this declining species.

Automated monitoring of a large-scale cod (Gadus morhua) migration in the open sea

2002 ◽  
Vol 59 (12) ◽  
pp. 1845-1850 ◽  
Author(s):  
Luc A Comeau ◽  
Steven E Campana ◽  
Martin Castonguay
Keyword(s):  
Large Scale ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
Seasonal Migration ◽  
Migration Routes ◽  
Eastern Canada ◽  
Migration Patterns ◽  
Migration Timing ◽  
Open Sea ◽  
And Migration

The migration patterns of marine fishes are poorly known, in part owing to the technical limitations associated with tracking the movements of animals in deep water. Here we document a large-scale, directed, migration of Atlantic cod (Gadus morhua) off eastern Canada. Our approach was based on the acoustic tagging of 126 fish and the deployment of 69 subsurface receivers, stretching over a 160-km distance along the edge of the Laurentian Channel. After 1 year of automated recording, we found that 65% of the fish migrated out of coastal waters in two distinct runs during the summer–autumn period. The offshore-migrating fish overwintered in deep Laurentian Channel waters, returning inshore in April. Individual migration routes and migration timing were variable, indicating that the cod did not aggregate in large schools during the seasonal migration events.

Late-summer carbon fluxes from Canadian forests and peatlands along an east–west continental transect

2006 ◽  
Vol 36 (3) ◽  
pp. 783-800 ◽  
Author(s):  
Carole Coursolle ◽  
Hank A Margolis ◽  
Alan G Barr ◽  
T Andrew Black ◽  
Brian D Amiro ◽  
...  
Keyword(s):  
Large Scale ◽  
Ecosystem Respiration ◽  
Late Summer ◽  
Ecosystem Productivity ◽  
Diurnal Courses ◽  
Continental Scale ◽  
Young Forest ◽  
C Cycle ◽  
Use Efficiency ◽  
East West

Net ecosystem productivity (NEP) during August 2003 was measured by using eddy covariance above 17 forest and 3 peatland sites along an east–west continental-scale transect in Canada. Measured sites included recently disturbed stands, young forest stands, intermediate-aged conifer stands, mature deciduous stands, mature conifer stands, fens, and an open shrub bog. Diurnal courses of NEP showed strong coherence within the different ecosystem categories. Recently disturbed sites showed the weakest diurnal cycle; and intermediate-aged conifers, the strongest. The western treed fen had a more pronounced diurnal pattern than the eastern shrub bog or the Saskatchewan patterned fen. All but three sites were clearly afternoon C sinks. Ecosystem respiration was highest for the young fire sites. The intermediate-aged conifer sites had the highest maximum NEP (NEPmax) and gross ecosystem productivity (GEPmax), attaining rates that would be consistent with the presence of a strong terrestrial C sink in regions where these types of forest are common. These results support the idea that large-scale C cycle modeling activities would benefit from information on the age-class distribution and disturbance types within larger grid cells. Light use efficiency followed a pattern similar to that of NEPmax and GEPmax. Four of the five recently disturbed sites and all three of the peatland sites had low water use efficiencies.

scholarly journals Quantifying Horizontal and Vertical Movements in Ho Chi Minh City by Sentinel-1 Radar Interferometry

2020 ◽  
Author(s):  
Dinh Ho Tong Minh ◽  
Yen-Nhi NGO ◽  
Thu Trang Lê ◽  
Trung Chon Le ◽  
Hong Son Bui ◽  
...  
Keyword(s):  
Time Series ◽  
Large Scale ◽  
European Space Agency ◽  
Ground Subsidence ◽  
Ho Chi Minh City ◽  
Vertical Movements ◽  
Space Agency ◽  
Permanent Scatterers ◽  
The City ◽  
East West

Ho Chi Minh City (HCMC), the most populous city and the economic center of Viet Nam, has faced ground subsidence in recent decades. This work aims at providing an unprecedented spatial extent coverage of the subsidence in HCMC in both horizontal and vertical components using Interferometric Synthetic Aperture Radar (InSAR) time series. For this purpose, an advanced InSAR technique PSDS (Permanent Scatterers and Distributed Scatterers) was applied to two big European Space Agency (ESA) Sentinel-1 datasets composed of 96 ascending and 202 descending images, acquired from 2014 to 2020 over HCMC area. A time series of 33 Cosmos SkyMED images was also used for comparison purpose. The combination of ascending and descending satellite passes allows the decomposition of the light of sight velocities into horizontal East-west and vertical components. By taking into account the presence of the horizontal East-west movement, our finding indicates that the precision of the decomposed vertical velocity can be improved up to 3 mm/year for Sentinel-1 data. The obtained results revealed that subsidence is most severe in areas along the Sai Gon river in the northwest-southeast axis and the southwest of the city with the maximum value up to 80 mm/year, consistent with findings in the literature. The magnitude of horizontal East-West velocities is relatively small and a large-scale westward motion can be observed in the northwest of the city at a rate of 2-5 mm/year. Together, these results reinforced the remarkable suitability of ESA's Sentinel-1 SAR for subsidence applications even for non-Europe countries such as Vietnam and Southeast Asia.

East-west inclination of large-scale photospheric magnetic fields

Solar Physics ◽  
1994 ◽  
Vol 153 (1-2) ◽  
pp. 131-141 ◽  
Author(s):  
J. A. Shrauner ◽  
P. H. Scherrer
Keyword(s):  
Magnetic Fields ◽  
Large Scale ◽  
East West

Resources, Environment, and Development

2019 ◽  
pp. 124-141
Author(s):  
Sara Lorenzini
Keyword(s):  
Cold War ◽  
Civil Wars ◽  
Large Scale ◽  
Well Being ◽  
Color Line ◽  
International Crises ◽  
Underdeveloped Countries ◽  
Global Issues ◽  
New States ◽  
East West

This chapter studies how the linkage between state power and large-scale projects that ruled during the modernization years entered a crisis in the 1970s, when modernity ceased to be an end in itself and new sensibilities replaced what in 1958 Nehru called the “disease of giganticism.” While development struggled to keep its promise to quickly grant underdeveloped countries wealth and well-being, problems related to industrialization appeared in the form of ecological imbalances. At the turn of the decade, development was considered a failure as a Cold War weapon, and there was widespread doubt about planning. Though ideology was still unyielding in the periphery, where international crises and civil wars stemming from decolonization and the failure of new states continued to fuel Cold War dynamics, in international organizations the East–West conflict rarely challenged the fundamental underlying agreement on global issues. Instead, a major cleavage ran along the old color line—between a rich, white, developed North and a colored, poor, underdeveloped South.

scholarly journals Terrestrial Ecosystem Impacts of Sulfide Mining: Scope of Issues for the Boundary Waters Canoe Area Wilderness, Minnesota, USA

Forests ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 747 ◽  
Author(s):  
Lee E. Frelich
Keyword(s):  
Boreal Forest ◽  
Large Scale ◽  
Mine Drainage ◽  
Terrestrial Ecosystem ◽  
Terrestrial Ecosystems ◽  
Migration Routes ◽  
Metal Mining ◽  
Mining Operations ◽  
Ecosystem Impacts ◽  
Mining Impacts

Large-scale metal mining operations are planned or underway in many locations across the boreal forest biome in North America, Europe, and Asia. Although many published analyses of mining impacts on water quality in boreal landscapes are available, there is little guidance regarding terrestrial impacts. Scoping of potential impacts of Cu-Ni exploration and mining in sulfide ores are presented for the Boundary Waters Canoe Area Wilderness (BWCAW), Minnesota USA, an area of mostly boreal forest on thin soils and granitic bedrock. Although the primary footprint of the proposed mines would be outside the BWCAW, displacement and fragmentation of forest ecosystems would cause spatial propagation of effects into a secondary footprint within the wilderness. Potential negative impacts include disruption of population dynamics for wildlife species with migration routes, or metapopulations of plant species that span the wilderness boundary, and establishment of invasive species outside the wilderness that could invade the wilderness. Due to linkages between aquatic and terrestrial ecosystems, acid mine drainage can impact lowland forests, which are highly dependent on chemistry of water flowing through them. The expected extremes in precipitation and temperature due to warming climate can also interact with mining impacts to reduce the resilience of forests to disturbance caused by mining.

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