A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Patterns in diurnal airspace use by migratory landbirds along an ecological barrier
Migratory bird populations and survival are affected by conditions experienced during migration. While many studies and conservation and management efforts focus on terrestrial stoppage and staging areas, the aerial environment through which migrants move also is subjected to anthropogenic impacts with potential consequences to migratory movement and survival. During autumn migration, the northern coastline of Lake Superior acts as an ecological barrier for many landbirds migrating out of the boreal forests of North America. From 24 observation points, we assessed the diurnal movements of birds throughout autumn migration, 2008–2010, within a 210 × 10 km coastal region along the northern coast of Lake Superior. Several raptor species showed patterns in airspace associated with topographic features such as proximity to the coastline and presence of ridgelines. Funneling movement, commonly used to describe the concentration of raptors along a migratory diversion line that either prevents or enhances migration progress, occurred only for Bald and Golden Eagles. This suggests a “leaky” migration funnel for most migratory raptors (e.g., migrating birds exiting the purported migration corridor). Passerines migrating during the late season showed more spatial and temporal structure in airspace distribution than raptors did, including funneling and an association with airspace near the coast. We conclude that (1) the diurnal use of airspace by many migratory landbirds is patterned in space and time, (2) autumn count sites situated along ecological barriers substantially underestimate the number of raptors due to “leakage” out of these concentration areas, and (3) the magnitude and structure of diurnal passerine movements in airspace have been overlooked. The heavy and structured use of airspace by migratory landbirds, especially the airspace associated with anthropogenic development (e.g., buildings, towers, turbines) necessitates a shift in focus to airspace management and conservation attention for these animals.
Patterns in diurnal airspace use by migratory landbirds along an ecological barrier
Migratory bird populations and survival are affected by conditions experienced during migration. While many studies and conservation and management efforts focus on terrestrial stoppage and staging areas, the aerial environment through which migrants move also is subjected to anthropogenic impacts with potential consequences to migratory movement and survival. During autumn migration, the northern coastline of Lake Superior acts as an ecological barrier for many landbirds migrating out of the boreal forests of North America. From 24 observation points, we assessed the diurnal movements of birds throughout autumn migration, 2008–2010, within a 210 × 10 km coastal region along the northern coast of Lake Superior. Several raptor species showed patterns in airspace associated with topographic features such as proximity to the coastline and presence of ridgelines. Funneling movement, commonly used to describe the concentration of raptors along a migratory diversion line that either prevents or enhances migration progress, occurred only for Bald and Golden Eagles. This suggests a “leaky” migration funnel for most migratory raptors (e.g., migrating birds exiting the purported migration corridor). Passerines migrating during the late season showed more spatial and temporal structure in airspace distribution than raptors did, including funneling and an association with airspace near the coast. We conclude that (1) the diurnal use of airspace by many migratory landbirds is patterned in space and time, (2) autumn count sites situated along ecological barriers substantially underestimate the number of raptors due to “leakage” out of these concentration areas, and (3) the magnitude and structure of diurnal passerine movements in airspace have been overlooked. The heavy and structured use of airspace by migratory landbirds, especially the airspace associated with anthropogenic development (e.g., buildings, towers, turbines) necessitates a shift in focus to airspace management and conservation attention for these animals.
Patterns in diurnal airspace use by migratory landbirds along an ecological barrier
Peterson, Anna C. (author) / Niemi, Gerald J. (author) / Johnson, Douglas H. (author)
Ecological Applications ; 25 ; 673-684
2015-04-01
12 pages
Article (Journal)
Electronic Resource
English
Ecology of migratory landbirds during migration in the Midwest
| British Library Conference Proceedings | 1997
Monitoring Canada's landbirds - an integrated approach
| British Library Conference Proceedings | 1997
Priority research needs for the conservation of Neotropical migrant landbirds
| British Library Online Contents | 2002
Value of park reserves to migrating and breeding landbirds in an urban important bird area
| Online Contents | 2015
| British Library Conference Proceedings | 2004