Desert riparian ecosystems are important breeding and stopover sites for many bird species but have been degraded due to altered hydrology and land management practices.
Birders flock to stopover sites like Cape May, N.J., to watch birds on their journeys to the far north in the spring and back to the tropics in the fall.
That's how the birds return to the same breeding, wintering, and stopover sites year after year.
"Stopover sites are crucial for species that have to cross inhospitable landscapes such as the Sahara," Dr. Noble noted.
In addition, urban sites can serve as "stopover sites" for birds that are looking for food and shelter along their migration route.
We mapped migration routes, stopover sites, breeding locations, and wintering locations (Fig. 1).
Kernel density estimation (program ArcMap 9.2, ESRI) was then applied separately for wintering areas, stopover sites on autumn migration and stopover sites on spring migration on a UTM31N projection.
New miniaturized geolocators allow for unraveling migratory routes, stopover sites and wintering areas of small birds in space and time.
In general, only when birds settle at breeding or stopover sites, they could spread their self-carrying viruses when in contact with other birds or poultry.
If a circle encompassed more than five points (corresponding to a time span of 48 hours), these points were assigned to stopover sites.
We considered 4 different locations: a wintering site in the Netherlands, stopover sites in the Baltic sea region and at the Kanin peninsula in Russia, and a breeding site N at the Barents Sea coast in Russia [35] (figure 1).
