Key Words: Argos system, red-crowned crane, oriental white stork, remote sensing, Landsat/TM
Abstract: Migration routes and habitats of red-crowned cranes and oriental white storks were studied by two kinds of satellite-based observation techniques, i.e. satellite tracking and remote sensing techniques. By the former we obtained bird location data; by the latter we investigated habitat ecosystem conditions. By combining these two techniques we analyzed the relationship between ground conditions and habitation patterns of wetland migratory birds. In the summer of 1999 small platform transmitter terminals were set on six red-crowned cranes and six oriental white storks in the wetlands along the Amur River in the Russian Far East. Their migration routes to wintering sites in China were tracked by using the satellite tracking technique. Locations of important places for breeding, stopover and wintering have been extracted from the migration data. Satellite remote sensing technique was used for investigating ground environmental conditions. The relationship between wetland ecosystems and habitation patterns of migratory birds was investigated.
1. Introduction
Recently wetlands are being recognized as important ecosystems for the conservation of biodiversity. They support wide variety of flora and fauna and serve as habitats for many kinds of creatures including migratory birds. However wetlands are disappearing at a rapid rate in East Asia due to human activities such as agricultural, residential, and industrial developments (Hussain, 1994). The decrease and environmental deterioration of wetlands are bringing quite a few species of migratory birds to face the danger of extinction. For the conservation of wetland ecosystems and wetland migratory birds, it is urgently needed to understand the actual situation of the decrease and environmental destruction of wetlands and to investigate the relationship between wetland ecosystems and habitation patterns of migratory birds.
In this study a satellite tracking system (Argos system, http://www.argosinc.com/) was used to pursue migration routes of two species of migratory birds, i.e. red-crowned cranes and oriental white storks, both of which are in danger of extinction. They can serve as good indicators of the conservation state of wetlands because they stand at the top of the wetland food chains. The satellite tracking data were used to extract locations of important places for breeding, stopover and wintering. We then used satellite images (NOAA/AVHRR and Landsat/TM images) for investigating the distribution and environmental conditions of the wetlands in East Asia. The relationship between wetland ecosystems and habitation patterns of migratory birds was analyzed by combining remotely sensed images and satellite tracking data of bird locations.
2. Satellite Tracking Of Migration Routes
In the summer of 1999 small platform transmitter terminals (PTT) were set on six red-crowned cranes and six oriental white storks in the wetland areas along the Amur River in the Russian Far East. Figure 1 shows the capture points. Their migration routes from the breeding sites in the Amur Basin to the wintering sites in China were tracked by the Argos system. The accuracy of the Argos system is indicated by the location class (Table 1). Basically we only used the data with the location classes higher than 1, which means the error of an estimated bird location is less than 1 km.
Fig. 1. Capture points. (Red: red-crowned cranes, Blue: oriental white storks).
