Table 1 Accuracy of the Argos system (http://www.argosinc.com/).
| Location
Class |
Estimated
accuracy in latitude and longitude
|
| 3
|
<150m
|
| 2
|
150m<accuracy<350m |
| 1 |
350m<accuracy<1000m |
| 0 |
>1000m |
| A |
no
estimate of location accuracy |
| B |
no
estimate of location accuracy |
| C |
(invalid
locations) |
Fig. 2. Migration routes of a red-crowned crane 21502 and an oriental white stork 20821.
Table 2 (a) Migration data in autumn 1999.
| ID |
Species |
Departure |
Arrival |
Days |
Destination |
| 20819 |
Red-crowned crane |
99/11/11 |
99/11/17 |
6 |
Yancheng marsh
|
| 21502 |
Red-crowned crane |
99/11/10 |
99/12/02 |
22 |
Yancheng marsh
|
| 20820 |
Oriental white stork
|
- |
99/12/07 |
- |
Poyang lake |
| 20821 |
Oriental white stork
|
99/09/19 |
99/11/18 |
70 |
Poyang lake |
| 20823 |
Oriental white stork
|
99/08/21 |
99/12/10 |
111 |
Poyang lake
|
Table 2 (b) Migration data in spring 2000.
| ID |
Species |
Departure |
Arrival |
Days |
Destination |
| 21502 |
Red-crowned crane |
00/03/01 |
00/04/04 |
34 |
Arkhara lowland
|
| 20821 |
Oriental white stork
|
00/03/17 |
00/05/02 |
47 |
Zhalong marsh
|
Among the twelve captured birds, we have succeeded in tracking the migration routes of two red-crowned cranes and three oriental white storks to their wintering sites in China. Moreover for one red-crowned crane and one oriental white stork the PTT's continued to function until the summer of 2000 and we could track the entire round-trip migration routes between their breeding sites in Russia and wintering sites in China (Figs. 2 (a) and (b)). Table 2 (a) and (b)
Fig. 3. Important habitats.
(Red: red-crowned crane,
Blue: oriental white stork ).
Fig. 4. Land cover map of China with a
migration route of an oriental white stork
20823.
summarizes individual migration data in autumn 1999 and spring 2000 respectively. From the bird location data we can extract important habitats of red-crowned cranes and oriental white storks for breeding, stopover and wintering. Figure 3 shows the locations of important habitats where birds stayed more than 10 days.
3. Analysis Of Habitat Conditions Using Satellite Imagery
To investigate the ground conditions of bird habitats we used satellite images. Figure 4 shows a part of a Chinese land cover map produced from NOAA/AVHRR and Landsat/TM images by Luo Di of the Institute of Remote Sensing Applications, Chinese Academy of Science. We overlaid bird locations on this map and studied in what kinds of land cover types the birds liked to stay. In Figure 4 the migration route of an oriental white stork (ID: 20823) is indicated as an example. Figure 5 shows the number of location data obtained at each of six land-cover types for two red-crowned cranes and three oriental white storks. We note that four out of five birds were found more frequently in farmlands than in wetlands. This frequent use of farmlands may be causing some friction with human activities in China. We also note that red-crowned cranes were found more frequently in grasslands than oriental white storks. This may be explained by the fact that the former is omnivorous while the latter is carnivorous.
