Steller’s Sea Eagle Movements
We radio tracked twenty-four juvenile Steller’s Sea Eagles via satellite from natal areas in Magadan, Kabarovsk, Amur, Sakhalin and Kamchatka. Nestling dispersal occurred 9 September – 6 December (n=24), mostly 14 September – 21 October. Dispersal date did not differ among regions or years. Most eagles made stopovers during migration, where they spent 4 –28 days. Migration occurred 9 September – 18 January, mostly along established routes (example of southward migration), and took 4 to 116 days to complete (n=18). Eagles averaged a minimum of 47.8km/day (SD = 54.9, n = 17) excluding the periods of time spent at stopover locations, and 22.9 km/day (SD = 10.7, n = 18) including stopovers. Mean degrees of latitude spanned during migration was: Kamchatka: 2.1 (SD=0.9, n=4); Magadan: 11.6 (SD=4.8, n=7); Amur: 7.3 (SD =0.8, n=6); Sakhalin: 1.1(n=1).
For the most part, birds used known wintering grounds. Sizes of ranges of eagles throughout the winter were variable. Eagle location estimates were concentrated in 1-3 sub-areas within their particular winter ranges. Mean size of first wintering sub-areas was 274 km2 (SD= 595, n=16), of second, 529 km2 (SD=700, n=5), of third, 1181(SD= 1697, n=3). For all birds that had at least two wintering sub-areas, the second was located south of the first.
Five birds were tracked into spring migration, which was initiated between 2 February and 31 March (n=4). Two eagles from Magadan were tracked onto summering grounds, which were well south of their natal areas. Both had early and late summering areas. One bird was followed for 23 months, but rate of data collection gradually declined. It initiated its second autumn migration in the first half of October and arrived on its wintering grounds on 26 December. Second autumn migration covered 1839 km (20.9-22.4 km per day). Unlike its first winter when it used two sub-areas, only one sub-area was used in 1998-99, but his was located near wintering areas used in 1997-98. It left its wintering ground between 13 April and 13 May, and arrived on summering grounds between 7 June and 8 July.
For details see:
McGrady, M.J., M. Ueta, E. Potapov, I. Utekina, V.B. Masterov, A. Ladyguin, V.B. Zykov, J. Cibor, M.R. Fuller, and W.S. Seegar. 2003. Movements by juvenile and immature Steller’s sea eagles Haliaeetus pelagicus tracked by satellite. Ibis 145: 318-328.
McGrady, M.J., M. Ueta, E. Potapov, I. Utekina, V.B. Masterov, M.R. Fuller, W.S. Seegar, A. Ladyguin, E.G. Lobkov, and V.B. Zykov. 2000. Migration and wintering of juvenile and immature Steller’s eagles. Pages 83-90, in M. Ueta and M.J. McGrady, eds., First symposium on Steller’s and white-tailed sea eagles in East Asia. Wild Bird Society of Japan, Tokyo, Japan.
McGrady, M., Potapov, E., and Utekhina, I. 1999. Feeding on Steller’s sea eagle (Haleaeetus pelagicus) nestling by a brown bear (Ursus arctos). Journal of Raptor Research 33 (4): 342-343.
McGrady, M. J. 1998. Radio-tracking of Steller’s Sea Eagle Yields Surprises. Russian Conservation News 14.
Potopov, E. R., I. Utekhina & M. J. McGrady 2000. Steller’s sea eagle in Magadan District and in the north of Khabarovsk District. Pp. 29-44. In: Ueta, M. J. and M. J. McGrady (Eds.) First Symposium on Steller’s and White-tailed Sea Eagles in East Asia. Wild Bird Society of Japan. Tokyo.
Ueta, M., M.J. McGrady, H. Nakagawa, F. Sato and V.B. Masterov. 2003. Seasonal change in habitat use in Steller’s sea eagles. Oryx 37:110-114.
Utekhina, I., E. Potopov & M. J. McGrady 2000. Diet of the Steller’s sea eagle in the northern Sea of Okhotsk. Pp 71-82. In: Ueta, M. J. and M. J. McGrady (Eds.) First Symposium on Steller’s and White-tailed Sea Eagles in East Asia. Wild Bird Society of Japan. Tokyo.