Oriental White Storks in the wild

The Number of the Storks in the Wild

Table: The number of the Stork in the wild (as of April 20, 2017). Figures in parentheses indicate storks in temporary captivity.

Year Hard

Release

Soft
Release
(Adult)
Soft
Release
(Young)
Fledglings

in the Wild

Wild

Storks

Total
2005 3 3
2006 1 4(1) 1 6(1)
2007 2 2
2008 2 4 6
2009 6 6
2010 6 6
2011 5 5
2012 9 9
2013 3 6 9
2014 2 8(1) 10(1)
2015 3 8 11
2016 4 11 15
Wild Storks 1 1
Total 4 6(1) 15 63(1) 1 89(2)

Reference:
Table: The Number of Oriental White Storks Released Outside Hyogo Prefecture (as of September 25th, 2016)

Year
Release Site
Hard
Release
Soft
Release
(Adult)
Soft
Release
(Young)
Fledglings

in the Wild

Wild

Storks

Total
2015
Noda City
2 2
2015
Fukui Prefecture
2 2
2016
Noda City
2 2
2016
Fukui Prefecture
2 2
Total 4 4 8

Handling Policy of Oriental White Stork in the Wild

(October 29th, 2014)
The Hyogo Park of the Oriental White Stork considers Oriental White Storks that have been reintroduced into the wild as wild birds and does not interfere with their lives except in the following cases:

  • When attaching bands to the legs of nesting young storks in the nest for identification.
  • When capturing storks to provide medical treatment that would also help maintain or revive the wild population (capturing of breeding pair, preventing inbreeding, reattachment of the leg bands, etc.)
  • When the storks trapped in deer nets can walk and fly after rescuing. When the storks have a treatable injury and it is judged to be capable of returning on their own with simple treatment.

In each case mentioned above, we proceed carefully while taking the thoughts of local residents into consideration.

Counting Method of Oriental White Storks in the Wild

(September 15th, 2013)
After releasing the Oriental White Stork into the wild for the first time in 2005, the Hyogo Park of the Oriental White Stork counted the storks one by one and reported the number. However, with a larger stork population, we could no longer accurately count the birds. So from September 15th, 2013, we started counting storks alive in the wild as described below. Our conventional counting method of wild storks included storks that had not been sighted for a long period, assuming that they were still living somewhere in Japan. However, it is always possible that such birds are no longer living or that they may have left Japan to the continental mainland. We no longer count storks that have not been sighted for over a year in Japan. They are assumed to be not living within Japan. Also, before we started attaching bands for identification to all nestling storks in 2013, a number of birds had left the nest before being banded. So there are a few storks without bands. When they get at least one year old, they look like adults and become indistinguishable from storks immigrating from mainland for wintering in Japan.Counting Method of Oriental White Stork in the Wild
As a general rule, we only count storks sighted in Japan that we can identify with their bands. However, if an unidentified stork is a mate of the pair, it is included in the count since storks normally do not change mates (Ezaki & Ohsako, 2012). (e.g. Shounji Pair Female: Ehime, Yamamoto Pair Male: J0011)

Calculating the Number of Storks Alive in the Wild
a. No. of the released storks + No. of the fledged storks in the Wild + No. of the immigrated wild storks
b. No. of retrieved storks into captivity + No. of died storks in the wild + No. of the missing storks + No. of the unidentified storks unbanded for more one year fledgling + No. of the temporarily retrieved storks into captivity
a – b = No. of storks alive in the wild

  • Storks that have not been sighted in over a year are called “Missing storks” and not included in the count. (Two individuals as of September 2013, J0003 from Yuruji nest in 2007 and J0400 soft released in 2009.)
  • Storks that have left the nest in the wild without being banded for identification will have distinctive juvenile feathers for one year. Such storks can be counted in the total as age 0. However, when they reach to age 2 and older, they will become indistinguishable from other unbanded storks. Therefore, these storks are called “Unidentified storks” and excluded from the count even though they still may be living. (as of September 2013: Each one offspring storks in the Izu Pair in 2009, Toshima Pair in 2012, and Nagadome Pair in 2012.)
  • Storks kept in captivity for bird management or emergency rescue are called “Temporarily retrieved storks” and not counted. (as of September 2013: Yuruji Pair’s offspring J0063 in 2013.)