Imbanuma, July 12, 97.

Imbanuma is a not too large waterbody surrounded by dykes not far from Narita airport in Chiba-ken. Before the Edo period it used to be a wide and shallow turn in the major Tonogawa river, if I understand things correctly. In the Edo period this Tonogawa was redirected as it caused to many floods in Tokyo. The whole area must have been a large marshland. More and more of the marshland has been cultivated into ricepaddies. Almost nothing is left. From the former S curve only two lakes remain. The western one has still some corners with reedland.

Eal and catfish, carp and bass belong to the specialities of freshwater fish caught in the lake. Restaurants in the neighborhood serve sashimi catfish and carp.

The large number of herons and bitterns must be a faint echo of a glorious past. Especially the Chinese little bitterns were a great delight: flying over the reedbeds and traveling from the reedbeds to the rice paddies. At one point an apparent family of two adult birds and one juvenile was observed flying to a ricepaddy. Flight activity seemed unusual high, perhaps due to the dark and rather rainy weather. There was hardly any wind, temperature about 26 C and towards noon more and heavier rain.

Main attraction is, of course, the supposedly breeding Eurasian Bittern.

Participants: Ikenaga-san, Honda-san and Fer-Jan de Vries.
  1. Little grebe Podiceps ruficollis [Kaitsuburi] 2 ex.
  2. Great cormorant Phalacrocorax carbo [Kawa-u] 4 ex.
  3. Mallard Anas Platyrhynchos [Ma-gamo] 1 ex.
  4. Spot-billed duck Anas poecilorhyncha [Karu-gamo] 4 ex.
  5. Little tern Sterna albifrons [Ko-ajisashi] 3 ex.
  6. Chinese Little Bittern Ixobrychus sinensis [Yoshi-goi] Between 15-20 flying individuals.
  7. Black-crowned night-heron Nycticorax nycticorax [Goi-sagi] At least 10.
  8. Little egret Egretta garzetta [Ko-sagi] At least 4.
  9. Intermediate egret Egretta intermedia [Chuu-sagi] At least 5.
  10. Great egret Egretta alba [Dai-sagi] At least 8. One with a yellow bill with a black tip.
  11. Gray heron Ardea cinerea [Ao-sagi] At least 6.
  12. Coot Fulica atra [Ou-ban] 2 ex.
  13. Common Gallinule Gallinula chloropus [Ban] 1 ex.
  14. Rudy crake Porzana fusca [Hi-kunia] 1 ex seen by Ikanaga-san.
  15. Rufous turtle dove Streptopelia orientalis [Kiji-bato] At least 3 ex.
  16. Common kingfisher Alcedo atthis [Kama-semi] 2 ex.
  17. Skylark Alauda arvensis [Hibari] Many, >30.
  18. Barn swallow Hirundo rustica [Tsubame] Many > 200.
  19. Fan-tailed warbler Cisticola juncidis [Sekka] Many > 20.
  20. Great reed warbler Acrocephalus arundinaceus [Ou-yoshikiri] Many > 40.
  21. Japanese reed bunting Emberiza yessoensis [Ko-jurin] Several > 5.
  22. Oriental greenfinch Carduelis sinica [Kawarahiwa] 1 ex.
  23. Tree sparrow Passer montanus [Suzume] At least 20.
  24. Gray starling Sturnus cineraceus [Mukudori] At least 5.
  25. Carrion crow Corvus corone [Hashiboso-garasu] At least 3, among which 1 juvenile.
  26. Jungle crow Corvus macrorhynchos [Hashibuto-garasu] At least 2.

Back to previous page Last modified: July 12, 1997.