We did a couple of "big days", one on May 8 and another on May 15. Both of these were "as long as we're seeing lots of birds, let's do a big day" kinds of things, and both far exceeded what I would have thought possible, with totals of 117 and 111, respectively. And to think I frittered away nearly an hour of each day trying to take pictures of things ..
There were some excellent flights of seabirds during the first half of the month, especially of phalaropes. One bird of particular interest on the 15th I originally identified as a Wedge-tailed Shearwater, which would be a remarkable occurrence this far north. The problem was that it was a dark bird, and these do not occur in Japan. Size, shape and flight were a good fit. It was obviously not a Sooty, Short-tailed or Flesh-footed. The only other outside possibilities are one of the dark pterodromae, but its size and underwing pattern (wholly dark) didn't fit with any of these. The numbers of Wedge-tailed Shearwaters we saw around the Ogasawaras at the end of the month did nothing to change my original opinion.
There were a few other interesting anomalies of spring migration. There was a very late Pale Thrush (which are rather scarce in this area at any time of year) on the 23rd, an Arctic Warbler at sea level on the 28th, and several Cattle Egrets (our first for Aomori). Also unusual was a male Mugimaki Flycatcher near Tsuta Onsen on the 15th.
There were also quite a few winter hangers-on, most oddly the Red-necked Grebe at Shiriya on the 15th. Individuals of most of the wintering ducks and gulls also remained long enough to make it onto the list. A few Dusky Thrushes hung on until the 14th.
It was also a good month for finding nests, including my "specialty", the woodpeckers. Great Spotteds nested at a place right on my way to work only six feet off the ground, where I could check on them daily. The eggs hatched (or began to) by the 21st. The June write-up will follow these birds (and others) along. We also located two White-backed nests around Tsuta Onsen. Both of these were very high above ground, and rather frustrated my attempts at photography. These birds appeared to be on an earlier schedule than the Great Spotteds, and I believe the young fledged before the end of the month. I heard indirectly from Ikenaga-San that the White-backeds we'd seen constructing a cavity on Amami-Oshima in early April finished up there in early May (this is much farther south, in case you linked in here from somewhere and aren't familiar with Japan).
We had the weather on our side, with rather calm, clear weekends and pleasant temperatures (speaking from my point of view). It did rain, but only while I was working in the office. This is the reverse of the normal pattern.
Arctic Loon (5/8,15(15+)) Ohamu Gavia arctica Pacific Loon (5/8(1),5/15(1)) Shiroeri-ohamu Gavia pacifica Little Grebe Kaitsuburi Podiceps ruficollis Horned Grebe (5/8(4)) Mimi-kaitsuburi Podiceps auritus Red-necked Grebe (5/15(1)) Akaeri-kaitsuburi Podiceps grisegena Great Crested Grebe Kanmuri-kaitsuburi Podiceps cristatus Streaked Shearwater Mizunagidori Calonectris leucomelas Wedge-tailed Shearwater ? (5/15(1)) Onaga-mizunagidori Puffinus pacificus Sooty Shearwater (5/8(1)) Haiiro-mizunagidori Puffinus griseus Short-t Shearwater (000's) Hashiboso-mizunagidori Puffinus tenuirostris Great Cormorant Kawa-u Phalacrocorax carbo Temminck's Cormorant Umi-u Phalacrocorax filamentosus Pelagic Cormorant (5+) Hime-u Phalacrocorax pelagicus Little Bittern (sp.?) (5/8(1)) (O?)-Yoshi-goi Ixobrychus, sp.? Black-cr. Night Heron (5/14(1H)) Goi-sagi Nycticorax nycticorax Cattle Egret (5/8(1),5/15(5)) Ama-sagi Bulbulcus ibis Little Egret (5/8(2)) Ko-sagi Egretta garzetta Gray Heron Ao-sagi Ardea cinerea Mute Swan Kobu-hakucho Cygnus cygnus Whooper Swan (3 disabled) O-hakucho Cygnus olor Bewick's Swan (1 disabled) Ko-hakucho Cygnus bewicki Mandarin Duck (10+) Oshidori Aix galericulata Mallard Ma-gamo Anas platyrhynchos Spot-billed Duck Karu-gamo Anas poecilorhyncha Common Teal Ko-gamo Anas crecca Falcated Duck (5/8(3)) Yoshi-gamo Anas falcata Gadwall (5/8,5/15) Okayoshi-gamo Anas strepera Eurasian Wigeon Hidori-gamo Anas penelope Northern Pintail Onaga-gamo Anas acuta Northern Shoveler (5/8,5/15,5/18) Hashibiro-gamo Anas clypeata Pochard Hoshi-hajiro Aythya ferina Tufted Duck Kinkuro-hajiro Aythya fuligula Greater Scaup Suzu-gamo Aythya marila Common Scoter (5/8(1)) Kuro-gamo Melanitta nigra Velvet Scoter (5/8(2),5/15(10)) Birodo-kinkuro Melanitta ?? Harlequin Duck (->5/15) Shinori-gamo Histrionicus histrionicus Common Goldeneye (5/8(2)) Hojiro-gamo Bucephala clangula Smew (5/8(2)) Miko-aisa Mergus albellus Red-breasted Merganser (5/8(1)) Umi-aisa Mergus serrator Osprey (5/8(1)) Misago Pandion haliaetus Honey Buzzard (5/23(1)) Hachikuma Pernis apivorus Black Kite Tobi Milvus migrans Japanese Lesser Sparrowhawk (5/12(1)) Tsumi Accipiter gularis Eurasian Sparrow Hawk (5/23(1)) Hai-taka Accipiter nisus Common Buzzard Nosuri Buteo buteo Asian Marsh Harrier Chuhi Circus spilonotus Peregrine Falcon Hayabusa Falco peregrinus Northern Hobby (5/23(1)) Chigo-hayabusa Falco subbuteo Green Pheasant (2) Kiji Phasianus colchicus Water Rail (5/15(3H)) Kuina Rallus aquaticus Moorhen (4) Ban Gallinula chloropus Eurasian Coot O-ban Fulica atra Little Ringed Plover (5/15(3)) Ko-chidori Charadrius dubius Kentish Plover Shiro-chidori Charadrius alexandrinus Mongolian Plover (5/15(6),5/18(3)) Medai-chidori Charadrius mongolus Pacific Golden Plover (5/15(4)) Munaguro Pluvialis pacifica Ruddy Turnstone (5/8(2),5/15(6)) Kyojo-shigi Arenaria interpres Red-necked Stint (5/15(20+)) Tonen Calidris ruficollis Sanderling (5/8(70),5/15(20)) Miyubi-shigi Crocethia alba Spotted Redshank (5/8,5/15(33)) Tsuru-shigi Tringa erythropus Greenshank (5/15(4)) Aoashi-shigi Tringa nebularia Gray-tailed Tattler (5/8(1),5/15(3)) Kiashi-shigi Tringa brevipes Common Sandpiper (5/8(1),5/15(4)) Iso-shigi Tringa hypoleucos Common Snipe (5/8(1)) Ta-shigi Gallinago gallinago Latham's Snipe (5/8->) Oji-shigi Gallinago hardwickii Red Phalarope (5/8(4),/15(35)) Haiiro-hireashi-shigi Phalaropus fulicarius Red-necked Phalarope (5/15(1000)) Akaeri-hireashi-shigi Phalaropus lobatus Common Black-headed Gull (50) Yuri-kamome Larus ridibundus Herring Gull (5/8(1),5/15(5)) Seguro-kamome Larus argentatus vegae Glaucous Gull (5/8(1)) Shiro-kamome Larus hyperboreus Slaty-backed Gull O-seguro-kamome Larus schistisagus Mew Gull (->5/15(3)) Kamome Larus canus Black-tailed Gull Umineko Larus crassirostris Black-legged Kittiwake (5/8(30),5/15(5))Mitsuyubi-kamome Larus tridactylus Spectacled Guillemot (10) Keimafuri Cepphus carbo Ancient Murrelet (5/8(6)) Umisuzume Synthliboramphus antiquus Rhinoceros Auklet Utou Cerorhinca monocerata Rufous Turtle Dove Kiji-bato Streptopelia orientalis Japanese Green Pigeon (5/16(3),5/23(1)) Ao-bato Sphenurus sieboldii Common Cuckoo (5/18(4)->) Kakko Cuculus canorus Oriental Cuckoo (5/9(1)->) Tsutsudori Cuculus saturatus Little Cuckoo (5/24->) Hototogisu Cuculus poliocephalus Ural Owl (5/8(1H)) Fukuro Strix uralensis White-thr. Needle-t. Swift (5/23(5)) Hario-amatsubame Chaetura caudacuta Common Kingfisher Kawasemi Alcedo atthis Japanese Green Woodpecker (2) Ao-gera Picus awokera Great Spotted Woodpecker Aka-gera Dendrocopus major White-backed Woodpecker (5) O-aka-gera Dendrocopus leucotos Japanese Pygmy Woodpecker Ko-gera Dendrocopos kizuki Skylark Hibari Alauda arvensis Bank Swallow (5/15(100),5/23(150)) Shodo-tsubame Riparia riparia Barn Swallow Tsubame Hirundo rustica Asiatic House Martin Iwa-tsubame Delichon ?? Gray Wagtail Ki-sekirei Motacilla cinerea Black-backed Wagtail Haku-sekirei Motacilla lugens Japanese Wagtail Seguro-sekirei Motacilla grandis Olive Tree Pipit (5/8->) Binzui Anthus hodgsoni Water Pipit (5/8(1),5/15(1)) Tahibari Anthus spinoletta Brown-eared Bulbul Hiyodori Hypsipetes amaurotis Bull-headed Shrike Mozu Lanius bucephalus Brown Dipper Kawagurasu Cinclus pallasi Wren Misosazai Troglodytes troglodytes Japanese Robin (5/15(1f)) Komadori Erithacus akahige Siberian Blue Robin (5/9->(15)) Ko-ruri Erithacus cyane Red-flanked Bluetail (5/8(1)) Ruri-bitaki Tarsiger cyanurus Blue Rock Thrush Isohiyodori Monticola solitarius White's Ground Thrush (5/9(1),5/15(1)) Tora-tsugumi Z. dauma Gray Thrush (5/8(2)) Kuro-tsugumi Turdus cardis Brown Thrush Akahara Turdus chrysolaus Pale thrush (5/23(1f)) Shirohara Turdus pallidus Dusky Thrush (->5/14) Tsugumi Turdus naumanni Short-tailed Bush Warbler (5/8(10)->) Yabusame Cettia squameiceps Bush Warbler Uguisu Cettia diphone Japanese Marsh Warbler O-sekka Megalurus pryeri Black-browed Reed Warbler (5/15->) Ko-yoshiki Acrocephalus bistrigiceps Great Reed Warbler (5/8->) O-yoshikiri Acrocephalus arundinaceus Arctic Warbler (5/12->) Meboso-mishikui Phylloscopus borealis Sakhalin Leaf Warbler (5/8(12)->) Ezo-mushikui Phylloscopus ?? Eastern Crowned Warbler (5/8->) Sendai-mushikui Phylloscopus occipitalis Goldcrest (5/9(1)) Kikuitadaki Regulus regulus Narcissus Flycatcher Ki-bitaki Ficedula narcissina Mugimaki Flycatcher (5/15(1m)) Mugimaki Ficedula mugimaki Asian Brown Flycatcher (5/18(1)) Ko-same-bitaki Muscicapa latirostris Long-tailed Tit Enaga Aegithalos caudatus Willow Tit Ko-gara Parus montanus Coal Tit Hi-gara Parus ater Varied Tit Yama-gara Parus varius Great Tit Shiju-kara Parus major Nuthatch Goju-kara Sitta europaea Creeper Kibashiri Certhia familiaris Japanese White-Eye Mejiro Zosterops japonica Meadow Bunting Hojiro Emberiza cioides Japanese Reed Bunting Ko-jurin Emberiza yessoensis Gray-headed Bunting Hoaka Emberiza fucata Black-faced Bunting Aoji Emberiza spodocephala Gray Bunting (5/9->(25+)) Kuroji Emberiza variabilis Reed Bunting O-jurin Emberiza schoeniclus Oriental Greenfinch Kawara-hira Carduelis sinica Long-tailed Rose Finch (5/8(3)) Beni-mashiko Uragus sibiricus Japanese Grosbeak (5/15(7),/22(4),/23(1))Ikaru Eophona personata Hawfinch Shime Coccothraustes coccothraustes Eurasian Tree Sparrow Suzume Passer montanus Red-cheeked Myna Ko-mukudori Sturnus philippensis Gray Starling Mukudori Sturnus cineraceus Jay Kakesu Garrulus glandarius Azure-winged Magpie Onaga Cyanopica cyana Carrion Crow Hashiboso-garasu Corvus corone Jungle Crow Hashibuto-garasu Corbus macrorhynchos Good birding, Mike and Lee