RESULTS

 The timing of the migration in autumn 1986

Martin D. Williams

 The timing of the migration noted by each of the autumn surveys was broadly similar. The following account is based on the autumn 1986 survey, and indicates the birds seen as the autumn progressed. (see also Appendix.)
  During the initial part of the survey, in late August, the daily maximum temperature re-mained at around 30°C (the range was 28.5-33°C), and minimum temperatures were be-tween 21.2 and 24°C. Shorebirds are among the earliest autumn migrants at Beidaihe (the records of La Touche 1920, 1921 and Hem-mingsen and Guildal 1968 suggest that the peak of autumn shorebird migration at Beidaihe occurs around the end of July and early August), and occurred in numbers, with over 2000 individuals of 34 species recorded on the 27th. White-winged Terns Chlidonias leucopterus were also common, the maximum count being 900 on 30 August (Hemmingsen had noted ‘countless numbers’ passing down the coast as early as the end of June). Over 9000 Pacific Swifts Apus pacificus were logged between 20 August and the end of the month, almost half this total passing in just two hours in the afternoon of the 30th. The survey’s first Relict Gull Larus relictus—and the only adult of this species seen during the autumn—was at the Sandflats on 23 August. Arctic Warblers Phylloscopus borealis, Yel-low-rumped Flycatchers Ficedula zanthopygia, Sooty Flycatchers Muscicapa sibirica, Grey-streaked Flycatchers M. griseisticta and Asian Paradise Flycatchers Terpsiphone paradisi were among the early passerine migrants.
  Counts of passing migrants were rewarding during the first half of September, when nota-ble totals included 2874 Pied Harriers Circus melanoleucos and 170 White-throated Nee-dletails Hirundapus caudacuta on 10th, and 170 Crested Honey-Buzzards Pernis pti-lorhyncus orientalis, 2957 Pied Harriers, 152 Japanese Sparrowhawks Accipiter gularis and 915 Oriental Pratincoles Glareola maldi-varum on 12th. In the early mornings, actively migrating passerines were evident, with counts including 483 Richard’s Pipits Anthus richardi on 13th, 1438 Yellow Wag-tails Motacilla flava on 6th and 189 Chinese
Grosbeaks (Yellow-billed Grosbeaks) Eo-phona migratoria on 7 September.
  The variety of passerines increased as Sep-tember progressed, with the first sightings of species such as the Siberian Rubythroat Erithacus calliope, the Red-flanked Bluetail (Orange-flanked Bush-Robin) Tarsiger cyanurus, the Chestnut-eared Bunting Em-beriza fucata and the Black-faced Bunting E. spodocephala during the second half of the month. There were two first-winter Relict Gulls at the Sandflats on 8 September; sight-ings of first-winter birds were to continue to the end of the survey.
  For much of the period between mid-September and the second week of October the weather was stable (anticyclonic) and ob-servations from the Lotus Hills were rather unproductive. Songbird movements contin-ued, e.g. 238 Olive-backed Pipits Anthus hodgsoni were logged on 24 September and 951 Chestnut-flanked White-eyes Zosterops erythropleura headed south on 20 September, and there were good numbers of Barn Swal-lows Hirundo rustica and Red-rumped Swallows H. daurica, with totals of over 950 and 2700, respectively, on 4 October. How-ever, the numbers of raptors were generally disappointing, the highest tally being 500 Pied Harriers on 20 September. On 23 Sep-tember, 3504 Grey-headed Lapwings Vanellus cinereus were recorded from the watchpoint.
  A sizeable influx of Radde’s Warblers Phylloscopus schwarzi was noted on 28 September, when 159 were recorded. Though this was the main species involved in the ‘fall’, there were good numbers of other grounded passerines, including six Siberian Rubythroats, eight Bluethroats Erithacus svecicus, five White’s Thrushes (Scaly Thushes) Zoothera dauma, 28 Lanceolated Warblers Locustella lanceolata, 114 Yellow-browed Warblers (Inornate Warblers) Phyl-loscopus inornatus, 21 Red-throated Flycatchers Ficedula (parva) albicilla and 209 Black-faced Buntings.
  A cold front moved eastwards over Beidaihe late on 9 October, and there was a flurry of migration the next day, when 146 Grey Her-ons Ardea cinerea, 160 Purple Herons A. purpurea and 16 species of rap-tors—including 56 Northern Goshawks Accipiter gentilis, 319 Common Buzzards Buteo buteo and five Greater Spotted Eagles Aquila clanga—moved south. From this date to the end of the survey period, the weather reverted to the periodicity which appears typi-cal of northeast China (Hemmingsen 1951), and successive arrivals of northerly air-streams, usually preceded by cold fronts, stimulated further ‘waves’ of migration. Cranes and geese began to occur in some numbers, and Upland Buzzards Buteo hemi-lasius were fairly common, the maximum count being 102 on 28 October. The first large Oriental White Stork Ciconia boyciana flock—numbering ca. 280 birds (over one-quarter of the known world population prior to the survey)—was seen at dusk on 29 Oc-tober. The highest day totals of Common Cranes Grus grus and Hooded Cranes G. monacha—1269 and 438, respectively—were logged on 5 November. The next day, Orien-tal White Stork numbers peaked, with a total of 742 resulting from just three sightings (flocks of ca. 360 and ca. 380, and two).
  The overall migration declined markedly in November, when most winter visitors became established. Late records included a Red-throated Flycatcher on 17 November.
  The Henghe Reservoir and the Sandflats were largely frozen over on 16 November, by which date there were relatively low numbers of passing birds, even on days with appar-ently good migration weather. Goosander (Common Mergansers) Mergus merganser were the last of the waterfowl to occur in numbers; 400 were recorded from the Lotus Hills watchpoint in the last week of the sur-vey. Red-crowned Cranes Grus japonensis, which seem to be the most cold tolerant members of the genus to pass Beidaihe, con-tinued to occur in small numbers, and the peak count of Great Bustards Otis tarda—70 birds—was made on 17 November.