10. Zeezoogdieren – Phocidae
Club van Zeetrekwaarnemers Verslagen , Volume 22 - Issue 1 p. 39- 41
Diver migration started late October along the coast of the Wadden Isles; on 23rd October 84 flew west in two hours, Terschelling. Large numbers along the coast of Texel and Holland not before late December, probably due to a severe winterperiod from 10th to 23rd of December. Maxima recorded: 319 south in two hours, Texel and 186 south in two hours, Scheveningen on 28th December. Out of 12 % identified, 95 % appeared to be Red-throated Diver. Heavy movements of Great Crested Grebes, recorded at Scheve- ningen the end of December, included 3.265 south in two hours on 28th December and 3.100 south in two hours on 30th. Most of de Red-necked Grebes were also recorded in this period, with peak numbers at Texel on 31st December; 10 flew south, 1 north and 3 others swimming near the site, in two hours. Due to the lack of stormy weather in September only very small numbers of Fulmars and shearwaters were recorded. Fulmar was seen irregularly in small numbers, best day on 11th October: 42 flew north in eight hours, Hondsbossche. Small numbers of Sooty Shearwater, maximum on 20th September: 21 south in seven hours, Hondsbossche. Single Balearic Shearwaters were seen on 31st July, Scheveningen and 7th August, Hondsbossche. Manx Shearwater was seen in small numbers aswell. The total number of Gannets, only 4.644, is rather small in comparison with preceding years (about 10.000). Some northwesterly gales in October produced somewhat heavier movements, maximum on 7th October: 421 north in eight hours, Hondsbossche. Migrating Brent Geese were most seen along the Wadden Isles, especially in October. Largest numbers were recorded on 16th October at Schiermonnikoog (808 west in three hours). Moult-migrating Shelducks passed by in July and August; peak numbers late July (25th July 580 flew north in five hours, Hondsbossche). Large numbers again in December, now heading south; 22nd December 556 south in two hours, Scheveningen. Wigeons were observed in good numbers along the coast of the Wadden-Isles in October. A heavy movement took place on 23rd October: 1.248 west in six hours, Schiermonnikoog. Very large numbers again in December: 21st December 4.942 south in two hours, Texel. Coldrushes on 17th December included Mallard, 1.679 south in six hours, Tufted Duck, 623 south in six hours and Pochard, 423 south in four hours, at Scheveningen. Most of the Eiders were, like always, recorded on Schiermonnikoog. Heavy movements in October: 23rd October 4.717 west in seven hours. Early August many Common Scoters were seen at Terschelling, probably most of the scoters involved were males: 10th August 2.087 west in five hours. The end of August several hundreds were staying near the coast of Schiermonnikoog, on 1st October ca. 3.000 were observed at Terschelling. Heavy movements again late October including 1.356 west on 23rd October, Terschelling and 3.025 east in two hours, Schiermonnikoog. Large numbers along the coast of Zuid Holland not before 19th December: 2.215 south in two hours, Scheveningen. Velvet Scoter especially in October and December including 113 west in two hours on 23rd October, Terschelling, 97 south in one hour on 6th December and 100 north in two hours on 22nd December, both at Texel. The autumn of 1981 produced good numbers of Mergansers (2.915). Migration started late September but a majority was recorded late October: on 16th October 87 west in four hours, Schiermonnikoog, and on 23rd October 133 west in two hours, Terschelling, Good numbers again in December: 27th December 75 flew south in four hours, Hondsbossche, 31st December 42 south and 32 north in two hours, Texel. As usual, Oystercatchers were recorded feeding on the beach in small numbers throughout the season, but rather good numbers were seen migrating especially in December (for instance: 1.800 west in one flock, Schiermonnikoog). Easterly winds in September produced many Lapwings (26th September 2.841 south, Hondsbossche). The 12th of December a large flock of Golden Plovers was recorded at Hondsbossche (1.000 south). Many Turnstones were observed on 19th December, feeding on the piers of IJmuiden (149). Curlews were seen passing by in December; on 17th December 684 flew south, Scheveningen. Bar-tailed Godwits frequented the sandy beaches of the Wadden Isles in summer, with peak numbers on 2nd August, 118, at Terschelling. At Scheveningen, the afternoon of 8th July produced good numbers of Redshanks (1.111 south). Sanderlings were commonest at the Wadden Isles. A flock of 450 Sanderlings was observed at Terschelling on 30th December. Great Skuas were fairly numerous, On 11th October 37 south and 14 north were recorded at several sites together. Most of the Pomarine Skuas recorded were seen on the same day: 21 south. Parasitic Skua was a rather common species in September. On 13th September peak numbers were registrated: 106 north, 28 south. From late September, increasing numbers of Great Black-backed Gull (were observed. Hourly totals sometimes reached about 100 individuals. Lesser Black-backed Gulls were seen regularly up to late October. Afterwards only small numbers were recorded. Heavy movements were seen in September and early October, peak numbers on 11th October: 1.080 south, Noordwijk. Common and Herring Gull both were common throughout the autumn, not showing any remarkable movements. Strong southward migration of Black-headed Gull was reported thrice. Largest numbers were recorded in October (max. 1.966 west on 16th October, Schiermonnikoog). Migration of the Little Gull was seen in October regularly including 307 south in eight hours on 11th October, Maasvlakte, aswell as in November including 353 south in eight hours on 24th, Scheveningen. A majority of the Kittiwake was also reported in those months; peak numbers on 13th November, 859 north in six hours, Hondsbossche. Black Tern appeared to be very scarce this year. On 8th August maximum numbers were recorded, at Hoek van Holland, totalling only 58 heading south in two hours. “Comic Terns”, and especially Common Tern in this case, were abundant in August. Along the coast of Zuid Holland, large numbers could be seen late in the afternoon. For instance 8.103 flew south in two hours (19.00-21.00h), Hoek van Holland. Normally northward migration was daily reported early in the morning, but numbers involved here were much smaller. Comic Tern migration was reported to be strong up to late September, almost complete southward. Little Terns were regularly seen in August along the coast of the Wadden Isles, including 105 west and 40 east in nine hours on 26th August, Schiermonnikoog, and along the coast of Noord and Zuid Holland in September, peak numbers on 14th , 80 south in one hour, Hondsbossche. Foraging Sandwich Terns were common in July and August (local breeding population), southbound migration not before September. On 13th September 426 flew south in five hours, Texel. Strong westerly winds in October and November could produce good numbers of Auks sp. (Razorbill or Guillemot). Peak numbers were reported on 13th November, 244 north and 9 south in six hours, Hondsbossche. A majority seemed to be Guillemot, as usual.
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