Rare Birds in The Netherlands in 2018

This is the 39th annual report on rare birds in the Netherlands to be published in Dutch Birding. A few adjustments have been made in comparison with previous reports, in order to improve the readability. Most records are from 2018 but there are also belated and reconsidered records dating back to 1964. These have been assessed by the Dutch rarities committee (Commissie Dwaalgasten Nederlandse Avifauna; CDNA), a joint committee of the Dutch Birding Association (DBA) and the Nederlandse Ornithologische Unie (NOU). Records are assessed digitally by eight voting members. This report contains 235 reviewed reports, resulting in 155 accepted records. Records of all taxa accepted up to and including 2018, as well as pending reports, can be found on the online database www.dutchavifauna.nl. Please note that some reports from 2018 and earlier are still under review or awaiting submission and are therefore not included.

Remarkable records in 2018
With at least 374 species recorded in 2018, it was an average year for species diversity. With a few reports still pending, this number may rise. The average over the last 10 years is 373 (figure 1). Grey-cheeked Thrush Catharus minimus was new to the Dutch list, whereas Whistling Swan Cygnus columbianus was removed. With these changes, the Dutch list still numbers 521 species. Furthermore a retrospective ‘eastern yellow wagtail’ Motacilla tschutschensis/macronyx/taivana from 2008 was a new ‘superspecies’. Other highlights include the second Black-headed Wagtail M feldegg, third Great Knot Calidris tenuirostris, fourth Hooded Merganser Lophodytes cucullatus and Eastern Black-eared Wheatear Oenanthe melanoleuca, fifth Eastern Bonelli’s Warbler Phylloscopus orientalis, sixth White-throated Wagtail M cinereocapilla, seventh and eighth Cirl Bunting Emberiza cirlus and ninth Red-eyed Vireo Vireo olivaceus. From 2016, a Dusky Thrush Turdus eunomus (third) and, from 2017, a White-throated Wagtail (fifth) were also accepted. In addition, 2018 was a record year for Pallid Swift Apus pallidus (14), Baltic Gull Larus fuscus fuscus (six), Lesser Grey Shrike Lanius minor (five), Blyth’s Reed Warbler Acrocephalus dumetorum (11), Iberian Chiffchaff P ibericus (six, equalling 2010) and Pied Wheatear O pleschanka (three, equalling 1999).

Additional committee work in 2018
There were two committee meetings, one in January and one in August. The August ‘meeting’ was unusual in the sense that we did not physically meet up but instead digitally decided on several issues. An interesting experiment but we now know a face-to-face meeting has our preference. Recent decisions with consequences for this report include: 1 The criteria for re-introduced species that occur as vagrants have been updated. Populations have to be self-sustaining in order to qualify for potential acceptance. For example, Bearded Vulture Gypaetus barbatus is currently not acceptable as a wild vagrant, since the CDNA considers all observed individuals to originate from (not yet fully self-sustaining) re-introduction programs in the Alps. 2 The criteria for species that require proof that they do not show any signs of captivity (‘omgekeerde bewijslast’) in order to get accepted, were updated. Marbled Duck Marmaronetta angustirostris was added to the list. In specific cases it is now possible to demand additional evidence for any record submitted when the committee decides this is necessary (in theory, a Harlequin Duck Histrionicus histrionicus at sea could be treated differently from one on a pond in an inland town). The committee also has the freedom to treat any potential new species according to these criteria. Finally, the state of a bird’s plumage and its behaviour now weigh more heavily in the assessment. 3 A strategy was developed for species that were ‘on hold’ awaiting expected new identification insights, or DNA information. This resulted in the rejection of all Tundra Peregrine Falcons Falco peregrinus calidus and all field sightings (without DNA analysis) of eastern ‘lesser whitethroat’ Sylvia curruca/althaea taxa. If new identification insights are published in the future, records can be resubmitted.

Chairman Eddy Nieuwstraten was invited by our German colleagues from the Deutsche Avifaunistische Kommision (DAK) to demonstrate our digital voting system and to explore possibilities for future international collaboration.

Members
The following CDNA members voted on records in this report: Garry Bakker, Christian Brinkman (secretary until early 2019), Thijs Fijen, Diederik Kok, James Lidster (treasurer since 2019), Eddy Nieuwstraten (chairman), Hans Schekkerman (new member since 2019), Vincent van der Spek (secretary since 2019) and Rik Winters (treasurer; departing member after two terms (eight years) in 2019). Gerjon Gelling (archivist) and August van Rijn (assistant) supported the committee as non-voting members by submitting many reports published on national and regional websites. At the start of 2018, Marcel Haas, the former archivist, was thanked for the huge amount of work he had done since January 2013.

Glossary
Details included for each record in this report are, if available: date(s); location and/or municipality (municipal divisions as of 1 January 2018); province; number of birds if more than one, plumage and sex; type of record if ringed, photographed, sound-recorded, videoed or found dead (and where specimen is stored, if known); names of up to three observers involved in finding, identifying and recording, and relevant references in the literature, which normally include (inter)national but not regional journals, and published photographs. Records from 2017 lasting into 2018 that already have been published in the 2017 report (Gelling et al 2018) are repeated here without reference. Observations not (yet) submitted but mentioned in the 2017 report are not repeated in this report. The sequence of the records in the species accounts is from the current year backwards, with records within one year presented per province (starting with the province with the first record of the year), and then chronologically within each province. Numbers after each (sub)species’ name refer to the total number of individuals 1 from 1 January 1800 to 31 December 1979, 2 since 1 January 1980 but excluding, and 3 the current year. Taxa marked with an asterisk * are new to the Dutch list.
For the sake of completeness, date extensions are presented in this report. Used abbreviations for provinces are: DR Drenthe, FL Flevoland, FR Friesland, GE Gelderland, GR Groningen, LI Limburg, NB Noord-Brabant, NH Noord-Holland, OV Overijssel, UT Utrecht, ZL Zeeland, and ZH Zuid-Holland. For ageing, calendar-year is abbreviated to cy prefixed with 1, 2, 3 or 4 to indicate first, second, third or fourth. The symbol # indicates corrections or extensions of date(s), location(s) or other details concerning a record.
Decisions regarding taxonomy have been delegated to the Dutch committee for avian systematics (Commissie Systematiek Nederlandse Avifauna; CSNA) and are not under the responsibility of the CDNA.

Submitting a report
Reports can be submitted through the electronic form on www.dutchavifauna.nl or by using the link on www.waarneming.nl.

records

Swan / Fluitzwaan Cygnus columbianus 0,0,0
Based on newly described identification features other than the amount of black on the bill (Visscher & van Duivendijk 2015), all five records were reassessed. According to Evans & Sladen (1980), only a small minority (4.3%) show more than 10% yellow on the bill. This minority type however seems to be over-represented in Dutch records. This was, eg, the case for a widely twitched bird in Drenthe, Friesland and Groningen in the winters of 1997/98 and 1998/99. ‘Hybrigades’ with Bewick’s Swan C bewickii are a realistic option, and Bewick’s with aberrant bills are not unheard of (Evans & Sladen 1980). Identification based on a single feature is therefore tricky, especially in birds with a relatively large amount of yellow on the bill. The presence of the new features could not be determined in the records. It was therefore decided that all records are no longer proven and, as a consequence, Whistling Swan was removed from the Dutch list.

King Eider / Koningseider Somateria spectabilis 1,16,2
FRIESLAND Waddenzee near Harlingen, Harlingen 12 January to 21 March, and Noordvaarder, Terschelling, 14 April, adult male, photographed (J van Bruggen, B Lagerveld et al; Dutch Birding 40: 130, plate 175, 2018).
NOORD-HOLLAND Noordzee, Paal 9 to Paal 18, 24 March to 6 May, and Krassekeet, Oost, 12-19 May, and Paal 17, De Koog, Texel, 6 October, also seen at Richel, Vlieland FR, 8 May, adult male, photographed, videoed (P Snoeken et al; Dutch Birding 40: 199, plate 265, 2018).
The shape and size of the bills differed which made it possible to determine that not one, but two individuals cruised the Wadden Sea.

Ring-necked Duck / Ringsnaveleend Aythya collaris 5,39,0
GRONINGEN Appingedam-Oost, Appingedam, 7 January to 4 April, adult male, photographed, videoed (M Jonker et al; Dutch Birding 40: 133, plate 182, 2018).
A returning individual first seen on 11 February 2017.

Scaup / Kleine Topper Aythya affinis 0,19,0
NOORD-HOLLAND Dijkwielen, Hollands Kroon, 7-8 and 27-28 April, adult male, photographed (F Visscher).
A returning individual first seen on 26 February 2017.

Buffelkopeend Bucephala albeola 0,7,1
ZUID-HOLLAND Gaatkensplas and surroundings, Barendrecht, 20 September 2017 to 13 May, also seen at Spaarbekken Petrusplaat, Brabantse Biesbosch, Drimmelen NB, 4 June to 27 August, adult male, photographed, videoed (G Duijf et al).
NOORD-HOLLAND Den Oever and IJsselmeer, Hollands Kroon, 13 October 2017 to 20 March, and 9 October to 13 February 2019, adult male, photographed, videoed.
UTRECHT Nedereindse Plas, IJsselstein, Utrecht, 6-8 March, photographed (E Schuller et al).
The records from Noord-Holland and from Noord-Brabant/Zuid-Holland concern long-staying and returning individuals, the latter already since November 2004. After 14 years, this bird did not return to Barendrecht in the winter of 2018/19.

Merganser / Kokardezaagbek Lophodytes cucullatus 0,3,1
UTRECHT Haarrijnse Plas, Vleuten, Utrecht, 5-6 November, 2cy male, photographed, videoed (B Kasius, E Schuller et al).

Blue-winged Teal / Blauwvleugeltaling Spatula discors 6,35,2
DRENTHE Vloeivelden Zuidzijde, Nieuw Buinen, Borger-Odoorn, 4-5 May, male, photographed (W Trip et al).
NOORD-HOLLAND Waterberging Twisk, Medemblik, 6 and 11 May, male, photographed (V Schouten et al).

Blue-winged Teal x Northern Shoveler / Blauwvleugeltaling x Slobeend Spatula discors x clypeata 0,1,1
UTRECHT Natuurplas Breeveld, Woerden, 25-26 March, adult male, photographed (D Kok et al).

Alpine Swift / Alpengierzwaluw Tachymarptis melba 7,59,2
ZUID-HOLLAND Meppelweg, Den Haag, Den Haag, 25 April, adult, ringed, photographed (M Wezenaar, V van der Spek, R van der Vliet et al; Dutch Birding 40: 203, plate 270, 2018).
UTRECHT Hoogekampse Plas, De Bilt, 13 October, photographed (T Morel, H A M Prinsen).
The bird in Den Haag was accidently sprayed off the gutter of a building with a high-pressure cleaner during renovation work. It was taken into care but appeared to be in good health and was released shortly after. Unsurprisingly, this concerns the first ringing record.

Swift / Vale Gierzwaluw Apus pallidus 0,12,14
ZUID-HOLLAND Kwade Hoek West, Goedereede, Goeree-Overflakkee, 13 October, 1cy, photographed (L de Waard, M Hornsveld et al); Telpost de Vulkaan, Westduinpark, Den Haag, 14 October, 1cy, photographed (R van der Vliet, E Verlind et al); Vrijheidsweg, Ouddorp, Goeree-Overflakkee, 12 November, 1cy, photographed (G Tanis); Telpost de Puinhoop, Katwijk aan Zee, Katwijk, 15 November, 1cy, photographed (G Twigt).
GRONINGEN Wadden Sea east of Rottumeroog, Het Hogeland, 15 October, 1cy, photographed (M Jonker et al; Dutch Birding 40: 427, plate 578, 2018).
FLEVOLAND Dodaarsweg, Zeewolde, 2 November, 1cy, photographed (P Julsing, J D Eerdmans et al).
NOORD-HOLLAND Zuidpier, IJmuiden, Velsen, and Telpost Parnassia, Nationaal Park Zuid-Kennemerland, Bloemendaal, 4 November, 1cy, photographed (S O’Brien, H Buckx et al); several locations, Texel, 9-13 November, maximum of three, 1cy, photographed, videoed (R Stolk, E Menkveld, K Stork et al; Dutch Birding 40: 412, plate 551, 2018, 41: 64, plate 87, 2019). FRIESLAND Meeuwenduinslid, Vlieland, 11 November, also seen at Vuurtoren, De Cocksdorp, Texel NH (see Noord-Holland), 1cy, photographed (P Lemmers et al).
UTRECHT Telpost de Horde, Lopik, 11 November, 1cy, photographed (A Boele, K de Leeuw).
ZEELAND Oranjezon Oost, Oostkapelle, Veere, 11-13 November, two, 1cy, photographed (M Capello et al; Dutch Birding 41: 64, plate 88, 2019); Kamperland, Noord-Beveland, 14 November, 1cy, found moribund, and brought to a bird hospital where it died, stuffed, photographed (B Plune via M Klootwijk).
Despite the first record being as recent as 2006 and the second in 2013, sightings have now become fairly predictable: in most years birds occur after (strong) southerlies in late autumn. The 2018 influx, however, that also reached other parts of north-western Europe, was something else! An astonishing 14 birds were seen, more than doubling the number of records. Surely, they must at least occasionally be present – but overlooked – during months when Common Swifts A apus are more plentiful? Note that on 11 November, no less than three individuals were present on Texel. In Flevoland, a second swift was initially reported to be a Common but eventually two Pallid were submitted. Only a few photographs showed diagnostic features and since it was unclear which bird was on which photograph, the CDNA decided to accept only one. Of interest is that none of the three not accepted records were certain Common Swifts. These birds were all considered unidentifiable swifts so in reality more Pallids could have been involved.

Crake / Klein Waterhoen Zapornia parva 36,32,1
GELDERLAND Korte Waarden, Elburg, 11 July, adult female, photographed (H van Dorp, H de Kroon; Dutch Birding 40: 348, plate 466, 2018).

Crake / Kleinst Waterhoen Zapornia pusilla 171,57,-
1976 # NOORD-BRABANT Polder Middelveld, Brabantse Biesbosch, Drimmelen, 27 May to 5 June (was 27 May to 5 June 1975), maximum of three territories.
The species is no longer considered since 1 January 2007 but the CDNA still welcomes reports from before this date.

Bustard / Kleine Trap Tetrax tetrax 32,14,1
ZEELAND Polder Burgh- en Westland, Haamstede, Schouwen-Duiveland, 4 December, photographed (N Godijn et al; Dutch Birding 41: 70, plate 96, 2019).

Bustard / Grote Trap Otis tarda -,25 (since 1986),0
1964 # NOORD-BRABANT Made, Drimmelen, and between Made and Den Hout, Oosterhout, 20-22 February (was Made, Drimmelen, 20 February) (J Veen via S Terlouw; Veen sine dato).
This concerns both a date and locality extension.

Shearwater / Kuhls Pijlstormvogel Calonectris borealis 2,3,0
A migrating bird seen from several seawatch sites in two provinces and subsequently also in Belgium in October 2018 is still under review.

Great Cormorant / Grote Aalscholver Phalacrocorax carbo carbo 7,46,-
2003 NOORD-BRABANT Ringselvennen, Budel-Dorplein, Cranendonck, 18 August, photographed (R Kastelijn, J Kastelijn).
This subspecies is no longer considered since 1 January 2009. Previously, reports from before that date were still welcomed but the committee has now decided that, from 2019 onwards, old records will no longer be considered since improved identification insights suggest this taxon was in fact too common to be considered in the first place. A similar decision was recently taken for Icelandic Redwing Turdus iliacus coburni.

Stone-curlew / Griel Burhinus oedicnemus 10 (since 1969),61,-
2004 ZEELAND Beekshoekpolder, Vrouwenpolder, Veere, 21 March, photographed (G Geertse).
1993 NOORD-BRABANT Maashorst-Steenbergen, Landerd, 25 April (J W Hermans, P van de Braak et al).
1984 ZEELAND Mosselbanken, Terneuzen, April, photographed (B Grootjans via P L Meininger and R J J Vlek).
The species is no longer considered since 1 January 2009 but the CDNA still welcomes reports from 1969-2008.

American Golden Plover / Amerikaanse Goudplevier Pluvialis dominica 1,51,2
ZEELAND Zandkreek Zuid, Wilhelminadorp, Goes, 1-2 May, 2cy, photographed (S Lilipaly et al; Dutch Birding 40: 270, plate 353, 2018).
GRONINGEN Dollardkwelders, Oldambt, 25-26 May, adult, photographed (L Brinkhuizen).

Golden Plover / Aziatische Goudplevier Pluvialis fulva 9,64,3
FRIESLAND Kroonspolders, Vlieland, 6-8 August, photographed (S Lagerveld).
ZEELAND Breeweg, Koudekerke, Veere, 23 August, adult summer plumage, photographed (S Lilipaly et al).
GRONINGEN Hornhuisterpolder, Hornhuizen, De Marne, 6 September, sound-recorded (J G Bosma, M Bot).
Save the rare blank year in 2003, this species has been annual since the turn of the century. With now on average more than two records a year, it will no longer be considered from 2019 onwards. The CDNA still welcomes records from before this date. For an analysis of all Dutch records, see Fijen et al (2019).

American/Pacific Golden Plover / Amerikaanse/Aziatische Goudplevier Pluvialis dominica/fulva 0,9,1
FLEVOLAND Marker Wadden, Lelystad, 13 July, summer plumage, photographed (M Poot, J van der Winden).
2004 ZEELAND Telpost Breskens, Sluis, 29 May, summer plumage, photographed (P L Meininger et al).
The 2004 bird probably concerned an American. Since Pacific Golden Plover will no longer be considered from 1 January 2019 onwards, the category for unidentified ‘lesser golden plover’ will also disappear (hence, unidentified ‘lesser golden plovers’ will from now on be rejected). The CDNA still welcomes reports from before this date.

Great Knot / Grote Kanoet Calidris tenuirostris 0,2,1
FRIESLAND Seerijp, Terschelling, 16-19 June, adult summer plumage, photographed, videoed (J J de Vries, W van Zwieten et al; Ebels et al 2019; Dutch Birding 40: 255, plate 331, 270, plate 354, 2018, 41: 147, plate 178-182, 2019).
While there was a 25-year gap between the first (1991) and second (2016), this bird was found only two years after the popular Texel bird in 2016. Given the major global importance of the Wadden Sea for waders (eg, for Red Knot C canutus), it is perhaps unsurprising that, just like the previous record, this one was found on a wader roost within this UNESCO biosphere reserve.

Sandpiper / Bairds Strandloper Calidris bairdii 0,14,1
OVERIJSSEL Bolwerksplas, Deventer, 2-3 November, 1cy, photographed, videoed (W Koch et al; Dutch Birding 41: 64, plate 89, 2019).
Remarkably, another individual was seen at practically the same inland site in 2012. The 2012 bird represents the only May record, whereas this one is the first for November. All other birds were found between July and September (with one remaining until early October). With 11 records since 2011, Baird’s Sandpiper seems to have transformed from a mega rarity to a near-annual species within a short period of time.

White-rumped Sandpiper / Bonapartes Strandloper Calidris fuscicollis 1,51,2
FRIESLAND Westhoek, Waadhoeke, 12 August, adult summer plumage, photographed, videoed (R van der Vliet et al); Griend, Terschelling, 17 August, adult, photographed, videoed (B Gnep).

Sandpiper / Grijze Strandloper Calidris pusilla 0,12,1
LIMBURG Haertelsteinveld, between Maas and Julianakanaal, Meerssen, 21 May, adult summer plumage, photographed (H A M Dolmans).
With this being the second for this inland province in two years’ time, the committee debated whether it could have been the same individual but there was no evidence to support this.

Yellowlegs / Kleine Geelpootruiter Tringa flavipes 2,48,4
ZUID-HOLLAND Berkenwoudsche Hoge Boezem, Krimpenerwaard, 15-24 February, photographed, videoed (S van Walsum et al). NOORD-BRABANT Lage Velden, Lith, Oss, 4-7 May, adult, photographed (D Benders et al).
NOORD-HOLLAND Dijkmanshuizen, Texel, 8 May, adult summer plumage, photographed (K de Jong et al); Polder R, Petten, Schagen, 28 June to 3 July, adult summer plumage, photographed (W A van Splunder et al).

Snipe / Poelsnip Gallinago media -,44,1
GELDERLAND Babberich, Zevenaar, 26 May, photographed (M de Vries, G Jenniskens; Dutch Birding 40: 272, plate 357, 2018).

Collared Pratincole / Vorkstaartplevier Glareola pratincola 5,21,0
1998 # ZEELAND Stinkgat, and Schakerloopolder Karrenvelden, Tholen (was Stinkgat, Tholen), 29 July to 1 August, photographed (N de Schipper).
This concerns a location extension for the final day of its stay.

Black-winged Pratincole / Steppevorkstaartplevier Glareola nordmanni 12,32,1
GELDERLAND Neerveldse Blok and Liendense Waard, Batenburg, and Schebbelaarse Veld, and Leurse Veld, Hernen, Wijchen, 21 October to 7 November, also seen at Demen and De Deelen, Lith, Oss NB, 18-30 November, 1cy, photographed, videoed (J Houkes, S Schmalgemeijer, M van Schaijk et al; Dutch Birding 40: 425, plate 575, 2018, 41: 63, plate 86, 2019).

Thick-billed Murre / Kortbekzeekoet Uria lomvia 5,4,1
FRIESLAND Westgat, Hollum, Ameland, 4 March, found dead, photographed, collected; skeleton and tail- and wing-feathers in private collection of R Pater (R Pater; Dutch Birding 40: 203, plate 273, 2018).
Despite increased observer coverage and better optics, there have only been three records over the past 25 years, implying that the species is genuinely rare. Nine out of the 10 birds on the Dutch list were found dead, including two weakened birds that were present for a couple of days before they deceased (1979, 2012). The only (seemingly) healthy individual concerns a fly-by photographed during an unprecedented stream of 3295 Little Auks Alle alle passing Schiermonnikoog, Friesland, on 23 October 2005.

Ross’s Gull / Ross’ Meeuw Rhodostethia rosea 1,16,1
ZEELAND Binnenhaven, and Westerschelde, Vlissingen, Vlissingen, 24 January to 21 March, 2cy, photographed, sound-recorded, videoed (J A Goedbloed, J Boot et al; Dutch Birding 40: 52, plate 51, 128, plate 169-171, 129, plate 172, 2018, 41: 19, plate 18, 2019).
The original 1979 Dutch Birding Association (DBA) logo showed a first-winter Ross’s Gull. DBA has matured since, and so has the gull in the logo (since 1987). However, after twitchable second-winters and adults in the past, it was not until DBA celebrated its 40th birthday that a youngster was available to the crowds. This crisp bird showed very well, and its calls could even be recorded.

Franklin’s Gull / Franklins Meeuw Larus pipixcan 0,11,1
NOORD-HOLLAND Dijkgatsweide, Noorderdijkweg, Hollands Kroon, 14 July, adult summer plumage, photographed (B Woets; Dutch Birding 40: 348, plate 467, 2018).

Baltic Gull / Baltische Mantelmeeuw Larus fuscus fuscus 0,37,6
ZUID-HOLLAND Binnenwatering, Katwijk aan Zee, Katwijk, 1 April, adult, wearing colour ring, photographed (A Marijnis, M Zevenbergen, H Zevenbergen); Binnenwatering, Katwijk aan Zee, Katwijk, 15-16 September, 2cy, wearing colour ring, photographed (A Marijnis, R Hoeben); Zandmotor, Ter Heijde, and ’s-Gravenzande, Westland, 5-6 October, adult, wearing colour ring, photographed (M Zevenbergen, J van der Ende); Zandmotor, Ter Heijde, Westland, 9-13 October, 1cy, wearing colour ring, photographed (M van Lopik).
ZEELAND North Sea, off Westenschouwen, 30 September, 1cy, wearing colour ring, photographed (M Klootwijk); Spuisluis, Brouwersdam, Schouwen-Duiveland, 24 October, adult, wearing colour ring, photographed (A Holzem).
2017 # ZUID-HOLLAND De Banken, ’s-Gravenzande, Westland, Zuid-Holland, 12 September, 3cy.
Acceptance was based on the presence of a Norwegian colour ring (erroneously reported as a Finnish ring in 2017 report).
2018 was a record year for this subspecies. All six birds were colour-ringed as chicks in the Horsvær archipelago, Norway. Helberg et al (2009) considered this to be fuscus area, and this was recently confirmed by Baggot et al (2018). On plumage, only 2cy birds can be identified with certainty during certain months only. Therefore, in all other plumages only birds ringed as chicks within known nominate fuscus colonies are accepted. This certainly leads to a huge under-representation on the list and one may therefore wonder whether this taxon really is a rarity.

Roseate Tern / Dougalls Stern Sterna dougallii 3,35,2
NOORD-HOLLAND De Putten, Camperduin, Bergen, 24-25 June, two adults, and Strand Zuidpier, IJmuiden, Velsen, 2-3 July, one adult, photographed, videoed (M Hotting, F van Groen et al; Dutch Birding 40: 275, plate 365, 345, plate 462, 2018).
One of the birds was wearing a metal ring on both legs (more or less proving British origin; by some field birders this unique way of ringing is regarded to be a pretty solid identification feature!), the other one was, more traditionally, ringed on the right leg only. It was the latter bird that was also seen at IJmuiden.

Black-winged Kite / Grijze Wouw Elanus caeruleus 1,27,6
FRIESLAND Blikplaatgat, Sennerplaat and Blikplaat, Lauwersmeer, Kollumerland en Nieuwkruisland, 21 October 2017 to 8 February, 2cy, photographed, videoed; See Hanne, Mirns, De Fryske Marren, 6 May, photographed (R Meurs, N van Dijk); Fochteloërveen, Ooststellingwerf, 21 August to 3 September, also seen at Kolonieveld, Fochterloërveen, Noordenveld DR, 1cy, photographed (J Molenaar et al; Dutch Birding 40: 349, plate 472, 2018).
ZUID-HOLLAND Zouweboezem, Ameide, Zederik, 16 April, also seen at Polder Mastwijk, Montfoort, Montfoort UT, and Telpost de Horde, Lopik UT and Polder Broek, Stuijvenbergseweg, IJsselstein, IJsselstein UT, photographed (S van der Steeg, A Boele, E Schuller et al).
LIMBURG Groote Peel, Ospel, Nederweert, 17-19 September, also seen at Groote Peel, Asten NB, 1cy, photographed (B Janssen et al; Dutch Birding 40: 425, plate 574, 2018).
NOORD-BRABANT Brobbelbies Noord, Landerd, 28 September, 1cy, photographed (S van Schaijk et al).
NOORD-HOLLAND Polder Waard-Nieuwland, Den Oever, Hollands Kroon, 10-13 November, and Wormer- en Jisperveld Noord, Wormerland, 17-18 November, also seen at Polder de Biesbosch, Dordrecht ZH, 19 November, 1cy, photographed (K Floris, K van den Brink et al; Dutch Birding 41: 65, plate 90, 2019).
The rise of Black-winged Kite continues. Over the past decade (2009-18), birds have been seen in eight out of 10 years, with on average a little over three a year. They have been recorded in every month of the year now (figure 2) but the fact that it has been recorded in winter (December-February) is caused by a single long-stayer. It is mainly a spring (March-May) and autumn (August-November) bird, with May and August as the best months. Only a decade ago, the idea of having enough data for a graph in the annual report would have sounded ridiculous! 

Griffon Vulture / Vale Gier Gyps fulvus 9,414,2
UTRECHT Leersumse Veld, Leersum, Utrechtse Heuvelrug, 27 May, two, photographed (J Verboom).

Lesser Spotted Eagle / Schreeuwarend Clanga pomarina 3,11,1
FRIESLAND Fochteloërveen, Ooststellingwerf, 11 May, 2cy, photographed (L Hoogenstein, D G Hoogenstein, L Schröder).

Greater Spotted Eagle / Bastaardarend Clanga clanga 15,17,3
UTRECHT Polsbroekerdam, and Polder Lopik, Lopik, 18 February, also seen at Polder Den Hoek, Lekkerkerk, and Loetbos, Berkenwoude, Krimpenerwaard ZH, 18-21 February, 2cy, photographed, videoed (K de Leeuw, A Boele, H Blom et al; Dutch Birding 40: 131, plate 176-178, 2018, 41: 20, plate 21, 2019).
NOORD-HOLLAND Wierholt, Hollands Kroon, 8 May, 3cy, photographed (F Visscher, R Visscher; Dutch Birding 40: 273, plate 359, 2018); Noordhollands Duinreservaat, Castricum, and Vennewaterspolder, Egmond-Binnen, Bergen, 26 May, and De Slufter, and Staatsbossen, Texel, 26-27 May, and Marsdiep, and De Kooy, Den Helder, 27 May, 4cy, photographed, videoed (R S A van Bemmelen et al; Dutch Birding 40: 273, plate 361, 275, plate 362, 2018).
There was a poor run of only one record between 2004 and 2015 but with six in 2016-18, the bad spell seems to be broken – at least for now. The population trends of this globally declining species on the nearest breeding grounds are anything but promising for the future. The Wierholt bird was not an easy record to assess since the sixth primary (from outside) was missing in both wings (see plate 528 for its identification).

Spanish Imperial Eagle / Spaanse Keizerarend Aquila adalberti 0,1,0
The 2cy that flew over Loozerheide, Weert, Limburg, and Cranendonck, Noord-Brabant, on 6 May 2007 remains accepted after reassessment (cf Weenink et al 2011).

Eastern Imperial Eagle / Keizerarend Aquila heliaca 0,2,0
The 3cy that flew over Kamperhoek, Dronten, Flevoland, on 3 April 2005 remains accepted after reassessment (cf van Beusekom 2007). The two older records of ‘imperial eagles’ were reassessed since the Eastern Imperial from September-October 2017 showed how extremely difficult to identify these twin species are in some plumages. Had it not been for the Hungarian ring, the 2017 bird might actually have stayed unidentified. In Toscana, Italy, the same individual was even identified as a (certain) Spanish (cf Janssen et al 2019)! The two older records (one of each species) were, however, in other, somewhat less challenging plumages and both the committee and consulted foreign experts remained confident that they were correctly identified.

Long-legged Buzzard / Arendbuizerd Buteo rufinus 1,8,1
GELDERLAND Jonkerstraat and surroundings, Netterden, Oude IJsselstreek, 6 July to 4 August, 3cy or older, photographed, videoed (R Schwartz et al).
Most of the time, this bird stayed across the border in Germany.

European Roller / Scharrelaar Coracias garrulus 52,20,2
FRIESLAND Delleboersterheide, Oldeberkoop, Ooststellingwerf, 19 May, 2cy, photographed (J Regtop, I Regtop-Hunneman, R Regtop et al; Dutch Birding 40: 350, plate 475, 2018).
NOORD-HOLLAND De Nederlanden, and Akiab, Texel, 24-26 September, adult, photographed, videoed (T van de Vondervoort, A Stiehl, A Wassink et al; Dutch Birding 40: 336, plate 445, 430, plate 587, 2018).
Most likely the Texel bird was seen at Sårup, Nordjylland, Denmark, on 16-28 October.

Red-eyed Vireo / Roodoogvireo Vireo olivaceus 0,8,1
NOORD-HOLLAND Krimbos, De Cocksdorp, Texel, 27-30 October, 1cy, photographed, videoed (A Wassink, F van der Meer, R van der Meer et al; Dutch Birding 40: 424, plate 573, 434, plate 595, 2018).
The first since 2005. Even in good autumns elsewhere in the WP, American passerines remain thin on the ground – very thin.

Daurian Shrike / Daurische Klauwier Lanius isabellinus 0,16,0
A bird seen on Griend, Friesland, on 14-15 October is still under review.

Lesser Grey Shrike / Kleine Klapekster Lanius minor 21,31,5
ZUID-HOLLAND Schaatsbaan, Ammerstol, and Polder Bergambacht-West, Bergambacht, Krimpenerwaard, 6 May, adult male, photographed, sound-recorded, videoed (S van der Wel, D-J van der Roest, J van Erkel et al).
NOORD-HOLLAND De Tuintjes, and Sebastopol, and Levensvreugd, and Witte Hoek, De Cocksdorp, Texel, 26 May, male, photographed (D Kok, R F J van Beusekom et al; Dutch Birding 40: 280, plate 375, 2018); Mariëndal, Den Helder, 10 June, photographed (J van Dillen-Staal, H Enklaar).
GRONINGEN Legeweg, Muntendam, Midden-Groningen, 6 June, photographed, videoed (P H Mulder via W-J Fontijn).
NOORD-BRABANT Keent, Oss, 16 June, photographed (R Reinders, E Roumen et al).
A record year with five, all on classic dates: 60% of all records are from May-June. The previous best year was 2013 with four.

Greater Short-toed Lark / Kortteenleeuwerik Calandrella brachydactyla 3,59,3
GELDERLAND Kootwijkerzand, Kootwijk, Barneveld, 22 April, adult, photographed (T Fijen, J Vlot; Dutch Birding 40: 203, plate 271, 2018); Friesse Veld, Harskamp, Ede, 25 May, photographed (H van Oosten).
LIMBURG Hartelstein, Itteren, Maastricht, 21 May, photographed (R van Tiel et al).

Cetti’s Warbler / Cetti’s Zanger Cettia cetti 163,67,-
1973 # NOORD-BRABANT Polder de Dood, Brabantse Biesbosch, Drimmelen, 28 October (was Dordtse Biesbosch, Dordrecht ZH), 1cy, trapped (ringed 16 July 1973 Lokeren, Oost-Vlaanderen, Belgium).
This species is no longer considered since 1 January 2004 but the CDNA still welcomes records before this date.

Greenish Warbler / Grauwe Fitis Phylloscopus trochiloides 6,76,-
1998 NOORD-HOLLAND Schoorlse Duinen, Camperduin, Bergen, 30 August, photographed (S Lagerveld, L Edelaar, J van der Laan et al).
This species is no longer considered since 1 January 2015 but the CDNA still welcomes records before this date.

Arctic Warbler / Noordse Boszanger Phylloscopus borealis 2,27,0
2016 FRIESLAND Bomenland, Vlieland, 17 September, photographed (M van Oss et al).

Radde’s Warbler / Raddes Boszanger Phylloscopus schwarzi 2,43,3
NOORD-HOLLAND Vogelringstation Castricum, Noordhollands Duinreservaat, Castricum, 8 October, 1cy, ringed, photographed (T S van der Meer et al; Dutch Birding 40: 428, plate 585, 2018).
FRIESLAND Kroonspolders, Vlieland, 17-24 October, 1cy, ringed and retrapped, photographed (H Vonk, H Bouwmeester, J Breidenbach); De Hon, Ameland, 19 October, photographed (J de Jong, R Offereins et al).

Western Bonelli’s Warbler / Bergfluiter Phylloscopus bonelli 5,39,2
FRIESLAND Hertenbosvallei, Schiermonnikoog, 13-14 May, photographed, sound-recorded (W van der Ham, W Monster, P Links et al; Dutch Birding 40: 276, plate 367, 2018).
NOORD-HOLLAND De Nederlanden, Texel, 30 August, 1cy, photographed (N van Houtum et al).

Western Bonelli’s x Wood Warbler / Bergfluiter x Fluiter Phylloscopus bonelli x sibilatrix 0,0,0
A record of a hybrid male paired with a female Wood Warbler P sibilatrix that raised three chicks at Noordhollands Duinreservaat, Heemskerk, Noord-Holland, has not yet been reviewed by the CDNA (Dutch Birding 40: 276, plate 366, 2018). The CDNA still awaits the results of the DNA analysis to become available.

Eastern Bonelli’s Warbler / Balkanbergfluiter Phylloscopus orientalis 0,4,1
NOORD-HOLLAND Berenweide, Noordhollands Duinreservaat, Heemskerk, 14 May, singing, photographed, sound-recorded (R S A van Bemmelen et al; Admiraal et al 2018, van Bemmelen 2019; Dutch Birding 40: 211, plate 283, 283, plate 380, 2018, 41: 91, plate 113-114, 2019).
Alarmed by the hybrid Western Bonelli’s x Wood Warbler P bonelli x sibilatrix (see above), a keen observer was primed on bonelli’s warbler as he cycled to work through the same dune reserve. Very much to his surprise, he actually heard one singing. With a laptop in his bag he was able to make a sonagram in the field only to see his suspicion confirmed: the bird he just found was the first Eastern Bonelli’s Warbler since 1993! It mainly sang and rarely uttered its diagnostic call in the morning and afternoon, while the reverse was true for the evening. With this bird, the hybrid (if accepted) and the Western Bonelli’s P bonelli on Schiermonnikoog, all present on 14 May, there was a remarkable ‘bonelli bonanza’ that day.

bonelli’s warbler / bergfluiter Phylloscopus bonelli/orientalis 4,6,2
FRIESLAND Bomenland, Vlieland, 15-16 September, photographed (L Steen et al); Horrekooi, Oosterend, Terschelling, 23 September, photographed (K Kraaijeveld, B de Lange, V Hart).

Iberian Chiffchaff / Iberische Tjiftjaf Phylloscopus ibericus 2,42,6
ZUID-HOLLAND Heerjansdam, Zwijndrecht, 26 April to 14 May, singing, photographed, sound-recorded (H van Rijswijk, W Schot et al); Polder Raepshille, Strijen, Hoeksche Waard, 7-20 May, singing, photographed, sound-recorded (M Korbijn, H Westerlaken et al).
NOORD-HOLLAND Ruijslaan, Staatsbossen, De Koog, Texel, 5 May to 23 June, singing, photographed, sound-recorded (D Kok et al).
FRIESLAND De Hon, Ameland, 6 May, singing, sound-recorded (J Postma, A Verbiest).
ZEELAND Boswachterij Westerschouwen, Westenschouwen, Schouwen-Duiveland, 11-28 May, singing, photographed, sound-recorded (T O V Muusse et al).
GELDERLAND De Woldberg, Epe, 16 May, singing, sound-recorded (N L M Gilissen, A Braam, B Timmer).
2016 ZUID-HOLLAND Kralingse Bos, Rotterdam, 13 April, singing, photographed, sound-recorded (G Bakker et al).
Another good haul for this increasingly recorded species, equalling record year 2010; 40 out of the now 50 records have been found after 2000 and it has been recorded annually over the past decade (2009-18).

Siberian Lesser Whitethroat / Siberische Braamsluiper Sylvia althaea blythi 0,7,0
The CDNA awaits the DNA analysis of two submitted records: a bird ringed in Castricum, Noord-Holland, on 16 September and a bird ringed on Schiermonnikoog, Friesland, on 8 October.

Sardinian Warbler / Kleine Zwartkop Sylvia melanocephala 0,9,2
NOORD-HOLLAND Parnassia, Kennemerduinen, Bloemendaal, 20 May, male (D Groenendijk).
FRIESLAND Burgumer Mar, Eastermar, Tytsjerksteradiel, 28 August to 3 November, adult male, ringed and retrapped three times, photographed, sound-recorded (A Timmerman, G de Vries, B Storm et al; Timmerman 2018; Dutch Birding 40: 428, plate 583-584, 2018).
This species remains remarkably rare. Not only were these the first records since 2006, the Eastermar bird was also the first twitchable since 1995. However, the crowds were hardly rewarded, since it was mostly heard and seldomly seen.

Eastern Subalpine Warbler / Balkanbaardgrasmus Sylvia cantillans 1,34,2
FRIESLAND Zwanewaterduinen, Nes, Ameland, 19 April, male, photographed (H Semeins, C Semeins).
NOORD-HOLLAND Vogelringstation Paradijsveld, Amsterdamse Waterleidingduinen, Zandvoort, 6 May, male, ringed, photographed (W Tamis, A de Winter).
2017 NOORD-HOLLAND Renvogelveld, Robbenjager, Texel, 9 September, adult male, photographed, sound-recorded (D Kok et al).
MtDNA analysis of the Amsterdamse Waterleidingduinen bird became available in GenBank in October 2019, well after it was accepted to species level. The genetic analysis indicates that the nomimate subspecies S c cantillans was involved – a new taxon for the Netherlands. This new information is currently under review but since that does not change its acceptance to species level the record is already included in this report.

subalpine warbler / baardgrasmus Sylvia subalpina/inornata/cantillans 4,38,0
2015 NOORD-HOLLAND Slufterhoek, Eierland, Texel, 22 June, male (M van der Post).
1990 FRIESLAND Engelsmanplaat, Noardeast-Fryslân, 30 May, female, photographed, caught and released (L Hofstee).
The 1990 bird flew into the island’s warden’s cabin, where it was caught by hand. The single slide taken got lost but was re-found nearly three decades later. Totals exclude birds accepted at species level.

Dartford Warbler / Provençaalse Grasmus Sylvia undata 1,10,1
ZEELAND Oranjezon, Vrouwenpolder, Veere, 7 January, photographed (J Walhout).
The CDNA could not assign this bird to subspecies. Totals include four birds accepted as S u dartfordiensis.

Booted Warbler / Kleine Spotvogel Iduna caligata 0,29,2
NOORD-HOLLAND Vogelringstation Castricum, Noordhollands Duinreservaat, Castricum, 5 September, 1cy, ringed, photographed (A Wijker, J Visser; Dutch Birding 40: 432, plate 592, 2018).
FRIESLAND Oostpunt, Vlieland, 14-17 September, 1cy, photographed (L Bregman, D Koppenol et al; Dutch Birding 40: 432, plate 591, 2018).
Most probably the bird seen at Oostpunt, Vlieland, was ringed at Kroonspolders, Vlieland, on 19 September; the CDNA awaits the DNA analysis of this submitted record.

Paddyfield Warbler / Veldrietzanger Acrocephalus agricola 1,41,1
NOORD-HOLLAND Vogelringstation Castricum, Noordhollands Duinreservaat, Castricum, 15-16 October, 1cy, ringed, photographed and retrapped (P Admiraal et al; Dutch Birding 40: 427, plate 581, 2018).

Blyth’s Reed Warbler / Struikrietzanger Acrocephalus dumetorum 0,41,11
ZUID-HOLLAND Groenedijk, Ouddorp, Goeree-Overflakkee, 27 May, photographed, videoed, sound-recorded (G Tanis et al).
FRIESLAND Kroonspolders, Vlieland, 5 September, 1cy, ringed, photographed (H Bouwmeester, H Huiskamp).
NOORD-HOLLAND Vogelringstation Castricum, Noordhollands Duinreservaat, Castricum, 6 September, 1cy, ringed, photographed (J Visser, T van der Meer); same site, 17 September, 1cy, ringed, photographed (A J van Loon, J Visser, C S Roselaar); same site, 25 September, 1cy, ringed, photographed (J Visser, R Reijnders, L Knijnsberg); same site, 4-5 October, 1cy, ringed, photographed and retrapped (J Visser, R Leurs, T van der Meer et al); same site, 5 October, 1cy, ringed, photographed (T van der Meer et al); same site, 7 October, 1cy, ringed, photographed (A Wijker, J Visser, P Admiraal; Dutch Birding 40: 433, plate 594, 2018); same site, 20 October, 1cy, ringed, photographed (A Wijker, T van der Meer, R Reijnders); Vogelringstation Paradijsveld, Amsterdamse Waterleidingduinen, Zandvoort, 15 September, 1cy, ringed, photographed (M Schalkwijk et al); Robbenjager, Texel, 5 October, 1cy, photographed, sound-recorded (D Kok et al; Dutch Birding 40: 433, plate 593, 2018).
A record year, beating the nine from 2013. With 10 birds between 5 September and 20 October, there was an obvious autumn influx, although this largely remained unnoticed in the field: all but one were trapped. Remarkably, no less than seven were ringed at Castricum, which brings the number of records for this site to an astonishing 18. The increase of records continues, and one may wonder how much longer the species will be considered. It was first recorded only in 1990 and has been annual since 2009 (figure 3).

Aquatic Warbler / Waterrietzanger Acrocephalus paludicola 11,145,-
1983 # FRIESLAND Drachten, Smallingerland, 23 September (was 25 September), found dead, collected.
The species is no longer considered since 1 January 1992 but the CDNA still welcomes reports from before this date.

*Grey-cheeked Thrush / Grijswangdwerglijster Catharus minimus 0,0,1
ZUID-HOLLAND Monster, Westland, 5 November, 1cy, caught, taken into care at Den Haag, Zuid-Holland (until 20 November), ringed, photographed, sound-recorded, videoed (via Vogelhospitaal de Wulp, V van der Spek et al; Dutch Birding 40: 419, plate 566, 2018, 41: 69, plate 95, 2019).
This weakened bird was picked up and taken into care, where it recovered well. After having spent two weeks in care, it was ringed and released at Ockenburgh, Den Haag, Zuid-Holland, on 20 November. The news was suppressed in order to avoid pressure on its caretakers. After its release, it immediately disappeared into the thickets, never to be seen again – despite the news being shared on release. DNA analyses showed that it belonged to the subspecies C m aliciae but this information has not (yet) been stored in GenBank and the subspecific identity was therefore not (yet) considered by the CDNA. To the best of our knowledge, this was the first DNA-tested Grey-cheeked Thrush in Europe. Despite the many records in Britain, this new species was not as expected as it may first seem: there are no records for Belgium and Luxemburg, none of the seven French records are from the northern part of the country and the single German record dates back to 1937; so in this part of north-western Europe it is an extremely rare bird.

Dusky Thrush / Bruine Lijster Turdus eunomus 2,1,0
2016 GRONINGEN Beijum, Groningen, 8-9 November, 1cy male, photographed, found dead on 11 November, collected; skin retained at Naturalis Biodiversity Center, Leiden, Zuid-Holland (J Welbedacht et al; Dutch Birding 38: 487, plate 742-743, 2016)
Despite many observers searching for the bird, it was not seen after the morning of 9 November. Two days later, it was found dead in a garden. It was obvious from the start that a rare, Asian thrush with (a lot of) Dusky Thrush genes was involved but several features did not perfectly match a ‘classic’ bird – whatever that may be within this species complex. In Asia, hybridisation or introgression with Naumann’s Thrush T naumanni occurs on a large scale and, to a lesser extent, also with the two ‘dark-throated’ thrushes (Red-throated Thrush T ruficollis and Black-throated Thrush T atrogularis). It was therefore a tough record to assess, and it circulated for a long time. The bird was included in the collection of Naturalis Biodiversity Center, where autopsy revealed it to be a male. The CDNA studied the specimen and found that the underparts were poorly marked for its gender (in the field it was even identified as a female by many). Furthermore, eg, a few orange breast-feathers were found and the shape of the dark cheek patch did not match most ‘undisputed’ young birds. The CDNA tried to get a clearer image of where plumage variation of this taxon ends and where introgression begins. For every presumed aberrant feature, we found examples on images of otherwise undisputed birds from Asia. Although we failed to find a bird that combined all of these ‘aberrant’ features, the CDNA decided that, based on current knowledge, this individual falls within the variation for Dusky and the record was therefore accepted. However, the committee remains interested in new insights in the complex situation of the Asian thrushes.

Black-throated Thrush / Zwartkeellijster Turdus atrogularis 0,10,1
GRONINGEN Scheemda, Oldambt, 21 January to 3 April, 2cy male, photographed, videoed, sound-recorded (fam Sietsma, E Jager, W-J Fontijn et al; Dutch Birding 40: 58, plate 66, 135, plate 186, 2018).
2017 FRIESLAND Kroonspolders, Vlieland, 30 October, 1cy female, ringed, photographed (P van Horssen, C Zuhorn, M van der Weide).

Red-spotted Bluethroat / Roodsterblauwborst Luscinia svecica svecica 24,52,2
NOORD-HOLLAND Gemaal Leemans, Den Oever, Hollands Kroon, 10 May, 2cy male, ringed, photographed (B Winters, M Laan et al; Dutch Birding 40: 283, plate 382, 2018).
GELDERLAND Nieuwe Steeg, Wageningen, 16 May, male, photographed (A G Hols).

Eastern Black Redstart / Oosterse Zwarte Roodstaart Phoenicurus ochruros phoenicuroides 0,11,1
GRONINGEN Dollard Zeedijk Zuidzijde, Nieuwe Statenzijl, Oldambt, 7 February to 14 March, 2cy male, photographed, sound-recorded, videoed (J Hakkert, M Glastra et al; Ebels et al 2018; Dutch Birding 40: 133, plate 180, 134, plate 185, 152, plate 201, 156, plate 211, 2018).
2005 FRIESLAND Kobbeduinen, Schiermonnikoog, 31 October, male (H Dufourny, C Nelo et al).
Based on new identification features (van der Spek & Martinez 2018), a formerly rejected report from 2005 was given its right place in Dutch ornithological history. No photographs were taken but the (foreign) birders that saw the bird made an excellent description that even included plumage features that until recently were unknown to be important to separate it from a hybrid Western Black P o ochruros x Common Redstart P phoenicurus.

Collared Flycatcher / Withalsvliegenvanger Ficedula albicollis 24,13,1
GELDERLAND Het Frusselt, Vierhouten, Nunspeet, 12-21 May, 2cy male, photographed, sound-recorded (R Winters et al; Dutch Birding 40: 280, plate 374, 2018).
During the final year of his second (and final) term, a then committee member found this singing bird whilst roller-blading.

Siberian Stonechat / Aziatische Roodborsttapuit Saxicola maurus 9,39,1
FRIESLAND Oostpunt, Vlieland, 6 October, 1cy male, photographed (M Hammers et al; Dutch Birding 40: 427, plate 579, 2018).

Isabelline Wheatear / Izabeltapuit Oenanthe isabellina 0,13,1
NOORD-HOLLAND Strand Zuidpier, IJmuiden, Velsen, 5 October, 1cy, photographed (L van Loo).

Desert Wheatear / Woestijntapuit Oenanthe deserti 1,41,2
NOORD-HOLLAND Zuidgesterkoog, Hollands Kroon, 26 January, 2cy male, photographed (L Kelder et al).
ZEELAND Brouwersdam Noordzeezijde, Ellemeet, Schouwen-Duiveland, 14 November, 1cy male, photographed (J-F Depuydt; Dutch Birding 41: 70, plate 97, 2019).

Eastern Black-eared Wheatear / Oostelijke Blonde Tapuit Oenanthe melanoleuca 1,3,1
NOORD-HOLLAND Eierlandse Duinen, Texel, 12-16 April, 2cy male, photographed, sound-recorded, videoed (B ter Keurs et al; Dutch Birding 40: 204, plate 276, 2018).

Pied Wheatear / Bonte Tapuit Oenanthe pleschanka 0,23,3
FRIESLAND Jachthaven, and Banckspolder, Schiermonnikoog, 28 October to 6 November, 1cy male, photographed (G Glerum, L Bregman et al; Dutch Birding 40: 430, plate 588, 2018, 41: 68, plate 93, 2019).
GRONINGEN Eemshaven-West, Eemsmond, 1-8 November, 1cy female, photographed, videoed (D Beuker, R J Jonkvorst et al; Dutch Birding 41: 69, plate 94, 2019).
ZUID-HOLLAND Weideveld, Bodegraven, Bodegraven-Reeuwijk, 11-14 December, 1cy female, photographed, videoed (M Veldt et al; Dutch Birding 41: 70, plate 99, 2019).

Alpine Accentor / Alpenheggenmus Prunella collaris 0,13,1
ZUID-HOLLAND Oostvoorne, Westvoorne, 29 April to 1 May, 2cy, photographed (A Romers via P Mout; Dutch Birding 40: 278, plate 371, 2018).
A birder’s neighbour showed photographs of an unknown species in his garden. Despite it lingering for three days, the unfortunate birder returned home a few days too late from a trip to actually see the bird himself.

Spanish Sparrow / Spaanse Mus Passer hispaniolensis 0,16,1
ZUID-HOLLAND Nieuwe Stuifdijk, Maasvlakte, Rotterdam, 3 November, male, photographed (F van der Lans, P Planken, P van Dam et al; Dutch Birding 41: 72, plate 106, 2019).

White-throated Wagtail / Witkeelkwikstaart Motacilla cinereocapilla 0,5,1
GRONINGEN Onnerpolder, Zuidlaardermeergebied, Groningen, 21 April to 9 July, male, photographed, sound-recorded, videoed (L Brinkhuizen, T Mulder et al; Dutch Birding 40: 205, plate 277, 278, plate 370, 2018, 41: 19, plate 20, 2019).
2017 FRIESLAND Kooiplaats, Schiermonnikoog, 3-5 May, male, photographed, sound-recorded (W van der Ham, R S A van Bemmelen et al).
Totals include two birds accepted as Ashy-headed Wagtail M c cinereocapilla. Since individuals of more common taxa with white throats also occur, and raspy song elements are sometimes mistaken for calls, recordings of the call remain required to get a record accepted. The territorial bird from 2018 remained in the area for nearly three months, allowing plenty of opportunities to record the diagnostic call. It mostly resembled Ashy-headed but the hint of a whitish eyebrow behind the eye made it impossible to separate it from an intergrade with Spanish Wagtail M c iberiae. The 2017 bird mainly resembled Spanish on plumage but sonagrams of the calls seemed to fit Ashy-headed a bit better. It was therefore not accepted on subspecific level. Out of the now six records, no (certain) Spanish has been recorded.

Black-headed Wagtail / Balkankwikstaart Motacilla feldegg 0,1,1
ZUID-HOLLAND Lentevreugd, Wassenaar, 11-12 May, male, probably 2cy, photographed, sound-recorded, videoed (J Lotz, J van Deijk et al; van Deijk et al 2018; Dutch Birding 40: 210, plate 282, 283, plate 383, 2018).
After a series of rejected records, mostly of birds of which no sound-recordings were available (which the CDNA requires for acceptance), the long-awaited first came in 2016. With a general increase in interest in wagtails by field observers that increasingly carry sound-recording devices, it is hardly surprising that the second came only two years later.

*eastern yellow wagtail / oostelijke gele kwikstaart Motacilla tschutschensis/macronyx/taivana 0,1,0
2008 FRIESLAND Westerse Veld, Vlieland, 13 October, 1cy, photographed, sound-recorded (H H van Oosten et al).
Based on Bot et al (2014), the sonagrams of the calls of this bird (figure 4) – found by one of the co-authors of the paper – matched eastern yellow wagtail and not one of the western taxa. The bird’s plumage also seemed to be consistent with an eastern bird (eg, grey bird, with long hind claw). A straightforward record then? Well... The subspecies could not be determined, and options included the much-debated Siberian Wagtail M t plexa. This taxon has not only been referred to as belonging to both the eastern and western clade, it has also been considered an intergrade by other authors and therefore invalid altogether. However, two recent papers (Drovetski et al 2018, Harris et al 2018) placed this taxon within the eastern group and this was adopted by the Dutch committee on systematics (CSNA 2019). Problem solved? Well... For Motacilla species, CSNA currently follows the phylogenetic species concept, splitting many taxa as separate species, more or less as in table 1 of Alström & Mild (2003). The CSNA is planning to decide whether the aforementioned new genetic studies may lead to changes but at present this record can only be accepted as an eastern yellow wagtail ‘sensu lato’. Despite the (sub)species could not be established, the 2008 bird for now represents the first record of a bird that belongs to the eastern clade. The CDNA welcomes the submission of reports of other photographed and sound-recorded birds from other years.

Citrine Wagtail / Citroenkwikstaart Motacilla citreola 0,55,3
ZUID-HOLLAND Lentevreugd, Wassenaar, 17 April, male, photographed (H Woudenberg).
FRIESLAND Banckspolder, Schiermonnikoog, 17 May, 2cy male, photographed (W E M van der Schot); Griend, Terschelling, 31 August, 1cy, photographed, sound-recorded (B Gnep).
This species is nominated to be no longer considered within a few years. Had there not been a remarkable series of blank years in 2003-05, it would have happened already.

Blyth’s Pipit / Mongoolse Pieper Anthus godlewskii 0,11,2
FRIESLAND Vliehors, Vlieland, 14 and 20 October, photographed, sound-recorded (H H van Oosten, F Jongbloed, K Kraaijeveld et al); Motorcrossveldje, and Vliehors, Vlieland, 20 October, also seen at De Tuintjes, De Cocksdorp, Texel NH, photographed, sound-recorded (O van Herwaarden, D Kok et al; Dutch Birding 40: 427, plate 577, 2018).
With five reports on Vlieland and one on nearby Texel within six days’ time, both on the ground and (seemingly) migrating, it was difficult to determine the number of individuals involved. Since Blyth’s Pipit is a very rare species, a conservative approach was adopted. Two individuals were accepted: one long-stayer (seen on three occasions in the same general area on 14 and 20 October) and one actively migrating bird that hopped islands between Vlieland and Texel, also on 20 October. However, it is quite possible that more individuals were involved.

Cirl Bunting / Cirlgors Emberiza cirlus 2,4,2
LIMBURG Weerter- en Budelerbergen, Weert, 20 April to 10 July, also seen at Cranendonk NB, male, photographed, sound-recorded (R M van Dongen, W Steenge, J Hendriks et al; van Dongen et al 2018; Dutch Birding 40: 204, plate 274, 209, plate 281, 283, plate 379, 2018, 41: 19, plate 19, 2019).
NOORD-HOLLAND Noordhollands Duinreservaat, Castricum, and Heemskerk, 14 May, male, photographed, sound-recorded (H Schekkerman, H Groot et al; Admiraal et al 2018; Dutch Birding 40: 211, plate 284, 2018).
With the previous one being in 2011, this year’s long-staying, territorial male on the border of Limburg and Noord-Brabant was much appreciated. Somewhat surprisingly, a second bird turned up along the coast but this one was very elusive. It was found right next to the singing presumed hybrid Western Bonelli’s x Wood Warbler Phylloscopus bonelli x sibilatrix (see above). The observers speculated that the similarity of their songs must have drawn the bunting to the site. The bird vanished into thin air within minutes after it was found. Despite 100s of birders being in the area for a nearby Eastern Bonelli’s Warbler P orientalis, only a handful caught a glimpse of this unpredictable bunting that moved over several kilometres within short time spans. A song analysis confirmed that, despite the distances between the sightings, only one bird was involved.

Pine Bunting / Witkopgors Emberiza leucocephalos 15,35,2
ZUID-HOLLAND Galgeweg, Goedereede, Goeree-Overflakkee, 25 February to 14 March, adult male, photographed, sound-recorded, videoed (G Tanis et al; Dutch Birding 40: 137, plate 191, 2018); Leeweg, Noordwijk, 12 March to 2 April, female, photographed (D van der Spoel et al; Dutch Birding 40: 203, plate 269, 2018).
The Noordwijk bird wore a foreign metal ring. Several attempts to read the code and to trap the bird unfortunately failed. While several numbers were deciphered, the country code unfortunately was not.

Not-accepted reports This list contains all reports not accepted by the CDNA. Reports marked with @ were not accepted by all committee members in the first or second voting. Most reports were rejected because the identification was not fully established (often due to lack of documentation) or when the bird showed signs of captivity, such as dubious rings, suspicious wear and/or aberrant behaviour.

Ross’s x Barnacle Goose / Ross’ Gans x Brandgans Anser rossi x Branta leucopsis 29 March, Stadse Gorzen, Stad aan ’t Haringvliet, Goeree-Overflakkee, Zuid-Holland, photographed (description incomplete and photographs show characters more related to Snow Goose A caerulescens; status doubtful). King Eider / Koningseider Somateria spectabilis 6 June, Zuidpier, IJmuiden, Velsen, Noord-Holland (description incomplete). Bufflehead / Buffelkopeend Bucephala albeola 14 July to 19 October, Vlinderbalg, Lauwersmeer, De Marne, Groningen, male, photographed (@ identification accepted but photographs do not document absence of rings). Hooded Merganser / Kokardezaagbek Lophodytes cucullatus 13 December to 30 January 2019, Luntershoek, Hulst, Zeeland, 1cy, photographed (@ identification accepted but photographs do not document absence of rings); 25-29 December, Surfplas, Reeuwijkse Plassen, Bodegraven-Reeuwijk, Zuid-Holland, photographed (identification accepted but based on photographs could not be proven to be fully winged). Ring-necked Duck / Ringsnaveleend Aythya collaris 28-29 April, IJsselmeer, Gaast, Súdwest-Fryslân, Friesland, adult male, photographed (@ photographs do not match the reported location, probable escape). Lesser Scaup / Kleine Topper Aythya affinis 1 April, Wolderwijd, Zeewolde, Flevoland, male, photographed, videoed (description incomplete and photograph and video lack details for positive identification). Alpine Swift / Alpengierzwaluw Tachymarptis melba 28 May, Julianaweg, Rheden, Gelderland (@ description incomplete); 30 May, Laar, Weert, Limburg (@ description incomplete). Pallid Swift / Vale Gierzwaluw Apus pallidus 14 October, De Nederlanden, Texel, Noord-Holland, photographed (description incomplete and photographs do not show enough detail to exclude Common Swift A apus); 11 November, Crezeepolder, Hendrik-Ido-Ambacht, Zuid-Holland, photographed (description incomplete and photographs show too little detail to exclude Common Swift A apus); 14 November, Polder Arkemheen-West, Nijkerk, Gelderland, photographed (@ description incomplete and photographs do not show enough detail to exclude Common Swift A apus). Little Crake / Klein Waterhoen Zapornia parva 27 May, Waterrijk-Oost, Overbetuwe, Gelderland, sound-recorded (sound and sonagram do not match classic Little). Pygmy Cormorant / Dwergaalscholver Microcarbo pygmaeus 21 May, Vreeland, Stichtse Vecht, Utrecht (@ description incomplete). American Golden Plover / Amerikaanse Goudplevier Pluvialis dominica 14 January Zandvoortweg, Middelburg, Veere, Zeeland (@ description incomplete). Pacific Golden Plover / Aziatische Goudplevier Pluvialis fulva 12 August, Serooskerke, Veere, Zeeland, photographed (@ description incomplete and photograph shows too little detail to exclude other taxa). Stilt Sandpiper / Steltstrandloper Calidris himantopus 6 October, Marker Wadden, Lelystad, Flevoland, photographed (@ poor photographs show Tringa sandpiper). Baird’s Sandpiper / Bairds Strandloper Calidris bairdii 17 July, Slootweg, Slootdorp, Hollands Kroon, Noord-Holland, photographed (@ description incomplete and photographs suggest Little Stint C minuta). Great Snipe / Poelsnip Gallinago media 27 May, Telpost de Vulkaan, Westduinpark, Den Haag, Zuid-Holland (@ description incomplete). pratincole / vorkstaartplevier Glareola maldivarum/nordmanni/pratincola 17 June, Punthorst-Rollecate, Staphorst, Overijssel (@ description incomplete). Ross’s Gull / Ross’ Meeuw Rhodostethia rosea 19 January, Trektelpost Camperduin, Bergen, Noord-Holland (@ description incomplete). Laughing Gull / Lachmeeuw Larus atricilla 3 October, Paal 18, Terschelling, Friesland (@ description incomplete). Ring-billed Gull / Ringsnavelmeeuw Larus delawarensis 19 January, Bangeweer, Hoogkerk, Groningen, Groningen (@ description incomplete). Baltic Gull / Baltische Mantelmeeuw Larus fuscus fuscus 17 October, Zandmotor, Ter Heijde, Westland, Zuid-Holland, photographed (@ ringed as adult female in nominate fuscus colony but mantle and moult pattern not fitting this taxon). Black-winged Kite / Grijze Wouw Elanus caeruleus 30 September, Vlagheide, Schijndel, Noord-Brabant, photographed (@ description incomplete and photograph shows too little detail to exclude other taxa). Bearded Vulture / Lammergier Gypaetus barbatus 27 May to 2 June, Klein Valkenisse, Veere, Zeeland, and Schoorl, Bergen, Noord-Holland, and Deventer, and Wildbaan, Olst-Wijhe, Overijssel, 3cy, photographed (identification accepted, but CDNA considers all unmarked birds as descendants of the not-yet self-sustaining reintroduction programme from the Alps; also see introduction). Steppe Buzzard / Steppebuizerd Buteo buteo vulpinus 18 May, Scholtinkstraat, Losser, Overijssel, photographed (@ photographs show Common Buzzard B b buteo). Long-legged Buzzard / Arendbuizerd Buteo rufinus 31 March, Oude Graauwpolder, Lamswaarde, Hulst, Zeeland, photographed (@ photographs show Common Buzzard B buteo); 5 June, Oosterbierum, Waadhoeke, Friesland (@ description incomplete). European Roller / Scharrelaar Coracias garrulus 7 June, A15, Rozenburg, Botlek, Rotterdam, Zuid-Holland (@ description incomplete); 8 June, Crezéepolder, Ridderkerk, Zuid-Holland (@ description incomplete). Syrian Woodpecker / Syrische Bonte Specht Dendrocopos syriacus 21 June, Zevenwegenbos, Cottessen, Vaals, Limburg (@ description incomplete). Radde’s Warbler / Raddes Boszanger Phylloscopus schwarzi 6 May, Corversbos, Baarn, Utrecht, photographed (@ photographs show Willow Warbler P trochilus). Bonelli’s warbler / bergfluiter Phylloscopus bonelli/orientalis 27 September, Krimbos, De Cocksdorp, Texel, Noord-Holland (description incomplete). Iberian Chiffchaff / Iberische Tjiftjaf Phylloscopus ibericus 13 June, Azelo, Hof van Twente, Overijssel, sound-recorded (@ sound-recording matches aberrant Common Chiffchaff P collybita). Siberian Lesser Whitethroat / Siberische Braamsluiper Sylvia althaea blythi 7-10 October, Midsland aan Zee, Terschelling, Friesland, two, photographed (@ following CDNA-policy, not eligible for acceptance; also see introduction); 9-18 November, Wiekense Gat, Netterden, Oude IJsselstreek, Gelderland, photographed, sound-recorded (@ following CDNA-policy, not eligible for acceptance; also see introduction). Booted Warbler / Kleine Spotvogel Iduna caligata 16 September, Zuidernollen, Noordhollands Duinreservaat, Castricum, Noord-Holland (@ description incomplete). Citrine Wagtail / Citroenkwikstaart Motacilla citreola 11 October, Telpost Kinderdijk, Overwaard, Molenwaard, Zuid-Holland (@ description incomplete). Pallas’s Reed Bunting / Pallas’ Rietgors Emberiza pallasi 19 April, Weerribben, Steenwijkerland, Overijssel, photographed (@ description incomplete and photograph shows too little detail to exclude other taxa).

2017
Ross’s Goose / Ross’ Gans Anser rossii 9 September to 16 October, Castelresche Heide, Castelre-Merkske, Baarle-Nassau, Noord-Brabant, photographed (several features pointed towards bird with Snow Goose A caerulescens genes). Bearded Vulture / Lammergier Gypaetus barbatus 12-13 March, Achterweg, Noordwijk, Zuid-Holland, 2cy, photographed (identification accepted, but following CDNA-policy not eligible for acceptance on status; also see introduction).

2016
White-rumped Sandpiper / Bonapartes Strandloper Calidris fuscicollis 29 May, Dijkgatsweide, Noorderdijkweg, Hollands Kroon, Noord-Holland, photographed, videoed (description incomplete and photographs and video images do not exclude other taxa). Spotted Sandpiper / Amerikaanse Oeverloper Actitis macularius 12 July, Vechtpark, Hardenberg, Overijssel, photographed (@ description incomplete and photographs show too little detail to exclude Common Sandpiper A hypoleucos). Long-billed Dowitcher / Grote Grijze Snip Limnodromus scolopaceus 17 September, Molenplaat, Markiezaat, Bergen op Zoom, Noord-Brabant (@ description incomplete). Tundra Peregrine Falcon / Toendraslechtvalk Falco peregrinus calidus 25 November 2015 to 10 January, Sudermarpolder Súdwest-Fryslân, Friesland, photographed (following CDNA-policy, not eligible for acceptance; also see introduction); 4 December 2015 to 14 April, Zwanenwater, and Buitengebied, Callantsoog, Schagen, and Mariëndal, Den Helder, Noord-Holland, photographed (following CDNA-policy, not eligible for acceptance; also see introduction). Blue Grosbeak / Blauwe Bisschop Passerina caerulea 25-31 October, Oostzeelaan, Zwolle, Overijssel, male, photographed (@ identification accepted, but not considered wild as the bird showed damage to plumage as well as aberrant moult).

2015
Griffon Vulture / Vale Gier Gyps fulvus 7 June, Koningsweg, Hoge Veluwe, Arnhem, Gelderland, 18 birds (@ description incomplete). Tundra Peregrine Falcon / Toendraslechtvalk Falco peregrinus calidus 21 April, Polder de Samenvoeging, Súdwest-Fryslân, Friesland, 2cy, photographed (following CDNA-policy, not eligible for acceptance; also see introduction); 25 November to 10 January 2016, Sudermarpolder Súdwest-Fryslân, Friesland, photographed (following CDNA-policy, not eligible for acceptance; also see introduction); 4 December to 14 April 2016, Zwanenwater, and Buitengebied, Callantsoog, Schagen, and Mariëndal, Den Helder, Noord-Holland, photographed (following CDNA-policy, not eligible for acceptance; also see introduction). Siberian Lesser Whitethroat / Siberische Braamsluiper Sylvia althaea blythi 27 January to 1 April, Callantsoog, Schagen, Noord-Holland, photographed (Dutch Birding 37: 135, plate 215, 2015), sound-recorded (@ following CDNA-policy, not eligible for acceptance; also see introduction); 7 September, Eemshaven-West, Het Hogeland, Groningen, photographed (@ following CDNA-policy, not eligible for acceptance; also see introduction). Siberian Stonechat / Aziatische Roodborsttapuit Saxicola maurus 11 June, Herikhuizerveld, Nationaal Park Veluwezoom, Rheden, Gelderland, photographed (@ description incomplete; photographs show male European Stonechat S rubicola).

2014 
Siberian Lesser Whitethroat / Siberische Braamsluiper Sylvia althaea blythi 19 January to 23 March, Beijum, Groningen, Groningen, photographed (@ following CDNA-policy, not eligible for acceptance; also see introduction); 29-30 October, Krimbos, Texel, Noord-Holland, 1cy, photographed (@ following CDNA-policy, not eligible for acceptance; also see introduction).

2013
Tundra Peregrine Falcon / Toendraslechtvalk Falco peregrinus calidus 2-9 February, Koudekerksche Inlaag, Haamstede, Schouwen-Duivenland, Zeeland, photographed (following CDNA-policy, not eligible for acceptance; also see introduction); 20 October, Telpost Brobbelbies Noord, Maashorst, Landerd, Noord-Brabant, 1cy, photographed (following CDNA-policy, not eligible for acceptance; also see introduction). Squacco Heron / Ralreiger Ardeola ralloides 17 May, Canisvlietsche Kreek, Westdorpe, Terneuzen, Zeeland (@ description incomplete).

2012
Greenland White-fronted Goose / Groenlandse Kolgans Anser albifrons flavirostris 7 December, Groot Eiland, Luntershoek, Hulst, Zeeland (@description incomplete).

2011
Eleonora’s Falcon / Eleonora’s Valk Falco eleonorae 18 September, Oostvaardersdijk, Oostvaardersplassen, Lelystad, Flevoland (@ description incomplete).

2010
Hume’s Whitethroat / Humes Braamsluiper Sylvia althaea 15 November, Ridderpark, Katwijk, Zuid-Holland, photographed (@ following CDNA-policy, not eligible for acceptance; also see introduction).

2004
Greenland White-fronted Goose / Groenlandse Kolgans Anser albifrons flavirostris 31 January, Diepenhoek, Someren-Heide, Someren, Noord-Brabant (not accepted after reassessment; photographs and description do not fully match this subspecies and suggest a hybrid Greater White-fronted x Tundra Bean Goose A albifrons x serrirostris). Western Bonelli’s Warbler / Bergfluiter Phylloscopus bonelli 30 April to 2 May, Oranjezon Midden, Oostkapelle, Veere, Zeeland (@ description incomplete).

2003
Desert Lesser Whitethroat / Vale Braamsluiper Sylvia althaea halimodendri 23 November to 1 December, De Wilbert – ’s-Heerenschoolbos, Katwijk aan den Rijn, Katwijk, Zuid-Holland, photographed (Zuyderduyn 2004; Dutch Birding 26: 83, plate 142-143, 2004; not accepted after reassessment; at the time this record was accepted as ‘Siberian/Desert Lesser Whitethroat Sylvia curruca halimodendri/minula’; following current CDNA policy, not eligible for acceptance; also see introduction),

1999
Whistling Swan / Fluitzwaan Cygnus columbianus 5-9 January, Lauwersmeer, De Marne, Groningen, and 10 January, Kwelderweg, Kollumerland en Nieuwkruisland, Friesland, photographed (not accepted after reassessment, also see 1997 and 1998).

1998
Whistling Swan / Fluitzwaan Cygnus columbianus 28 November 1997 to 8 February, Veendam and surroundings, Veendam, and Hoogezand, Midden-Groningen, Groningen, and Nieuw-Annerveen, and Spijkerboor, Aa en Hunze, Drenthe, and 18-28 December, Gieterveen, and Eexterveen, Aa en Hunze, Drenthe, photographed (not accepted after reassessment; also see 1997).

1997
Whistling Swan / Fluitzwaan Cygnus columbianus 28 November to 8 February 1998, Veendam and surroundings Veendam, and Hoogezand, Midden-Groningen, Groningen, and Nieuw-Annerveen and Spijkerboor, Aa en Hunze, Drenthe, photographed (de Bruin & Klunder 1997, 1998; Dutch Birding 19: 317, plate 324, 1997, 20: 50, plate 20a, 279, plate 238, 1998, 21: 67, plate 57, 1999; not accepted after reassessment; see main text).

1996
Pallas’s Leaf Warbler / Pallas’ Boszanger Phylloscopus proregulus 8 October, Begraafplaats Westkapelle, Veere, Zeeland (@ description incomplete). Arctic Redpoll / Witstuitbarmsijs Acanthis hornemanni 19 January, Ooijen, Broekhuizenvorst, Horst aan de Maas, Limburg (record withdrawn by observer and therefore not accepted after reassessment).

1992
Whistling Swan / Fluitzwaan Cygnus columbianus 9 December, Eenrum, De Marne, Groningen (not accepted after reassessment; see main text).

1986
Whistling Swan / Fluitzwaan Cygnus columbianus 23 November, Lauwersmeer, De Marne, Groningen (Dorèl & van Gool 1989; not accepted after reassessment; see main text).

1984
Roseate Tern / Dougalls Stern Sterna dougallii 27 June, Middelplaten, Goes, Zeeland (@ description incomplete).

1981
Whiskered Tern / Witwangstern Chlidonias hybrida, Braakman Zuid, Terneuzen, Zeeland (@ description incomplete). Rustic Bunting / Bosgors Emberiza rustica 9 May, Berkenplas, Schiermonnikoog, Friesland (@ description incomplete).

1980
Whistling Swan / Fluitzwaan Cygnus columbianus 7-15 February, Polder Arkemheen, Nijkerk, Gelderland (Slagboom 1987; not accepted after reassessment; see main text).

1976
Whistling Swan / Fluitzwaan Cygnus columbianus 15 February, Zonnemaire, Schouwen-Duiveland, Zeeland, photographed (Mullié 1980; Sterna 24: 77, 1980; not accepted after reassessment; see main text).

1975
Eurasian Stone-curlew / Griel Burhinus oedicnemus 14 April, Assendelft, Zaanstad, Noord-Holland (@ description incomplete).

Acknowledgements
Chris Batty, José Luis Copete, Nils van Duivendijk, Bob Flood, Dick Forsman, Paul French, Morten Bentzon Hansen, Albert de Jong, Peter de Knijff, Hans Larsson, Nial Moores, Killian Mullarney, Brian Small, Terry Townshend and Fred Visscher kindly shared their expertise on at least one of the assessed sightings in this report, which was greatly appreciated. René Dekker and Pepijn Kamminga were helpful at Naturalis Biodiversity Center, where we examined the skin of the Dusky Thrush. Jan van der Laan once again provided figure 1. Bram Rijksen provided a beautiful frontpage illustration (Great Knot): he has done so since 1998. The editors of British Birds kindly shared several identification papers. Christopher König kindly invited us for a DAK-meeting. Last but certainly not least we would like to thank Jeroen van Vianen. It is amazing how quickly and efficiently he adjusts our digital platform to our latest wishes.

References
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Gerjon Gelling, Ieplaan 112, 2565 LR Den Haag, Netherlands (gerjon.gelling@dutchbirding.nl)
Vincent van der Spek, Acaciastraat 212, 2565 KJ Den Haag, Netherlands (v.vanderspek@gmail.com)
James Lidster, Oldenhof 3, 6665 DP Driel, Netherlands (lidsterjames@gmail.com)CDNA, p/a Ieplaan 112, 2565 LR Den Haag, Netherlands (cdna@dutchbirding.nl)

FIGURE 1 Number of species recorded in the Netherlands per year in 2009-18 (average 373) / aantal vastgestelde soorten per jaar in Nederland in 2009-18 (gemiddeld 373)

FIGURE 2 Monthly distribution of Black-winged Kite Elanus caeruleus in the Netherlands in 1971-2018 (n=34), with months in which individuals were found in blue and months in which they were present in red / verspreiding per maand van Grijze Wouw Elanus caeruleus in Nederland in 1971-2018 (n=34), met in blauw maanden van ontdekking en in rood maanden waarin ze daarna nog aanwezig waren

FIGURE 3 Records of Blyth’s Reed Warbler Acrocephalus dumetorum in the Netherlands in 1990-2018 (n=52); nearly two out of every three records concern ringed birds (n=33) / gevallen van Struikrietzanger Acrocephalus dumetorum in Nederland in 1990-2018 (n=52); bijna twee derde van de gevallen betreft geringde vogels (n=33)