This paper documents six cases of natal dispersal (maximum distance 46 km) and one case of breedi... more This paper documents six cases of natal dispersal (maximum distance 46 km) and one case of breeding dispersal (confirmed, distance 33 km) of Eurasian Oystercatchers - Haematopus ostralegus. The cases refer to birds ringed in the Province of Fryslân, The Netherlands, and recorded breeding in and around the city of Groningen, The Netherlands. Almost the entire population in Groningen is nesting on roof tops.
This note documents two inland records of a Northern Fulmar Fulmarus glacialis from the province ... more This note documents two inland records of a Northern Fulmar Fulmarus glacialis from the province of Groningen (The Netherlands) in the end of October 2017. Both birds were found during a severe gale. The first one was found exhausted in a city park in Groningen on 29 October (23 km from the coast). It was taken into care the next day. The bird was emaciated and died a few days later. The second bird was found at Ten Boer on 30 October (16 km from the coast). It was taken into care on the same day. This bird was released on 5 November. The species is very rare in the inland of The Netherlands with no records from the land-locked province of Drenthe. Both birds concern the farthest inland records for the province of Groningen. In 1990, a bird was found dead at a distance of 9 km from the coast.
Issue 24 of a serial publication with a selection of notable ring-recoveries (reports of ringed b... more Issue 24 of a serial publication with a selection of notable ring-recoveries (reports of ringed birds) from the province of Groningen. Details of each ring-recovery are given, with a brief explanation of its importance. Issue 1 of this serial publication was published in volume 24 (1996) of De Grauwe Gors (the journal of the regional ornithological society Avifauna Groningen).
Free-living Egyptian Geese are present in the province of Drenthe (northern Netherlands) since at... more Free-living Egyptian Geese are present in the province of Drenthe (northern Netherlands) since at least 1980. This paper presents developments in the number of non-breeding birds for the seasons 2001/02 - 2015/16 (a season runs from 1 July - 30 June), together with an overview with records of colour-ringed birds in Drenthe. Most ringing data are derived from recently started standardized colour-ringing projects on breeding populations in urban habitats in The Netherlands. Most data on numbers were collected during the standardized monthly counts of non-breeding geese and swans (including Egyptian Goose) in September-April. These surveys are part of the national waterbird census scheme in The Netherlands. The data were derived from tables with counted numbers in annual reports of Sovon, the Dutch Centre for Field Ornithology. Data on systematic surveys in mid July of moulting flocks of geese (including Egyptian Goose) were used as well (derived from De Boer 2014-17). Both the numbers in January and the seasonal maximums showed a strong increase with a maximum for January of 1937 birds in 2013 and a seasonal maximum of 2503 birds in November 2012 (Table 1, Fig. 1). This strong increase was also the case for estimates of the year-round number of goose days spent in Drenthe (Fig. 2). Peak numbers (see also Fig. 3) were recorded in October (4 times), in November (4 times), in December (2 times), in January (3 times) and in February (2 times). A strong increase was not recorded for the same period in the adjacent province of Fryslân (Van Dijk 2017). Specific counts in July (partly listed in Table 1) yielded 740 (2013), 1003 (2014), 1127 (2015), 1041 (2016) en 865 (2017) birds (in July 2013 a total of 994 birds were counted during a systematic survey of the entire province of Drenthe). Details about the amount of imputed values and about months and sites (counting units) used for the calculations for the estimates of seasonal averages (Fig. 2) were unavailable, unnoticed changes of the estimates were noted as well (Table 2). Insight in the robustness of the data presented in Figure 2 is thus lacking. A technical report with for all species of waterbirds tables with counted numbers for each month and for each province and for all seasons since 1975/76, together with all details about all imputed values and all data which have been used / excluded to calculate all estimates, is urgently needed. In total 30 birds marked elsewhere in The Netherlands were recorded in Drenthe. One was ringed as after 1cy during the winter, five were ringed as breeding bird, all others were ringed as nestling. These 30 birds were originating from Sittard (n=1, nestling), The Hague (n=1, nestling), Wieringen (n=1, after 1cy), Amsterdam (n=3, one nestling), Arnhem (n=5, all nestlings) and from a study site in and around the city of Groningen (n=19). Several records refer to birds which stayed for only a very short period of time in Drenthe, indicating a considerable level of turn-over. Exchange with Germany was also recorded (including the sighting of a nestling from Germany). Five birds, including two nestlings from Arnhem, were sighted in moulting flocks in Drenthe (not 100% sure that all of them were actually moulting). There was no conclusive evidence for breeding in Drenthe for any of these birds. Eight birds were (ultimately) reported as shot. Two others were (ultimately) reported as dead (one as a road casualty, another ones with an uncertain cause of dead). The large majority of the records refer to sightings, often supported by photographs. Several of these birds have a long life history with sightings at various sites. The data support earlier findings (Majoor & Voslamber 2013) about a random dispersal of the Dutch population of this species (although there is no insight in the activity patterns in time and space of the ring readers outside the main study areas).
The ongoing decline in the numbers of breeding meadowbirds in The Netherlands is mainly driven by... more The ongoing decline in the numbers of breeding meadowbirds in The Netherlands is mainly driven by changes in agricultural grassland management. Several parties, however, keep claiming that a high level of predation is responsible for this ongoing decline. These parties often argue that predators are ‘too numerous’ and that predator control must be intensified. Views of such parties are mirrored in an Action Plan for breeding meadowbirds in the Province of Groningen which was released on 28 May 2018 (Terwan 2018). Conservation groups and nature managers such as Avifauna Groningen, Vogelbescherming Nederland, Natuurmonumenten and the State Forestry Service, as well as the local game shooting clubs and the regional division of the Dutch Federation of Agricultural and Horticultural Organisations are among the twelve parties that have signed the Action Plan. These parties have committed themselves to collectively undertake and promote the proposed measures. The text of the Action Plan can be interpreted in various ways, especially when taking into account the veiled language used when dealing with predation. Also the frequency with which terms are used is illuminating: predation (38x) and predator (24x), for example, much more frequently than biodiversity (7x). The Action Plan states several times that predator control must be intensified. The local game shooting clubs intend to register all potential predators in their fields (including several species of raptors, i.e. being predators of meadowbirds). Managers of nature reserves have complied with providing local game shooting clubs with inventories of predators in their reserves (ditto surveys of breeding raptors by local raptor groups). Carrion Crow Corvus corone is listed as a predator of which persecution should be intensified (killing them throughout the year is legal in The Netherlands, including destroying their nests). Parties supporting this view use the Action Plan to argue that crow traps should be provided in areas with breeding meadowbirds. Enquiries about by-catches of crow traps used in the recent past in the northern part of The Netherlands revealed that these were not registered (although mandatory). Parties in favour of predator control exploit the Action Plan to argue that nests of Buzzards must be removed from areas which are important for breeding meadowbirds. These parties also use the Action Plan to start a debate about a ceiling in the number of harriers allowed to breed in Groningen (3-4 species of harriers are currently breeding in Groningen, though in small numbers). We fear that the Action Plan will further increase illegal persecution of raptors in Groningen.
Peregrine Falcon Falco peregrinus bred successfully in the city of Groningen, The Netherlands, fo... more Peregrine Falcon Falco peregrinus bred successfully in the city of Groningen, The Netherlands, for the first time in 2016. Breeding took place in a nest box on top of the Gasunie headquarters and this case was extensively monitored (Van Dijk & Jansen 2017). This article documents a consecutive case of breeding at the same site in 2017, together with an overview of all prey remnants collected in both years. In mid February 2017 two web cams were installed by Gasunie. They enabled the public closely following the entire breeding cycle of that year. The nest contained four eggs of which three hatched, the first one on 24 April. The young were colour-ringed on 17 May (photo's on page 54 and page 57, taken during ringing) and all three females fledged. The photo on page 55 was taken from the terrace below the nest box (also taken during ringing, view to the north). Later on that year on 17 October one of the juveniles was reported to be found dead nearby a wind turbine at Hamburg harbour, Germany (distance 227 km, direction east). Injuries revealed that this bird was most likely a wind turbine victim. Prey remnants in the nest box were collected twice, respectively on 14 February, before the 2017 breeding season, and on 26 September. The nest box was cleaned entirely from prey remnants for the first time on the last occasion. Table 1 presents a list with all 200 prey remnants which were collected in both years (minimum numbers, according to guidelines in Bijlsma 1997). Column '2016' lists prey items from 2016 (derived from table 2 in Van Dijk & Jansen 2017). Column 'Feb 2017' lists prey items from the nest box in February 2017. They were most likely prey caught predominantly during the 2016 season. Column 'Sept 2017' lists prey items from the nest box in September (including a small number collected in May during ringing). At least 71 of the 87 remnants of Feral Pigeons Columba livia were identified by their leg rings as racing pigeons ('postduif', C. l. domestica). Only one of the 87 remnants was an incomplete carcass with two unringed legs and was therefore listed as a free-living (local) Feral Pigeon. The identification of the other 15 remnants ('duif') remained inconclusive. They were mainly wings which were separated from legs (not excluded that most or all of them were as well racing pigeons). The findings indicate that the falcons were predominantly catching racing pigeons and that individuals of the local population of free-living Feral Pigeons (several 100s) were hardly caught. Starling Sturnus vulgaris was another common prey item (n=59). All 5 Common Noctules Nyctalus noctula (n=5) were retrieved from the nest box, the photo on page 56 depicts one collected on 26 September 2017.
This paper is a detailed description of the life histories of four colour-ringed Egyptian Geese A... more This paper is a detailed description of the life histories of four colour-ringed Egyptian Geese Alopochen aegyptiacus: the male white F / yellow N (WFYN, photo 1) and his three partners. WFYN was ringed as an adult (after 2CY) on 8 June 2011 and was observed for the last time on 19 December 2016. WFYN was a breeding bird in a city park in Groningen, The Netherlands, in any of the years between 2011 and 2016. WFYN was successively paired with three females. His first partner, red J / white 0 (RJW0, photo 2 & 3), was ringed as an adult breeding bird on 21 June 2011. This female incubated for a prolonged period of time in 2011-2013 (up to almost four months in 2011), young never hatched. RJW0 was observed for the last time on 30 August 2013. His second partner, white R / yellow U (WRYU, photo 4 & 5), was ringed as young in a nearby city park in June 2011. The pair raised three fledglings in 2014 and had a double brood in 2015 (three fledglings from the first brood, one fledgling from the second brood). WRYU was found dead, most likely as road casualty, nearby her nest (photo 6) on 20 March 2016. She was at that moment incubating for around two weeks. WFYN was single for only four days. His third partner, red J / white 8 (RJW8, photo 7), was ringed as young in June 2013 in another city park in Groningen (different parents). RJW8 used the same nest, nine young were hatched on 26 May, six fledged. The pair was seen for the last time on 6 December 2016. On 10 December 2016, RJW8 was paired with another male. This pair bred successfully in a nearby city park in 2017 (six young fledged). I describe as well the timing of the wing moult of the colour-ringed birds and the sites used during wing moult (photo 3 & 5). I argue that several details about the breeding biology and about the moulting strategy of colour-ringed Egyptian Geese can only be documented when observers do not limit themselves to register only date and site of their records.
This paper is an overview of records in the province of Fryslân, The Netherlands, of colour-ringe... more This paper is an overview of records in the province of Fryslân, The Netherlands, of colour-ringed Egyptian Geese Alopochen aegyptiacus. Egyptian Geese are nowadays breeding all over the province and flocks of non-breeding geese are present throughout the year. Table 1 on page 15 lists counted numbers in Fryslân during systematic surveys of non-breeding waterbirds (part of the national waterbird census scheme in The Netherlands) for 14 consecutive seasons (a season runs from 1 July - 30 June). Presented are numbers during the midwinter count in January (left column, counted numbers), the seasonal maximum (middle column, counted numbers) and the month of this seasonal maximum (right column). The seasonal maximum varied between 656 (September 2013) and 1,205 (March 2006). Figure 1 on page 13 presents seasonal patterns of the counted numbers of non-breeding geese for four seasons (counting period September - April). A separate survey during the moulting period in July 2015 yielded a counted total of 1,086 birds.
Almost all colour-ringed Egyptian Geese were marked elsewhere in The Netherlands and are part of standardized RAS-projects (Retrapping Adults for Survival) of Vogeltrekstation Arnhem (the national Ringing Scheme). The focus is on records of Egyptian Geese which were ringed in the urban habitat in and around Groningen, in total 242 (183 as nestling) in the period 2010-2017. Figure 2 on page 14 (taken in Groningen on 22 August 2014), depicts a female of a breeding pair, to the left, with three of her young (freshly fledged). Six records in Fryslân refer to birds ringed in Groningen. All six were ringed as nestling. Two of them are breeding birds and thus cases of natal dispersal. A male from 2012 was photographed on 17 June 2016 nearby Earnewâld with an unringed female and with two young of a few days old, distance 42 km, direction WSW. It is unknown if the young fledged. The bird was reported from the surroundings on 28 February 2017 as shot. A female from 2014 bred successfully in Leeuwarden in 2017, distance 51 km, direction W. Five young fledged (Figure 3 on page 15, female to the right, picture taken on 30 June 2017). This female is also depicted in Figure 2 on page 14 (to the right). A young from 2014 was shot in NE-Fryslân in October 2014 (distance 29 km) and a young from 2016 was shot in SW-Fryslân in February 2017 (distance 76 km). A young from 2016 (born on 21 May) was photographed nearby Harlingen on 22 September 2016 (Figure 4 on page 16) and was returned to Groningen in December 2016 (distance 76 km). A young from 2010 was sighted in January 2011 in SW-Fryslân (distance 77 km) and was recorded in 2014, 2015 and 2016 as breeding bird in Groningen (a female, five young fledged in 2016, other breeding attempts unsuccessful).
Six other records in Fryslân refer to birds ringed as nestling elsewhere in The Netherlands. Three of them were born in Amsterdam: a young from 2012 was reported as shot in mid-Fryslân in January 2014, a young from 2014 was sighted in mid-Fryslân in November 2014 (returned to Amsterdam in March 2015), and a young from 2016 was sighted nearby Harlingen in August and September 2016 (returned to Amsterdam in March 2017). Three others were born in Arnhem: a young from 2012 was sighted in Drachten in April and May 2013, a young from 2012 was sighted in February 2013 in S-Fryslân (returned to Arnhem in April 2013, lateron shot), and a young from 2013 (sighted in Germany in November 2013) was shot in SW-Fryslân in March 2015. An Egyptian Geese with a yellow neck-collar was photographed nearby Haule on 28 September 2013 (Figure 5 on page 17). This bird was ringed in Germany (last sighting on 5 September 2013) and was returned to Germany on 26 October 2013 (distance 155 km, direction S).
The records reveal that some Egyptian Geese stay for only a very short period of time in the province of Fryslân. The records support earlier findings that Egyptian Geese of the NW-European breeding population show random dispersal. Six of the twelve birds marked elsewhere in The Netherlands were (ultimately) reported as shot. This indicates a rather substantial level of shooting pressure on this species. Observers of colour-ringed Egyptian Geese showing breeding behaviour outside the main study areas are requested to document these cases extensively with photographs and with notes of the behaviour of the birds.
Roars Transactions, a Journal on Research Policy and Evaluation (RT), 2017
This case study about the ethical behaviour in the field of scholarly publishing documents an exc... more This case study about the ethical behaviour in the field of scholarly publishing documents an exception on the rule for research articles in the medical journal BMJ Open that ICMJE disclosure forms of authors must be made available on request. The ICMJE, the International Committee of Medical Journal Editors, has developed these forms for the disclosure of conflicts of interest for authors of medical publications. The case refers to the form of the corresponding author of an article in BMJ Open on retraction notices (Moylan and Kowalczuk, 2016). The corresponding author is a member of the council of COPE, the Committee on Publication Ethics. I will argue that the unavailability of the form relates to personal conflicts of interest with the corresponding author about my efforts to retract a fatally flawed study on the breeding biology of the Basra Reed Warbler Acrocephalus griseldis. I describe my attempts to get the form and I will argue that its unavailability can be attributed to partial behaviour by BMJ, the publisher of BMJ Open. This study complements other sources reporting ethical issues at COPE.
Peregrine Falcon Falco peregrinus is an annual breeding bird in the province of Groningen, The Ne... more Peregrine Falcon Falco peregrinus is an annual breeding bird in the province of Groningen, The Netherlands, since 1998. Breeding in the city of Groningen was recorded for the first time in 2016. This article documents this case. Breeding took place in a nest box on top of the Gasunie headquarters, a building with a height of 89 meter. The nest box was put up in 2008. The breeding site is regularly monitored since that year. It remained unoccupied for several years. Peregrine Falcons were regularly observed since early 2016, territorial behaviour was observed onwards from the beginning of March. The entire breeding cycle was closely monitored. Four young, a male and three females, were colour-ringed on 24 May, photo on page 25, all four fledged. Fledging took place on 14 June. One young was found dead a few days after fledging. The photo's at the upper part of page 24, dated 10 June, depict the young in front of the nest box. The photo at the lower part of page 24 is taken from inside the Gasunie headquarters. The photo, dated 17 June, depicts a fledgling. Calculations based on measurements taken during ringing (Table 1, 'geslacht' = sex; 'vleugel' = wing length, maximum chord, mm; 'gewicht' = body mass (g); 'klauw1' = claw span incl. nails (mm); 'klauw2' = claw span (only pads, mm); 'krop' = crop) indicate that egg-laying commenced around 29 March and that hatching of the first young was around 30 April. Sightings from the ground confirm these dates. Both adults were unringed. Their origin and age are thus unknown. In total 54 prey remnants were collected (Table 2), mainly Feral Pigeons Columba livia (n=20, at least 11 of them racing pigeons) and Starling Sturnus vulgaris (n=10). Table 3 lists the residence of the owners of these racing pigeons. A Redshank Tringa totanus is depicted on page 27 (photographed on 17 May). This prey remnant was situated at a plucking site on an inaccessible site of the building. Peregrine Falcons are regular winter visitors in the city of Groningen since the end of the 1990s. It is estimated that in 2016 just less than 10 breeding pairs were present in the province of Groningen. Their territories are spread over the province and include ground dwelling breeders on uninhabited Wadden Sea islands.
Egyptian Geese Alopochen aegyptiacus are nowadays common breeding birds in large parts of The Net... more Egyptian Geese Alopochen aegyptiacus are nowadays common breeding birds in large parts of The Netherlands. BWP (Cramp & Simmons 1980) mentions the main criteria how to age and how to sex them, but I have experienced that most ringers and birdwatchers have no knowledge about these details. The criteria are as well not listed in almost all recent field guides on European birds. I have therefore decided to make an overview based on recent field work on ringed birds of spontaneous settlements in Dutch cities, in particular Groningen (53°13’ N; 06°34’ E). Almost all pictures refer to birds ringed as nestlings, mostly with a known hatching date. Calls are the key feature to separate both sexes. Males make husky, asthmatic, breathing sounds, females make quacking or trumpeting sounds. The preliminary results indicate that fledglings start to develop an adult sound at an age of around four months. Males accompaning a foraging female are often very noisy (photo 1, female to the left). The colour of the leg of incubating females is often very pale (photo 2, female to the right, same bird as in photo 1). This characteristic disappears soon after hatching. Preliminary results on biometrics show that males have longer wings (average wing length 421 mm, range 405-438, SD 9.5, N=14, maximum chord) compared to females (average 391 mm, range 380-405, SD 8.1, N=11), with obvious differences between both sexes in pairs (Table 1). Comparable size differences are obvious between siblings when they are (almost) able to fly (Table 2). Preliminary results indicate that these size differences are related to sex (female the smallest ones, males the largest ones). An attempt to sex young of almost eight weeks by cloacal examination was unsuccessful. The rather uniform brown feathers of the neck and the head of fledglings (photo 3, three young of eleven weeks old, just fledged, mother to the left) are quickly replaced, soon resulting in birds closely resembling adults (photo 4, a young of almost five months, photo 5, a young of half a year). Such individuals can only be aged by a close look to the colour pattern of their greater and median upper wing-coverts. Adults (defined as birds moulted their primaries at least once) always have pure white median upper wing-coverts and pure white greater upper wing-coverts with an obvious black subterminal bar (photo 6, breeding pair, female to the right, both ringed as adults in 2010, note that the features refer to the visible parts of the wing-coverts). The greater wing-coverts of immatures (defined as birds with first generation primaries) are pale grey brown at the proximal side of the black subterminal bar and often have some black terminal mottlings (photo 7, fledgling of four months). The median wing-coverts of immatures are not pure white, but suffused pale grey brown, with dark tips (photo 8, three siblings of 3½ months, see also photo 7). The preliminary results indicate that this feature can be used until the first time a bird sheds its primaries, though always in combination with a close look to the amount of wear of the tips of the outer primaries. The findings indicate that a variable amount of juvenile wingcoverts are replaced in the course of the time. Photo 9 depicts a female of just over one year old with clearly visible juvenile wing-coverts. This bird started a few days later with its primary moult. Photo 10 depicts a male trapped on 21 May and aged as 2CY, based on a combination of worn primaries and juvenile wing-coverts. The findings indicate that the species exhibits an annual wing moult, though one young started at an age of 1½ year with its first primary moult. Our preliminary results reveal a strong natal dispersal for males. This implies that we loose track of males ringed as nestling. Sightings of colour-ringed birds are always highly welcome and can be reported at www.geese.org. We appreciate it very much to receive detailed information on sexe and breeding status of colour-ringed birds recorded outside our core study area (Amsterdam, Arnhem, Groningen, The Hague).
This paper documents six cases of natal dispersal (maximum distance 46 km) and one case of breedi... more This paper documents six cases of natal dispersal (maximum distance 46 km) and one case of breeding dispersal (confirmed, distance 33 km) of Eurasian Oystercatchers - Haematopus ostralegus. The cases refer to birds ringed in the Province of Fryslân, The Netherlands, and recorded breeding in and around the city of Groningen, The Netherlands. Almost the entire population in Groningen is nesting on roof tops.
This note documents two inland records of a Northern Fulmar Fulmarus glacialis from the province ... more This note documents two inland records of a Northern Fulmar Fulmarus glacialis from the province of Groningen (The Netherlands) in the end of October 2017. Both birds were found during a severe gale. The first one was found exhausted in a city park in Groningen on 29 October (23 km from the coast). It was taken into care the next day. The bird was emaciated and died a few days later. The second bird was found at Ten Boer on 30 October (16 km from the coast). It was taken into care on the same day. This bird was released on 5 November. The species is very rare in the inland of The Netherlands with no records from the land-locked province of Drenthe. Both birds concern the farthest inland records for the province of Groningen. In 1990, a bird was found dead at a distance of 9 km from the coast.
Issue 24 of a serial publication with a selection of notable ring-recoveries (reports of ringed b... more Issue 24 of a serial publication with a selection of notable ring-recoveries (reports of ringed birds) from the province of Groningen. Details of each ring-recovery are given, with a brief explanation of its importance. Issue 1 of this serial publication was published in volume 24 (1996) of De Grauwe Gors (the journal of the regional ornithological society Avifauna Groningen).
Free-living Egyptian Geese are present in the province of Drenthe (northern Netherlands) since at... more Free-living Egyptian Geese are present in the province of Drenthe (northern Netherlands) since at least 1980. This paper presents developments in the number of non-breeding birds for the seasons 2001/02 - 2015/16 (a season runs from 1 July - 30 June), together with an overview with records of colour-ringed birds in Drenthe. Most ringing data are derived from recently started standardized colour-ringing projects on breeding populations in urban habitats in The Netherlands. Most data on numbers were collected during the standardized monthly counts of non-breeding geese and swans (including Egyptian Goose) in September-April. These surveys are part of the national waterbird census scheme in The Netherlands. The data were derived from tables with counted numbers in annual reports of Sovon, the Dutch Centre for Field Ornithology. Data on systematic surveys in mid July of moulting flocks of geese (including Egyptian Goose) were used as well (derived from De Boer 2014-17). Both the numbers in January and the seasonal maximums showed a strong increase with a maximum for January of 1937 birds in 2013 and a seasonal maximum of 2503 birds in November 2012 (Table 1, Fig. 1). This strong increase was also the case for estimates of the year-round number of goose days spent in Drenthe (Fig. 2). Peak numbers (see also Fig. 3) were recorded in October (4 times), in November (4 times), in December (2 times), in January (3 times) and in February (2 times). A strong increase was not recorded for the same period in the adjacent province of Fryslân (Van Dijk 2017). Specific counts in July (partly listed in Table 1) yielded 740 (2013), 1003 (2014), 1127 (2015), 1041 (2016) en 865 (2017) birds (in July 2013 a total of 994 birds were counted during a systematic survey of the entire province of Drenthe). Details about the amount of imputed values and about months and sites (counting units) used for the calculations for the estimates of seasonal averages (Fig. 2) were unavailable, unnoticed changes of the estimates were noted as well (Table 2). Insight in the robustness of the data presented in Figure 2 is thus lacking. A technical report with for all species of waterbirds tables with counted numbers for each month and for each province and for all seasons since 1975/76, together with all details about all imputed values and all data which have been used / excluded to calculate all estimates, is urgently needed. In total 30 birds marked elsewhere in The Netherlands were recorded in Drenthe. One was ringed as after 1cy during the winter, five were ringed as breeding bird, all others were ringed as nestling. These 30 birds were originating from Sittard (n=1, nestling), The Hague (n=1, nestling), Wieringen (n=1, after 1cy), Amsterdam (n=3, one nestling), Arnhem (n=5, all nestlings) and from a study site in and around the city of Groningen (n=19). Several records refer to birds which stayed for only a very short period of time in Drenthe, indicating a considerable level of turn-over. Exchange with Germany was also recorded (including the sighting of a nestling from Germany). Five birds, including two nestlings from Arnhem, were sighted in moulting flocks in Drenthe (not 100% sure that all of them were actually moulting). There was no conclusive evidence for breeding in Drenthe for any of these birds. Eight birds were (ultimately) reported as shot. Two others were (ultimately) reported as dead (one as a road casualty, another ones with an uncertain cause of dead). The large majority of the records refer to sightings, often supported by photographs. Several of these birds have a long life history with sightings at various sites. The data support earlier findings (Majoor & Voslamber 2013) about a random dispersal of the Dutch population of this species (although there is no insight in the activity patterns in time and space of the ring readers outside the main study areas).
The ongoing decline in the numbers of breeding meadowbirds in The Netherlands is mainly driven by... more The ongoing decline in the numbers of breeding meadowbirds in The Netherlands is mainly driven by changes in agricultural grassland management. Several parties, however, keep claiming that a high level of predation is responsible for this ongoing decline. These parties often argue that predators are ‘too numerous’ and that predator control must be intensified. Views of such parties are mirrored in an Action Plan for breeding meadowbirds in the Province of Groningen which was released on 28 May 2018 (Terwan 2018). Conservation groups and nature managers such as Avifauna Groningen, Vogelbescherming Nederland, Natuurmonumenten and the State Forestry Service, as well as the local game shooting clubs and the regional division of the Dutch Federation of Agricultural and Horticultural Organisations are among the twelve parties that have signed the Action Plan. These parties have committed themselves to collectively undertake and promote the proposed measures. The text of the Action Plan can be interpreted in various ways, especially when taking into account the veiled language used when dealing with predation. Also the frequency with which terms are used is illuminating: predation (38x) and predator (24x), for example, much more frequently than biodiversity (7x). The Action Plan states several times that predator control must be intensified. The local game shooting clubs intend to register all potential predators in their fields (including several species of raptors, i.e. being predators of meadowbirds). Managers of nature reserves have complied with providing local game shooting clubs with inventories of predators in their reserves (ditto surveys of breeding raptors by local raptor groups). Carrion Crow Corvus corone is listed as a predator of which persecution should be intensified (killing them throughout the year is legal in The Netherlands, including destroying their nests). Parties supporting this view use the Action Plan to argue that crow traps should be provided in areas with breeding meadowbirds. Enquiries about by-catches of crow traps used in the recent past in the northern part of The Netherlands revealed that these were not registered (although mandatory). Parties in favour of predator control exploit the Action Plan to argue that nests of Buzzards must be removed from areas which are important for breeding meadowbirds. These parties also use the Action Plan to start a debate about a ceiling in the number of harriers allowed to breed in Groningen (3-4 species of harriers are currently breeding in Groningen, though in small numbers). We fear that the Action Plan will further increase illegal persecution of raptors in Groningen.
Peregrine Falcon Falco peregrinus bred successfully in the city of Groningen, The Netherlands, fo... more Peregrine Falcon Falco peregrinus bred successfully in the city of Groningen, The Netherlands, for the first time in 2016. Breeding took place in a nest box on top of the Gasunie headquarters and this case was extensively monitored (Van Dijk & Jansen 2017). This article documents a consecutive case of breeding at the same site in 2017, together with an overview of all prey remnants collected in both years. In mid February 2017 two web cams were installed by Gasunie. They enabled the public closely following the entire breeding cycle of that year. The nest contained four eggs of which three hatched, the first one on 24 April. The young were colour-ringed on 17 May (photo's on page 54 and page 57, taken during ringing) and all three females fledged. The photo on page 55 was taken from the terrace below the nest box (also taken during ringing, view to the north). Later on that year on 17 October one of the juveniles was reported to be found dead nearby a wind turbine at Hamburg harbour, Germany (distance 227 km, direction east). Injuries revealed that this bird was most likely a wind turbine victim. Prey remnants in the nest box were collected twice, respectively on 14 February, before the 2017 breeding season, and on 26 September. The nest box was cleaned entirely from prey remnants for the first time on the last occasion. Table 1 presents a list with all 200 prey remnants which were collected in both years (minimum numbers, according to guidelines in Bijlsma 1997). Column '2016' lists prey items from 2016 (derived from table 2 in Van Dijk & Jansen 2017). Column 'Feb 2017' lists prey items from the nest box in February 2017. They were most likely prey caught predominantly during the 2016 season. Column 'Sept 2017' lists prey items from the nest box in September (including a small number collected in May during ringing). At least 71 of the 87 remnants of Feral Pigeons Columba livia were identified by their leg rings as racing pigeons ('postduif', C. l. domestica). Only one of the 87 remnants was an incomplete carcass with two unringed legs and was therefore listed as a free-living (local) Feral Pigeon. The identification of the other 15 remnants ('duif') remained inconclusive. They were mainly wings which were separated from legs (not excluded that most or all of them were as well racing pigeons). The findings indicate that the falcons were predominantly catching racing pigeons and that individuals of the local population of free-living Feral Pigeons (several 100s) were hardly caught. Starling Sturnus vulgaris was another common prey item (n=59). All 5 Common Noctules Nyctalus noctula (n=5) were retrieved from the nest box, the photo on page 56 depicts one collected on 26 September 2017.
This paper is a detailed description of the life histories of four colour-ringed Egyptian Geese A... more This paper is a detailed description of the life histories of four colour-ringed Egyptian Geese Alopochen aegyptiacus: the male white F / yellow N (WFYN, photo 1) and his three partners. WFYN was ringed as an adult (after 2CY) on 8 June 2011 and was observed for the last time on 19 December 2016. WFYN was a breeding bird in a city park in Groningen, The Netherlands, in any of the years between 2011 and 2016. WFYN was successively paired with three females. His first partner, red J / white 0 (RJW0, photo 2 & 3), was ringed as an adult breeding bird on 21 June 2011. This female incubated for a prolonged period of time in 2011-2013 (up to almost four months in 2011), young never hatched. RJW0 was observed for the last time on 30 August 2013. His second partner, white R / yellow U (WRYU, photo 4 & 5), was ringed as young in a nearby city park in June 2011. The pair raised three fledglings in 2014 and had a double brood in 2015 (three fledglings from the first brood, one fledgling from the second brood). WRYU was found dead, most likely as road casualty, nearby her nest (photo 6) on 20 March 2016. She was at that moment incubating for around two weeks. WFYN was single for only four days. His third partner, red J / white 8 (RJW8, photo 7), was ringed as young in June 2013 in another city park in Groningen (different parents). RJW8 used the same nest, nine young were hatched on 26 May, six fledged. The pair was seen for the last time on 6 December 2016. On 10 December 2016, RJW8 was paired with another male. This pair bred successfully in a nearby city park in 2017 (six young fledged). I describe as well the timing of the wing moult of the colour-ringed birds and the sites used during wing moult (photo 3 & 5). I argue that several details about the breeding biology and about the moulting strategy of colour-ringed Egyptian Geese can only be documented when observers do not limit themselves to register only date and site of their records.
This paper is an overview of records in the province of Fryslân, The Netherlands, of colour-ringe... more This paper is an overview of records in the province of Fryslân, The Netherlands, of colour-ringed Egyptian Geese Alopochen aegyptiacus. Egyptian Geese are nowadays breeding all over the province and flocks of non-breeding geese are present throughout the year. Table 1 on page 15 lists counted numbers in Fryslân during systematic surveys of non-breeding waterbirds (part of the national waterbird census scheme in The Netherlands) for 14 consecutive seasons (a season runs from 1 July - 30 June). Presented are numbers during the midwinter count in January (left column, counted numbers), the seasonal maximum (middle column, counted numbers) and the month of this seasonal maximum (right column). The seasonal maximum varied between 656 (September 2013) and 1,205 (March 2006). Figure 1 on page 13 presents seasonal patterns of the counted numbers of non-breeding geese for four seasons (counting period September - April). A separate survey during the moulting period in July 2015 yielded a counted total of 1,086 birds.
Almost all colour-ringed Egyptian Geese were marked elsewhere in The Netherlands and are part of standardized RAS-projects (Retrapping Adults for Survival) of Vogeltrekstation Arnhem (the national Ringing Scheme). The focus is on records of Egyptian Geese which were ringed in the urban habitat in and around Groningen, in total 242 (183 as nestling) in the period 2010-2017. Figure 2 on page 14 (taken in Groningen on 22 August 2014), depicts a female of a breeding pair, to the left, with three of her young (freshly fledged). Six records in Fryslân refer to birds ringed in Groningen. All six were ringed as nestling. Two of them are breeding birds and thus cases of natal dispersal. A male from 2012 was photographed on 17 June 2016 nearby Earnewâld with an unringed female and with two young of a few days old, distance 42 km, direction WSW. It is unknown if the young fledged. The bird was reported from the surroundings on 28 February 2017 as shot. A female from 2014 bred successfully in Leeuwarden in 2017, distance 51 km, direction W. Five young fledged (Figure 3 on page 15, female to the right, picture taken on 30 June 2017). This female is also depicted in Figure 2 on page 14 (to the right). A young from 2014 was shot in NE-Fryslân in October 2014 (distance 29 km) and a young from 2016 was shot in SW-Fryslân in February 2017 (distance 76 km). A young from 2016 (born on 21 May) was photographed nearby Harlingen on 22 September 2016 (Figure 4 on page 16) and was returned to Groningen in December 2016 (distance 76 km). A young from 2010 was sighted in January 2011 in SW-Fryslân (distance 77 km) and was recorded in 2014, 2015 and 2016 as breeding bird in Groningen (a female, five young fledged in 2016, other breeding attempts unsuccessful).
Six other records in Fryslân refer to birds ringed as nestling elsewhere in The Netherlands. Three of them were born in Amsterdam: a young from 2012 was reported as shot in mid-Fryslân in January 2014, a young from 2014 was sighted in mid-Fryslân in November 2014 (returned to Amsterdam in March 2015), and a young from 2016 was sighted nearby Harlingen in August and September 2016 (returned to Amsterdam in March 2017). Three others were born in Arnhem: a young from 2012 was sighted in Drachten in April and May 2013, a young from 2012 was sighted in February 2013 in S-Fryslân (returned to Arnhem in April 2013, lateron shot), and a young from 2013 (sighted in Germany in November 2013) was shot in SW-Fryslân in March 2015. An Egyptian Geese with a yellow neck-collar was photographed nearby Haule on 28 September 2013 (Figure 5 on page 17). This bird was ringed in Germany (last sighting on 5 September 2013) and was returned to Germany on 26 October 2013 (distance 155 km, direction S).
The records reveal that some Egyptian Geese stay for only a very short period of time in the province of Fryslân. The records support earlier findings that Egyptian Geese of the NW-European breeding population show random dispersal. Six of the twelve birds marked elsewhere in The Netherlands were (ultimately) reported as shot. This indicates a rather substantial level of shooting pressure on this species. Observers of colour-ringed Egyptian Geese showing breeding behaviour outside the main study areas are requested to document these cases extensively with photographs and with notes of the behaviour of the birds.
Roars Transactions, a Journal on Research Policy and Evaluation (RT), 2017
This case study about the ethical behaviour in the field of scholarly publishing documents an exc... more This case study about the ethical behaviour in the field of scholarly publishing documents an exception on the rule for research articles in the medical journal BMJ Open that ICMJE disclosure forms of authors must be made available on request. The ICMJE, the International Committee of Medical Journal Editors, has developed these forms for the disclosure of conflicts of interest for authors of medical publications. The case refers to the form of the corresponding author of an article in BMJ Open on retraction notices (Moylan and Kowalczuk, 2016). The corresponding author is a member of the council of COPE, the Committee on Publication Ethics. I will argue that the unavailability of the form relates to personal conflicts of interest with the corresponding author about my efforts to retract a fatally flawed study on the breeding biology of the Basra Reed Warbler Acrocephalus griseldis. I describe my attempts to get the form and I will argue that its unavailability can be attributed to partial behaviour by BMJ, the publisher of BMJ Open. This study complements other sources reporting ethical issues at COPE.
Peregrine Falcon Falco peregrinus is an annual breeding bird in the province of Groningen, The Ne... more Peregrine Falcon Falco peregrinus is an annual breeding bird in the province of Groningen, The Netherlands, since 1998. Breeding in the city of Groningen was recorded for the first time in 2016. This article documents this case. Breeding took place in a nest box on top of the Gasunie headquarters, a building with a height of 89 meter. The nest box was put up in 2008. The breeding site is regularly monitored since that year. It remained unoccupied for several years. Peregrine Falcons were regularly observed since early 2016, territorial behaviour was observed onwards from the beginning of March. The entire breeding cycle was closely monitored. Four young, a male and three females, were colour-ringed on 24 May, photo on page 25, all four fledged. Fledging took place on 14 June. One young was found dead a few days after fledging. The photo's at the upper part of page 24, dated 10 June, depict the young in front of the nest box. The photo at the lower part of page 24 is taken from inside the Gasunie headquarters. The photo, dated 17 June, depicts a fledgling. Calculations based on measurements taken during ringing (Table 1, 'geslacht' = sex; 'vleugel' = wing length, maximum chord, mm; 'gewicht' = body mass (g); 'klauw1' = claw span incl. nails (mm); 'klauw2' = claw span (only pads, mm); 'krop' = crop) indicate that egg-laying commenced around 29 March and that hatching of the first young was around 30 April. Sightings from the ground confirm these dates. Both adults were unringed. Their origin and age are thus unknown. In total 54 prey remnants were collected (Table 2), mainly Feral Pigeons Columba livia (n=20, at least 11 of them racing pigeons) and Starling Sturnus vulgaris (n=10). Table 3 lists the residence of the owners of these racing pigeons. A Redshank Tringa totanus is depicted on page 27 (photographed on 17 May). This prey remnant was situated at a plucking site on an inaccessible site of the building. Peregrine Falcons are regular winter visitors in the city of Groningen since the end of the 1990s. It is estimated that in 2016 just less than 10 breeding pairs were present in the province of Groningen. Their territories are spread over the province and include ground dwelling breeders on uninhabited Wadden Sea islands.
Egyptian Geese Alopochen aegyptiacus are nowadays common breeding birds in large parts of The Net... more Egyptian Geese Alopochen aegyptiacus are nowadays common breeding birds in large parts of The Netherlands. BWP (Cramp & Simmons 1980) mentions the main criteria how to age and how to sex them, but I have experienced that most ringers and birdwatchers have no knowledge about these details. The criteria are as well not listed in almost all recent field guides on European birds. I have therefore decided to make an overview based on recent field work on ringed birds of spontaneous settlements in Dutch cities, in particular Groningen (53°13’ N; 06°34’ E). Almost all pictures refer to birds ringed as nestlings, mostly with a known hatching date. Calls are the key feature to separate both sexes. Males make husky, asthmatic, breathing sounds, females make quacking or trumpeting sounds. The preliminary results indicate that fledglings start to develop an adult sound at an age of around four months. Males accompaning a foraging female are often very noisy (photo 1, female to the left). The colour of the leg of incubating females is often very pale (photo 2, female to the right, same bird as in photo 1). This characteristic disappears soon after hatching. Preliminary results on biometrics show that males have longer wings (average wing length 421 mm, range 405-438, SD 9.5, N=14, maximum chord) compared to females (average 391 mm, range 380-405, SD 8.1, N=11), with obvious differences between both sexes in pairs (Table 1). Comparable size differences are obvious between siblings when they are (almost) able to fly (Table 2). Preliminary results indicate that these size differences are related to sex (female the smallest ones, males the largest ones). An attempt to sex young of almost eight weeks by cloacal examination was unsuccessful. The rather uniform brown feathers of the neck and the head of fledglings (photo 3, three young of eleven weeks old, just fledged, mother to the left) are quickly replaced, soon resulting in birds closely resembling adults (photo 4, a young of almost five months, photo 5, a young of half a year). Such individuals can only be aged by a close look to the colour pattern of their greater and median upper wing-coverts. Adults (defined as birds moulted their primaries at least once) always have pure white median upper wing-coverts and pure white greater upper wing-coverts with an obvious black subterminal bar (photo 6, breeding pair, female to the right, both ringed as adults in 2010, note that the features refer to the visible parts of the wing-coverts). The greater wing-coverts of immatures (defined as birds with first generation primaries) are pale grey brown at the proximal side of the black subterminal bar and often have some black terminal mottlings (photo 7, fledgling of four months). The median wing-coverts of immatures are not pure white, but suffused pale grey brown, with dark tips (photo 8, three siblings of 3½ months, see also photo 7). The preliminary results indicate that this feature can be used until the first time a bird sheds its primaries, though always in combination with a close look to the amount of wear of the tips of the outer primaries. The findings indicate that a variable amount of juvenile wingcoverts are replaced in the course of the time. Photo 9 depicts a female of just over one year old with clearly visible juvenile wing-coverts. This bird started a few days later with its primary moult. Photo 10 depicts a male trapped on 21 May and aged as 2CY, based on a combination of worn primaries and juvenile wing-coverts. The findings indicate that the species exhibits an annual wing moult, though one young started at an age of 1½ year with its first primary moult. Our preliminary results reveal a strong natal dispersal for males. This implies that we loose track of males ringed as nestling. Sightings of colour-ringed birds are always highly welcome and can be reported at www.geese.org. We appreciate it very much to receive detailed information on sexe and breeding status of colour-ringed birds recorded outside our core study area (Amsterdam, Arnhem, Groningen, The Hague).
Aim: Fraudulent studies in peer-reviewed journals are contaminating the academic record. They the... more Aim: Fraudulent studies in peer-reviewed journals are contaminating the academic record. They therefore need to be retracted. This article examines allegations of fraud in a field study on the breeding biology of the Basra Reed-Warbler Acrocephalus griseldis, an Endangered bird species which is almost exclusively breeding in Iraq.
Methods: The study was published in July 2013 in 'Zoology in the Middle East', a peer-reviewed journal of publisher Taylor & Francis (TF). The journal was informed in September 2013 that the study was not based on valided facts. TF is since 2016 in the possession of two reports with investigations about the veracity of the study. I present and discuss, (a) the main findings of both reports, (b) relevant information collected later on, and (c) comments from stakeholders and others on (a) and (b).
Results: Numerous efforts in 2015-2020 to get the raw research data were unsuccessful. There is no evidence that they exist. Several experts have confirmed that the study is based on fraud. TF, the journal and others have not provided experts with opposing views. TF and the journal have not provided rebuttals of the main findings of both reports. The first author, responsible for collecting all field data, has indicated that he is willing to retract the study.
Main conclusions: TF does not take its responsibility to maintain the integrity of the academic record. The current acting of TF is worrisome for a proper development of the field of bird conservation science. TF is therefore urged to retract the study. The present article highlights the wish of many scientists that it becomes mandatory for all articles in all Web of Science journals that the raw data are available for all readers.
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Almost all colour-ringed Egyptian Geese were marked elsewhere in The Netherlands and are part of standardized RAS-projects (Retrapping Adults for Survival) of Vogeltrekstation Arnhem (the national Ringing Scheme). The focus is on records of Egyptian Geese which were ringed in the urban habitat in and around Groningen, in total 242 (183 as nestling) in the period 2010-2017. Figure 2 on page 14 (taken in Groningen on 22 August 2014), depicts a female of a breeding pair, to the left, with three of her young (freshly fledged). Six records in Fryslân refer to birds ringed in Groningen. All six were ringed as nestling. Two of them are breeding birds and thus cases of natal dispersal. A male from 2012 was photographed on 17 June 2016 nearby Earnewâld with an unringed female and with two young of a few days old, distance 42 km, direction WSW. It is unknown if the young fledged. The bird was reported from the surroundings on 28 February 2017 as shot. A female from 2014 bred successfully in Leeuwarden in 2017, distance 51 km, direction W. Five young fledged (Figure 3 on page 15, female to the right, picture taken on 30 June 2017). This female is also depicted in Figure 2 on page 14 (to the right). A young from 2014 was shot in NE-Fryslân in October 2014 (distance 29 km) and a young from 2016 was shot in SW-Fryslân in February 2017 (distance 76 km). A young from 2016 (born on 21 May) was photographed nearby Harlingen on 22 September 2016 (Figure 4 on page 16) and was returned to Groningen in December 2016 (distance 76 km). A young from 2010 was sighted in January 2011 in SW-Fryslân (distance 77 km) and was recorded in 2014, 2015 and 2016 as breeding bird in Groningen (a female, five young fledged in 2016, other breeding attempts unsuccessful).
Six other records in Fryslân refer to birds ringed as nestling elsewhere in The Netherlands. Three of them were born in Amsterdam: a young from 2012 was reported as shot in mid-Fryslân in January 2014, a young from 2014 was sighted in mid-Fryslân in November 2014 (returned to Amsterdam in March 2015), and a young from 2016 was sighted nearby Harlingen in August and September 2016 (returned to Amsterdam in March 2017). Three others were born in Arnhem: a young from 2012 was sighted in Drachten in April and May 2013, a young from 2012 was sighted in February 2013 in S-Fryslân (returned to Arnhem in April 2013, lateron shot), and a young from 2013 (sighted in Germany in November 2013) was shot in SW-Fryslân in March 2015. An Egyptian Geese with a yellow neck-collar was photographed nearby Haule on 28 September 2013 (Figure 5 on page 17). This bird was ringed in Germany (last sighting on 5 September 2013) and was returned to Germany on 26 October 2013 (distance 155 km, direction S).
The records reveal that some Egyptian Geese stay for only a very short period of time in the province of Fryslân. The records support earlier findings that Egyptian Geese of the NW-European breeding population show random dispersal. Six of the twelve birds marked elsewhere in The Netherlands were (ultimately) reported as shot. This indicates a rather substantial level of shooting pressure on this species. Observers of colour-ringed Egyptian Geese showing breeding behaviour outside the main study areas are requested to document these cases extensively with photographs and with notes of the behaviour of the birds.
Almost all colour-ringed Egyptian Geese were marked elsewhere in The Netherlands and are part of standardized RAS-projects (Retrapping Adults for Survival) of Vogeltrekstation Arnhem (the national Ringing Scheme). The focus is on records of Egyptian Geese which were ringed in the urban habitat in and around Groningen, in total 242 (183 as nestling) in the period 2010-2017. Figure 2 on page 14 (taken in Groningen on 22 August 2014), depicts a female of a breeding pair, to the left, with three of her young (freshly fledged). Six records in Fryslân refer to birds ringed in Groningen. All six were ringed as nestling. Two of them are breeding birds and thus cases of natal dispersal. A male from 2012 was photographed on 17 June 2016 nearby Earnewâld with an unringed female and with two young of a few days old, distance 42 km, direction WSW. It is unknown if the young fledged. The bird was reported from the surroundings on 28 February 2017 as shot. A female from 2014 bred successfully in Leeuwarden in 2017, distance 51 km, direction W. Five young fledged (Figure 3 on page 15, female to the right, picture taken on 30 June 2017). This female is also depicted in Figure 2 on page 14 (to the right). A young from 2014 was shot in NE-Fryslân in October 2014 (distance 29 km) and a young from 2016 was shot in SW-Fryslân in February 2017 (distance 76 km). A young from 2016 (born on 21 May) was photographed nearby Harlingen on 22 September 2016 (Figure 4 on page 16) and was returned to Groningen in December 2016 (distance 76 km). A young from 2010 was sighted in January 2011 in SW-Fryslân (distance 77 km) and was recorded in 2014, 2015 and 2016 as breeding bird in Groningen (a female, five young fledged in 2016, other breeding attempts unsuccessful).
Six other records in Fryslân refer to birds ringed as nestling elsewhere in The Netherlands. Three of them were born in Amsterdam: a young from 2012 was reported as shot in mid-Fryslân in January 2014, a young from 2014 was sighted in mid-Fryslân in November 2014 (returned to Amsterdam in March 2015), and a young from 2016 was sighted nearby Harlingen in August and September 2016 (returned to Amsterdam in March 2017). Three others were born in Arnhem: a young from 2012 was sighted in Drachten in April and May 2013, a young from 2012 was sighted in February 2013 in S-Fryslân (returned to Arnhem in April 2013, lateron shot), and a young from 2013 (sighted in Germany in November 2013) was shot in SW-Fryslân in March 2015. An Egyptian Geese with a yellow neck-collar was photographed nearby Haule on 28 September 2013 (Figure 5 on page 17). This bird was ringed in Germany (last sighting on 5 September 2013) and was returned to Germany on 26 October 2013 (distance 155 km, direction S).
The records reveal that some Egyptian Geese stay for only a very short period of time in the province of Fryslân. The records support earlier findings that Egyptian Geese of the NW-European breeding population show random dispersal. Six of the twelve birds marked elsewhere in The Netherlands were (ultimately) reported as shot. This indicates a rather substantial level of shooting pressure on this species. Observers of colour-ringed Egyptian Geese showing breeding behaviour outside the main study areas are requested to document these cases extensively with photographs and with notes of the behaviour of the birds.
Methods: The study was published in July 2013 in 'Zoology in the Middle East', a peer-reviewed journal of publisher Taylor & Francis (TF). The journal was informed in September 2013 that the study was not based on valided facts. TF is since 2016 in the possession of two reports with investigations about the veracity of the study. I present and discuss, (a) the main findings of both reports, (b) relevant information collected later on, and (c) comments from stakeholders and others on (a) and (b).
Results: Numerous efforts in 2015-2020 to get the raw research data were unsuccessful. There is no evidence that they exist. Several experts have confirmed that the study is based on fraud. TF, the journal and others have not provided experts with opposing views. TF and the journal have not provided rebuttals of the main findings of both reports. The first author, responsible for collecting all field data, has indicated that he is willing to retract the study.
Main conclusions: TF does not take its responsibility to maintain the integrity of the academic record. The current acting of TF is worrisome for a proper development of the field of bird conservation science. TF is therefore urged to retract the study. The present article highlights the wish of many scientists that it becomes mandatory for all articles in all Web of Science journals that the raw data are available for all readers.