Skogsøy Webshop Home Travel Gullfjell Contact
Tjeldstø Galleries Offshore Equipment  U.K. Links

Øygarden Services Advertising Accomodation Books

White-billed Diver - GulnebblomGavia adamsii
Vitnäbbad Islom  - Hvidnæbbet Lom  - Jääkuikka - Plongeon à bec blanc


White-billed Diver in flight, Skogsøy, Norway

Above and below: Adult White-billed Divers (Yellow-billed Loon) heading north past Skogsøy, May 2016

Adult White-billed Diver, Skogsøy, Norway, May 2016



The White-billed Diver is a regular migrant in both spring and autumn at Skogsøy, although appears more numerous in spring when it is the second commonest diver species. The first birds turn up towards the end of April, though most pass in May with a peak in the first half of the month; occasional birds are observed into June. Daily counts of less than 10 are the norm but during the peak passage period double figure counts are not unusual - the record count is over 40 individuals in one day.

During the autumn White-billed Diver appear to be a lot less regular with occadional singles being noted. This could indicate some kind of loop migration whereby the autumn migration takes place further to the west.

The diagram below shows the maximum counts per 3-day period using my own sporadic and non-systematic counts. The blue line shows the number of visits and the orange the number of days White-billed Diver have occured - the two are almost concurrent in the first half of May indicating that is quite normal to see this species at this time at Skogsøy. The green line shows the maximum count per three day period.

Maximum counts of White-billed Diver at Skogsøy

During the spring the majority of birds are adults and they often pass at close range.

Based on my 8 visits during the spring of 2005 well in excess of 200 individuals are estimated to have passed Skogsøy. This estimate was derived using the same method as Folvik and Mjøs used (see references).

Numbers of White-billed Diver at Skogsøy far exceed those at Utsira and in the Shetlands and relatviely few are observed further south so this species either has a secret wintering ground in the North Sea, which I consider to be unlikely, or, more likely they come in from the west, "over the top" of Scotland, hit the Norwegian coast and head north along it.

Large numbers of White-billed Diver are observed at Slettnes each spring as they head east. The number of sightings off Shetland also seem to be increasing as the numbers at Skogsøy also appear to be doing. 
Trends in the population are poorly known as is the location of the species wintering grounds.

Spring migration in Alaska is 15 May-9 June; in Canada 28 May-15 June.  Fall migration in Alaska is late August-early October, in Canada late Aug and Sept.; along Pacific coast of Asia is October.  (Michael North pers. comm.)


References
Folvik, A., Mjøs, A.T. 1995. Spring migration of White-billed Divers past southwestern Norway. British Birds 88: 125-129
Tveit, B.O., Mobakken, G. og Bryne, O. 2004 Fugler og fuglafolk på Utsira. Utsira Fuglestasjon
Ellis,P., Harvey, P.,Heubeck,M.,Okill, D., Osborn, K.,Pennington,M.,Riddington, R. Birds of Shetland. 2004.






Links

Diver / Loon Specialist Group



I



2.4050882408938E+142visits to this side since September 17, 2005.
All content on this site, including Natural Born Birder logo, is copyright © 2005-2016.  No data to be used without permission.
High resolution versions of most images on this website are available. Please Contact Me for further details or other enquiries


Birding Top 500 Counter