Greenland White-fronted Geese tracked in Wales

Greenland White-fronted Goose is endemic to the British Isles during winter. It has been declining by 3.5% p.a. since the late 1990s and the population has now decreased by ca.40%. Fewer than 25 birds now winter on the Dyfi Estuary, Wales and constitute one of only two regularly monitored flock in Wales. The Dyfi Estuary flock is declining faster than the global average, implying that conditions at this site might be unusually poor, and that this is leading to emigration from the site or poor survival/productivity among the local birds. Because it is a declining endemic, Greenland White-fronted Goose is a UK Red Listed and globally Endangered. It is an EU Annex 1 species, subject of a recent African Eurasian Waterbird Agreement (AEWA) Action Plan.

Two Greenland White-fronted Geese were marked on the Dyfi Estuary in west Wales as part of joint initiative project funded by the Welsh Government. The catching and marking was carried out by the Wildfowl & Wetlands Trust (WWT) and the Royal Society for the Protection of Birds (RSPB Cymru). The goal is to provide future management advice for the wintering site through detailed mapping of local feeding and roost areas within the estuary over winter. In addition, location data will hopefully shed insights into migration strategies and the location of the breeding quarters in west Greenland. The large-scale movements of the tagged birds, in both spring and autumn 2017, are summarised below.

Tags WHIT01 and WHIT02, two adult females, were caught on the Dyfi Estuary, west Wales in early December 2016 (details below).

Autumn 2017

  • 27 Sept 2017. WHIT01 is seen in Iceland. Together with her mat (V05) she has four goslings.
  • 21 Sept 2017. WHIT01 arrives back in southern Iceland (near Hvolsvöllur) from west Greenland.
  • 10 Sept 2017. WHIT02 arrives back in southern Iceland (near Hvolsvöllur) from west Greenland.

Summer 2017

  • .June-August 2017. Both tagged birds spend the summer in west Greenland. WHIT01 at about 68 degrees north and WHIT02 at about 67 degrees north. Analysis of the daily location data suggest that WHIT01 probably attempted to breed, and may have been successful, while WHIT02 appears to start a nesting attempt, but abandons it after a few days.

Spring 2017

  • 6 May 2017. Close behind, WHIT02 finally crosses the Greenland ice cap and arrives in west Greenland.
  • 5 May 2017. WHIT01 is logged crossing the Greenland ice-cap.
  • 2 May 2017. WHIT01 gives its last location in southern Iceland. Hopefully she too has left for west Greenland.
  • 29 April 2017.WHIT02 gives its last location in southern Iceland. Hopefully she has left for west Greenland.
  • 7 April 2017. After four days of 'radio silence' WHIT02 makes contact again. She has made it to Iceland and is recorded 10km from WHIT01 near Hvolsvöllur, a small town in the south of Iceland about 100 km to the east of Reykjavík. Although the location data are missing, it is probable that WHIT02 left west Wales at about the same time as WHIT01, although we don't know the route that she took, or how long the crossing took.
  • 4 April 2017. WHIT01 moves further west along the southern Iceland coast.
  • 2/3 April 2017. WHIT01 leaves the Dyfi sometime during late evening on 2 April. By midnight, she is recorded flying to the north west of Anglesey and by 4am it arrives on Mull (Argyll). At 6am, she flies over Rum and at 7am she flies over Stornoway (Western Isles). At 6pm she is recorded near Hofn (SE Iceland).

Winter 2016/17

  • 10 Mar 2017. WHIT02 leaves Portmadoc and heads south back to the Dyfi. She is recorded feeding in exactly the same field in which it was caught and marked three months earlier.
  • 9 Mar 2017. WHIT02 leaves Wexford, crossing the Irish Sea to Portmadog in North Wales. She is here from Noon until 6pm. Is this the start of spring migration?
  • 20 Feb 2017. WHIT01 remains on the Dyfi Estuary and is mapping out the feeding and roosting sites on a daily basis.WHIT02 remains at Wexford
  • 18 Dec 2016. WHIT01 remains on the Dyfi Estuary, while WHIT02 remains at Wexford.
  • 12/13 Dec 2016. Tag WHIT02 moves south to North Slob, Wexford, Ireland and roosts at the traditional site (Raven Point).
  • 11/12 Dec 2016. Tag WHIT02 roosts on the RSPB Ynys Hir reserve, but by midday on 12 December, WHIT02 had moved north west to near Stabannan, County Louth, Ireland (a known wintering site of Greenland White-fronted Geese), 55km north of Dublin.
  • 4 Dec 2016. Tags WHIT01 and WHIT02 are caught and GPS tags are deployed. The first few days show local movements between feeding fields and the roosts.

The marking initiative is funded by the Welsh Government and forms part of a larger study involving the following partners: Welsh Government, The Wildfowl & Wetlands Trust (WWT), the Royal Society for the Protection of Birds (RSPB Cymru), Mick Green (ecologist), Natural Resources Wales, The British Association for Shooting and Conservation (BASC) and the Dyfi, Mawddach & Dysynni Wildfowlers’ Association (DMDWA). We are extremely grateful for the support given during fieldwork by Michael and Theresa Sherman.

The data and maps are for illustrative purposes only and may not be used without prior written consent of WWT/RSPB Wales.

© WWT/RSPB Wales 2017