Oystercatchers returning from inland breeding grounds

Sunday, July 23rd, 2017

Species: Oystercatcher

Project: Quantifying the effects of disturbance for wintering oystercatchers at the Vliehors (CHIRP)

The Wadden Sea is one of the most important wintering areas of the Eurasian Oystercatcher Haematopus ostralegus. From the Wadden Sea, the oystercatchers move to their inland breeding grounds in February or March. Most bird return to the Wadden Sea in July or August. Last winter, 20 oystercatchers were equipped with GPS trackers on the Vliehors for the CHIRP project. Many of those birds were ‘lost’ during the breeding season when they were inland. Over the last weeks, the first birds have returned to the Vliehors and the data from the trackers has been downloaded by the permanent antennae network on Vlieland.

Currently, five birds have returned to the large sandflats of the Vliehors. One of those birds, named Wietske (5445), was observed near Den Helder at the intertidal area Balgzand in March, but her breeding site could not be retrieved. Now it turned out she has bred near Schagen, about 12 kilometers south from the Balgzand area. Two other birds visited the western Dutch inland. One bird stayed in the vicinity of Heerhugowaard (5424), while another bird went to the meadow areas southeast of Woerden in the province of Utrecht (5437). Interestingly, this oystercatcher went early in the year for a short trip to Woerden, but returned after three days to the Vliehors area again. One oystercatcher bred in the Slufter on the Wadden Island Texel (5438), which is very close to the Vliehors. This was already suspected in winter, as the bird frequently commuted between the Vliehors area and the Slufter. Finally, an adult female oystercatcher (5346) spend the breeding season in Germany, close to the Jümmesee near the small village Detern. During the spring migration, stayed for a one-day stopover at the island of Schiermonnikoog.

Spring migration of oystercatchers wintering on Vliehors. Data 15 February 2017 – 10 May 2017. Trackers Red: 5346, Blue: 5424, Green: 5437, Grey: 5438, Orange: 5445.


The number of oystercatchers on the high tide roost are increasing daily and we expect more incoming oystercatchers during the coming weeks. Keep track of the oystercatchers with the near real-time data applet at the CHIRP project page.

Oystercatcher high tide roost at the military airplane training grounds on the Vliehors.


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