söndag 21 augusti 2011

Arctic Waders vs. Lemmings / Arktiske vadere vs. Lemen

The Little Stint / Dvergsnipe (Calidris minuta) and The Curlew Sandpiper / Tundrasnipe (Calidris ferruginea) are small waders with their breeding grounds in the High Arctic and their overwintering grounds in Africa and Asia. August and September are usually very good months for observing long-distance migrants on their migration south, and this autumn unusually many Little Stints and Curlew Sandpipers can be seen on the mudflats in Troms - with the Litttle Stints even outnumbering the Dunlins/Myrsnipe sometimes!

Why are there so many of these tiny waders this year? Some studies suggest that the breeding success of little stints and curlew sandpipers may be related to the abundance of lemmings (Lemmus lemmus). When there are few lemmings, predatory birds like e.g. skuas and snowy owls take many little stints and curlew sandpipers, but when lemmings are abundant, they prefer the lemmings. It is well known from all over Scandinavia that 2011 has been an extraordinary good lemming year http://nordlysfoto.blogspot.com/2011/05/norwegian-lemmings-lemenar.html with unusually many breeding pairs of Snowy Owls and other species that depend on the lemmings and maybe this is, at least part, of the reason why these two species are so abuntant this year?

A quick look on the Norwegian report system for birds: http://artsobservasjoner.no/fugler/ shows that the number of "expected reports" for these two species (compared to the number of reports from the same period from earlier years (2007 - ), have increased by 88% and 59% for curlew sandpipers and little stints respectively.

Other species such as dunlins, ringed plovers, ruffs, spotted redshanks, redshanks and sanderlings (and an occasional crazy bird-watcher) may also be seen on the mudflats around Tromsø..

Curlew Sandpiper (Calidris ferruginea)

Little Stint (Calidris minuta)

Curlew Sandpiper


Little Stint


Flock of Little Stints on Kvaløya, Norway

Is there a connection between some Arctic Waders and Norwegian Lemmings (Lemmus lemmus)?

4 kommentarer:

  1. beautiful photo,and beautiful blog, congratulations! From Romania Sebi

  2. Imteressant teori :) Trodde først det var en spøk :P Tror kanskje at dvergsnipene liker det gode været vi har også :o) Fine bilder!


  3. Migration strategies could also change due to weather and timing, but loads of birds along our shorelines in the moment!! Do not know the Lemming-status in Siberia where these guys comes from!?
    Great shots as always!!

  4. Stein: Riktignok er det svært mange faktorer som kan spille inn her.. Muligens bestemte seg også mange predatorer for å ikkje dra hele veien opp til nord-Sibir kysten i år da det fanns mye mat lenger sør..?