Unravelling the mysteries of the Dotterel

The higher ridges and plateaus rising high above our study areas in Ammarnäs are home to an elusive bird: the Dotterel. Over the years, whilst working on Long-tailed Skuas and Red-necked Phalaropes, we have often heard Dotterels displaying and passing by from one ridge to another. Yet, our knowledge about their breeding ecology, habitat use and migration ecology is rather limited. Therefore, we have started a colour ringing project by which we hope to learn about their basic ecology such as habitat use, survival and site faithfulness.

Dotterels breed in low densities which makes it difficult to find a nest; over the years we have only incidentally found one. This year we have managed to find 8 nests! We find nests by following a male, which is the breeding sex, back to the nest. This may not seem difficult, but the bird’s plumage matches perfectly with their habitat which makes it almost impossible to locate a breeding individual, especially since they are only flushed when approached very closely. The trick is to search for a foraging male, and to stick with it when found! So far, we have caught seven males on the nest, using a walk-in-trap, for colour-ringing and sampling.

The males have proven to be very committed fathers. It amazes us that some males stay on the nest until we mildly push it off to measure the eggs and estimate the stage of incubation. The males behave very calm and often continue breeding as soon as we have finished our measurements as if nothing happened.

mirakel

On the other hand, female Dotterels are less committed to their brood and leave most of the breeding duties to the male. It is thought that females migrate further north after completing a clutch to do another breeding attempt. Surprising was our observation of a breeding female on the nest! Most females we encounter are in small groups of 2-6 birds. We have managed to catch some of these females using mist nets and tape lure. Let’s find out if we can get some ring recoveries in future seasons, possibly further north…

The 2018 field season is almost at an end. A few days are left to check Dotterel nests, ring chicks and explore some ridges before we migrate back south.

Morrison Pot

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