Journal of Avian Biology

Empirical and theoretical research in ornithology

Published by The Nordic Society Oikos

A water rail tale with an unexpected twist

Submitted by Johan on 17 December 2020.

The elusive and secretive habits of water rails make them challenging for ecologists to follow. Until recently, little was therefore known about movements in the species. In the current study, modern tracking technology proved highly useful to reveal some of the species’ secrets.

By tagging birds in southernmost Norway with geolocators, we for the first time managed to document the movements of water rails throughout the year. For many years, rails were also colour-ringed to monitor their presence in the study area over time.

We found that 1) birds wintering in Norway came from breeding areas located further east, on both sides of the Baltic Sea, 2) a single local breeding bird spent the winter in N Italy, and 3) some birds occasionally did not migrate but stayed in the study area all year.

Surprisingly, some water rails even travelled during the breeding season, presumably breeding, or attempting to breed, at different locations. This strange behaviour is rarely known in birds and was highly unexpected since the water rail is described as monogamous, bi-parental, and territorial during the breeding season.

Our study was only possible due to the huge efforts made by Sven Rislaa who ringed the birds. He literally lives with his study objects throughout the year, as his house is situated next to a local reedbed inhabited by many water rails – especially in winter.

Watch the following video clips Sven made at the study site and you will probably understand our fascination with the water rail.

To facilitate ringing and observations, Sven regularly provided birds with oatmeal:

The supplemental food often attracted many birds:

Reading colour-ring combinations of ringed birds was much easier at the feeding spots than when birds were moving around in the dense reed:

Supplemental feeding also made it easier to trap the birds:

Breeding was confirmed several times in the study area but never more than one breeding pair at a time. On this video clip the parents are taking turns to incubate the eggs: