Spotted Rail

Crakes of the genus Porzana are among the least known and rarest native birds in Germany. They are related to the more common, but likewise rarely seen Water Rail (Rallus aquaticus), and inhabit extensive reeds and marshlands. Melioration of these habitats in the 20th century has drastically reduced their populations in Germany. According to the Red Lists, Spotted Crake (Porzana porzana) and Little Crake (P. parva) are considered to be endangered or critically endangered, whereas Baillon’s Crake (P. pusilla) is close to extinction as a breeding bird.

 

Habitat of crakes during breeding season 2008

However, during the past years populations of crakes recovered in areas with recent measures of renaturation. During the spring season 2007 two breeding records could be noted for Baillon’s Crake in the lower valley of Peene, Mecklenburg-Vorpommern (MV), the first ones for eastern Germany for 90 years. The same areas hosted around 30 pairs of Little Crake, 160 pairs of Spotted Crake, and 250 pairs of Water Rail. As the first federal state of Germany, in 2000 Mecklenburg-Vorpommern initiated an extensive marsh recovery program including re-wetting measures. Altogether 130.000 ha of formerly used marshland habitats are targets of renaturation. During the last decade, already 20.000 ha of marshlands have been converted into their original stages.

Since 2008, the Brehm Fund supports field studies (2008-2010) at lower Peene valley (MV) in order to fill gaps in knowledge on the biological traits and life histories of these endangered crakes. This project is under supervision of Dr. Angela Schmitz-Ornés (Vogelwarte Hiddensee, University Greifswald) and includes a dissertation by Alexanders Eilers, M.Sc.. It covers analyses of habitats and niching of all three crake species during the breeding season, directed to reveal ecological overlaps and specializations, individual time-spatial use of territories, social interactions, and intra- and interspecific territorial behaviour. Furthermore biotic and abiotic habitat factors will be described, and breeding success or predation rates will be used as parameters for the quality of habitats and territories. Finally, the ornithologists examine the effects on Porzana populations caused by the presence of the Water Rail.

 

Field work: Setting traps for rails means high efforts

In spring and summer 2008, first results could be obtained. So far, more than 20 Water Rails, seven Spotted Crakes, and 25 Little Crakes were ringed and partly equipped with small transmitters, of which seven individuals are still surveyed. The high logistic efforts may lead to further success in marking birds; more than 150 traps and numerous volunteer helpers and students may help to gather data from up to 200 Water Rails, 40 Spotted Crakes, 15-25 Little Crakes, and an unknown number of Baillon’s Crakes. Thus, additional data on breeding success, sexual ratios, and species composition in relation to habitat or vegetation type are provided. Moreover, the scientists collect tissue samples for population genetic studies. Altogether the extent of these studies can be regarded as unique for Germany. 

The primary goal of the project is to elaborate effective measures of conservation and management in order to re-establish Porzana porzana, P. parva, and P. pusilla in Germany, accompanied by the marshland recovery program.

 Typical black plumage: chick of Little Crake

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