Nest size variability and interspecific nest reuse in Little Crake

In this study, we describe the nest size characteristics and the breeding attempt of Little Crake ( Zapornia parva) in the abandoned nest of Common Coot ( Fulica atra) at the small mid-field pond in the Masurian Lake District, northeast Poland. Based on the 6-year study during five breeding seasons, we found 123 nests of Little Crake, but such an instance was observed only once. To the best of our knowledge, this observation is the first record of the use of the same nest by two species of rallids. We discuss what could force crakes to make such a decision, why this breeding attempt failed and why such instances are so rare in marsh-nesting species. The nest size in mid-field ponds localized in northern Poland was slightly smaller than that recorded in fishponds in the Czech Republic, but larger than the records obtained in lakes in Germany and Russia.