Summary

Multi-year monitoring (1958–1998) of avian fauna in a study area at the “Zhemchuzhny” Rice Farm near the city of Arseniev (Primorsky Terrritory) allowed for exact dating of the emergence (in 1984) and disappearance (in 1989) of an isolated settlement of reed parrotbill Paradoxornis heudei. Such short-time existence of this enclave is explained by its low ecological capacity: systematic burning of reeds, especially in autumn, and probably predation by Eurasian sparrowhawk in wintertime. This paper presents a chronology of all encounters with these birds and observations of their habits and behavior. A focus is made on their «loneliness syndrome» behavior caused by loss of a partner mate which is characterized by very intensive flying activities including flights far beyond typical habitats. It was shown that “the ecological corridor”, through which the birds of the Khanka population managed to reach the intermontane trough in the inner area of Sikhote-Alin Mt. Range earlier inaccessible due ecological reasons, and for this population might have been the treeless strip along the railroad and highway some 40 km long.