Notes on the technique of the otter field survey

摘要: Data (2083 sites visited) collected during the otter Lutra lutra (Linnaeus, 1758) survey of Poland in 1991-1994 were used to evaluate some factors affecting efficiency technique. The success detecting signs was found be significantly affected by presence "spraintable" bridges and other potential sprainting on banks. Decreased technique noted specific habitats, eg large rivers, canals surrounded open fields or meadows, any aquatic habitats with few It is suggested that modifications: spot checks at additional extended searches river banks, could improve reliability areas low numbers signs.