Hybridisation between House Martin Delichon urbicum and Sand Martin Riparia riparia: a new observation and review of past occurrences as a case study into hybrid reporting rates

摘要

Hybridisation between Barn Swallow Hirundo rustica and House Martin Delichon urbicum is well known but hybridisation between Barn Swallow and Sand Martin Riparia riparia or between House and Sand Martin has been recorded less frequently. Here, we discuss details of five UK records in the context of several historical records of putative hybrid House x Sand Martins in Europe, and suggest that there is a need for more systematic collection of data on avian hybrids.