Migrant Common Eider, <em>Somateria mollissima</em>, Collisions with Power Transmission Lines and Shortwave Communication Towers on the Tantramar Marsh in Southeastern New Brunswick

Between 1971 and 2009, 85 dead, injured, or grounded Common Eiders, Somateria mollissima , were recorded on the Tantramar Marsh in southeastern New Brunswick, apparently the result of collisions with power transmission lines and shortwave communication towers. Of 82 location observations, 53 (65%) were near a series of power transmission lines and 21 (26%) were in the vicinity of shortwave communication towers. Of the 85 birds observed, 43 (51%) were found dead, 18 (21%) were found alive on the ground with undetermined injuries, 5 (6%) were found alive with broken wings, and 9 birds (11%) were found alive with no obvious external injuries and were released in water. A further 10 live birds (12%) were observed on small bodies of water and appeared unable to fly. Occurrences appear to be predominantly during fall migration, with most sightings recorded between 9 October and 21 December (99%, n = 73). The effects of cumulative mortality on Common Eiders should be considered if further infrastructure within the Tantramar Marsh or infrastructure involving other known overland routes used by Common Eiders during migration is proposed.