Ancient murrelet Synthliboramphus antiquus population increases and Cassin’s auklets Ptycgoramphus aleuticus re-establish on Langara Island, Canada, following the eradication of brown rats Rattus norvegicus

  • Published source details Regher H., Rodway M., Lemon M. & Hipfner J. (2007) Recovery of the Ancient Murrelet Synthliboramphus antiquus colony on Langara Island, British Columbia, following eradication of invasive rats. Marine Ornithology, 35, 137-144


This study is summarised as evidence for the following.

Action Category

Control mammalian predators on islands for seabirds

Action Link
Bird Conservation
  1. Control mammalian predators on islands for seabirds

    A controlled before-and-after study on Langara Island (3,270 ha), British Columbia, Canada (Regher et al. 2007), found that the estimated population of ancient murrelets Synthliboramphus antiquus increased from 13,000 (1999) to 24,000 (2004), following the eradication of brown rats Rattus norvegicus in 1995 through brodifacoum poisoning. This followed a period of population decline between 1981 and 1999. On islands without eradication programmes (and on Langara Island between 1981-99), ancient murrelet populations declined if rats were present (22% over ten years on Lyell Island, 50% over seven years followed by extirpation on Kunghit Island) and were stable or increasing on islands without rats. A population of Cassin’s auklets Ptychoramphus aleuticus (previously extirpated on Langara) also re-established following rat eradication.


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