Bermuda Petrel
(Pterodroma cahow)


Picture of bird
© Richard Crossley - License

The Bermuda Petrel is one of the rarest seabird species on the planet, thought to be extinct for 300 years. The global population is estimated at less than 200 mature individuals (BirdLife International 2019), although the population is slowly increasing as a result of intensive conservation and management efforts. Only known to nest on the Castle Harbour islands in Bermuda, recent tagging studies reveal that adults range into deep waters off eastern Canada in April and May to search for food. Data are not sufficient to determine a change in the population status in Canada relative to about 1970.


Main designations for the species
DesignationStatusDateSubspecies, population
IUCN (Global)Endangered2018 
Partners in Flight (North America)Watch list - red2017 
Wild Species (Canada)Unrankable2015 
State of North America’s BirdsWatch list2016 

Population status

Geographic area or populationPopulation change relative to ~1970ReliabilityStatus in relation to goal
CanadaData DeficientData DeficientData Deficient

Population estimate

Geographic area or populationPopulation estimate
Canada< 100 adults

Distribution maps


Migration strategy, occurrence

Seasonal visitor

Responsibility for conservation

Geographic areaResponsibility based on % of global population
CanadaTo be determined

Conservation and management

Their population is increasing due to successful conservation efforts at the breeding colony, but the extremely small population makes them vulnerable to a number of threats. The main threats to the population include the lack of suitable nesting locations, predation by introduced species, and competition for available nest sites (Madeiros 2005). Intensive management efforts that minimize predation, competition, and human disturbance, that protect and enhance breeding habitat, and that include the establishment of a new nesting colony have contributed to the recovery of this very rare species (Madeiros et al. 2014).


Bird conservation region strategies

Environment and Climate Change Canada and partners have developed Bird Conservation Region Strategies in each of Canada’s Bird Conservation Regions (BCRs). In these strategies, selected species are identified as priorities for one or more of the following reasons:

  • conservation concerns (i.e., species vulnerable due to population size, distribution, population trend, abundance, or threats)
  • stewardship responsibilities (i.e., species that typify the regional avifauna or have a large proportion of their range or population in the sub-region)
  • management concerns (i.e., species that require ongoing management because of their socio-economic importance as game species, or because of their impacts on other species or habitats)
  • other concerns (i.e., species deemed a priority by regional experts for other reasons than those listed above or because they are listed as species at risk or concern at the provincial level)

Select any of the sub-regions below to view the BCR strategy for additional details.

BCRs, marine biogeographic units, and sub-regions in which the species is listed as a priority
RegionSub-region and priority type