American Bittern
(Botaurus lentiginosus)

Summary

Picture of bird
© Tony Battiste
For additional photos and vocalizations, visit Dendroica. (Link opens in a new window.)

Highly dependent on wetlands throughout its annual cycle, the American Bittern population showed a sharp decrease in Canada in the 1970s that has been linked to habitat loss and degradation (Lowther et al. 2009). Results from the Breeding Bird Survey indicate that the decrease ended by the mid-1980s and, during the most recent years, the population has increased slightly. The American Bittern’s elusive behaviour means that the magnitude of long-term change remains somewhat uncertain, but overall, the national population has shown little change relative to 1970. This species has been identified as a priority for conservation and/or stewardship in one or more Bird Conservation Region Strategies in Canada.

Designations

Main designations for the species
DesignationStatusDateSubspecies, population
IUCN (Global)Least concern2018 
Wild Species (Canada)Secure2015 
Bird Conservation Region StrategyPriority Species2013 

Population status

Geographic area or populationPopulation change relative to ~1970ReliabilityStatus in relation to goal
CanadaLittle ChangeHighAt an Acceptable Level
 

Population estimate

Geographic area or populationPopulation estimate
CanadaNot yet available
 

Distribution maps

 

Migration strategy, occurrence

Short-distance migrant

Responsibility for conservation

Geographic areaResponsibility based on % of global population
CanadaTo be determined

General nesting period in Canada

Nesting period starts between late April and late May and ends between mid-July and late July, depending on the region. Before or after this period, the probability of an active nest is lower.
 

Conservation and management

The American Bittern is an area-sensitive, marsh-nesting obligate (Brown and Dinsmore 1986). Given its reliance upon freshwater wetlands during both the breeding and non-breeding seasons, the American Bittern is highly sensitive to habitat change (Lowther et al. 2009). Broad-scale declines across the United States have been attributed to the loss of many important wetlands and to degradation or contamination of remaining marshes (Lowther et al. 2009); similar habitat changes may be impacting Canadian breeders (Timmermans 2007). Additional insight into the basic ecology and habitat requirements of this secretive species is needed to identify the factors involved in population regulation, and to address the possibility that severe wetland loss and degradation in the United States may be driving the population northward (Lowther et al. 2009).

 

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
Atlantic Northern ForestsAtlantic Northern Forests, sub-region and priority type: Atlantic, NB -- Other
Atlantic Northern ForestsAtlantic Northern Forests, sub-region and priority type: Atlantic, NS -- Other
Atlantic Northern ForestsAtlantic Northern Forests, sub-region and priority type: Atlantic, PE -- Other
Atlantic Northern ForestsAtlantic Northern Forests, sub-region and priority type: Quebec -- Other
Boreal Hardwood TransitionBoreal Hardwood Transition, sub-region and priority type: Quebec -- Other
Boreal Softwood ShieldBoreal Softwood Shield, sub-region and priority type: Atlantic, NL -- Other
Boreal Softwood ShieldBoreal Softwood Shield, sub-region and priority type: Ontario -- Conservation
Boreal Softwood ShieldBoreal Softwood Shield, sub-region and priority type: Prairie and Northern -- Conservation
Boreal Softwood ShieldBoreal Softwood Shield, sub-region and priority type: Quebec -- Other
Boreal Taiga PlainsBoreal Taiga Plains, sub-region and priority type: Prairie and Northern -- Conservation
Great BasinGreat Basin, sub-region and priority type: Pacific and Yukon -- Other
Lower Great Lakes/St. Lawrence PlainLower Great Lakes/St. Lawrence Plain, sub-region and priority type: Ontario -- Conservation
Lower Great Lakes/St. Lawrence PlainLower Great Lakes/St. Lawrence Plain, sub-region and priority type: Quebec -- Other
Northern Pacific RainforestNorthern Pacific Rainforest, sub-region and priority type: Pacific and Yukon -- Other
Northern RockiesNorthern Rockies, sub-region and priority type: Pacific and Yukon -- Other
Prairie PotholesPrairie Potholes, sub-region and priority type: Prairie and Northern -- Other
Taiga Shield and Hudson PlainsTaiga Shield and Hudson Plains, sub-region and priority type: Ontario -- Conservation
Taiga Shield and Hudson PlainsTaiga Shield and Hudson Plains, sub-region and priority type: Prairie and Northern -- Conservation
Taiga Shield and Hudson PlainsTaiga Shield and Hudson Plains, sub-region and priority type: Quebec -- Other
 

References