A generalist that forages on a variety of organisms (e.g., fish, invertebrates, amphibians, small mammals) at dawn and dusk as well as overnight, the colonial Black-crowned Night-Heron breeds in the prairies and in the Great Lakes/St. Lawrence area. The Breeding Bird Survey suggests that there has been an overall decrease in numbers since 1970, with some regional variability. This species has been identified as a priority for conservation and/or stewardship in one or more Bird Conservation Region Strategies in Canada.
The Black-crowned Night Heron’s diet of fish and other aquatic organisms leaves it vulnerable to contaminant-induced reproductive failure, although concentrations of pesticides and other industrial toxins may rarely be high enough to impede breeding (Hothem et al. 2010). Human impacts on coastal and wetland environments and the habitat alteration expected with future climate change also pose a threat (Hothem et al. 2010), while interspecific competition with Double-crested cormorants may restrict access to nesting sites and limit population growth (Cuthbert et al. 2002, Hothem et al. 2010). Management of cormorant populations on the Great Lakes can also negatively affect the Black-crowned Night-Heron, likely due to human disturbance (Wyman et al. 2018).
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:
Select any of the sub-regions below to view the BCR strategy for additional details.
