Yellow-crowned Night Heron

The Yellow-crowned Night Heron’s striking breeding plumage offsets its preference for dark, forested wetland gloom. It specializes in crustaceans, particularly crabs (Watts 2020). Like other herons, they are colonial breeders, but they nest in scattered, small colonies or as isolated pairs, often around urban reservoirs and in residential neighborhoods. In coastal Virginia, more than 95% of the active nests found between 1986 and 1987 were in loblolly pine (Pinus taeda) (Watts 1989).

Breeding Distribution

Within the Coastal Plain, the Yellow-crowned Night Heron was well-covered during the Second Atlas by the 2018 Virginia Colonial Waterbird Survey, a coastal census conducted by the Center for Conservation Biology in collaboration with the Virginia Department of Wildlife Resources and The Nature Conservancy. The survey identifies nesting locations of this and other species that breed in colonies. Therefore, there was no need to model its distribution within that region. For information on where the species occurs in Virginia’s Coastal Plain, please see the Breeding Evidence section.

Outside of the Coastal Plain, Yellow-crowned Night Herons are found in small patches in the Northern Virginia area and near the city of Roanoke (Figure 1). The likelihood of Yellow-crowned Night Heron occurrence is slightly positively associated with developed cover as this species is adaptable to urban environments and capable of persisting in areas where they are disturbed or even harmed, unlike many other colonial waterbirds.

 

View Environmental Associations

Figure 1: Yellow-crowned Night Heron breeding distribution based on probability of occurrence (Second Atlas, 2016–2020). This map indicates the probability that this species will occur in an Atlas block (an approximately 10 mi² [26 km²] survey unit) based on environmental (including habitat) factors and after adjusting for the probability of detection (variation in survey effort among blocks). Blocks in gray are outside the species' core range and were not modeled.

Breeding Evidence

Given that the locations of nesting colonies were documented by the Virginia Colonial Waterbird Survey in 2018, Yellow-crowned night Herons in the Coastal Plain are unlikely to have nested in blocks without confirmed breeding evidence. There were additional breeding confirmations reported by Atlas volunteers in other years of the Second Atlas period. Outside of the Coastal Plain, where there is no systematic survey to identify nesting colonies, the nesting status of the species in blocks without confirmed breeding evidence is less clear.

Yellow-crowned Night Herons were confirmed breeders in 34 blocks and 11 counties and were probable in an additional two counties (Figure 2). In the Coastal Plain, most records were from six cities in the Hampton Roads area: Chesapeake, Hampton, Newport News, Norfolk, Portsmouth, and Virginia Beach. The densest concentrations of nests were in urban residential neighborhoods here (Watts et al. 2019). They also bred on Tangier and Watts Islands in Accomack County and on several barrier islands in Northampton County. Away from the coast, they bred around reservoirs and urban streams in Fairfax County in the Piedmont. In the Mountains and Valleys region, they nested in Roanoke and Salem. Thus, this species was observed breeding in all major physiographic regions of the state, with obvious clusters in these regions during both Atlas periods (Figures 2 and 3).

Nest building was observed beginning in late March and continued through mid-June (Figure 4). Young were in the nest starting in mid-May through July 6, and fledglings were observed through July 31. For more general information on the breeding habits of the Yellow-crowned Night-Heron, please refer to All About Birds.

Figure 2: Yellow-crowned Night Heron breeding observations from the Second Atlas (2016–2020). The colored boxes illustrate Atlas blocks (approximately 10 mi² [26 km²] survey units) where the species was detected. The colors show the highest breeding category recorded in a block. The numbers within the colors in the legend correspond to the number of blocks with that breeding evidence category. Nesting is unlikely outside of confirmed blocks.

Figure 3: Yellow-crowned Night Heron breeding observations from the First Atlas (1985–1989). The colored boxes illustrate Atlas blocks (approximately 10 mi² [26 km²] survey units) where the species was detected. The colors show the highest breeding category recorded in a block. The numbers within the colors in the legend correspond to the number of blocks with that breeding evidence category.

Figure 4: Yellow-crowned Night Heron phenology: confirmed breeding codes. This graph shows a timeline of confirmed breeding behaviors. Tick marks represent individual observations of the behavior.

Population Status

The Yellow-crowned Night Heron had too few detections during the Atlas point count surveys to develop an abundance model. However, the distribution and size of Yellow-crowned Night Heron colonies derived from the 2018 Virginia Colonial Waterbird Survey are displayed on the CCB Mapping Portal.

Virginia’s Colonial Waterbird Surveys show that in coastal Virginia, from 1993–2018, Yellow-crowned Night Herons increased by 55% from 388 to 602 pairs, which is a 55% increase (Watts et al. 2019). In 2023, the estimated number of breeding pairs rose to 650, an 8% increase between 2018 and 2023 (Watts et al. 2024). These estimates do not include inland populations.

Figure 5: Yellow-crowned Night Heron population trend for Virginia’s Coastal Plain. This chart illustrates the number of breeding pairs as estimated by the Virginia Colonial Waterbird Survey (Watts et al. 2024). A data point is not included for 1998, as the Survey covered a smaller geographic area in that year. The vertical light blue bars represent the periods corresponding to the First Atlas (1985–1989) and Second Atlas (2016–2020).

Conservation

Yellow-crowned Night Heron populations are apparently stable in Virginia, but they are vulnerable to habitat loss due to development, sea-level rise, and marsh loss. Because most of the population breeds in urban neighborhoods, there is also potential for human-wildlife conflict. Dedicated management strategies that partner with communities and residents should be prioritized.

Interactive Map

The interactive map contains up to six Atlas layers (probability of occurrence for the First and Second Atlases, change in probability of occurrence between Atlases, breeding evidence for the First and Second Atlases, and abundance for the Second Atlas) that can be viewed one at a time. To view an Atlas map layer, mouse over the layer box in the upper left. County lines and physiographic regional boundaries (Mountains and Valleys, Piedmont, and Coastal Plain) can be turned on and off by checking or unchecking the box below the layer box. Within the map window, users can hover on a block to see its value for each layer and pan and zoom to see roads, towns, and other features of interest that are visible beneath a selected layer.

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References