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Contact information
For information on Wisconsin's rare vertebrate animals, contact:
Rich Staffen
Conservation Biologist
For information on Wisconsin's rare invertebrates, contact:
Jay Watson
Conservation Biologist

Yellow-crowned Night-Heron (Nyctanassa violacea)



Yellow-crowned Night-Heron (Nyctanassa violacea), listed as Threatened in Wisconsin, is found in swamps and river bottomlands. The required avoidance period is May 10 to August 1.

State status

Status and Natural Heritage Inventory documented occurrences in Wisconsin

The table below provides information about the protected status - both state and federal - and the rank (S and G Ranks) for Yellow-crowned Night-Heron (Nyctanassa violacea). See the Working List Key for more information about abbreviations. Counties shaded blue have documented occurrences for this species in the Wisconsin Natural Heritage Inventory database. The map is provided as a general reference of where occurrences of this species meet NHI data standards and is not meant as a comprehensive map of all observations.

Note: Species recently added to the NHI Working List may temporarily have blank occurrence maps.

Documented locations of Nyctanassa violacea in the Natural Heritage Inventory Database as of July 2015.
Summary Information
State StatusTHR
Federal Status in Wisconsinnone
State RankS1B
Global RankG5
Tracked by NHIY

Species guidance

Yellow-crowned Night-Heron (Nyctanassa violacea) has very few known occurrences in the state and is of the highest priority for conservation; we encourage you to consult with your District Ecologist or an NHI Zoologist for specific recommendations for your site.

Note: a species guidance document is not available at this time. Information below was compiled from publication ER-091.

Identification: Adult has all gray body. Distinct head markings include a black head with a whitish crown and cheek patch. Fairly long yellow legs are also distinguishing field marks.

Habitat: Ponds, wooded swamp, riparian forest, and lowland deciduous forest.

State Distribution: Uncommon migrant south, rare migrant central. Rare summer resident south and central. Extends northward in the state along major river valleys, including those of the Mississippi and Wisconsin rivers, as well as the smaller Wolf River. They are limited to very large tracts of forest habitat, and are known from only about six breeding populations. A map outlining Pre-1977 and 1997 to Present Distribution is available.

Diet: Mainly crayfish; also mussels, frogs, aquatic insects, snails, small snakes, and leeches.

Clutch: 4-5 pale blue-green eggs; laid from May to June.

Incubation: 21-25 days, by both parents. Young fledge 25 days after hatching.

Nest: Sturdily built of sticks and twigs lined with grass, leaves, reeds, and fibrous roots; 30-40 feet above ground or lower.Mainly crayfish; also mussels, frogs, aquatic insects, snails, small snakes, and leeches.

Management Guidelines: This species is vulnerable to habitat fragmentation; requires extensive, mature floodplain forests. Nest abandonment can be avoided by preventing human encroachment into nesting areas during the breeding season. Yellow crowns forage in open water, mud flats, and in partially submerged vegetation; the species requires shallow water habitats with an abundance of aquatic invertebrates.Mainly crayfish; also mussels, frogs, aquatic insects, snails, small snakes, and leeches.



Yellow-crowned Night-Heron

Photo © Nick Anich.

Yellow-crowned Night-Heron

Photo © Nick Anich.

Yellow-crowned Night-Heron

Photo © Len Blumin.

Wildlife Action Plan

Wisconsin Wildlife Action Plan graphic

Natural community (habitat) associations

The table below lists the natural communities that are associated with Yellow-crowned Night-Heron. Only natural communities for which Yellow-crowned Night-Heron is "high" (score=3) or "moderate" (score=2) associated are shown. See the key to association scores for complete definitions. Please see the Wildlife Action Plan to learn how this information was developed.

Ecological landscape associations

The table below lists the ecological landscape association scores for Yellow-crowned Night-Heron. The scores correspond to the map (3=High, 2=Moderate, 1=Low, 0=None). For more information, please see the Wildlife Action Plan.

This map shows the probability of Yellow-crowned Night-Heron occurring in each of Wisconsin's Ecological Landscapes.  Actual scores can be found in the table to the left.

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Landscape-Community combinations of highest ecological priority*

Ecological priorities are the combinations of natural communities and ecological landscapes that provide Wisconsin's best opportunities to conserve important habitats for a given Species of Greatest Conservation Need. The 10 highest scoring combinations are considered ecological priorities and are listed below. More than 10 combinations are listed if multiple combinations tied for 10th place. For more information, please see the Wildlife Action Plan.

* Ecological priority score is a relative measure that is not meant for comparison between species. This score does not consider socio-economical factors that may dictate protection and/or management priorities differently than those determined solely by ecological analysis. Further, a low ecological priority score does not imply that management or preservation should not occur on a site if there are important reasons for doing so locally.

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Issues/threats and conservation actions

Conservation actions respond to issues or threats, which adversely affect species of greatest conservation need (SGCN) or their habitats. Besides actions such as restoring wetlands or planting resilient tree species in northern communities, research, surveys and monitoring are also among conservation actions described in the WWAP because lack of information can threaten our ability to successfully preserve and care for natural resources.

Threats/issues and conservations actions for rare animals

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Last revised: Thursday, October 08, 2020