Black-crowned Night-Heron (Nycticorax nycticorax) William C. Scharf Status: Special Concern (MNFI) Detroit Zoo, MI. 6/11/2008 © Joan Tisdale (Click to view a comparison of Atlas I to II) Known by the elegant black and white of its Distribution Black-crowned Night-Herons in Michigan adult plumage and its red-eyed stare, the Black- historically have had their colonies along the crowned Night-Heron is a voracious and shores and islands of Lake Erie, the Detroit stealthy predator of fish, frogs, mice, and River, Lake St. Clair and Lake Huron with new especially young gulls, terns and other birds. colonies since Scharf (1998) expanding into Many potential prey animals should heed its northern Lake Michigan, Lake Huron, the St. “quawk” call in the night. A widespread species, Marys River and eastern Lake Superior. They it is found nesting on every continent except seek nesting on islands or other similar insulated Australia and Antarctica (Davis 1993). They are spots protected from predators. Twelve breeding colonial breeders, and are often found breeding colonies were documented on the Great Lakes and foraging with other species of herons as islands or along the shoreline of the NLP and well as other species of colonial nesting UP during MBBA II. This seems to indicate an waterbirds. increase in northward nesting for this species. A noteworthy coincident change has been that new Suitable wetland habitat for nesting and colonies established in Ontario are northward of foraging influences Black-crowned Night Heron the traditional nesting areas by 72 km (48 mi) distribution. Sites of Black-crowned Night (Cadman 2007). Many newer observations in Heron colonies in Michigan include Great Lakes MBBA II are from inland swamps, marshes, islands with suitable shrubs for nesting and riverine habitats, or other non-Great Lakes sites proximity to coastal wetlands. Inland swamps in the SLP, but only one of these is a confirmed and marshes continue to attract Black-crowned breeding record. Many similar inland Night-Herons during the nesting season, usually observations from MBBA I, especially in the with only small colonies confirmed away from NLP, were vacated between MBBA I and the Great Lakes in Michigan. Wintering MBBA II. distribution includes the coastal southeastern U.S. with some going as far as the Caribbean (Byrd 1978). © 2010 Kalamazoo Nature Center Black-crowned Night-Heron (Nycticorax nycticorax) William C. Scharf Status: Special Concern (MNFI) Breeding Biology supply of nestling gulls and terns occur at the Black-crowned Night-Herons are primarily same site. nocturnal. Most birds leave colony sites at night; foraging and courtship take place at night. They Conservation Needs return to the colony before sunrise (Davis 1993). Despite the increase in the number of confirmed Wetland nests near foraging sites are normal, nesting colonies cited above, the total number of but it has been shown in Wisconsin that Black- nests in MBBA II was not available for crowned Night-Herons may fly up to 24 km (14 comparison with former numbers, and MNFI mi) to feed (Hoefler 1979). Small trees and has listed Black-crowned Night-Herons as a brush such as white cedar, aspen, cottonwood, species of Special Concern. Illinois and Indiana box elder, willows, wild plum, elderberry, list them as endangered (Kleen et al. 2004 and dogwood, and mulberry are chosen nest sites. Castrale et al. 1998). The North American Trees in one colony varied in height from 11-16 Waterbird Conservation Plan (Kushlan et al. m (32-51 ft) (Hoffman and Prince 1975). In 2002) considers the continental populations of contrast, the herons have also nested in cattails Black-crowned Night-Heron to be declining. (pers. obs.). At Michigan latitudes, this species The northeastern U.S. populations have declined is single brooded, but will re-nest if disturbed or by 50% since 1970 (McGowan et al. 2008). attacked by predators. Yearling herons, with Loss of wetlands is probably the major cause of brownish streaked plumage, are known to be the species’ decline. Strict enforcement of breeders (Custer and Davis 1982), but most wetland protection, continuance of strictures birds typically breed at age two or three. The against removing vegetation near the riparian cryptic brown plumages of juvenile and first zone, and zoning to keep industrial, commercial summer birds coupled with thick vegetation and residential development away from the make them inconspicuous and hard to count. In water’s edge will preserve nesting and foraging mixed heron species colonies, Black-crowned habitat. Unfortunately, much damage to riparian Night-Heron nests are usually smaller and zones has already occurred from a variety of located closer to the trunk among the lower human impacts. The largest Black-crowned branches of trees tending to cause the censuses, Night Heron colony in Michigan, the Saginaw both aerial and ground, to underestimate their Bay CDF, has been considered for a county true numbers (Erwin 1980). park. Intensive recreational development is incompatible with colonial bird nesting. Abundance and Population Trends Records of breeding distribution in MBBA I Additionally, the prolific cormorant population show confirmed nesting in 15 townships; 4 in must be checked at some locations. Recently the UP, 6 in the NLP, and 5 in the SLP. In initiated control programs by USDA Animal MBBA II, nesting was documented in 25 and Plant Health Inspection Service personnel in townships; 10 in the UP, 8 in the NLP, and 7 in cooperation with tribal management teams and the SLP. This represents an increase of 67% Michigan DNRE biologists may accomplish since MBBA I. The state-wide increase in such reductions. This could free former habitat colonies of this species has been from the UP for Black-crowned Night-Herons at sites where and NLP. An upsurge in the number of nests to cormorants have displaced herons such as at 210 in one NLP Great Lakes colony (Cuthbert Goose Island in northern Lake Huron (pers. and Wires 2008) can be attributed to nearly obs.). The aquatic habitat that produces fish, ideal habitat at the Saginaw Bay Confined frogs, invertebrates, and, indirectly, the gull and Disposal Facility (CDF) where an increase in tern chicks that are prey for nesting herons, woody nesting vegetation and a convenient food should be monitored for ecosystem health. © 2010 Kalamazoo Nature Center Black-crowned Night-Heron (Nycticorax nycticorax) William C. Scharf Status: Special Concern (MNFI) Environment Canada, Ontario Field Due to their place high on the food chain, Ornithologists, Ontario Ministry of Natural Black-crowned Night-Herons accumulate toxic Resources, & Ontario Nature, Toronto, xxii environmental contaminants, which may have + 706 pp. caused some part of their continental decline in Castrale, J.S., E.M. Hopkins, and C.E. Keller. recent years. Added to the contaminants is the 1998. Atlas of Breeding Birds of Indiana. destruction of nesting habitat through shoreline Indiana Department of Natural Resources, development. This species’ population is still Division of Fish and Wildlife, Nongame and but a small fraction of its historical numbers Endangered Wildlife Program. Indianapolis, described by Barrows (1912) and Wood (1951) IN. who enumerated several colonies with more Custer, T.W. and W.E. Davis, Jr. 1982. Nesting than 500 nests in Michigan. Continued by one-year-old Black-crowned Night- monitoring of toxic contaminants in herons Heron on Hope Island, Rhode Island. Auk (Custer et al. 1991) and clean-ups of polluted 99:784-786. sites along the Great Lakes could aid this Custer, T.W., B.A. Rattner, M. Ohlendorf, and species. M.J. Melancon. 1991. Herons and egrets as proposed indicators estuarine contamination Monitoring Black-crowned Night-Heron in the United States. Proc. Int. Ornithol. numbers can help us follow the decline or Congr. 20:2474-2479. increase in nesting colonies in Michigan, but Davis, W.E. Jr., 1993. Black-crowned Night- ultimately, the survival of the species depends Heron (Nycticorax nycticorax). In The Birds on conserving natural diversity of coastal of North America, No. 74 (A. Poole and F. marshes, and keeping both the mainland and Gill, Eds.). Philadelphia: The Academy of island nesting sites free of toxic contaminants Natural Sciences; Washington, D.C.: The and human disturbance. American Ornithologists’ Union. Erwin, R.M. 1980. Censusing waterbird Literature Cited colonies: some sampling experiments. Trans. Linn. Soc. NY 9: 77-85. Barrows, W.B. 1912. Michigan Bird Life. Hoefler, J.E. 1979. Status and distribution of Special Bulletin. Michigan Agricultural Black-crowned Night-Herons in Wisconsin. College. Lansing, MI. Proc. Colon. Waterbird Group 3: 75-84. Byrd, M.A. 1978. Dispersal and movements of Hoffman, R.D. and H.H. Prince. 1975. six North American ciconiiforms. Pp. 161- Vegetative structure and nest distribution in 185 in Wading Birds (Sprunt et al., Eds.). a Black-crowned Night Heron heronry. Nat. Aud. Soc. Res. Rep. No. 7, New York. Jack-Pine Warbler 53: 95-99. Cuthbert, F.J. and L.R. Wires. 2008. Long-term Kleen, V.M., L. Cordle, and R.A. Montgomery. monitoring of colonial waterbird populations 2004. The Illinois Breeding Bird Atlas. in the great lakes: improving the scientific Special Publication No. 26. Illinois Natural basis for conservation and management History Survey. Champaign, IL. years 1 (2007) AND 2 (2008) Progress Kushlan, J.A., M.J. Steinkamp, K.C. Parsons, J. Report. Submitted to USFWS, Fort Snelling, Capp, M.A. Cruz, M. Coulter, I. Davidson, MN. Nov 2008. L. Dickson, N. Edelson, R. Elliot, R.M. Cadman, M.D., D.A. Sutherland, G.G. Beck, D. Erwin, S. Hatch, S. Kress, R. Milko, S. Lepage, and A.R. Couturier (eds.). 2007. Miller, K. Mills, R. Paul, R. Phillips, J.E. Atlas of the Breeding Birds of Ontario, Saliva, B. Sydeman, J. Trapp, J. Wheeler, 2001-2005. Bird Studies Canada, and K.