Black-crowned Night Heron, Nycticorax nycticorax
Black-crowned Night Heron, Nycticorax nycticorax hoactli, Juvenile. Photographs taken off a dock in Puerto Adolfo Lopez Mateos, May 2017.
Black-crowned Night Heron, Nycticorax nycticorax hoactli. Photographs taken in the greater Zihuatanejo area, Guerrero, March 2018. Photographs courtesy of Ron Woheau, Zihuatanejo.
Black-crowned Night Heron, Nycticorax nycticorax hoactli. Birds photographed in the greater Mexico City area, March 2021. Photographs and identification courtesy of Marina Sutormina, Stockholm, Sweden.
Black-crowned Night Heron, Nycticorax nycticorax hoactli. Bird photographed in the coastal region of San Diego, California, February 2017.
The Black-crowned Night-Heron, Nycticorax nycticorax hoactli, is one of four subspecies of Black-crowned Night-Heron one of which is found in Mexico. They are a member of the Ardeidae Family of Herons, Egrets and Bitterns, which has forty-nine members placed in fourteen genera, and one of five global species of the Nycticorax Genus. They are known in Mexico as martinet común.
The Black-crowned Night-Heron is mid-sized in stature with a stocky build with a relatively short neck and legs. The sexes appear similar, but the males are larger than the females. The adults have a distinctive black cap, upper back and scapulars, gray wings, rump and tail and a white head and neck sides, and white to pale gray underparts. Their bill is stout with upper mandible being entirely black during breeding season and is olive green when not breeding and the lower mandible is black, their iris is bright red, and their legs are yellow-green when not breeding.
The Black-crowned Night-Heron are found in a wide variety of habitats including fresh, brackish or saltwater environments in areas with aquatic vegetation or on forested margins of shallow rivers, streams, lagoons, pools, ponds, lakes, swamps, marshes and mangroves. They are also common in zones of human habitation. They are opportunistic forages that feed on a wide variety of terrestrial and marine organisms that include birds, crayfish, fish, large aquatic insect larvae and mammals. They are also known to practice cannibalism on small nestlings. They roost large groups that can number a thousand individuals. They are opportunistic forages that feed on a wide variety of terrestrial and marine organisms that include birds, crayfish, fish, large aquatic insect larvae and mammals. They are also known to practice cannibalism on small nestlings.
The Black-crowned Night-Heron is found throughout Mexico during the winter months, primarily in coastal regions at elevations below 4,800 m (15,700 feet). Their migrations patterns vary depending on climate and food availability moving either short distances or long-distances and some populations are non-migratory.
The Black-crowned Night-Heron is a straightforward identification but is similar in size and appearance to the Yellow-crowned Night-Heron, Nyctanassa violacea (yellow-crown and bold black and white face).
From a conservation perspective the Black-crowned Night Heron is currently considered to be of Least Concern with stable, widely distributed populations. In some regions their populations are decreasing but in North America populations are increasing. They are utilized as environmental indicators and an indicator of estuarine contamination by herbicides, pesticides and heavy metals. Their long-term viability is threatened by habitat destruction.