Birds of the Hackensack:

Black and Yellow-Crowned Night-Herons

 

By Ivan Kossak

 

As the day’s sun sets, two species of heron, the Black-crowned night-heron (Nycticorax nyticorax) and the Yellow-crowned night-heron (Nyctanassa violacea), stir as they prepare to forage for dinner. Black-crowned prefer fish while the Yellow-crowned’s diet consists primarily of crabs. As their names imply, these two species are more active at night, but are also fairly frequently seen about during the day.   These birds are somewhat small, stocky herons; only about half as tall as the familiar Great blue heron. The Yellow-crowned stands about 2 feet tall, with the Black-crowned only slightly taller. Both night-herons also have blunter, shorter bills than the Great blue heron. In addition to the black on the top of its head, the Black-crowned also has a black back, gray wings, a light gray neck and whitish underparts. The Yellow-crowned is mostly gray about the body with a bold black and white facial pattern topped by the namesake yellow crown. During the breeding season both species sport two long white plumes that extend back from the rear part of the crown.

Both the Black-crowned nightheron (shown above) and the Yellow-crowned nightheron are considered threatened in New Jersey.

 

In flight, one way to tell these two species apart is by the distance that their legs extend out past their bodies.  The Black-crowned’s legs barely extend beyond its tails while the Yellow-crowned has a much “leggier” appearance. Even while standing, the Yellow-crowned appears taller while the Black-crowned shows a somewhat hunchbacked posture.

 

As is the case with most herons, these birds frequent both fresh water and salt water marshes. The Yellow-crowned also roosts in wet woodlands. The Black-crowned night-heron breeds throughout most of North America, while the Yellow-crowned breeding range is restricted to the Southeast and up the Atlantic Coast as far as southern New England. In winter, both species retreat to areas of open water. During this time, The Black-crowned is more widespread in North America, being found on both the Atlantic and Pacific coasts. The Yellow-crowned’s North American winter range is restricted to Florida and both the Atlantic and Pacific coasts of Mexico.

 

Both species nest in colonies, often with other heron species. Black-crowned night-herons can be found breeding along Coastal New Jersey as well as in selected sites inland. Yellow-crowned night-herons breed in smaller numbers, mainly along a more restricted section of New Jersey’s coast. The Black-crowned night-heron and the Yellow-crowned night heron have experienced different population trends in the past hundred or so years but, sadly, neither species has enjoyed the numbers that they had boasted in the past. In fact, both species’ populations are considered threatened in New Jersey.  As with most wildlife, the primary culprit for these declining populations is loss of habitat. Thanks to the efforts of Hackensack Riverkeeper, the remaining 8,400 acres of the Meadowland’s wetlands remain undeveloped to host breeding populations of both of these striking bird species. Both species of night-heron have been frequently seen during our eco-cruises, especially in flight as the sun sets.