MORRISTOWN — Blue herons are back at their rookery on the Red Barn Preserve in Morristown.

The rookery has over 60 active nests and has been home to the birds for many years. Hikers and bird watchers can observe the birds along the Blue Heron Hiking Trail established last year by the Morristown Gateway Museum.

The preserve is at 518 River Road East, between the village of Morristown and Jacques Cartier Park. It is a one quarter mile hike from the entrance of the farm property back to the boardwalk viewing area. Visitors should bring waterproof footwear, warm hiking clothes and binoculars. The nests are about 500 feet from the trail at the end of a large pond.

While Blue herons are not uncommon to see in the North Country, it is uncommon to see their nesting sites known as rookeries. No more than two are known in the North Country, according to Chris Coffin of Morristown Gateway Museum and Red Barn Preserve.

This species breeds in colonies, in trees close to lakes or other wetlands. Adults returned to the colony site after winter and arrived at the Red Barn Preserve Rookery at the end of March. Nests are often reused for many years, he said.

According to Wikipedia, herons are socially monogamous within a single breeding season, individuals usually choose new mates each year. Males arrive at colonies first and settle on nests, where they court the females; most males choose a different nest each year.

The female lays three to six, pale blue eggs. The incubation period is approximately 27 days. During that time the males will sit on the nest for 10 hours a day and the female the remainder of the time.

The first chick to hatch usually becomes more experienced in food handling and has aggressive interactions with siblings- this results in the chick growing more quickly than the other chicks. Both parents feed the young at the nest by regurgitating food. By the time the birds are 45 days old they weigh about 85% of an adult weight. After 55 days young herons take their first flight. They return to the nest to be fed for another 3 weeks. They begin to follow adults to foraging areas and gradually disperse from their original nest.

Adult herons, due to their size, have few natural predators, but blue heron eggs and young birds are taken by turkey vultures, crows, black bears and raccoons.

The Gateway Museum is a not for profit organization located in Morristown New York. Additional information about the museum and the Red Barn Preserve can be found at the museum’s website: www.morristowngatewaymuseum.org.