The Great Blue Heron rookery along the Rail Trail in Methuen is buzzing with activity as many of the 30 plus nests are filled with 2, 3, and even 4 nestlings.  Typically, wing-flapping has been observed as early as the fourth week, and chicks have been observed making short hops into branches near their nest at 7 wk.  Sustained flights have been observed in Great Blue Herons around the 60 day mark.  Chicks may depart their nests around 2.5 months of age.  Young herons are far from attractive, either in appearance or behavior, at any age; at first they are feeble and helpless, but later on they are awkward, ungainly, and pugnacious. If undisturbed, they remain in the nest until as large as their parents and fully fledged; but when nearly grown they are easily frightened and leave the nest to climb awkwardly over the surrounding branches and perhaps fall to the ground or water below, which often results in death, as their parents do not seem to have sense enough to rescue or even feed them.  These nestlings should fledge very soon!