Wrentham Home to the Great Blue Heron

 On a humid but breezy Sunday afternoon, a group of thirty naturalists, bird enthusiasts, and simply the curious followed noted wildlife expert Peter Alden (pictured)on a hike to gaze upon the local colony of great blue herons. The hikers' ages ranged across a wide spectrum of decades and all were treated not just to the sight of a relatively large heron rookery, but they were also entertained and educated about the local plant life and the conditions that may have led to the development of the spring and early summer homes of the herons.

The hike started in the parking lot at the end of Elysium Street, at the Wollomonopoag Conservation Area, and followed a dirt path that descended towards a large beaver pond. Along the way, Alden would spot and discuss local plants like sassafras, spotted wintergreen, club moss, and huckleberry. He explained the increase in mid-sized carnivores in this area such as the fisher. "We've had an explosion of carnivores," Alden said in large part to the passing of the legislation in the 1990s to reduce trapping. He pointed out witch hazel and the American chestnut which he called an extinct tree because of its inability to grow to maturity due to a blight that kills it once it flowers. "At one time the American chestnut tree made up close to 25% of our forests," he said.

The trail leveled off and led to a large pond that was built by beavers. Alden explained that when the beaver constructs its damn, the water level in the pond rises and this kills the trees rooted in the pond. The tops of the dead trees are where the great blue heron makes giant stick nests which are clearly visible from the path running along the pond. The site seemed almost Triassic with the great blue herons taking on the roll of the pterodactyl with its seven foot wing span and long beak. The nests at this time contained babies which probably number around 4 offspring. "This is a healthy colony," Alden said. 

While the rookery (pictured)had a prehistoric appearance, it is a relatively new sight today. "They were very rare 50 years ago," Alden said. The Wrentham rookery held about 38 nests. The giant birds will abandon their Wrentham home in July but will hopefully return the following March. Alden says that about 100 towns in Massachusetts are home to great blue heron colonies.
 
The walk and talk lecture was arranged by the Open Space Committee and funded by the Sweatt Fund. There will be future lectures on falconry and edible plants as well as a presentation on bees this Wednesday, June 9 at 7:30 pm at Fiske Public Library.