Sunday, August 22, 2021

Osprey Overlook Park: Weymouth Back River salt marshes with nesting poles

Upper tidal marsh with nesting pole seen from the Osprey Overlook just south of the Great Esker Park
The osprey is found in a wide variety of habitats—as long as the habitat is situated near a body of water. The coastal brackish waters of the Weymouth Back River southeast of Boston in Massachusetts are such a place. This habitat provides the favorite diet of the piscivorous bird: fish, herring in particular. The man-made nesting poles therein attract osprey pairs to come for breeding in spring and stay over the summer to raise their chicks.

Osprey nesting pole
The Osprey Overlook Park is part of the Back River parklands, which include the Great Esker Park north of the overlook. The loop trail around the overlook hill takes you close to the upper tidal marshes and river banks. Standing on top of the hill allows a survey of the salt marsh scenery around the confluence point of the Fresh River and the Mill River. Two osprey nesting towers can clearly be spotted. When I was visiting in early August 2021, both nests were occupied. One osprey was circling above the overlook area—its white underparts with patterns of brown streaks nicely visible.  

The overlook site features an informative panel touching on various aspect of Back River osprey life. Extractions of the panel text are given in the following.   

 

About habitat and diet:

Osprey are often found near water bodies as their diet consists almost exclusively of live fish (99 percent). The Back River is particularly productive for osprey due to its strong herring run—one of the few sources of food for osprey in the early spring. In fact, a healthy osprey population is considered a strong indicator of healthy, productive fisheries, which in turn mean productive estuaries and bay waters.


About tree-nesting:

Like many Massachusetts bird species, osprey are tree-nesters meaning they build and spend their resting time in nests high above the ground, often over water. Their conspicuous stick nests are often constructed atop dead trees, channel markers, cell or radio towers, and even utility poles. In effort to attract nesting pairs to the Back River, several manmade towers have been maintained in the salt marshes since the 1990s, providing safe places for the birds to raise newborn chicks.


About mating and migration:

Osprey mate for life and will return to their nesting sites year after year. Typically they arrive in Massachusetts in late March or early April. The males gather sticks and other materials (grass or seaweed, for example) to construct the nests while the females complete the actual construction. A nest can be as large as four feet across and three feet deep. Hatching typically occurs in late May or early June. Come September, the birds leave Massachusetts to migrate as far south as Brazil, spending their winters in South America. Osprey make this trip in about two to three weeks.


Getting there

The entrance of the Osprey Overlook Park is located at the end of Wharf Street in Weymouth, Massachusetts. It can also be accessed from the north via the Back River Trail through abutting Great Esker Park.


Kajakers visiting the Osprey Overlook area

 

More to explore

Osprey Overlook Park. North and South Rivers Watershed Association. URL: https://www.nsrwa.org/listing/osprey-overlook-park/.

Osprey Overlook and Great Esker Park. The Wine-Dark Sea, May 5, 2020. URL: https://www.thewinedarksea.com/2020/05/05/osprey-overlook-and-great-esker-park/.

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