The Great Blue Heron: A Reflection of the Health of Our Waters

Out and About for Sebago Lakes Region of Maine June 26 – July 2
June 26, 2014
Maine Lakefront Property Owners Can Get Help to Stop Erosion
Maine Lakefront Property Owners Can Get Help to Stop Erosion
June 29, 2014

The Great Blue Heron: A Reflection of the Health of Our Waters

The Great Blue Heron: A Reflection of the Health of Our Waters

Great Blue Heron Stalks Its Prey

by Leigh Macmillen Hayes

Either sitting on the porch of our lakefront camp on Moose Pond in the Sebago Lakes Region or from our kayaks, we have the joy of watching wildlife up close and personal. Just this morning, the tremolo of two loons alerted me to the presence of a predator — a bald eagle was flying by, chasing a smaller bird. Yesterday, it was a large family of Canada geese parading by. And the other day, a great blue heron fishing in the cove.

 

 

 

 

 


Danielle D’Auria is a wildlife biologist with the Maine Department of Inland Fisheries and Wildlife. Since 2009, MDIFW has tracked great blue heron colonies to better understand their statewide population status. Recently, she shared this information with us:
Mention the great blue heron and you undoubtedly envision a large bird with long legs and neck, knee-deep in water slowly stalking its prey. In the spring and summer, you may have the pleasure of viewing Maine’s largest wading bird feeding amongst the cattails in the marsh or along the shallow shoreline of the lake. These wetland icons also rely on trees, both live and dead, for nesting. They build large platform stick nests 8-100 ft up in trees and nest in groups or colonies. Chances are the herons you see feeding nest in a colony within 2.5 miles, a distance they don’t mind traveling in order to find a good meal for themselves and their young.
In Maine, nesting colonies occur on coastal and freshwater islands, in beaver flowages, and in upland settings. Their nests are built in hardwoods and softwoods and can be in live, dead, or dying trees. Great blue heron colonies may contain a few pairs to over a hundred, often with multiple nests occupying the same tree. Colony habitat preference is not completely understood, but they are most often located within 2.5 miles of several important feeding wetlands; in areas with few roads and little human disturbance; and within large contiguous forest stands. Nesting in colonies helps in terms of predator avoidance, but also makes them vulnerable to disturbance and habitat loss. Thus, impacts to the colony and even brief disturbance events near or in the colony can affect dozens of breeding pairs.
Maine’s great blue herons migrate south in winter to find ice-free feeding areas. As early as mid-March they begin to return, and by mid-April many are building nests. Individuals tend to return to the same colony location each year. In Maine, some colonies have persisted for several decades.
During the nesting season (1 April–15 August), the birds are extremely sensitive to disturbances caused by human intrusion, noise and predators, and may even abandon a colony as a result. Their sensitivity varies in relation to the stage of breeding; the intensity, duration, and proximity of a new activity; woodland buffers or topography; and pre-existing uses on adjacent lands. The three most sensitive periods tend to be just before incubation (early May) and after the young are between 4-6 weeks old (late June) and nearing fledging (late July).
The adults and young have extremely high energetic demands during the nesting period. The reproductive success of great blue herons is limited by the parents’ ability to gather food. For this reason, herons have a high fidelity to feeding sites, especially if the food source remains rich at these sites over time. Foods include fish, invertebrates, amphibians, reptiles, small mammals and young birds. They are most commonly observed feeding in shallow wetlands or along shallow shorelines, both freshwater and saltwater, but will also forage in grasslands.
Herons are strictly carnivorous and are near the top of the wetland food chain, making them important biological indicators of the health of our waters. It is important to protect the wetlands these birds depend on for nesting and foraging. Beaver flowages need beavers to maintain them; allowing beavers to persist in these areas to some extent will help maintain stable water levels. Landowners can protect wetlands and streams and shorelines of lakes and ponds by adopting land use practices that protect water quality, limit erosion, and conserve native wildlife and vegetation.
Perhaps the next time you see a great blue heron, you will also envision the rich waters in which it finds food and the relative quiet in which it chooses to nest, and consider yourself lucky.
If you find a great blue heron nest, please contact Danielle at 207-941-4478. For more information about this effort, visit the Heron Observation Network of Maine’s blog at http://maineheron.wordpress.com.
To learn more about lakefront properties for sale on Moose Pond in Bridgton, click on the green box above.
To learn more about Moose Pond and Bridgton, check out these blog links.
Moose Pond in the Sebago Lakes Region of Maine, Offers Views, Fishing, Recreation and Clean Water
Hikes Near Lakefront Property in Bridgton, Maine
Bridgton, Maine, Offers Plenty To Do Throughout the Year

 

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