An online resource based on the award-winning nature guide

Herons

Fishing Methods Of Birds With Spear-shaped Bills

10-10-17 great blue heron with fish 049A5631How do herons, egrets, bitterns, kingfishers, loons and other fish-eating birds with spear-shaped bills capture their prey? Do they use their bill as a spear and pierce through a fish, or do they grab the fish between their mandibles? You often read about one of these birds “spearing” a fish. However, a majority of these birds, most of the time, do not spear fish, but open and shut their bills fast enough to capture a fish in them — the spear shape of their bill lends itself to the tong-like action it performs. In addition, its shape enhances the movement of the bill through the water as the bird dives (its head or body) into the water to grasp the fish between its upper and lower mandibles.

One exception to this rule is the Anhinga, which does run its bill (which is equipped with backward grooves to prevent slippage) through fish in order to capture them. After spearing a fish, an Anhinga then shakes it vigorously off its bill, tosses it in the air, and catches and swallows it headfirst. (Photo: Great Blue Heron)

 

 

 

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Green Heron Feet

8-9-17 green heron feet2 049A1710The structure of a Green Heron’s foot lends itself to a life of wading at the water’s edge while foraging for food and not sinking into the sand. Three long toes pointing forward and one pointing backward create a considerable amount of surface area, and the more the surface area the less pressure that is placed on the sand. Webbing between its outer toes adds to the snowshoe effect (and also aids the heron when it dives below the surface of the water for prey and must swim back to shore).

This foot structure comes in handy when wading in shallow water, standing on emergent vegetation or perched a low-hanging branch at the water’s edge. As testimony to this, the pictured Green Heron spent an entire morning navigating from water lily pad to water lily pad foraging for fish, insects, frogs and other aquatic life.


Snowy Egrets Becoming More Colorful

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For those New Englanders fortunate enough to live on the coast, Snowy Egrets are a welcome sight this time of year as they return from their wintering grounds to breed. Like most herons and egrets, they acquire plumes – long, wispy feathers – on their back, neck and head during the breeding season. (These plumes were highly sought after by the women’s hat trade in the late 1800’s and early 1900’s. They were valued at $32 per ounce, twice the price of gold at the time. Eventually laws were passed to protect the birds.)

Something slightly more subtle but equally as dramatic as ornate plumage highlights the appearance of these birds in the breeding season and that is a change in bill and feet coloration. Different species of herons and egrets exhibit different color changes. Snowy Egrets’ greenish-yellow feet turn a much richer orange-yellow hue during the breeding season, and the patch of bare skin at the base of their bill (lore) changes from a yellowish color to a pinkish/reddish color, only seen at this time of year.

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Silver Lining to Low Water Levels

9-27-great-blue-heron-20160911_7746The low water level of most small ponds and streams this fall has at least one silver lining, and that is that consumers of fish and other aquatic creatures expend far less energy finding prey, for it is all concentrated in much smaller bodies of water. The few puddles of water in small streams contain a vast amount of life, as do small ponds.

The Great Blue Heron has the advantage of having a varied diet that is found in a variety of habitats, so it forages in grasslands, marshes, intertidal beaches, riverbanks and ponds. While amphibians, invertebrates, reptiles, mammals, and birds are all known to have been eaten by Great Blue Herons, fish are their mainstay. They often forage in ponds, where they typically wade or stand in wait of prey in shallow water, which has not been in short supply this summer and fall. While the low water level is wreaking havoc with beavers and muskrats, it provides bountiful fuel for herons, egrets, kingfishers and other birds that forage in small ponds and streams as they wend their way southward.

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Green Herons Migrating

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Green Herons (Butorides virescens) are small, crested, wading birds that inhabit wetland thickets throughout most of North America. After breeding, most tend to wander to more favorable foraging areas before migrating south to Florida, Central and South America. Migration begins in late August/early September and by mid-October, most Green Herons have departed.

Green Herons are among the few species of birds that use tools in order to lure fish to within their striking distance. Bread, mayflies, twigs, leaves, berries, earthworms and feathers are among the lures they have been observed dropping into the water as bait. To watch a video of a persistent and successful Green Heron fishing with a lure, go to https://www.youtube.com/watch?v=Porp5v5lLKk .

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Juvenile Green Herons Becoming Independent

8-4-15 juv. green heron IMG_5807Green herons are typically solitary and secretive birds, but if you find one, you often have an extended period of time to observe it, as they often slowly stalk their prey, or pose statue-like, sometimes for minutes at a time, while waiting to strike at a fish, frog or invertebrate. Three characteristics tell you that the green heron in this photograph is a juvenile: the few tufts of down that remain on its head, its streaked neck (adults have solid rufous necks) and its yellow legs (adults have orange legs).

After fledging when about three weeks old, they can soon fly. The juvenile fledglings continue to be fed by the adults for a period of time and are taught how to forage for fish. Green herons are one of very few bird species that are known to occasionally use a tool (insects, earthworms, twigs, feathers) to catch their food – they simply drop the lure and wait for small fish to appear. (A wonderful video of a green heron successfully using bread for this purpose can be seen at https://www.youtube.com/watch?v=Porp5v5lLKk.)

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Great Blue Herons Mating

4-15-15  great blue herons copulating2  IMG_8954Great Blue Herons have returned to their nesting colonies in the Northeast and their breeding season is underway. These birds are monogamous for the duration of any given breeding season. A study found that most Great Blue Herons choose a new mate every year. After elaborate courtship displays have taken place, the pair copulates, frequently on the nest, and usually in the early morning or evening, as the female is away from the nest mid-day.

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