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Posts tagged “Herons

How Great Blue Herons Stay Cool

Birds have a number of ways of keeping cool, which is a good thing,  given the number of hot days we’ve experienced this summer, and probably for summers to come.  They don’t sweat, nor do they pant, but birds do have several  behavioral adaptations which reduce their temperature.  Often, while exposed to the relentless heat of the sun, Great Blue Heron nestlings resort to what is called gular fluttering.  They open their mouths and “flutter” their  neck muscles, promoting heat loss – an avian version of panting.   An even easier behavior to observe is the position Great Blue Herons will often assume on a hot day.  They droop their wings (see photograph) while standing, which allows air to circulate across their body and sweep away the excess heat.


Great Blue Heron Fishing

Although Great Blue Herons are colonial nesters, they forage by themselves, usually by slowly wading or standing in wait of prey in shallow water.  Fish are the mainstay of their diet, but they also consume amphibians, invertebrates, reptiles, mammals, and birds.  When prey is located (by sight), the heron rapidly thrusts its neck forward and grabs it with its beak.  If it is small, it is sometimes tossed in the air before it is swallowed, as the photograph depicts.  Most prey are swallowed whole.


Juvenile Green Heron

Green 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 the photograph is a juvenile: the tufts of down that remain on its head, its streaked neck (adults have solid rufous necks) and its yellow legs (adults have orange legs).