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Articles by Wayne Bierbaum

A brilliant topic

A peacock’s tail is actually brown. But it possesses structural surface properties that create a bright rainbow of hues. The colorful display is due to iridescence.
    The simplest example of iridescence is the colorful shine of a drop of oil floating on water. When the oil film is thin enough, light gets bent as it hits the oil-water interface in a process called refraction. That light may be only one wavelength, one color, as determined by the thickness of the oil. The thinner the oil, the shorter wavelength of light that bounces back. The thicker spots are reddish and the thinner bluer.
    Animals of all sorts have created structural coloration not from pigments. In some, like a snake called the rainbow boa, it is from a thin film that changes thickness and color as the snake stretches and compresses while moving. Other colors are created by a static bio-coating or structures that create refraction of a particular wavelength, as with the peacock or the throat patch of a ruby-throated hummingbird.
    The angle of the light hitting the throat patch sometimes hits that sweet spot where the refraction amplifies the bounced light. In the photos presented here —taken within two minutes — the light was too bright for my camera’s sensor. 
    Iridescence is used for coloration by many plants and animals. It is, however, uncommon in mammals. 
    Look around and decide if the color you see is due to pigment or to light-bending iridescence.

Maybe that's because it's what this sparrow eats?

    Many animals are named by the sounds they make or the food that they eat. The grasshopper sparrow is named for both. These little birds live in grasslands from Canada to Florida, where they like to perch on any stick or fence and sing a song that sounds like a flying grasshopper. They also feed on grasshopper and other grasshopper-like insects.
    In the summer, they make nests by clumping grass near the ground. Thus their nests are at risk during hay cutting. Some farmers purposefully put off cutting while the birds are nesting. With fewer open grass fields, more grass cutting and many other reasons, the population has dropped 75 percent since 1968. The Florida sub-species is almost extinct.
    To help protect populations of grass-nesting birds and animals, most states have established large tracts of grasslands that are not cut until after nesting is finished. In Maryland, the largest tracts are at Fair Hill and Soldiers Delight, with a smaller grassland at Sands Road Park.

Don’t crowd this little bird off the beach

“The birds are taking over the beach.”     

            I heard that complaint as parts of a beach were being roped off because of nesting birds.

            The bird under protection is likely the tiny piping plover. 

            In the 1850s, piping plovers were very common along the East Coast and the shores of the Great Lakes. The population collapsed as they were hunted so their feathers could decorate women’s hats. The Migratory Bird Treaty Act of 1918 stopped the hunting, and the population stabilized.

            With human development along the coast, the population was again threatened. By 1986, just 790 breeding pairs survived on the Atlantic Coast. That is when they gained protection under the Endangered Species Act. Even with protection, the most recent surveys still place the Atlantic population at fewer than 2,000 pairs. 

            Piping plovers nest in small depressions in beach sand. They lay their speckled, sand-colored eggs in depressions about the size of a footprint. The eggs are very hard to see.

            The eggs take 25 days to hatch, emerging at about the size and shape of a miniature marshmallow. The tiny chicks hide by freezing in place, as they cannot fly for another 30 days. Eggs and young are very vulnerable to predatory animals and to being stepped on or run over by motor vehicles and bikes.

            Adults also have difficulty feeding the chicks when people are too close. After the chicks have learned to fly, they are no longer as vulnerable. By September, the plovers start their migration south along the Florida coastline to the Bahamas.

            These little birds need space to survive as a species. Four thousand birds along the hundreds of miles of Atlantic coastline is not very many. Help them out by avoiding nesting areas, and keeping your pets out, too.  

A story of special devotion to the least of creatures

     Patricia Terrant of Blue Angel Rescue in Lusby — featured in the August 28 Bay Weekly — is in the process of a difficult rehab of a baby squirrel. It appears to Pat that the mother squirrel tossed the little one from the nest when it was about two weeks old, or less. At that age, the baby was about the size of the last joint of her thumb. For several weeks, she has been hand-feeding it a homemade nutrient solution....

But this hummingbird is a moth

     The hummingbird clear-wing moth looks and acts like its namesake bird. This is one of the few moths that actively feed during the day. They hover and fly like a hummingbird, drinking flower nectar with their long tongue. To complete the mimic, they have a greenish back and a pale belly. Their steering tail, however, looks more like a shrimp’s.
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Help this native do its pollinating job by avoiding insecticides
     Our local bumblebees number 20 species. Varying from the size of a honeybee to about an inch long, they are classified by the length of their mouthparts, proboscis and tongue.
     Bumblebees, our native bee, are very important for pollination.
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Tree frogs celebrate after a good rain 
     After a soft rain in mid summer there is frequently a chorus of tree frogs saying how great the rain was. The loudest and deepest voice is the gray tree frog; the next loudest is the barking tree frog. The green tree frog has a higher, lighter voice and makes a chirping sound.
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Cicadas turn up the volume 
      Cicadas are a group of insects that spend most of their life underground but emerge in the summer to sing and breed. They have been present since the Upper Permian Period, about 250 million years ago, with some giant specimens found with conifer fossils. Now they are present all around the world with more than 3,000 species.
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These guys really stand out 
      When I’m asked, What is the name of the red bird I see around here? there are four birds that I consider.
      They are the male northern cardinal, the male scarlet tanager, the male summer tanager and the male house finch. I assume that the pattern is obvious: Only the males of the species are red; The females are brown or yellowish.  
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Hire these scary-looking longfellows to eat your mice
     I  have been seeing comments about black rat snakes getting into bird-nesting boxes. A smooth support with a critter guard will generally keep them out.
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