Posts Tagged ‘Science’

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Who made a saguaro hole in one?

March 26, 2017

Out in the desert, you may hear a loud “Chirrr” sound. Look up, and you may see a flash of black and white wings, then see a brown-headed individual running or hopping up the trunk of a tree, if there are any trees around, or a cactus. If it’s a cactus, that’s got to be a fairly death-defying move, navigating among the thorns.

When you see all of these clues together in southern Arizona or northwestern Mexico, it’s quite likely you have spotted a Gila Woodpecker.

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You can recognise Gila Woodpeckers, Melanerpes uropygialis, both male and female birds, from the thin vivid black and white bars across their wings and back, and their brown heads. In addition, the male has a red patch on his forehead. And, as well as their distinctive “Chirrr” call, they also make loud peeps.

In an unusual and clever tactic, they use their tails to prop them up vertically as they locomote, hunting for insect meals on bark or cactus skin, or when they hammer out nests.

The big black holes you see in the sides of many saguaros? Credit goes to these folks!

They use their strong beaks on their well-cushioned heads to whack nest holes into the sides of saguaro cacti, and if they can find any, other tall woody plants of the desert, including cottonwoods.

The nest holes they excavate in saguaros, which are often used by other birds, eventually harden into “saguaro boots.” These woody, rounded, boot-shaped forms remain even after the saguaro dies, and have been used as containers by humans since the olden days.

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The fog comes.

January 23, 2017

on little coot feet.

You may have already heard the correct quote the way Carl Sandburg originally wrote it—”The fog comes. on little cat feet…” But this is different. This is coot, not cat. And coots have strange and amazing feet.

Well, just look at them—first of all, they are quite big feet, not little feet!

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And they are not long and skinny-toed like crow feet. Or wide and webbed like duck feet.

Instead, coots do have skinny toes, but with foldable fins on each toe.  So the contrast with crow feet is clear—coots are water birds.

But the contrast with ducks, those other water birds, is extremely interesting. Ducks have webbed feet, with webbing between the toes. When ducks pick up their feet, or move them forward in the water, the whole foot folds, to reduce drag. Then, as they push back, their feet flatten out again, so they press against a lot of water to propel them forward.

Coots use a more subtle system. For them, foldable skin flaps extend out on either side of the toes. When they lift a foot, or move it forward in the water, the flaps fold, reducing the drag against the water. Then when they push back, the flaps widen out and provide a lot of surface area for propulsion. This also helps them walk confidently over bogs or swamps or other kinds of squishy ground.

Plus, these clever feet are picturesque—green and gray and black and white—with striking patterns and colors for someone we think of as just little monochrone water birds.

Well, yes, not to mention red eyes and a red-brown forehead badge, and a charcoal back and white tailfeathers, and their pleasing football-shaped bodies.

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New Desert Creatures Mysteries e-book

August 12, 2014

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Now you can get a great Desert Creatures Mysteries e-book.

It goes into detail about the strange animals of the desert, and some of the cool science about them.

https://www.smashwords.com/books/view/455225