The Amazing Ant Lion

Someday, in your travels, you might spot a small round hole in the dirt, about the size of a drinking straw.

And even better, surrounding the hole, there might be a downward pointing cone of dirt or sand, maybe several inches across, leading down into the hole.

If you see both of these, you may have found the dwelling of an Ant Lion, or as it is sometimes spelled, Antlion!

(The cones in this image are about 2 inches across)

Given the size of the hole, you may suspect this creature is not really a lion, and you would be right.

But it is not an ant either! To the regret of nearby ants.

In fact, to an ant, it must seem as fierce and deadly as a lion! Because the whole point of the hole in the ground and the slippery-slope funnel-cone leading down to it is to trap ants, which will then be grabbed by the horrific looking jaws of the Ant Lion, injected with venom and enzymes, and sucked completely dry of life!

Yiiiiikes!

Crazy-ferocious Ant Lion, photo courtesy of Phil Meyers

It sounds like something from a horror movie! So much so, in fact, that the Ant Lion was used as a model for a sand-dwelling monster in the movie Dune!

Like many other insects, Ant Lions go through several surprising life stages. As adults, Ant Lions look like frail dragonflies, who fly around for a few days, then lay eggs and die.

The eggs eventually hatch and grow into larvae, what we usually think of as worms or grubs. Ant Lion grubs are certainly remarkable looking, with those immense jaws, sticking out front like lobster claws. Their bodies, generally an inch long or less, are covered with dark hairs and bristles, adding a wild and wooly look to their ferocity.

And here’s another clue—near the sand-funnel with the hole at the bottom, you may notice a meandering trail in the dirt, like a little ditch. And this wandering line, which looks something like a doodle you might draw on paper, gives the Ant Lion its other name—the Doodlebug!

But why do they do the doodling they do?

Well, look at the size of their jaws! Because their jaws are so enormous compared to their body size, they have to walk around backwards! You would probably meander too, if you had to walk around backwards all the time.

Ant Lions are so clever that they are found all over the world, so you can look for them even if you are not in the desert. And, given how many kinds there are, when being formal, we will not be specific, but just call them by their family name, Myrmeleontidae.

So watch for, and warn any ants, if you see the signs of these remarkable predators!

 

Who made a saguaro hole in one?

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.

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.

The fog comes.

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!

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.

See nictitating membranes in action!

There’s a great nature event happening right now. Biologists have set up video cameras to watch a growing bald eagle family in the US National Arboretum in Washington DC, and anyone with an internet connection can watch them at any time.

You can visit the DC EagleCam, 24 hours a day, at  http://dceaglecam.eagles.org

Even though this is the east coast, bald eagles also winter in the desert, usually in the high country. But the relevant  feature right now is that sometimes you can get a glimpse of the eagle’s nictitating membranes at work.

Here’s how. It’s best to watch in the day time. Click on one of the two cameras so you can more easily see the adult eagle’s eye, and enlarge the image, by clicking the bracket-box at the lower right corner of the video.

You will most often just see the eagle blinking–but every so often, you get to see the “third eyelid” swipe part way or all the way across the eye, starting from the corner nearest the beak. Wow!

And if you get so busy watching the adults and chicks and their activities you forget the third eyelid, that’s OK too!

…..Image taken April 6 2016 from dceaglecam.eagles.org © 2016 American Eagle Foundation, EAGLES.ORG

Check out the nictitating membranes!

If you had to make your living in a desert, or under water, or by sticking your head into a rotting carcass to get your food, you’d probably appreciate a handy combo of goggles and windshield wipers.

And that’s what many creatures, including Turkey Vultures, have.

But instead of using the awkward term “combo-goggles-windshield-wipers,” we use the sleek and easy to remember name, “nictitating membranes.”

Uh huh!

Nictitating membranes are also called third eyelids, and are often translucent, so the eyes get protection while allowing some vision.

Sometimes these thin membranes rest under the lower eyelid, and rise from there, but more often, they are tucked into the corners of the eyes nearest the nose, and move back toward the sides of the head when in operation.

It can be unnerving the first time you see them in motion, a space-alien moment. But when the membrane is closed, it often just looks like a gray or white eyelid.

Here’s a Turkey Vulture doing a demo for you!

First picture, nictitating membrane is open, and in the second, the translucent membrane is covering the eye.

Wildlife Rescue Open House

If you are near the Phoenix, Arizona area next weekend, you have an opportunity to meet and learn about some of the cool creatures of the hot desert.

The open house is on November 21 and 22, 2015, at the Adobe Mountain Wildlife Center.

www.azwildlifecenter.net/events.asp

Because this is a wildlife rescue station, the population changes all the time. Depending on who is recovering there, you may see eagles, desert tortoises, bobcats, falcons, or ringtails.

Or maybe even the creative and industrious packrat!

Ocotillos and visitors

So, the original idea here was to talk about how Ocotillo plants (Fouquieria splendens) in bloom seem to host bird or pollinator visitors at almost any time of day.

It seemed like a good idea to do at least one random sample of observation before declaring this.

And sure enough, during a 3 minute segment one spring afternoon, a few days into full bloom for the ocotillo, there were two bird visitors and several pollinator insects. Now this was just one casual observation, but it indicates how often you see creatures near or on these plants.

As noted in an earlier post, Verdins, (Auriparus flaviceps) the very small birds with yellow heads, are frequent visitors, apparently looking for insects. Finches are also common. And hummingbirds can be seen throughout the year.

It is amazing that any birds can find a firm foothold on the thorny stems. Clever feet.

Remember that the ocotillo is not a cactus, although it may look like one during some parts of the year. It’s in a completely different group. In fact, for most of the year, it looks like a bundle of dead sticks, and if you first saw one for sale in a garden center, you might wonder what they were trying to sell.

New Desert Creatures Mysteries e-book

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

Leafing again: the strange case of the ocotillo

One of the odder native residents of the Sonoran desert is the ocotillo bush. It typically consists of several spindly branches, vertically striped and spiny, up to 20 feet tall, that are leafless for long periods, only to sprout thick lines of small leaves within a few days after a rain.

Ocotillo branches with few leaves

Its desert adaptation of dropping leaves and playing possum is so complete that ocotillo plants for sale, in their leafless phase, with their branches tied in a bundle and roots bare, look thoroughly dead.

Ocotillo branches with many leaves

In the spring, they produce numerous red tubular blossoms at the ends of the branches that attract insects and birds of many species. They make great landscape plants because of their sparse sculptural look, and extremely low water requirements, and striking seasonal changes.