Life and Death

Around here, if a scorpion doesn't get you, the ants will. This Arizona desert scorpion (Hadrurus arizonensis) I found on the sidewalk probably met its death by a crushing foot, but it did not take long for tiny Southern fire ants (Solenopsis xyloni) to swarm in for a feast.  At least the scorpions usually hunt solo. 

Also known as the Giant Hairy Scorpions for short stiff hairs along the sides of their legs, this species is reputed to be the largest in the U.S., measuring up to six inches long from the tip of their stinger to the small, sharp jaws or chelicerae. Add on all those legs plus the formidible claws, or pedipalps, and they are quite impressive. This one was about four inches long based on my calculations as sized up to my pen. (I need to add a small ruler to my pack for observations like this.) The ants are just a teensy fraction-maybe a sixteenth of an inch-or a couple of millimeters apiece if you prefer metric. Although scorpions can deliver a painful sting, they rarely cause a serious reaction in humans, and this one is actually one of the least toxic, despite its size. The dark back and pale legs also distinguish this species from the smaller, more dangerous and much more common bark scorpion (Centruroides exilicauda) that haunts the SW deserts. 

As gruesome as a scene like this may be, it is a reminder that all life thrives on death, humans included...unless you like your meat very fresh!

Exoskeletons

After a month or two spent mucking about in a pond for food, the aquatic larvae, or nymphs, of dragonflies crawl out of the water, crack open the skin on their back, and begin new lives as aerobatic adults. I found these exoskeletons, or exuvia, of roseate skimmers (Orthemis ferruginea) clinging to a cement wall along the Central Arizona Project canal, where a trough of still water serves as a year round breeding ground for dragonflies, as well as dozens of other insects. The exuvia are perfect casts of the fearsome jaws and giant eyes that make the larvae successful predators. I would like to have witnessed the magical hour when dragonflies emerged from these chitonous skins. Even more, I would like to be able to shed my own skin and fly! 

This trough on top of the CAP canal collects debris and mud,
creating a year-round pond that is brimming with aquatic life.

An adult Roseate Skimmer rests on a blade of grass.

Dragonfly larvae blend in with muck at the bottom of the pond.

Mussels and Clams

Quagga mussels (Dreissena rostriformis ssp. bugensis) and Asian clams (Corbicula fluminea) have claimed some territory along the Central Arizona Project canal, far from their native habitats in Ukraine and southeast Asia respectively. A small pile of shells is spread out across the trail after being scraped out of pipes in a water treatment plant in north Glendale, looking quite out of place in this arid scene.

Hitching rides on ships and then on smaller boats, both species have become naturalized in many freshwater systems in North America including the Colorado River and its system of reservoirs and canals. The clams are considered to be symbols of prosperity in Asia and have also been intentionally introduced through the aquarium trade and as a source of food.

Katydid

This Elegant Bush Katydid (Insara elegans) appeared on my window screen recently. Also called a Mesquite Katydid, they are distinguished from other katydids by the long narrow wings marked with white stripes. Katydids are nocturnal, so this one seemed content to let me photograph it mid-day as it rested. The males are the source of some of the rasping night sounds coming from high in the trees during the summer around here.  The name "katydid" is supposedly and onomatopoeia for this sound, but that's a real stretch, at least for this species.  Elegant, yes, for the slim wings and extraordinarily long  antennae. This was the first year in twelve that I've seen this species in our neighborhood, which makes me wonder: Have they always been around, and I just haven't noticed, or are they having an especially good year, so more abundant? 

Desert Shaggy Mane

The desert shaggy mane mushroom (Podaxis pistillaris) or "black powderpuff" is actually a type of puffball. Open it up and, depending on the ripeness, it will either be filled with thick white goo or erupt in a cloud of dark spores. These began popping up in gravel along Highway 17 after monsoon rains at the end of July this year. Sadly, they are reported as being inedible not due to toxins, but because they are just plain foul-tasting, as well as tough and woody. However, if you are truly desperate, or just curious, munching on an immature stalked puffball won't kill you.  This species is common in desert regions around the world. Australian aborigines have used the spores mixed with water for body paint and the dry spores for hair dye.

Tailless Whip Scorpion

Last night we had an unusual visitor on our front patio: a tailless whip scorpion (Paraphrynus mexicanus). These long-legged relatives of spiders and scorpions are actually quite common in the Sonoran Desert, but they are normally very secretive nocturnal creatures. At rest it will fold up all of its legs and become an innocuous looking black blob about the size of a quarter. But when it extends all of its appendages, the whip scorpion expands to the diameter of a dessert plate. Crawling sideways like a crab, it rivals any sci-fi creation ever imagined by Hollywood.

Two serrated claws, or pedipalps, are curled up in front of the face, which is beaded with five shining eyes. A pair of forelegs serve as long thin antennae that it waves around to feel for potential prey.
They are members a group of arachnids called Amblypygids, which means "blunt rump," because they lack the curved tail that their cousins, the scorpions, wield for weapons. They have no venom or stinger, so are reportedly harmless to humans. Amblypygid moms carry their newly hatched young on their backs, a trait shared by scorpions; I like that these scary looking animals exhibit nurturing behavior.

Our visitor was very patient with us, posing for photographs and demonstrating its graceful movements without dashing away. Perhaps we'll be lucky enough to have a family of Amblypygids take up residence in our yard to help control the cricket population that has been keeping me awake at night. Or maybe they already have; it's been a little quiet around here lately.

Toad-ally!

On warm summer nights, some central Arizona neighborhoods are visited by these princes (and princesses) in disguise, Sonoran Desert Toads (Incilius alvarius). The New River corridor is a popular stretch of habitat for these wide-mouthed, warty amphibians. Although the adults are terrestrial, and content to spend most of the year in burrows that may be miles from any water, permanent or temporary ponds are necessary for reproduction. 

They will take advantage of nearly any water source we provide for them, intentionally or unintentionally, to re-hydrate. Dog dishes, bird baths and shallow steps of swimming pools are perfect places to sit for a while and fatten up after a long winter below ground. Toads imbibe water through their skin, especially through a special "drinking patch" on their belly and hind legs. A few hours sitting in a mud puddle can make the difference between a "full" toad and a skinny toad. Although many folks regard them as pests, because they are also quite toxic, especially to dogs that harass them, having a few toads around can serve as effective pest management, since they will eat huge quantities of insects. 

Toad scat is dry and ashy, essentially the keratinous remains of the insects they have eaten. This large sample of toad  scat is compared to my ring; it's as thick as my finger, but not gooey at all. If you step on it, the turd turns to dust and blows away on the wind. Just another fun little nature tidbit for you!