There are wrens in our desert world. Big, raucous, busy Cactus wrens are always here. And there are wrens that pass through: eye-browed and long-tailed Bewick’s wrens in spring and fall; a Rock wren usually comes around a few times in the winter, and even a House wren once, on its way to its breeding grounds uphill from here.

Today we had a new-for-the-yard visitor: a Canyon wren “jeeting” around on the back porch. It was early morning, and we were up for our Papago Park walk, but before we left I spotted a small dark form flitting in and out of small spaces under the bentwood rocker. At first I thought it might be a rodent, but after better looks, it proved to be a Canyon wren, its cinnamon and gray back and white throat clear even in the early light. It was actively foraging first on the canes of the chair, and then between the flower pots by the pool.

Canyon wrens live in arid places, but usually not in lowland deserts. They are characteristic denizens of precipitous canyon terrains in higher elevations, like the Mogollon Rim or the Grand Canyon, the Superstition Mountains, and such hard-surfaced vertical spaces as those, where their clear descending call rolls down the rock, and absolutely means “Desert Mountains” to many of us who live or visit there. Perhaps there’s a downward movement of a small percentage of the birds from higher elevations for winter, so some birds must pass through occasionally, but it’s a bird we’ve neither seen nor heard in our yard before, nor in Papago Park, where the buttes provide habitat more like what it would naturally occupy.

Canyon wrens are structurally specialized for probing stony crevices for delicacies: their bill is long and straight, and according to Sibley, their spine is attached to the skull at the back, instead of from underneath, which gives the small bird both maximum probing capacity and a nearly constant upward-tilt to its head.

Amazingly — it’s a very active subject — E managed to get these two photos of this morning’s bird, a bit blurry but very identifiable. The last we saw of it was its little rusty tail disappearing into the dark spiny interior of the Mexican fan palm. Then we lost track of its “jeet” call, and we didn’t see it again.

For the record, this week in October seems to be one each year when it’s possible to find species on the move: last year, this was the part of the month when an Ovenbird, a tiny, unexpected out-of-range thrush-like warbler made a brief appearance under the backyard mesquite, as if it belonged there. White-crowned sparrows have also recently returned for their winter stay, making themselves known by their characteristic and pleasing song, along with the male Red-winged blackbirds, who trickle in a few at a time and stay until spring.

To hear a Canyon wren sing go to ASU’s Ask a Biologist and under “Sound files” click on “click to open” then click on the right-pointing triangle to play.

Photos by E. Shock.

The first day of autumn has been a red letter day in our yard. Not only was there a Western screech owl calling last night — a new species for the yard, as far as my observations go — but this afternoon, in the heat of the day, a young Desert iguana raced under a creosote bush in the front yard, when I went out to get the mail.

I whipped out my tiny Canon Elph but the little ‘zard was all warmed up from hanging out in the midday sun, and it sped away before hiding in the shade under the creosote where I could see him but couldn’t get a picture. So I pinched this nice photo by Jason Penney from the excellent Reptiles of Arizona website which you can check out for more detailed info about this lizard. When full grown, Desert iguanas (Dipsosaurus dorsalis) are large lizards — almost 6″not counting tail and up to 16″with it — with a blunt face, long tail, and distinctive buffy coloration below a colorful pattern of speckles. This little guy shone pale gold as it raced across the cement driveway; its color gave away its identity even before I got close enough to see him well. Tiger whiptails (Aspidoscelis tigris) the lizards we see most often around here, are darker and lower to the ground.

The little iguana was also exhibiting another trait of its kind: it was out in the hot part of the day, when most other lizards have retired to shaded shelter or underground to rest and digest their forage. Diet is another thing that makes Desert iguanas distinct from our other lizards — they’re largely herbivorous when mature, eating a variety of desert vegetation, including the yellow flowers of creosote bushes, which they will climb to feast on. The first Desert iguana I ever saw was among the spring wildflowers at the Desert Botanical Garden, grazing in the hot sun like a small-scale reptilian cow, even leaving behind it large (for a lizard) fibrous pellets of poop like plant-eaters do. And, yes, they are related to their better known cousins, the Green “Tastes Like Chicken” Iguanas (Iguana iguana) of Mexico and Central America. I don’t know what something that feeds on pungent creosote blooms would taste like.

But this is why seeing him was especially exciting: there are only a few in the neighborhood, and that number appears to be shrinking, at least by informal observation. It’s only a theory, but mortality of Desert iguanas (specifically in our neighborhood) seemed to accelerate after the City re-coated our streets with a dark sealant. It makes for good basking, perhaps, the dark surface heating up earlier and staying warm later than the old gray road, and sadly, for several weeks, I would see Desert iguana roadkill regularly: three along one stretch of a heavily-used street nearby alone. So, seeing this little guy who was perhaps this year’s hatch, or more likely a yearling, was a very welcome sight.

Etymological notes:

Dipsosaurus is constructed of Greek elements, meaning “thirsty lizard”; dorsalis refers to the spine, which in Desert iguanas is protected by prominent, keeled scales.

Tiger whiptail, photo by E. Shock

Aspidoscelis tigris: Aspidoscelis is also from Greek elements, and means “shield leg” because of the sturdy scales on the whiptail’s legs, and “tigris” because it is stripy.

Last night was a busy night in the yard. Well, I suppose they’re all busy nights, but last night I was awake to appreciate it. Before human bedtime, the geckos were at their posts under the porch lights (our yard residents are the non-native Mediterranean Geckos, not the indigenous Western Banded, but they’re still charmingly rubbery voracious devourers of insects, especially moths), and the Butte was going off sporadically, the coyote pack’s yelps ricocheting off the slickrock. There might have been the sharp yip of a Gray Fox, which also inhabit the neighborhood, but it was faint. Somewhere, the spadefootlets must have been hopping around foraging in the dark, as well.

After “bedtime” though, things really got going. A female raccoon marauded past the bedroom trailed by at least one kit from this year. Last year there were two separate families, one with two, the other with three kits each. That’s a lot of pounds of raccoons living off the yard, plus Papa, too, who has only half of a tail, diminishing his raccoon-gestalt but not his swagger. We’re not sure how many there are this year, because our view of them is most often through the arcadia door, and sightings are limited to who rolls by the framed glass, like watching a dog show on the TV animal channel.

Last night the main event (for me), however, was again being awakened by an owl. Not the Great Horned owl this time, but an owl I’d never heard in our yard: a Western screech owl. They’re not uncommon in the area — I’ve seen them peering out from day-roosts in saguaro cavities at the nearby Desert Botanical Garden — but we’ve never heard or seen them in our little scrap of modified desert. This one called from just after 2 am until the Butte really exploded about half an hour later, when the owl stopped. Its mellow short hoots were emitted in a cluster which descended slightly at the end. It sounded much like the “Morse code call” of its cousin the Whiskered screech owl, but that species doesn’t live in this part of Arizona. The call was soft but regular, and started up again at 4 am, and went on for at least 45 minutes, when I fell back to sleep.

So far, like the generously rainy Monsoon of 2008, this has been a generously owly season in the yard, and this Western screech owl, who may always have been here, or who may be a new neighbor, ushered in fall last night; I’m glad I was awake to hear it. With luck maybe we’ll catch a glimpse of it sometime, hunting pocket mice and crickets under the desert trees. Right now, though, I think I need a nap: the first nap of Autumn!

“The northern autumnal equinox takes place today, Monday, Sept. 22nd, at 15:44 UT (11:44 a.m. EDT) when the sun crosses the celestial equator heading south for the year. Autumn begins in the northern hemisphere, and spring in the southern hemisphere. Happy equinox!” (Spaceweather.com)

***

Update to an earlier post:

Our local Great horned owl has a friend. Last night from about 4 am we listened to two owls duetting and singing antiphonally for about half an hour, the higher hoots of the female alternating with the lower calls of the male. It’s early in the year for coursthip, but my guess is that these are our usual, established owls reinforcing their pair bond.

Last night at 3.00am exactly, I heard the Great horned owl call. Very close, somewhere right in the back yard. The windows were open because a light monsoon event had brought fresh rain-cooled air, so the call, though soft, carried clearly.

Great horned owls are regulars in our area because there are plenty of perches, and plenty for them to eat. A favorite owly destination is a big Aleppo pine in our back yard. At night that tree is stuffed with roosting doves and other perching birds, a veritable Fresh and Easy for owls. Sitting outside at dark with friends, we’ve watched a horned owl glide stealthily into mid-level branches and then listened as panic ensued among the roosting doves as the owl hopped between branches as if it were going aisle to aisle in a grocery store, filling a cart. Finally it burst out of the needles with a meal clutched in its talons. We got a good look at it is it slid past us, sihouetted against the lights of the house. The feather pool under the pine the next morning was evidence that it had enjoyed a bit of mourning dove.

They are not called “Flying tigers” for nothing. Horned owls, like toadlets, will eat anything that moves and fits down the gullet. Rock squirrels, snakes, desert cottontails, other birds (even other owls), insects, and bats — all are fair game. Even small pets may be at risk, if left unsupervised after dark. The first owl I ever saw was at the family dinner table when I was a kid: a thump, a commotion, and we looked up to see the underside of a Great horned owl pressed to the window, wings flapping against the glass. The owl was trying to separate the family cat (a calico named Ringo, to give you an idea how long ago this was) from the window ledge. A grown cat is awfully heavy prey, however, and the owl had to give up after a few seconds. No one was hurt, but the bird went away hungry. (It was a spectacular view of an owl in action, and I’ve wondered if that was THE bird for me, in a formative sense — I was no more than seven). The boldest hunters are often adults with young to feed — a nest full of hungry owlets requires a lot of sustenance. During that time of the year, parent owls sometimes can be seen hunting even during daylight, working a day job to put food on the table. So, hatching and fledging are timed to coincide with the local peak of yearly rodent production, usually spring, but in the desert areas often much earlier.

Our local owls have reproduced, and sometimes I’ve heard the distinctive, raspy oink of a horned owlet begging, installed on the top of a phone pole while its parents search the alleys for rats or young cottontails to stuff into it. (If you enjoy camping, you’ve heard a sound like it: the creak made by the plastic hinge on a cooler lid when it’s raised.) The female makes the same sound during courtship while soliciting her mate for food. In our area, courting owls can be seen and heard duetting on phone poles and rooftops, visible against the fading sunset sky. As they call together or alternately — the male and female have slightly different voices and cadences — they bow and “hoo.” She holds her tail up, soliciting attention from the male, who strikes a courtly pose to “sing,” tail raised and wings down, maximizing himself like an operatic baritone (he’s smaller than her). Here’s an excellent quote, where the author’s voice slides from ornithologist to owl, almost inadvertently:

“Courtship is fairly boisterous and involves bowing, bobbing, posturing, vocalizing, and allopreening. These elaborate activities lead, as one might hope, to copulation.” (from Hans Peeters, Field Guide to Owls of California and the West, my current favorite owl sourcebook. In the same series as the excellent book on Horned lizards, the California Natural History Guides, published by the UC Press)

If it’s still light enough while all this is going on, you can see flashes of white feathers at their throats, the “gular patch”, flashing as each hoot puffs the owl’s throat briefly. It’s a semaphore for them, like the feather tufts on the top of the head: a way of producing meaningful signals to each other: facial expressions without flexible tissue like lips or eyebrows.

As big, powerful generalist predators, Great horned owls can make it almost anywhere. Their range is right across the US and Canada through Central America and into northern South America. They live in urban, rural, and wilderness areas: desert, woodlands, mountains, wetlands, grasslands and cities, so the chances are you have them where you live, too. Keep an eye open, an ear cocked, and the Chihuahua in at night.

Below are Horned owl salt and pepper shakers from Three Star Owl. Each pair is an adult with an owlet in different stages of development ($48/pair).

It is a long thin snake.

Working this morning in the backyard, E heard the scolding of cactus wrens, thrashers and other regulars of our deserty neighborhood. He tracked down the source: a sleek and mottled coachwhip marauding, trying to take advantage of the monsoon “bloom” of young animals. Coachwhips (Masticophis or Coluber flagellum) are swift and tireless daytime foragers, searching the ground for favored foods such as lizards, and easily climbing our shrubby, tangled palo verdes looking for eggs and nestlings.

They are patterned cryptically, and look like the long braided látigo used by Mexican stockmen. (We called these whips “bullwhips” as kids — favored souvenirs of weekends in Ensenada, primarily used to harass each other.)

The coachwhip’s pattern is surprisingly cryptic, because like the Gila monster, it’s pink and brown, yet it still manages to disappear effectively against pebbly desert soils, and is nearly invisible even slung in the green branchlets of a palo verde, where it looks just like a rosy-brown dead branch lodged there. They’re not aggressive animals — although irritable might be the word — and they’re more likely to use their notable speed as a defense than to bite, unless handled. The Coachwhip actually earns the rattler-hunting reputation the Gophersnake enjoys less deservedly, and will eat anything it can catch and swallow, including other snakes, even rattlers.

More info on the Coachwhip here, at Tom Brennan’s excellent website on reptiles and amphibians of Arizona.