Desert Clouds

Although our skies are often dramatic, it is unusual for a Tucson day to actually be cloudy, especially in the morning. Such a day occurred on my last rove. When I arrived at Tohono Chul Park at 8 AM, the sky was churning with clouds. It had rained over the weekend, and everything smelled damp and delicious. The cold, moist air seemed literally to caress my skin as I walked along the Desert View Trail, watching and listening to birds and looking for jackrabbits.

Evidence of the weekend’s rain could be seen all along the trail.

As I neared the end of the trail the clouds closed in and I could see only a tiny dot of blue sky.

Just after I left the Park, the clouds opened up and it began to pour, a surprise for mid-January.

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Desert Skies

After record-breaking low temperatures last week (in the high teens), yesterday we broke the record high (low eighties). And today it’s cloudy and mild. The sky has been spectacular. Here are a few sky shots, including one from Sabino Canyon last Sunday:

And from various locations in my yard:

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A Blast of Winter

The cacti are still wearing their styrofoam “hats,” and will continue to do so for several days, as winter has made a big comeback. We’re at the beginning of a five-day hard freeze, nearly unprecedented in this area. The last such, though it didn’t last as long, was two years ago. This is possibly the result of global warming.

Tohono Chul Park was very cold but beautiful today. There were plenty of birds, among them: phainopeplas, white-crowned sparrows, mourning doves, goldfinches, Abert’s towhees, Gila woodpeckers, curve-billed thrasher, pyrrhuloxia, house finch, house wren, cardinal and Gambel’s quails. But we saw no hummingbirds; this weather is hard on them. It kills the nectar flowers and small insects they subsist on. I hope that this year at least a few survive, because two years ago very few did. The biggest surprise today was this ice sculpture in the riparian area:

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Cactus Hats and Hints of Spring

The New Year has brought cold weather to the Sonoran Desert. But because we’ve had some rain and because it was so warm through most of December there are pockets of wildflowers coming up here and there, as well as blooms by some flowers that won’t be stopped by anything but a hard freeze.

                               

Desert Marigolds and Chiltepin fruits                           Arizona Bluebells

In most of Tohono Chul Park, our plants meet more hospitable conditions than those out in the desert. We irrigate many flower beds, and surround them with wire to keep out rabbits and javelinas. And we cover many non-native plants on nights when freezing conditions are expected.

These Mexican Fence Posts and other columnar cacti grow from the top of the stem, so it’s necessary to protect the delicate growing tip from freezing. We do this with styrofoam drinking cups. The next morning it is always a cheery sight, with the covered cacti looking something like a Shriner’s convention. (I personally think we should put tassels on the cups, but so far nobody has taken my suggestion.)

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Christmas in the Sonoran Desert

It’s chilly here in the early morning—in the forties—so I have to bundle up for my rove at Tohono Chul Park. Below two cold, Christmasy sights:

We have neither partridges nor pear trees at the Park, so how about six mourning doves in an agave?

As for snow on the ground, we don’t have that either, but on very cold days frost forms along the trails. Here’s a video of frost on a prickly pear skeleton, sublimating into the air as the sun begins to warm the desert floor.

Steaming cactus skeleton

Happy holidays to all my readers!

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Ducks!

Yes, I live in a desert, and no, we don’t have a coastline here in southern AZ. But we are fairly close to the Gulf of California, and we get a lot of shore birds passing through and/or spending the winter right here in Tucson and in other parts of southern Arizona.

If you like ducks (and who doesn’t?) there are a number of places in the Tucson area where you can see them.        

Ducks in Reid Park, Tucson, Arizona

Sweetwater Wetlands, a sewage treatment plant fairly near my home,  does not smell sweet but harbors water birds all year round, and particularly in the cool/cold months. Water birds also frequent Aqua Caliente Park, a beautiful nature preserve in the far eastern part of Tucson, that is fed by natural warm springs. The city of Tucson itself is graced with a number of large city parks with ponds and artificial waterfalls and fountains.

I visited one of these parks, Reid Park, twice in the last ten days. Reid Park, which also has a zoo and a golf course, is in the center of town. Its two large ponds not only attract ducks, they also draw migrating and overwintering waterfowl of many different sorts. Last week, for example, I saw a cormorant, a great blue heron, and a seagull! The park itself is grassy and dominated by large evergreen, palm, and eucalyptus trees, which many of the waterfowl seem happy to perch in.

Here are some of the beautiful birds I saw on my recent visits:

                

These photos are of a Great Egret that was visiting the pond. I watched it swallow a fairly large fish, which you could follow down that long, slender neck. It’s a gorgeous bird that seems to like to roost in a eucalyptus tree.

                

These are two of my favorite ducks, the ring-necked duck on the left, which I like because it is beautiful and because it has a prominent ring on its bill (a much fainter one on its neck); and the coot, which is beautiful shiny black and has blue feet with weird-looking toes, padded for walking on marshy ground. The first time I saw a coot’s feet, I thought they looked like blue crayfish.

Finally, I saw a large, gorgeous bird I had never seen before, a black-crowned night heron, which posed both in a tree and beside the pond:

            

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Mid-October Birding at Tohono Chul Park

Today was a terrific day for a bird walk in the Park: clear blue skies and temps in the low seventies. I was greeted almost as soon as I arrived by white-crowned sparrows, which I had not seen since early spring.

In the front of the Park, a rare treat: a cactus wren building a nest in the saguaro at the top of the trail that enters the Park!

                     

Cactus wrens build messy, football-shaped enclosed nests throughout the year. Nobody knows why they build multiple nests—possibly some of them are decoys. It’s not unusual in any given month to see a cactus wren with nesting material in its beak.

  This wren repeatedly selected material from either side of the path, flew up into the cactus, added the new nesting materials, arranged them carefully, then flew back to the ground to repeat the process. Here is a brief video showing the bird’s efforts.

Cactus wren building nest in saguaro at Tohono Chul Park, Tucson AZ

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Why do hummingbirds fight?

“Cool it, guys! There’s plenty for everybody!”

Yes, I do talk to my birds, and often exhort the hummers to play nice with one another and stop fighting over the feeders. These fierce little jewels always ignore my advice. I recently read a discussion on a hummingbird mailing list that goes a long way toward explaining this aspect of hum-behavior.

According to Lanny Chambers, a hummingbird expert whose excellent website, Hummingbirds.net, is packed with photos and information on hummingbirds, hummers fight because:

 

…they treat feeders essentially the same as flowers. A good patch of wildflowers in the middle of nowhere will provoke chases and battles, as one bird tries to defend the territory against all intruders. So, the real question is, "why are hummingbirds so territorial?"

The answer for adult males in spring is easy: the birds with the best territories attract the most females, and get the most sex. Hens want strong genes for their chicks, and they know where to find them: the nastiest, meanest, most evil-tempered studs will be successfully holding down the most desirable food resources.

Outside of that scenario, each flower contains a tiny amount of nectar, replenished slowly over time. A hummer doesn't want another bird to get the nectar first, since it will have to wait until the flower produces more, so the resource is jealously guarded. I don't think a hummingbird has any concept of unlimited supply, so they defend feeders for the same reason.

There are some occasions on which hummingbirds will share food. I myself have observed this, most often at the end of the day or during a cold snap. A couple of years ago two young male Costa’s hummingbirds uneasily co-guarded my patio feeder, as I described here. But this behavior is very rare.

Nancy L. Newfield of Louisiana, author and hummingbird expert, believes the hummingbirds’ perception of the rarity of nectar is “the crux of the whole matter.Every drop of nectar is regarded as the last drop of food on Earth.  They defend their food source because their very life depends on food.” 

Adds Sheri L. Williamson, another expert, who is author of the indispensable Peterson’s Field Guide to Hummingbirds of North America, “It’s all about that limited resource and walking (well, hovering) a very fine line between survival and starvation.”

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Butterfly Sex Notes

Birds do it, bees do it, and butterflies do too. Early fall is butterfly heaven in Tucson, and Tohono Chul Park is jam-packed with many beautiful species of butterflies. 

Here are some beautiful queen butterflies, sampling the delights of ageratum:

            

The butterflies are males (as evidenced by the black-enclosed white dot on their hindwings), and they are imbibing an alkaloid that will help them produce a pheromone that some references say “aids in mating.” My butterfly app says that the pheromone enables them to “subdue the female,” so you might think of it as a butterfly date drug.

These pipevine swallowtails were caught mating in the top of a palo verde tree:

Two days ago, while on a bird walk, my buddy Sue and I saw a young butterfly emerge from its chrysalis. In this brief video you can see the flashes of color appear:

It was a beautiful Gulf Fritillary,

but we had to move on before it had dried out and pumped up its wings.

The very early life of a butterfly is fraught with peril. See how I rescued one in my earlier post on Butterfly First Aid.

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Late September Morning Miscellany

The season is in transition. It’s still hot during the day, but mornings have been beautiful and cool. Today I had a lovely walk, just after moonset…

        Almost-full moon setting behind my bird garden

…during which I saw and/or heard phainopeplas. pyrrhuloxias, curved-billed thrashers, cactus wrens, a pair of verdins, Gambel’s quail, and several house finches.

A couple of days ago at Tohono Chul Park I followed a roadrunner for some distance, hoping to get a quick video. Unfortunately, every time I started the camera he stopped moving, as if he were deliberately trying to thwart me. Here are a couple of still shots he allowed me to take:

                                                  

And below is a really nice wolf spider hole, surrounded by its signature parapet: These holes (with parapets) can be seen to the sides of most trails these days. I have not been able to find out why wolf spiders construct parapets, but have heard that they sit on them to see prey coming down the trail. I doubt this, since I’ve never seen a spider on one. If anyone reading this knows the answer, please leave it in the comments.

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My Sonoran Desert Toad

I have written here several times about Reptile Ramble, the program at Tohono Chul Park in which two herpetologists and a handful of docents talk about and demonstrate live reptiles (snakes, lizards, and turtles mostly).

Yesterday was one of the days when I was privileged to participate in the show. As usual, I got to demonstrate my favorite snake, Leo the Common Kingsnake, whom I babysat for this summer. But I also got to demonstrate a different type of herp, an amphibian: the Sonoran Desert Toad. We don’t usually have a toad, and I had never even held one before.

Sonoran Desert Toad

These toads are surprisingly large (the size of a bullfrog). They spend most of the year underground, waiting for the rainy season. From late May through the summer they emerge to mate in temporary rain pools or permanent streams. Their voices when mating are said to sound like a sheep being strangled.

I am wearing gloves in the above photo because the toads exude a toxin from their parotid glands (large, wart-like protruberances behind their mouths). This toxin has psychedelic properties, and was used by Native Americans to bring visions. It is dangerous and even fatal to dogs, however, and any dog that licks or mouths a toad must have its mouth washed out with a hose (from the side) and taken to a veterinarian for treatment.

                                 

The most fun thing to me about the Sonoran Desert Toad is its exuberant hopping. We had a few dozen first-graders at the program yesterday, and they screamed and laughed in delight when I set the toad on the ground. It began hopping around, fast and high, no doubt trying to escape. I had a heck of a time re-catching it, but finally did. What an amazing creature it is!

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My nectar bats

For the last several years, nectar bats have drained my hummingbird feeders at night from the end of August through mid-October. I usually leave two or three feeders up for them, then set out fresh feeders for the hummers in the early morning.

I don’t mind doing this, because the two species of nectar bats that work the Tucson valley, the Lesser Long-nosed Bat (Leptonycteris curasoae) and the Mexican Long-tongued Bat (Choeronycteris mexicana) are both imperiled. The “Choero” is threatened, while the “Lepto” is endangered. How could I deny either of them a little sugar water?

a

Lesser long-nosed bats (“Leptos”), photograph by Ted Fleming

Both species are important to our ecosystem, pollinating agaves and saguaros. Although I have yet to meet one in person, I’ve been assured that these bats, particularly the “lepto,” are very gentle. They are, as you can see above, amazing animals.

Last night, a very knowledgeable graduate student from Toronto set up a recording array on my back porch that will let him track the number of bats (and the species) during the night.   He specializes in bat communication—a bat linguist, if you will. He told me that these bats can see well enough to find food on a brightly moonlit night, but that most of their food-finding is done entirely through echolocation. Their “sonar” shows them exactly where the feeders are, down to the tiny feeding holes.

The bats also communicate with each other, which is important since they come to the feeders in large groups. It’s not known what their calls mean, of course, but they are probably something on the order of “Coming in, now!” “Watch out!” “I’m next!”

      

Leptos feeding. Note the tiny droplets of nectar.

If you want to know more about these beautiful and important animals, check out the Marana Bat and Hummingbird Feeders Study. The stunning photos of Leptos in this post are by Ted Fleming, one of the coordinators of the Study.

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Soggy Rove and Farewell to Leo

It rained gently for the start of my rove yesterday. There were a lot of birds out, including a beautiful, beautiful broad-billed hummingbird (he’s been there about a week). Not much else going on, except I saw an amazing pair of cactus wren nests on the North Trail.

 

They were amazing because they were covered with what appeared to be fiber-fill. Cactus wrens like to decorate their nests, and will use things like tinsel, yarn, cellophane, even Kleenex. So this wren must have found a pillow somewhere!

After the rove, the owner of Leo (The Snake in my Guest Room)  came over to pick him up. I will miss Leo, for sure. Here are a couple of pictures from his next-to-last day with me.

        

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Monday Miscellany

I love the feeling of living close to nature, here in the foothills and at Tohono Chul Park. Even on days when nothing particularly noteworthy happens, there is always beauty nearby.

For instance, yesterday morning before dawn, I got to see what was left of the Blue Moon, shining very brightly down on our driveway.

While I was on the way to my rove at the Park, I watched a thin, blond coyote carefully look both ways before crossing a busy street.

The Park itself was heavy with humidity and extremely lush, which made seeing birds problematic, though I did catch glimpses of Abert’s towhees, black-tailed gnatcatchers, and surprisingly a Bell’s vireo. While looking for birds, some visitors and I saw these odd tracks along the trail:

 

At first we thought they must be termite tunnels—but why would they be on a rocky trail? I decided to open one, and found that it was just a stick—oddly covered with a thin film of sand. This was presumably some phenomenon of wind and rain, but I haven’t heard a good explanation yet. There were several other of these “tracks” on some of the other trails.

Finally, I got to see a Palo Verde tree near the Five Seasons Garden, decked out as if for Christmas…

The hanging balls turned out to be coyote gourds, growing from a long vine. 

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