Monday, March 13, 2017

How is a Snake Like Ginger Rogers?

It was said of  the actress/dancer Ginger Rogers that she could do everything her partner, Fred Astaire, could do--but she did it backwards and in high heels.

It’s sort of the same way with snakes.
Looking at these amazing creatures, you can’t help but notice how different a snake's outer (superficial) body plan is compared to the four- and two-legged creatures we are most familiar with. And yet--at the same time--snakes are in many ways very much like us--they have a brain, a heart, digestive and reproductive organs, and many other similarities, some obvious and some not so (for example, they only have one functioning lung). They can feed and shelter themselves, protect themselves from danger, procreate--in fact, do just about anything a creature with arms and legs can do…

But they do it all without  arms or legs, hands or feet.  How do snakes manage their amazing acts of survival? They do it through a series of anatomical adaptations that allow them to use their mouths in ways we bipeds could only dream of, and their strong, muscular bodies to help manipulate objects. Let’s take a closer look at how some of these amazing adaptations work.
Image from
The best place to start is with the skull. Snake skulls are mobile compared to mammal skulls. Whereas our skulls are solid, with the different parts fused together, the separate parts of a snake's skull are more loosely connected, with ligaments, allowing the bony parts of the skull to move in ways our skulls cannot. For example, Instead of a bony inner ear, snakes (and birds) have an extra bone connecting the lower jaw to the skull, which allows a snake to open its mouth as wide as 180 degrees. This ability helps explain how a snake can swallow something bigger than its head.

Another important difference between us and snakes is that the  two halves of a human’s lower jaw are fused together at the chin. Snakes don’t have a chin; instead, their jaws are connected by a ligament, which allows the two halves to move separately. Snakes’ teeth (not including fangs, which are used to deliver venom in venomous snakes) are small, sharp, and pointed backward--toward the gullet. Thus, when a snake has prey in its mouth, its sharp teeth can hold the object tightly while the snake uses the two sides of its jaws alternately to  “walk” the prey back, through the mouth and toward the gullet. No need for a knife and fork, or even for grasping hands or paws.
The snake’s windpipe has a special extension, the glottis, that allows the snake to breathe while it is swallowing something large. As the meal moves further along, the body begins to expand because of another anatomical feature--or rather, the lack of one. Unlike humans and other mammals, snakes don’t have a breastbone to tie the ribs together in the front of the body, so the ribs can expand as the meal makes its way down the digestive tract.

The below photo, by Carlton King, shows how this all works: it is the last in a series of photos showing a kingsnake devouring a diamondback rattlesnake that was seemingly bigger than the kingsnake!

Snakes have  many other amazing adaptations that allow them to live their slithery lives, and I hope to discuss more of them in future posts. I find snakes awesome in every sense of the word, and I hope this short discussion has helped you begin to feel that way too.

Sunday, September 04, 2016

As the Dove Turns....A Tale of Obsession and Devotion in the Desert

 Friends on social media know that for the last several weeks I've been obsessed with a particular white-winged dove that nests on my private patio above my sliding door. White-winged doves are among my favorite birds for many reasons I have detailed in an earlier post. This particular bird drew my interest more than three weeks ago when nearly all the other neighborhood white-wings returned to Mexico before a storm arrived. I have been thinking of her as Paloma, Spanish for Dove (and for the Holy Spirit). 

I assumed Paloma was waiting for her babies to fledge, but it soon became clear there were no dovelets in the nest, at least none that I could see. Worse, an egg fell to the ground one day and two days later another egg appeared on the edge of the nest, balanced but not being brooded. Doves usually lay two eggs per clutch, and obviously neither of these would hatch. So why was she still up on the ledge?

I speculated that maybe Paloma was too young to realize she was supposed to join her friends in flying to Mexico. Or that she had been abandoned by her mate. Or... Or... really, why was she still sitting on that nest?

Yesterday, I found out why, when Palomita, Paloma's adorable baby, appeared on the ledge, next to the balanced egg. But this produced a new obsession. Where was Paloma herself?
I did not see her for the rest of yesterday afternoon, even late in the day, and she was not on the nest this morning.  

 Had something happened to her, after all the hard work of brooding this sweet baby dovelet? Would I have to find some way to remove the fledgling from the ledge and learn how to feed it?

By late this morning, still no sign of Paloma. And then I happened to walk by one of the glass sliders to the back yard, and there she was on top of the fountain.

I looked through my binoculars to make sure it was the same dove (she has a healing injury next to her right eye). It was almost as if she had landed there, and stayed there, to make sure I would see her and know that she and her baby are safe. Please join me in wishing them well when they begin their perilous journey back to Mexico. 

Thursday, August 04, 2016

Ant Orgy!

The monsoon, which has been hit-or-miss so far this year, was very active the last several days, culminating in choking humidity this morning before dawn. I thought I saw rain falling, and briefly opened the sliding door, but smelled no moisture. When it began to get light, I saw that something indeed was falling: thousands of small insects!  

I have seen these creatures before. They are flying ants--the sexually mature members of a tribe of harvester or leafcutter ants--which form huge, rotating mating vortices up to twenty feet high. They are very like dust devils, made up entirely of mating insects. They are often thick in the neighborhood at the height of the monsoon. This is the first time I have ever seen a mating cloud form directly above my little patio, giving me a front-row seat.

At one point the fallen ants were so thick you could scarcely see the brick floor of the patio.

 My cats stared in disbelief, occasionally batting at an ant that had somehow made it inside the house. These photos give only an approximation of how intense this event was. When it got a little lighter I went out front and took a video of the mating vortex, showing hundreds of insects falling, while others continue to join the swarm and rise into the air.
By later in the morning most of the ants had disappeared. I didn't see anything eating them, but in the past I've seen birds congregate at the bottom of a swarm to feast.

 I found an excellent description of the ant mating swarms, with great closeup photos, on the “Tortoise Trails” blog, which is written by a fellow Tucsonan named Pam: Flying Ants. In it, Pam explains how these mating vortices form, and what happens to the ants afterward.  (Spoiler: they couple and fall to the ground still mating; the males soon die and the females go off to form new colonies. I got an excellent look at this in person this morning, though did not see any of the spent couples sharing a tiny cigarette.)

Tuesday, July 19, 2016

July Bird Count at Tohono Chul Park

For the last few years I’ve been privileged to take part in official Audubon-sponsored bird counts at Tohono Chul Park. The purpose of the annual Tucson Bird Count (TBC), which takes place each spring, is to document what birds occur on each of over 800 points throughout the Tucson Valley and Saguaro National Parks East and West. Additional, quarterly counts take place in several good birding areas, including Tohono Chul. According to Jennie McFarland, TBC Coordinator, the purpose of the count is not only to learn more about our ever-changing bird population, but to determine how Tucson residents can better share their space with native birds.

At Tohono Chul, the counts are led by a very experienced birder, Jim Hayes, who is retired from the National Science Foundation. At Jim’s invitation, he is joined by three or four Tohono Chul docents who have varying degrees of birding experience.
We begin the count in the eastern parking lot around 5:15 just before the sun comes up, to see/hear owls or other night birds, and to be able to more clearly hear the first dawn songs. Each birding area has six official points, where the group stops and records all birds positively identified. The rules require that the group leader must personally see or hear the birds at the official point. The point counts last five minutes each. Birds seen and heard on the way from one point to another are also recorded (by number and sex, if known). Anything unusual, such as a bird actively building a nest or a rattlesnake, is also noted. The photos in this post are from the midsummer bird count at Tohono Chul, on July 10, 2016.

Point 1.  This point is at the western end of the Park, at the bottom of the Saguaro Discovery Trail. It's a good area for seeing desert birds as well as other wildlife in the wash west of the trail. 

We saw and/or heard a number of typical birds at this point, including: brown-crested flycatcher, cactus wren, Gila woodpecker, house finch, pyrrhuloxia, verdin,  and white-winged dove. 
 On the way to the next counting point we saw a nesting purple martin, in the same saguaro it had used the previous year. (It was sticking its head out of the nest hole, just like the bird in the above photo.) These birds are new to Tohono Chul, having first appeared last year. We knew they were likely to be on or near "their" saguaro, because they'd been seen recently by docents. But we could not note the species in the official point count because the bird couldn’t be seen from the official point, so it was placed on the "supplemental" list. When I asked about the strictness of the rules, I was told that they help make certain that the counts are consistent from year to year.

Point 2.  We picked up a supplemental Lesser goldfinch on the way out of front entrance and to the next official point, in the front parking lot. Sometimes that is where we start the count, and we've been there in the cold dark of a winter morning, where the early birds are already vocalizing. At this point we picked up a few more species (in addition to several we already had), including bronzed cowbird, mourning dove, Abert's towhee, and Bell's vireo, as well as supplemental phainopepla, en route to the next point. When you're on a bird count, you try to identify every bird you see, including distant wire birds, such as this pair of doves:
 We now headed to the next two official points on northeast side of the Park.  On the way we passed a pile of eucalyptus logs, all that remain of the giant tree that shaded the front of the Park for more than forty years, serving as a home to numerous birds, including several Cooper's hawks.
 As we approached the third official counting point, on the Desert View Trail, the sun was just peeking over the Catalina Mountains. 
Points 3 and 4. After  five minutes at the third stop, it was already starting to get hot, so we hurried over to the next point, on the other side of the loop trail, where we were protected by shade, but it was also a bit harder to see birds. 
Points 5 and 6.  We returned to the interior of the Park for the last two official counting points. There were few new species by this time, since it was already too hot for most of the birds (the hummers were still busy drinking nectar--we saw three species overall: Costa's, Anna's, and my favorites, broadbills). We saw more birds than I have mentioned in this report, but I will not enumerate them all except to say that there were approximately 25 species. There was plenty to see besides birds. Tohono Chul is known for its outdoor art, and we saw some new metal sculptures near the fifth point, in the Sundial Plaza:
Heading to our final stop, in the shady Riparian area, we were all hot and tired. On the way we were rewarded with the sight of a supplemental Western diamondback, which didn't move a muscle as the five of us trooped by.
A bush of beautiful morning glories,

A colorful leaf-cutter ant trail,
And the beautiful Texas ranger the ants were dismantling.
We finished the bird count around eight AM, hot and sweaty but satisfied. It is so exhilarating to be out in the desert, even on a hot July day, before dawn. I even love doing bird counts in the winter. Because Jim and usually one or two of the other birders are so experienced, I always learn a lot (for example, this time I learned that the brown-crested flycatcher is most likely to sing his complete, complex song at dawn). I always pick up tips for when I lead my own bird walks at Tohono Chul or the Desert Museum. No matter how many species we "get," there is always the pleasure of seeing and hearing the birds, being with like-minded people on an important purpose, and, at least for the Tohono Chul walk, seeing some of the changes in the ever-changing venue.

For more information on the Tucson Bird Count, as well as ways you can attract birds to your yard, visit the Tucson Audubon Society website.

Saturday, March 19, 2016

Springtime Changes at Tohono Chul

This post is for the many friends I've known at Tohono Chul, especially those who have not seen the changes that began in the last two or three years, including a new designation as Tohono Chul Bistro, Galleries, and Gardens. This post is also for anyone who loves the Sonoran Desert in the springtime. (For some typical flowers, click here.) Spring has started three or four weeks early this year, but is still gorgeous, exciting, and thrilling. If you are in the Tucson area or planning to visit, please stop by. You will be glad you did.

Remarkable Penstemons, near the entrance
Early-blooming hedgehog, across from Overlook
Spring Garden (So far--lots of flowers still to come)
New Orchard east of the former cholla forest
"Living Fence" (ocotillos) north of Ethno Garden
Closeup of living fence leafing out, with early blooms
Old Penstemon Garden
New Penstemon Garden, currently hidden behind cloth fence
Desert Hibiscus on the way to parking lot, saying "Come back soon!"

Wednesday, January 20, 2016

Life and Death of a Saguaro

For eleven years, my husband and I lived in a sprawling brick house on an acre of beautiful desert in the Catalina Foothills of Tucson, Arizona. Many of my blog posts here have been about things I observed and studied from my office, back porch, and front porch. One of my favorite views, from the back of the house, was of a beautiful large saguaro that was probably 150 - 200 years old (they can live as long as three centuries!). Here are some of my favorite photos of that saguaro over the years.
The saguaro in its prime

Whitewing dove at dawn

Once saguaros have grown to a large size they are safe from most dangers except those posed by weather--severe freezes, severe rain and wind events, and lightning. It was lightning that felled our beautiful giant, a few months after we downsized and moved out of the house. 

It took about a month for it to deteriorate to this point

RIP, beautiful saguaro. Let's remember it on a glorious sunset evening.

Monday, October 12, 2015

Reptile Ramble--Close up and Personal

I have written here many times about Reptile Ramble, the educational show we present at Tohono Chul Park in the warm weather. The program is helmed by two professional scientists who are assisted by two or three docents each week, and sometimes I'm lucky enough to be one of the docents.

The aim of the Ramble is to demystify snakes for our audience, and demonstrate why no one ever need fear them. At the same time, we introduce our visitors to many of their local neighbors, including lizards, amphibians, turtles, and four to six live snakes, usually including rattlesnakes. Last week I was one of the assistants, and was fortunate to demonstrate my favorite snake, Leo the common kingsnake. A visitor took a video of my presentation, though it was so windy the sound is very bad. Still and all, this is a good idea of what Reptile Ramble is like, on the docent's side.