Wednesday, April 29, 2015

Snake sex!

You've probably seen a photo or video of two snakes standing on their tails, intertwined, swaying back and forth, and may have thought this was a picture of snakes copulating. Nothing could be farther from the truth--when two snakes engage in this sort of "dance," as it is called, they are most likely males engaged in ritual combat. 
Oregon rattlesnakes, via Wikipedia
 The snakes I have observed having sex are much more sedate: generally they lie next to one another, with the male's tail wrapped around the female, holding their bodies close together while the male inserts his hemipenes (two penises) into the female's cloaca. The beautiful kingsnakes (Lampropeltis splendida) below began their romantic activities in the afternoon a couple of days ago, and I was told they were still together at sunset, but were gone by the next morning.

Photo by RobandUrsula Garrwald
The pair of western diamondback rattlesnakes (Crotalus atrox) in the photo below began copulation during a live music show at Tohono Chul Park one Sunday afternoon, and were still at it when I took the photo the next day. I was told that the female occasionally wandered off (to eat?) and then returned to resume activity.

Here is the possible outcome of such amorous activity: several baby diamondbacks from a group of eight that were born in a hole underneath an organpipe cactus a few months later, not far from the scene of the mating.

Note that the baby rattlers are so young their eyes are still cloudy

Friday, April 24, 2015

Do Hawks Fly for Fun?

On a beautiful spring day early this week my docent buddies and I were roving at Tohono Chul Park, enjoying the weather and the beauty all around us. Our resident pair of Cooper’s hawks seemed to be roving too--soaring from one end of the Park to the other, sometimes seeming to chase each other, sometimes simply moving in the brilliant blue sky in perfect synchrony. One of my friends, a retired scientist, speculated on what the birds were up to--was this a mating ritual, perhaps, or were they competing for food? They have already started a nest, so mating seemed unlikely to me, and there didn’t seem to be any competition or hunting going on. I remarked that they just seemed to be having fun, to be told by my friend that I was veering dangerously close to anthropomorphism.

I’ve written about this topic previously, and invite you to read the earlier post and the lively comments it engendered. I believe that invoking anthropomorphism is a defense mechanism used by those who study and sometimes harm animals to suppress their own natural empathy. Anyone who has ever had a pet has certainly seen a full range of emotions and behaviors exhibited by the pet, from love and excitement to fear and even deceit. I’m quite sure that wild animals too experience these feelings and perform these behaviors. I will never forget the grief and despair I saw a mother dove exhibit when a gopher snake devoured her fledglings. She remained on the ground underneath the nest for hours, looking forlornly up. The next day I saw her sitting on the empty nest. You will never convince me she was not feeling emotional pain.

I keep forgetting that anthropomorphism is still an accepted principle of scientific thought--something to be shunned lest you not be thought a serious scientist. I have a lot of scientist friends, and imagine that most of them still have this dogmatic view of anthropomorphism. But it’s also true that attitudes have been changing for quite a while, and many very respectable scientists now accept at least the possibility that animals have feelings too. Certainly not feelings exactly like human feelings, because they sense the world in different ways, but feelings nevertheless. Franklin D. McMillan, a brilliant veterinarian, has written about this topic in his book Unlocking the Animal Mind. Dr. McMillan points out that it doesn’t make sense that emotions suddenly emerged full-blown in human beings, without first having evolved in other animals.  

This lovely photo is used with permission of the photographer, Sharon Elizabeth Yocum
Anyway, back to the hawks. They continued to soar above us as our discussion went on. As their beautiful streamlined bodies flashed in the sunlight, I imagined them having breakfast together, then one of them communicating something like, “It’s such a beautiful day, let’s go for a soar!” And so they did, their seeming joy in this beautiful spring desert day mirroring the joy of the four humans on the ground watching them.

Monday, April 20, 2015

Cactus Color Wheel

April is a great month in the Sonoran Desert because wildflowers and trees are still blooming and the cactus have begun to chime in with their gorgeous, waxy flowers. The flowers pictured here are mostly from the staghorn cholla, Cylindropuntia versicolor. "Versicolor" refers to the fact that each plant has a different color flower. Most are in various shades of red, orange, and pink. The last flower in the series is from a different but related cactus, which I believe is cane cholla. I took all of these photos on a walk on desert trails in Tohono Chul Park.

Saturday, April 04, 2015

Palo Verde Glory

This is the best time of year in the Sonoran Desert: Spring, lasting from sometime in February to usually the end of April or even into May. We looked at some wildflowers in the previous post, and I'll post pictures of cactus blooms soon, but today I want to highlight the amazing and startling palo verde blossoming, which has just begun and will last another couple of weeks.

Everywhere you go in town and out of it, particularly in the foothills, you will be awed by the brilliant displays of palo verdes in bloom.

These gorgeous trees were flowering alongside the Rillito River
There are two main types of palo verdes--the Blue Palo Verde, which blooms first, and the Foothills Palo Verde, which blooms a week or so later. The Blue blossoms are a deeper yellow color, like the filling in a lemon pie. The Foothills is paler, more like lemon pie with meringue. The difference is caused by the fact that the petals on a Blue Palo Verde are all yellow, while the Foothills tree has one white petal on each flower.

Blue Palo Verde Blossom
Foothills Palo Verde Blossom
This beautiful Blue Palo Verde greets visitors in the central part of Tohono Chul Park:

 Whenever I'm driving around, my heart feels as if it has stopped when I come upon one of the thousands of our glorious palo verdes and its magnificent blossoms. I'll leave you with a long shot and closeup of this stunning tree that I saw a couple of years ago in a medical plaza.