Tag Archives: desert

Birds of the Sonoran Desert

Birds, ,

 

Black-throated Sparrow

I am a wild flower guy.  But this is the worst wild flower year in Arizona in at least 15 years and perhaps ever. So I have been forced to adapt.  Instead of wild flowers I have pursued birds. I love birds too, but unlike flowers, they don’t often stay in one place. That makes photographing them tricky.

“In many experts’ view, dinosaurs never really went extinct. Small ones, whose scales were modified into feathers, can be seen almost anywhere you look.”[1]

Any creature that lives in the desert has a big challenge–how to survive. Surprisingly many creatures do survive here. Some even thrive.

At first that sounds hard to believe. After all water, which is absolutely essentail for any animal to survvie is hard to find. Added to that, it is often hot here and as it heats up so does evaporations, tending to elminate what little war was here in the first place. As if that is not enough an animal’s need for water increases as the temperature increases. I can testify to that. Sometimes, on a hike, I have thought water was not required. That is always a mistake. I try to make sure I always have water along, and usually I need it.

Finally, when it is hot it is difficult for organisms to maintain their correct body temeprature. So how do they do?

The answer is that every creature that tries ot live here must have a survival strategy. And it must be a good one. That applies to mammals, insects, and birds.

The most common strategy is avoidance. Like lazy boys who hate work do their best to avoid it, so animals of the desert try to avoid the heat. Many do that by sleeping during they day. Usually there are more animals active at night than during the day.

The birds that are nocturnal like owls or crepuscular (dusk-to-dawn) have an advantage. For example. Owls use this strategy. Despite the challenges I was surprised to learn from a veteran birder, that out of the 50 states in the United States Arizona had the third highest numbers of distinct species. Only California and Texas beat it! And both Texas and California have long coasts with wonderful sea birds and shorebirds. Even Florida and Alaska which are both famous for their birds, have less varieties that can be found there.

Why is that? The answer is diversity. Arizona has diversity of terrain. It has mountains, it has plains, it has grasslands, and of course, it has deserts. Add those up and that makes birds. Surprisingly many bird species.Despite the challenges I was surprised to learn from a veteran birder, that out of the 50 states in the United States Arizona had the third highest numbers of distinct species. Only California and Texas beat it! And both Texas and California have long coasts with wonderful sea birds and shorebirds. Even Florida and Alaska which are both famous for their birds, have less varieties that can be found there.

According to Wildbirds.com, California has 664 species of birds, Texas 644, and Arizona 555. Manitoba by comparison has a paltry 390.

Why is that? The answer is diversity. Arizona has diversity of terrain. It has mountains, it has plains, it has grasslands, and of course, it has deserts. Add those up and that makes birds. Surprisingly many bird species.

 

The House Finch was introduced in the eastern USA and over time has expanded its range from their to most of North America, including both Manitoba and Arizona.

Contrary to what I just said, the Cactus Wren is not shy and will stand still for a photograph, unlike my even more lovely grand daughters.

[1] Douglas H. Chadwick, Enduring America, (1995) National Geographic Society, p. 96

Sonoran Desert

religion,

 

We have been staying in southern Arizona for 3 months for the 4th year in a row. Where we live is part of the Sonoran Desert. It is fantastic place. It is what keeps us coming back.

According to A Natural History of the Sonoran Desert it contains 100,000 sq. miles according to the current definition of what constitutes a desert. In any event it is big.

Usery Regional Park where we spend a lot of time contains about 120,000 acres of the Sonoran Desert. This is really just a small part of it. The park is part of the Maricopa Municipal Park system, the largest such system in the United States.

We have often gone on guided walks with Ranger B from Usery Park. He said that when he first appeared in the Sonoran Desert after living in Wisconsin he thought he had landed on another planet. I know what he means. I had the same experience when I first saw the Sonoran Desert and compared it to Manitoba. It was a different world. All the plants and all the animals were so different.

On one of our guided walks, Ranger B asked us what was the toughest thing in the desert. One person said the Gila Woodpecker, another said the rattlesnake, one said mountain lion, and another said coyotes. Ranger B disagreed. He said in his opinion the the toughest thing must be a plant. Plants of the desert are very tough. The animals can move. They can find shady spots when the sun is hot and a warmer spot when it is cold. Plants are stuck in one place. They have no choice but to adapt. If it is 120 °F that is just too bad for the plant. It must accept that for it cannot run away or hide.

There are about 2,500 plant species in the Sonoran Desert and many of them are extremely tough. Otherwise they would not be able to survive here.

The Sonoran Desert has the greatest biodiversity of any of the 30 (or so) deserts of the world. That is because it has more precipitation than most deserts and the granitic soils are permeable and hold water well. It also has mild winters. Some deserts get very cold in winter. It is also blessed by having 2 rainy seasons, one in summer and one in winter. This diversity is quite visible in Usery Park. Looking at the desert from inside that park makes one appreciate the variety of plants. Vegetation is not as sparse as one might expect.

This is from San Tan Mountain Regional Park, another park we frequently visit.

Ranger B explained that this year this year however it received a lot less rain than normal and to make things even worse, with higher than normal temperatures. That is not a good combination for deserts. He said in his 15 years here he has never seen the desert so stressed. That is really bad for a wild flower guy like me. It is the worst wild flower season he has seen in 15 years and it might the worst ever. That is how dry and hot it has been. Great for tourists; not so great for wild flowers. This is a big disappointment for me, as I love to photograph wild flowers.

In extremely dry years plants do not even issue forth leaves, let alone blossoms. The roots lie dormant and wait for better years and thoughts of reproduction are tamped down until the good times return.

Meanwhile wild flower photographers like me gnash our teeth.

Deserts

Natural History, religion

 

What is a desert? That is not as simple as I thought. Deserts are defined by water—or rather, by the absence of water. Dryness and sunlight are what deserts are all about. Buckets of sunlight, rather than buckets of rain. Plants or animals that don’t like that cannot survive here. Some plants, amazingly, even prefer the south facing side of the mountain.

Geographers define deserts as land where evaporation exceeds rainfall. I was surprised to learn that there is no specific amount of rainfall that serves as an agreed upon criteria as what is and what is not a desert. Deserts range from extremely arid regions to those that are ample for the support of life. Geographers classify rainfall into semi-deserts that are ones that have precipitation between 150 and 300 to 400 mm per year. So called “true deserts” are those that have rainfall below 150 mm per year and extreme deserts as those with rainfall below 70 mm per year.

Deserts occupy about 26% of the continental areas of the world. Deserts occur in 2 distinct belts. One is between 15º and 35º latitude in both the Northern and Southern hemispheres—the Tropic of Cancer and Tropic of Capricorn.

There are 14 deserts in the world (depending on who is counting) with an area larger than 52,000 sq. km (20,100 sq. mi.). It may surprise some that the largest desert in the world is not the Sahara desert. It is only the second largest. The largest is Antarctica not often thought of as a desert, but that is what it is. Antarctica has 14,000,000 sq. km. and the Sahara with 9,000.000 sq. km.

There are 5 distinct deserts in the American Southwest: the Sonoran, The Chihuahuan, The Great Basin, and the Mojave. Some also include the Colorado as a separate desert. Although each is a desert, each is also different.

The Sonoran Desert, where we have been living for the 4th year,  is semi-arid desert and it covers part of southern California and Arizona as well as northern Mexico. Because of summer’s “monsoons” and winter storms this is the wettest of all the North American deserts. It is most well known for its iconic tall Saguaros cactus some of which can reach 50 feet in height.

The Great Basin is the most characteristic of the Southwest with its canyon, mesas, buttes, and cliffs.

The Mojave Desert is a large desert that spreads across northern Arizona, Nevada, and California. It is dry most of the year but a small amount of winter rain can bring it to life.

The Chihuahuan desert is found mainly in Mexico but reaches north to Albuquerque, New Mexico, so we spent some time in it too.

One of the things that struck me about the desert was the amazing way that plants grow there. If you have a pine forest, unlike our pine forests, the trees are not crowded. They are well spaced. Where shrubs cover a mountainside, they do so in the most spotty of fashions. Vegetation never covers the ground, even where it grows best. The plants demand space from all around them—like snooty royalty.

The plants even want some separation from those fantastic rocks that I love so much. Usually they are found well-spaced, like surprisingly obedient school children. Willa Cather put it well. She said,

From the flat red sea of sand rose great rock mesas, generally Gothic in out-line, resembling vast cathedrals. They were not crowded together in disorder, but placed in wide spaces, long vistas between them. This plain might once have been an enormous city, all the smaller quarters destroyed by time, only the public buildings left.