I have always looked forward to the month of April in southeastern Arizona, for it brings a great diversity and large numbers of migrant birds to the land – or does it? The first time that I birded the San Pedro River was in April of 1977. In a word, that was a stunning experience. The numbers of birds were incredible, as were the variety of species. Today, the story could hardly be more different.
Migrant songbirds (and other migratory species) have been steadily declining ever since Europeans began to populate the North American continent. The rate of decline was slow at first, but it has increased continually through the centuries. During the past several decades, declines in bird populations have become so severe that some birds have become extinct, while others are persisting by the thinnest of threads.
Here in the Middle San Pedro Valley, I have been participating in avian surveys and have been keeping detailed records of local bird life for 21 years. The data is disheartening, but this year has been the worst thus far. Numerous species that have appeared on schedule at our property every past April are simply not appearing. Many others are here in very low numbers. Sadly, close to 100% of these declines are attributable to mankind. Overpopulation, urban expansion, climate change, pesticides and herbicides, tremendous habitat losses, loose house cats, and more add up to a world that is becoming quieter and quieter every spring.
What is spring without bird song?
Other happenings in the natural world have been occurring as well, ones that are not disheartening. Lizards and snakes have awakened from their winter brumation to add their grace, color, and life to the land. A few days ago, a Sonoran gopher snake appeared a few feet from my doorway, followed by the year’s first diamondback rattlesnake and the emergence of Clark’s spiny lizards. Our resident ravens, Mike and Mavis, have successfully hatched yet another brood and are very busy keeping their youngsters well fed. A nice abundance of wildflowers is coloring the upland slopes.
Every year in this valley seems to bring its own explosion of certain insects. Earlier this month, incredible numbers of crane flies could be seen. I recall walks where every step flushed 20 or more from the surface of the ground. Crane flies belong to the family Tipulidae, with over 15,000 species worldwide. They are a successful and adaptable group of insects, for their presence in the fossil record dates back over 70,000,000 million years.
Late in the evening of April 17th, new sounds could be heard emanating from the surrounding mesquite bosque. Barely audible but familiar from prior years, the sounds were raspy, tremulous, unique. They were the first thin cries of hatchling ravens, born to none other than our pair of resident Chihuahuan ravens, Mike and Mavis. This new brood marks their seventh successful nesting on our property and their first in the new nest (described in my previous blog post). As always, we are honored to share habitat with these regal birds. We look forward to watching them raise and teach their young. Few North American birds spend as much time rearing and educating their young as ravens do.
The past year has been the driest I have ever witnessed in southeastern Arizona. Last year’s crucial summer rains barely happened here in the Middle San Pedro River Valley, and the following winter rains were extremely sparse. The landscape is desperately dry, even for a desert, so signs of spring have been more welcome than ever. One of them appeared several weeks ago when a black swallowtail flew in to get a drink from a muddy patch of soil near one of our bird water dishes. Butterflies play very important roles in the ecology of this ecosystem. They grace our lives with their flight and their remarkable beauty.
Another sign of the changing seasons was the emergence of a beetle known as the fiery searcher. Just over an inch in length, these beetles display gorgeous coloration; an indigo-purple head, thorax, and legs with emerald green, iridescent elytra (wing coverings). This marked the first time that I have ever encountered this species here in a mesquite woodland. Usually, I find them in the riparian cottonwood-willow forests along the San Pedro River.
Another certain sign of spring is the emergence of reptiles. A few weeks ago, I had a surprise when I retrieved a wheelbarrow from an open shed. I always keep wheelbarrows flipped over so that rain water cannot accumulate inside and rust them out. When I flipped the wheelbarrow over, here is what I found…
I have found rattlesnakes under my wheelbarrows more than once in the past. All snakes – including rattlesnakes – are always welcome on our land. We never kill them. Once in a rare while, I will capture and move one to a safer locale, but usually I simply let them be, like this one. I do my best to respect all life!
Yesterday, another sign of spring showed up nearby, a beautiful glossy snake. They are among the most common snakes in local mesquite bosques. Glossy snakes can reach lengths approaching four feet and feed on mice, kangaroo rats, lizards, and other snakes.
The local stands of mesquite furnish very high quality firewood in addition to providing crucially important habitat to numerous wildlife species. Recently, a dead mesquite was felled here on our place that was threatening to crush one of our buildings if it were allowed to fall naturally. I sawed it into firewood. Other dead trees are left standing, for they are very important to many living creatures and to the health of the soil that they will eventually become a part of.