NATCHEZ NATURALIST NEWSLETTER:
April 7, 2002
GREEN TO MAKE THE HEAD SWIM
The other morning I was staring into this three-dimensional super-greenness while listening on the radio about the upcoming Shuttle lift-off, and about the project in store for it upon reaching the orbiting International Space Station. The juxtaposition of this green-staring and radio listening conjured a flash of insight, or maybe even a vision.
But first, you should know that the Space Station is a gangling thing bristling with solar panels. You can see it on the Web at spaceflight.nasa.gov/gallery/images/station/assembly/h tml/sts105-707-055.html. If nothing else, that picture shows that NASA understands about life's fundamental and elemental needs and priorities.
My fleeting, radio-listening "vision" was this: The Sweetgum saplings around me right now are doing exactly what NASA is doing with the orbiting Space Station. Both the Sweetgums and the Space Station are putting out their solar panels to capture energy needed to function and stay alive. For a split second I could see my Sweetgums as just as vulnerable and desperate for energy as the people in the Space Station, and I could see so clearly that once all romance is swept away, the basics are the same everywhere.
Both the Sweetgum saplings around me and NASA are confirming and celebrating a fundamental formula around which Earth life has crystallized. That formula is this:
the sun --> capture of sunlight energy --> that energy used to grow and evolve
These little piles of crumbly dirt aren't made by ants, but rather by Digger Bees -- bees who excavate tunnels in the soil and dump the removed dirt at the tunnel entrances, like ants. The bees are small ones, very similar to "Sweat Bees." Technically I think they are called Andrenid Bees, of the family Andrenidae. You can see one at www.pollinator.com/gallery/andrena1.jpg
Like thousands of tiny black helicopters flying no higher than an inch (2 cm) above the ground they dart, zigzag and hover. Sometimes one will drop, enter a tunnel and return and take flight again, but it all happens so quickly that my sluggish nervous system can't register what they are doing. I can't see that they accomplish anything with their interminable maneuvers, but they must be doing something important because of all the energy they invest in it, hour after hour.
Females dig the tunnels, lay eggs in them, then provision the cells with nectar and pollen as food for their eventual offspring.
The Internet provides many pages about these bees, mainly because some people worry that the bees will damage their lawns or sting them -- though they don't damage lawns and they won't sting unless you rough them up. On the other hand, it's hard to find information on the bees' natural history. After much searching I found one site in California mentioning that they have an "obligate pollination relationship" with certain rare plant species. That means that certain Digger Bees have co-evolved with certain plants so that they need one another -- their relationship has become obligatory. Kill the bee, and the plant may disappear because of the lack of a pollinator.
On the Web many pages tell how to kill the bee, but I could find only this one saying why the bee is any good at all.
This time last year I had just a few scattered individual plants which hardly showed up in the grass. This year their abundance surprises me. But it's a good kind of surprise to have.
I know these fish from my childhood in Kentucky, for they along with crayfish inhabited the drainage ditch running by our farm, making that ditch one of the most fascinating places imaginable for a little boy. Back then I wondered how such a tiny fish could make its way into that drainage ditch, since the nearest real stream was miles away, and the ditches in between were choked with cattails and other clutter. My wonder is no less today.
On the Internet you can find plenty about this fish for two main reasons. First, a lot of attention has been given it as a "biological control agent" against mosquitoes. The fish eat the mosquitoes' aquatic larvae, the "wiggletails." Second, in some places, such as Australia, introducing the fish for mosquito control has proved to be a big mistake.
It's been a mistake for the same reason it's nearly always a mistake to introduce alien plants and animals into a natural setting. As has been the case here with European Starlings and Asian Kudzu, when the exotic species arrive without their natural predators and competitors they often push native species aside and take over. In Australia our Mosquitofish eat the eggs and fry of native fish, hurting those populations, plus our Mosquitofish doesn't eat any more mosquitoes than the native Australian species.
Once Mosquitofish are introduced into an area their populations can explode. A female gives birth to an average of 40-100 live fry, 3 or 4 times a year. Note the words "live fry." The mother's eggs hatch inside her body, so when the fry emerge they are fully formed and ready to go.
You can see a picture of Mosquitofish and read about their mosquito-control possibilities (including the fact that ten Mosquitofish in a large birdbath will control mosquito larvae hatching there) at www.mda.state.md.us/mosquito/mosqfish.htm
That's because most birders develop an uncanny talent for precisely locating the positions of singing birds with their ears before they begin looking with their eyes. I seldom notice this ability until it's gone. This week, with one ear closed down, I have been at a loss to say whether a bird was before me or behind me, to the right or left.
There's a benefit to this loss, however, assuming that the hearing returns as it always has. That is, this reminds me of what an amazing invention the human body is. I am reminded of all the things that can go wrong with a body to affect not only its hearing, vision and the other senses, but also the sense of balance, blood-sugar level, the functioning of the heart and brain...
Sometimes I reflect on the fact that back in 1947 the button on my body-machine was pushed, and I've been going every since with very modest maintenance, just providing it with fuel. In college I studied the chemical pathways involved in metabolism and respiration, how blood pH is buffered... It is all so complex, so majestically ingenious. It is amazing that we can ever feel good for a moment, yet I feel good nearly all the time. Every moment of feeling good is a tremendous gift...
THIS WEEK'S MIGRATING BIRDS
The most conspicuous change since last week is the arrival of the Red-eyed Vireos. Last week there were none, this week 19 -- and their numbers will only grow. This is another species which most fervent backyard birders may never have heard of, despite the statement in Robbins' Birds of North America that this is "The most abundant bird in eastern deciduous forests." The trick is the forest part; it likes the woods. Sometimes it does occur in city parks and even among shade trees in some woodsy suburbs, but it is a small bird that usually stays high and well hidden. You hear fifty for every one you see. There's one pictured at www.assateague.com/data-bird/vireo-red-eyed.jpg