Have you ever wondered how scientists know when the population of a species is increasing or decreasing? Do they go out and count every single one to see how many there are? Or is there an easier way to do it?
A food web is a way of seeing how energy is transferred from organism to organism. All living things need energy. They use it to move, to grow, to reproduce. That energy has to come from someplace. Drawing a food web is a great way to get an idea of how that energy is captured by producers, and passed from organism to organism. It helps us see that even things that we usually don't like, such as weeds and mosquitos, play an important role in the ecosystem.
I got the idea for this experiment while watching the sand hill cranes feeding in the fields around Hastings, Nebraska. To most people, bird watching means trying to identify different kinds of birds. Really, that is bird spotting. Bird watching means finding a bird and watching it, to see what it is doing.
Now that we live in Johnson Canyon, Utah, we have all sorts of wildlife wandering through our yard, but we saw plenty of wildlife even when we lived in the city. All it takes is a walk to the neighborhood park.
I photographed this unusual tree in a park in Jacksonville, Florida. The orange things are ripe fruit, and the green ones are .....green fruit. What is this tree, and why is considered to be an undesirable, invasive species?