Inquiring Minds Want to Know!
By Jackie Willis
May 1, 2003
Mrs. Macht's 5th grade class at the Hillside School in Bridgewater - Raritan, New Jersey has given me a list of questions that they have composed regarding the ecology of BCI. I chose to answer these:
1- Why are some organisms so particular about their habitat requirements and others are not?
Organisms tend to use one of two main strategies for success-- either they generalize or they specialize. Generalists are not very particular. A generalist may eat a great variety of foods or use many ways to catch their food. Specialists are very picky. Specialists have a well-developed or highly- practiced way of feeding on perhaps just a few kinds of food.
For example, in New Jersey, blue jays may feed variously on insects, seeds, fruits, and garbage. They are intelligent birds with bills that are not special, and they use their intelligence to handle many different kinds of food. They can live in a variety of habitats-- different forest types or even in parks in cities.
Hummingbirds have long, thin bills that are best used for reaching into flowers and sipping the nectar inside. A blue jay can't do this at all; but this is almost the only way a hummingbird can feed. They can also fly up and grab an insect in mid-air, but it must be tiny. So hummingbirds are restricted to habitats that have lots of flowers that produce large quantities of nectar,
usually hidden inside a tube- or trumpet-shaped flower.
It's sort of like the difference between a supermarket manager and a baker in a bakery. The supermarket has all kinds of food, and may even have baked goods, so it's a convenient place to pick up lots of food. This is a generalist store, run by someone not skilled in baking. A baker is skillful in one task and the bakery specializes and usually has only baked goods-- but the bakery can usually produce better cakes and bread than a supermarket. Both can succeed as long as people need good cakes as well as a convenient way to shop for many foods.
2- How can there be so many different species of insects on a single tree?
When we look more closely at specialization, we find that it's a great way for many species to live in the same habitat without competing for food or other necessities. One species of insect might feed on the inner bark of the tree, while another eats only the tender buds. A third species feeds only on the mature leaves but lives just within the space between the upper and lower surfaces of the leaves. Being small is an advantage, and being specialized also helps. If each species eats only one small part of one type of structure on the tree, the various species may never even meet each other! So specializing makes it possible for many insect species to coexist.
3- Have there ever been poachers on BCI?
Yes, indeed! There aren't any poachers now on BCI, and probably not for several years. There still are poachers in the park areas on the peninsulas near BCI. We are glad to have a group of brave and watchful game wardens (guardabosques) who patrol the island day and night in boats and on foot to protect the forest from hunters and tree-cutters. About 12 years ago a game warden was killed by a poacher on one of those peninsulas, so this is a risky job. It's thought that poachers in the past contributed to the extinction of several species on BCI.
For example, white-lipped peccaries are a type of native wild pig, and very delicious. They were apparently hunted to extinction in this part of Panama. Their predators, pumas , were also exterminated from BCI. We are fortunate that some pumas have recently crossed the water to live on BCI again. Tapirs are among the first mammals to be killed off by hunters because they are very large and edible. Tapirs have such odd faces, they are cute rather than ugly, and are the largest animals living in the tropics of the western hemisphere. We value the small population of tapirs living on BCI.
Tree-cutters in many parts of Panama also destroy entire sections of forest by taking away the trees. This loss of habitat is even worse than killing individual animal species. Without the forest, there is no place for the resident animals to live. We have been working to study many species before they die off because of habitat loss. People who wish to help preserve habitats or support the study of existing habitats can contribute to various funds for research, such as "Habitats for Wildlife" or Adopt-an- Ocelot Fund.
Thank you for your excellent questions: we don't know all the answers, so there's plenty for you to explore when you grow up. Hopefully we will preserve enough that you will have something to investigate!