Building on student interest in animals and the environment, this lesson starts with a review of “Outback Steakhouse” by Marina Kamenev, an article we recently read on this topic. And, no, it is not about the restaurant but is about Australia and a certain type of meat that may soon be on menus there: camel. These animals were brought there many years ago to work but were eventually let loose in the wild when trucks and trains took over their jobs. With no natural predators, the number of camels skyrocketed. Now they have become a nuisance damaging property and destroying the fragile desert environment of central Australia.
Right away a student asks, “Just what is an invasive species? And how come you sometimes say invasive alien species?” I tackle the last part first by replying “If someone came here from another planet we would call that creature an alien, right? That’s because they are not natural to Earth’s environment – human beings, oak trees, fungus and thousands –probably millions- of other organisms are, but not Martians.” Then to address the first part of his question, we go to invasivespecies.gov and students spend a few minutes with a partner going over the Invasive Species Fact Sheet to clarify the meaning of invasive species. When asked if they found anything interesting, they have wonderful connections to share. One student mentions that it makes sense to wash off hiking boats to stop the spread of a species from one place to another because “my boots always have gunk on them and who knows what lives in that!” Another student offers to find out what invasive species are in our area. I encourage him to do so and to share what he discovers with us.
For the next part of the lesson, students have the opportunity to become the expert on one type of invasive species: Burmese pythons, fire ants, killer bees, zebra mussels or Asian carp. I arrange students into mixed ability groups of five and pass out packet that contain five articles to each person. You can just give each table group one set of articles from which the students each take one, but I find that they enjoy this topic so much that many want to read them all! They talk among themselves to decide who will read each one. The articles about snakes and ants are at a lower reading level, so I direct struggling readers to these. I try to do confer with those students before class starts so they do not feel uncomfortable in front of peers and will be able to access the content of the text and fully participate in the activity.
Using the “Outback Steakhouse” article as an example, we decide that for a species to become invasive a few things need to happen, first they have to end up there or arrive. Then the right factors must exist, as mentioned earlier, for them to survive and a species becomes invasive when they thrive and take over an environment. I write these three words on the board and students write them in the margin of the article. As they read the text, they will add an A next to information about the species arrival, an S next to areas that explain how the species survived, and a T next to areas about how the species takes over an their new habitat. Along the way, I discover the need to clarify directions, as explained here.
The rest of the class is spend in silent reading and in the completion of the annotating process. I circulate among the table groups answering questions and checking in with the readers. There are some questions about unfamiliar terminology but for the most part everyone is on task, engaged and successfully making meaning of the text.
Using the same annotating system on each article will allow us to pool information from all five to deepen our understanding of the environmental problems created by invasive species, but that is another lesson…