a) Students are usually very interested in the Rainforest theme and can be easily encouraged to read and write.
b) We have an expository text on the Rainforest in our reading series and I am required to base lessons off of our core curriculum materials. (So I would have to do this anyway.)
c) There are hundreds of free resources and extensions available online.
d) Our school was in the middle of FSA testing. Although I don't have any students testing this year, the resource teacher next to me is testing every day which means my class needs to be close to silent for the entire morning block. Brutal (for the kids and me.....so I held out the carrot....if we were super quiet in the morning then we could do some fun, noisy rainforest activities in the afternoon.)
One of my favorite things we did with the unit was to write our own Rainforest Riddles. I found a free pdf from First Grade Hip Hip Hooray on Teachers Pay Teachers. The set gives several rainforest riddles already written that the students have to solve. It has a nice set of graphics for a simple read, then cut and paste activity. Finally, it also includes graphic organizers to help students write their own riddles.
My class really loved writing their riddles "in secret" and creating their animal from pieces from our arts and crafts scraps/materials. We then combined all of our animal creations to make a rainforest bulletin board.
Here's our bulletin board. Sorry! The picture is a bit fuzzy and I still need to add "forest floor" to our layers.