Hearing
While humans commonly use their ears for very important functions in language, often the sounds of nature are ignored as background noise. But if we take seriously our call to listen to what God is saying, then it seems that is central to our lives as Christians.
To begin, have your group sit and be silent, simply observing the different sounds that they can hear around them. It is remarkable how many more sounds became apparent if one is fully paying attention. Have the campers describe the sounds as best they can and indicate the direction from which they heard the sounds [1]. Ask the campers to discuss how they hear God's voice, and if God might be heard in the world around them.
Next, play a memory game by having the campers close their eyes and listen again to the sounds around them. This time they must remember, as best as they are able, the direction from which the sounds are coming. As they are listening, make a quick map of the sounds in the area, so that you can quiz the campers at the game's conclusion. After they open their eyes, ask them to point to the direction from which a certain bird called, and so on. This activity emphasizes how vital sound is in making an animal aware of its environment.
Like humans, animals use sounds for a wide variety of purposes, one of which is finding each other. Assign each member of your group a species of animal to imitate - lion, bird, horse, sheep, etc. There should be two or more members imitating the same animals. And then with eyes closed, have the entire group make their sounds and attempt to find each other based on the noises. While the cacophony that results will be confusing, the participants should be able to hear their own particular species among the din. Sounds, just like visual field marks, are distinct for each species. For interested or more advanced campers, this observation can be a segue to more intense attempts to identify birds by their songs.
Much like binocular vision, the ears must also work together in order to determine the location of noises. Prove by having the campers sit in a cluster all facing one direction. Have them close both eyes and plug their right ear with the index finger. The naturalist should then move around the cluster hooting intermittently, with the campers pointing at the sound. With only one ear open, the sound appears to come from a very different place then where the naturalist is actually standing. After a few hoots, have the campers open their eyes and see how close (or far) they have come to pointing at you. Repeat the activity with the other ear closed and then with both ears open. Discuss how important hearing is to animals and the great value of having two ears to more accurately tell the location of a sound. I often add a point about owl ears being slightly offset (one higher and one lower on the head) to make the process of honing in on an object even more sensitive.