Edwards YMCA Camp
and Conference Center
N8901 Army Lake Rd
East Troy, WI 53120
Phone: (262) 642-7466
Fax: (262) 642-5108
Email: camped@campedwards.org
Night Hawks
Summary TO KNOW THE DARK By Wendell Berry To go in the dark with a light is to know the light. To know the dark, go dark. Go without sight and find that the dark, too, blooms and sings, And is traveled by dark feet and dark wings. Explanation: We use our senses to take in information and learn what is happening in our environment. Our five external senses (sight, taste, touch, hearing, and smell) receive information about things outside our body. Normally we depend on our eyesight more than any other sense. At night, our vision is limited so we must depend more upon our other senses. Nighttime is a good time to find out how keen our other senses are. After setting the guidelines for the night hike, proceed outside and begin the hike. Every 5 or 10 minutes stop and do one of the activities. You may not have time to complete all of the activities. Activities Scents Take a scented container from the Night Hike Bag (Keep the containers tightly closed until ready to use.) Have the group form a circle before explaining you will be passing around something to smell. Ask the students to smell the container's contents but to not share the name of the item. When it has gone around the circle, ask for responses and discuss how they came to their decision. Repeat with the other containers. After smelling one or two items, ask the students to think about a dog's nose. It is wet and the moisture helps carry the scent. To demonstrate this, the students can lick their finger and rub the underside of their nose before they smell the next scent. Ask if they notice a difference. Natural and Unnatural Sounds Have the class gather in a circle and listen for any sounds they hear. After identifying sounds, have the students decide whether the sounds are natural (made by plants and animals) or unnatural (made by people). Next point out sounds the students may have missed. Some natural sounds to listen for could be owls hooting, trees squeaking, wind in the trees or grasses, water gurgling, ice cracking, falling objects, etc. Unnatural sounds may include radios, cars, people talking, airplanes, etc. Using their hands cupped around their ears, have students listen to see if they can hear any animals. Their hands funnel in sounds. Many predators and prey have large ears to help hear other animals. Explanation: Sound travels farther at night because of the wind dying down. We are also acutely aware of sounds as our world closes in due to the darkness. Touchy Feely Ask the students to pass natural objects i.e. a pinecone, around the group, feeling each of the objects as it passes by. Using their sense of touch only, ask them to identify the objects. When using plant materials, take the class to the place where you found the objects if possible, and ask the students to try to locate the trees from which the leaves or other objects may have fallen. Night Vision Ask the students to stand in a circle and cover one eye-it doesn't matter which one. (Tell them to cover it well so that no light will enter that eye.) Have them keep the other eye open. Explain that you are going to light a candle and you want them to stare at the flame until you blow it out (about a minute or until the story is done). After you blow it out, have the students open their covered eye and close the other. Can they describe any differences between what they can see with the eye that was covered and with the uncovered eye? While the students are staring at the lit candle you can share the story of "Utie" to pass the time staring at the flame. This story also starts to explain night vision. (Story is included in Resources section.) Explanation: Looking with what had been their covered eye, things should appear closer and brighter. This is due to a chemical called Rhodopsin. Our eyes produce this chemical in low-light situations to improve our night vision. In fact, within 5 minutes of being in the dark, we can see 1000 times better than when we initially went into the dark. The catch is that when our eyes are exposed to light, all of the Rhodopsin we have been producing is instantly destroyed, making our night vision poor again. Our eyes will not be able to produce the Rhodopsin again until we are out of the light. Colored Paper Hand out a 2 x 3 piece of colored paper to each child. Ask them to look at it (in the darkness) and guess what color they think it is. Have the students put the paper in a pocket. When you return to light, have them check to see if they were right. Explanation: Colors are nearly impossible for humans to see at night. We have two types of cells in our eyes: rods and cones. Rods are helpful for seeing black and white and shades at night and cones allow for seeing in color. We have many more cone (color) cells than rod (night vision) cells, therefore our color vision is great during the day and our night vision is poor. The only animals that see colors nearly as well as humans are diurnal birds. Wintergreen Lifesaver Activity In a darkened area, have the students pair off and face each other. Give each student a wintergreen lifesaver. One member of the pair should be instructed to watch the mouth of his/her partner to observe what is going to happen. The other member is instructed to put the lifesaver into his mouth and crunch down on it, keeping his/her mouth open so the partner can observe. (Do not tell them what they will or should see.) The students will be surprised to see sparks occurring with every bite. The other partner should then crunch on his/her lifesaver so their partner has the opportunity to also observe the sparks. Explanation: When sugar is fractured charges jump from one side to the other. When electrons hit nitrogen in the air they cause the emission of tiny blue-white bolts of light the same wavelength as natural lightning. Wintergreen, like the paint on a black light poster, is fluorescent. When the candies are cracked, some of the light emanating from the sugar is ultraviolet and that gets absorbed by the wintergreen and is re-emitted as bright, blue-green light that our eyes can see. Solo Walk or Soo Sit Discuss how it feels to be in the forest at night as part of this group. Ask students if it would feel different to be in the forest alone. Have one leader walk approximately 50 feet ahead. Then have students walk silently one at a time toward the leader that has walked ahead. (Do not force anyone to do this if they are not willing.) Follow up with a discussion of their feelings. This can also be done by having the students spread out along a section of the trail, sitting them alone in a place away from the other students. With a chaperone/leader at the beginning and the end of the group, have them sit quietly for 5-10 minutes. What did they see? Hear? Feel? Optional Activities Sky Watching If your group is not going to be doing astronomy, it is nice to stop and look at the night sky for a few minutes. Point out a few note-worthy items (constellations, or planets) and watch for things like shooting stars. Just give the students a few minutes to observe the night sky. Many never see a clear star light night due to light pollution in urban areas. Night Fears Brainstorming and Poetry This activity can be done inside or outside. Introduce this activity by discussing some common fears about the night and how they might come to be (i.e. some students may be afraid of the dark because they hear new, strange noises that they weren't aware of during the day.) Have the students write down one or two words or phrases on a piece of paper about their feelings of the night. You may have things like: spooky, scary, quiet, dark, can't see, scurrying creatures, peaceful, etc. (At the end of the hike, write all the thoughts and words on the board or a flip chart and have students write a piece of poetry or a short story incorporating all the things listed.) Sounds Around Prior to the lesson, take a personal hike and tape record the sounds you hear along the trail. Have the students listen carefully to the recording and try to identify the different sounds. Have each student write down what they think the sounds were without talking to one another. Listen to the tape a second or third time to see if they hear other things they missed previously. Encourage students to share what they have listed. Play the tape again so students can try to identify sounds others may have noted. This would be a good rainy day activity if a tape is made in advance. Wrap-Up Activities Review the activities of the night hike with the class/group. Ask how they now feel about the night and the dark. Did some students' personal feelings change, even for a little while? Determine if the students feel they can "see" more about the night than they did before by discussing the following statements:
Resources UITE (an Indian legend) Uite was an Indian who lived long ago. When Uite reached a certain age, he was able to be initiated into the tribe as a man. But before he could go through the ceremony, he had to prove he was worthy of the honor. A whole week was set aside during which Uite had to prove that he had learned all the skills that were necessary to be an adult Indian. Each day the chief of the tribe set a new challenge upon Uite. Each day Uite overcame the challenges with ease. Finally on the last day, all the Uite had to do was show respect for his elders by doing any favors they asked of him. The whole day went by and no one had approached Uite. He thought since he passed all his other tests so well that he would probably get off easily this day. Finally a messenger came to Uite and told Uite the chief wanted to see him. Uite went to the chief's wegawa and stepped inside. The chief handed Uite some water skins and told him to go down the path to the river and fill the water skins. Although Uite had been down the path many times during the day, he was wary of going down it at night-especially alone. To get strength, Uite sat down next to the fire in the middle of the village and stared into the flames. Finally he got up and ran down to where the trail started. He ran down the trail and was tripped when something reached out and grabbed his ankle. He got up and ran even faster down the trail. Something grabbed at his shoulder and ripped his shirt. As he neared the river, he could hear something laughing at him-perhaps an evil spirit? He dipped the skins quickly into the water and ran back to the village. He stepped into the Chief's wegawa and handed him the water skins. What little water he had gotten was shaken out from his run back. The chief silently handed the skins back to Uite. He knew that he must return with water after this trip. This time he walked to the start of the trail and stood there silently. He noticed the longer he stood at the edge of the woods, the better he could see. He could make out the familiar path and actually tell one tree from another. He even spotted some animals going by. This time, he walked down the trail quietly and slowly. He came to a spot in the trail where the passing of many footsteps had exposed the roots of a big tree. He realized that the roots were what had tripped him earlier. He came to a bramble patch where he had eaten many berries during the daytime. The thorns from these berries had been what had clawed at his shoulder. Since he was walking so quietly this time, he heard an owl calling for its mate-the evil spirit! This time he carefully dipped the skins in the river and filled them with water. He returned to the wegawa and handed the skins to the chief who set them aside because he wasn't really interested in the water. He said, "Uite, today you have become a man." Animals of the Evening Owls - localize sound in an amazing but fairly simple manner. Of all land animals, owls are the best at locating a moving target in three-dimensional space. While a human is as good as an owl at identifying the source of a sound in one plane-say, to the right or left while standing on the ground-owls are far better at localizing sounds that come from above or below. This superior ability is based on the asymmetrical positions of the owl's outer ears. A person can tell if the sound comes from the right, the left, or straight ahead because a sound from the left strikes the left ear first and the brain interprets this as direction. Owls can do the same, but can localize sounds above or below their heads because the left ear is much higher on the head than the right. Bats - Some bats employ the technique of echolocation to determine where things are in relation to themselves. They emit a steady stream of approximately ten clicking noises each second. These are called ultrasounds. Bats hear extremely faint echoes of ultrasounds as they return from distant objects. When the bat hears a pattern of echoes from an airborne mosquito or moth, it increases the ultrasounds to as many as 200 per second. There are only a few milliseconds of silence between clicks, but in that blip of silence the bat's receptors detect the echoes. The signals are sent to the brain where they are processed and decoded. The brain creates a "sound map" that the bat uses to maneuver and to capture the insect without even seeing it. Python - The python and other "pit" snakes use thermoreceptors to help them hunt at night. The thermoreceptors are located in pit areas around a snake's mouth. The receptors are responsive to body heat (infrared energy) of its prey, which are much warmer than the night air. They notify the brain which assesses the signals and determines the location of the prey. The snake can then strike with precise accuracy without evening seeing the prey. The same snake, however, may slither past a motionless but edible frog. The frog's skin is cool and blends in with the background colors. The snake does not have receptors to detect it or a neural program. Frogs - Certain species of frogs use sound frequency to determine local populations, even in the dark. The ears of the female cricket frogs are sensitive only to a very narrow band of frequencies due to their locality. The calls of the males also vary geographically in the frequency (somewhat analogous different groups of humans having a particular dialect). A female's lack of response to a distant male's "dialect" may be due to a mismatch between her ears and his call. She may be deaf to the frequency of his calls. Thus, the males and females of the same locality are able to locate one another and communicate without disturbances or interference from frogs in a different locality even if they are of the same species. Adaptation Games Owl/Prey - Discuss how owls use sound in locating prey. Heave 2 people designated as owls. They stand facing each other on opposite sides of the trail with flashlights. The other people are mice and will try to sneak past the owls who are blindfolded. When they hear a mouse, owls flash their lights on the sound. If the "mouse" is hit by the flashlight beam, they have been caught for supper. (You may have to act as the official for any decisions.) Discuss how rain would affect the catch rate. Also discuss the impact of noises from different ground covers (i.e. dry leaves versus hard-packed trail) Bat/Moth - (Note: You will need an open area for this activity.) Have 3 or 4 students designated as bats and the rest as moths. All will have to make some sort of sound (, hand clapping, finger snapping). Have the moths scatter over the area. The bats (blindfolded) will make the sound and then the moths return the sound to simulate the sonar effor the capture. Touching the moth completes the capture. Firefly Tag - One player with a flashlight is the firefly and everyone else tries to catch the firefly. The firefly must occasionally reveal its position by flashing the light. Whoever catches the firefly becomes the firefly in the next round. |