This is an outside "hide and retrieve" game illustrating the memory capabilities of the Clark's nutcracker.
Grades: 7 – 12
Time: 1 –2 hours
Subjects: Math, biology, economics
Information about research on whitebark pine communities and inter-relationships between wildlife and the pines can be found at the Whitebark Pine Ecosystem Foundation's website.
- 2 packages of food coloring
- Approximately 3 lb. (1.5 kilograms), or 1/4 cup per student, raw or salted striped sunflower seeds (from bird food source)
- 6 containers (jars, beakers, recycled plastic butter tubs)
- One paper plate for each student
- Newspaper for drying colored seeds
The Clark’s nutcracker is medium-sized gray bird with black wings, related to the jays and crows. It lives at elevations between 3,000 and 12,000 feet (1,000 – 4,000 kilometers) and feeds mostly on seeds. Whitebark pine seeds are its preferred food, because they are high in fat and therefore, calories. Nutcrackers nest in February, when the snow is still in the mountains. For that reason, they need a reliable and efficient form of food, to feed both their young and themselves.
Because the seed production varies from year to year in most plants, nutcrackers have developed a strategy to store food for that critical time. During August, September and early October, they gather seeds (especially whitebark pine seeds) in their gular pouches (like 2 big pockets below their beaks), sometimes as many as 100 at a time, and bury them at 25,000 different sites every year! Usually, they bury the seeds three or four at a time, an inch deep in warmer, south-slope openings near the treeline. This is where the sunshine makes snow depths thinner. This is also the perfect place and depth in the soil for whitebark pines to germinate, or begin growing. Whitebark pine seeds will not germinate unless the seed covers are slightly scratched – about the same amount that nutcrackers scratch them while burying!
Of the 100,000 seeds they bury in 25,000 places every year, they only make it back to about 4,000 of those spots to retrieve the seeds, which means that over 80,000 whitebark pine seeds are “planted” in 20,000 perfect places every year by one bird!
Clark’s nutcrackers spread their seed caches over a 14-mile radius. How do they remember where they are? Studies have shown that they, like us, use visual landmarks and their memory – 25,000 places stored in a bird-brain. If a landmark is moved over two feet, they dig two feet over in the same direction! They also recognize landmarks buried under a foot of snow!
Both whitebark pine and the Clark’s nutcracker have dropped drastically in numbers in the Waterton-Glacier International Peace Park over the last 50 years. It is a double problem. Without nutcrackers, whitebark pines can barely reproduce. Without whitebark pines, nutcrackers can barely reproduce, and the populations of each continue to drop…
1. The coloring of the seeds can be done either by yourself prior to class, or by the students a half-hour before the activity.
The 4 primary food colors in the package can be mixed to make 2 other colors, orange and purple, and plain seeds make another color, for a total of 7 different colors. For each student’s 100 seeds (just under 1/4 cup) the colors should be mixed in the following ways:
- Red – 10 drops red color, 10 drops water, stir dry seeds with mixture.
- Yellow – 10 drops yellow color, 10 drops water, stir dry seeds with mixture.
- Blue – 10 drops blue color, 10 drops water, stir dry seeds with mixture.
- Green – 10 drops green color, 10 drops water, stir dry seeds with mixture.
- Orange – 5 drops red, 5 drops yellow, 10 drops water, stir dry seeds with mixture.
- Purple – 3 drops blue,7 drops red, 10 drops water, stir dry seeds with mixture.
2. Air dry colored seeds for 1/2 hour.
3. The activity is best done outdoors. A wild area is the best choice and the schoolyard second best. This activity is also very appropriate to be team-taught by a math and a science teacher.
4. Read the narrative about Clark’s nutcrackers to the students, asking them to take careful notes on the numbers they hear.
5. Ask the students to calculate the ratios between the total number of seeds distributed by a nutcracker each year, and the number of sites where they bury seeds (should be 4 : 1).
6. Ask them to calculate the ratio of the number of seeds retrieved by nutcrackers compared to the seeds left behind (1 : 5). Why would they want to bury so many seeds if they were only going to retrieve one-fifth of them?
7. Then, ask students to shrink the 14-mile radius into a manageable radius for their game of “cache and retrieve”. (For example, in a classroom, one foot equals one mile would be appropriate – outside, 20 feet equals one mile might work).
8. Start at a point near the center of your “playing field”. Count out 100 seeds (a gular pouch-full). All 100 seeds each student has should be one color. Match students together who have different colored seeds (i. e. if you have prepared seven different seed colors, the students should be partnered in a group of seven, all with seeds of a different color).
9. Assign each group an area where they can pace out their own “14-mile radius”, to scale, of course.
10. After they have set their own areas, they are to play “nutcracker” and hide the seeds, 4 at a time, in different areas of their “radius”. How many sites would that mean, with 100 seeds?
11. They will be asked to remember where the seeds are and retrieve them later, so ask them to think about a strategy for remembering all of their hiding spots. Mention spacing, landmarks, doing a rhyme or rap --- these are all good memory strategies which, coincidentally, fit a multiple intelligences framework. (This part may also give you some hints about their learning styles for future teaching and assessment!)
12. Give them 10 -15 minutes to hide their seeds and return to the central area. Use your best judgement about how well to hide the seeds. They may have to bury them on a bare school ground, or hide them under leaves or snow (covering their tracks), depending on conditions. The seeds should be hidden well enough so that any other “nutcracker” in their group would have some difficulty finding another’s seeds.
13. Ask students to share their “remembering” strategies. Encourage the discussion by mentioning landmarks, mathematical patterns, poems, music, artistic, interpersonal, or whole-body kinesthetic approaches. Do you think that the Clark’s nutcracker brain is well developed in certain areas compared to ours? Considering that when the snow falls, the landscape changes, do you think nutcrackers use large or small landmarks?
14. After discussion, ask the students to retrieve their seeds. Give them 10 minutes.
15. Ask them to calculate their percentage of success. Compare the success of different memory strategies in numerical terms (perhaps by averaging the success % for each strategy). This is a short-term memory exercise. Ask students to consider these questions: How well do you think you would do if you had to distribute 100,000 seeds in 25,000 places, and remember them all for a year? Do you think you would do better if your life depended on remembering most of the sites? You have heard of the “chicken and egg question”. So, which came first, the whitebark pine or the nutcracker?
16. Explain to students that this relationship between pine tree and bird is a classic example of a type of symbiosis called mutualism, wherein all parties of a relationship benefit. Are there relationships among humans or relationships between humans and other species which fit this mutualism model? Could the whitebark pine exist without the Clark’s nutcracker? Vice versa? Which would have the best chance of surviving extinction if the other was gone? (adaptability, ability to move to other areas for better conditions, etc.) Why are the whitebark pine and nutcrackers disappearing?
17. Toward the end of this unit, we will be answering that very question.
Variations and Extensions:
- You may want to reinforce the activity by having students taste pine nuts from the local grocery. These are usually pinon pines from the American southwest, and they are stored and eaten by the Clark’s nutcrackers there.
- Drawing a whitebark pine krummholz to look like a Japanese bonsai tree, and a nutcracker in the Japanese style, as well as doing a Haiku poem to accompany it, will extend the activity into international social studies.
- Using the Crown of the Continent Ecosystem map, estimate the range of whitebark pines in the Crown of the Continent Ecosystem and calculate the number of nutcrackers it would take to effectively cover the area of the International Peace Park.
- Ask your students to observe the area where seeds are still buried. Are there birds, mice or squirrels which find seeds you missed? How did they find them?
- If you used raw sunflower seeds for the activity, students may want to see if any of their “whitebark pines” (sunflowers) germinate and eventually grow. If they do, and can be protected from mowing, they will provide a future food source for animals in the fall!
The above questions are a general rubric showing the basic comprehension levels of concepts. You may also wish to have students journal about the game. Encourage the development of formulas generalizing the mathematical calculations they performed, writing or poetry entries, art expressing the bond between nutcracker and pine, group discussions about mutualism at school and in society, etc.