Introduction
In the wild, populations are normally controlled by limiting factors that are either biotic or abiotic. These prevent the population from continually growing and reaching their carrying capacity. This experiment will teach one what it is like to study real populations and to help one use and learn the meanings of certain words. Hypothesis:
Investigation 1
If both the male and female owl hunt both 2 times a day in the spring with favorable mouse conditions then, the owls will live and eat well almost every day because there are many mice, 2 owls, and no predators.
Investigation 2
If both the male and female both hunt twice a day with 25% (20 mice) of the population dead then, the owls will eat good for the first few days, but will slowly decrease until death in the 7th through 9th day, because in order to live one must get a total of 4 mice within 3 days and after one hunts for a few days, the mice will get scarcer and scarcer, until there are none left.
Investigation 3
If the male and female both hunt 2 times a day with snakes as competitors which eat 6 mice a day then the owls will survive for 6 to 8 days then die off because with the owls eating mice and then snakes taking out 6 mice every day, that is 36 mice the snakes have eaten in just 6 days. Eventually, the mice will completely die off.
Materials
The materials one will need are: masking tape, yard stick or tape measure, pipe cleaners bent into 10 x 10 cm squares to represent the owls, colored pencils, graph paper, large bag of pinto beans (or other dried beans) to represent mice, and a student data sheet.
Methods
Procedures for investigation 1
First one would lay down a 4ft. x 4ft. square with the masking tape, on the cleared floor. Next, form a group of four: Bean Counter, who would scatter beans between rounds, removes and adds beans. Recorder, who would read directions and record the data collected.
Female Owl, who would stand a 1ft. to 2ft. outside of the square and toss its 10 x 10 cm pipe cleaners bent into a square. Male Owl, who would stand a 1ft. to 2ft. outside of the square and toss its 10 x 10 cm pipe cleaners bent into a square. Then, scatter 80 beans (mice) all over the 4ft. x 4ft. quare or hunting field. After that, the male and female owl should stand 1ft to 2ft away from the square or hunting field and toss the 10 x 10 cm square or the representation of the owl.
Remove any beans that the “owl” ate or that were in the 10 x 10 cm square. Repeat. Each owl has two hunts a day so each owl should toss the square twice a day add the beans (mice) together to get the total for the day after each day add 10% of what is left in the 4ft x 4ft back in to symbolize births. The owls must eat 4 or more mice a day in any three day period, so if ones owl eats fewer than 4 mice in a three day period it dies. Continue this process until the ten day period is up, one runs out of mice, or one dies.
Procedures for Investigation 2
First one would lay down a 4ft. x 4ft. square with the masking tape, on the cleared floor. Next, form a group of four: Bean Counter, who would scatter beans between rounds, removes and adds beans. Recorder, who would read directions and record the data collected. Female Owl, who would stand a 1ft. to 2ft. outside of the square and toss its 10 x 10 cm pipe cleaners bent into a square. Male Owl, who would stand a 1ft. to 2ft. utside of the square and toss its 10 x 10 cm pipe cleaners bent into a square.
Then, scatter 60 beans (mice) all over the 4ft. x 4ft. square or hunting field (this is different from the first procedure because one adds in a abiotic limiting factor: the glade has had drought like conditions and killed 25% of the mouse population). After that, the male and female owl should stand 1ft to 2ft away from the square or hunting field and toss the 10 x 10 cm square or the representation of the owl. Remove any beans that the “owl” ate or that were in the 10 x 10 cm square. Repeat.
Each owl has two hunts a day so each owl should toss the square twice a day add the beans (mice) together to get the total for the day after each day add 10% of what is left in the 4ft x 4ft back in to symbolize births. The owls must eat 4 or more mice a day, so if ones owl eats fewer than 4 mice in a three day period it dies. Continue this until the ten days are up one runs out of mice or one dies.
Procedures for Investigation 3
First one would lay down a 4ft x 4ft square with the masking tape, on the cleared floor. Next, form a group of four: Bean Counter, who would scatter beans between rounds, removes and adds beans.
Recorder, who would read directions and record the data collected. Female Owl, who would stand a 1ft to 2ft outside of the square and toss its 10 x 10 cm pipe cleaners bent into a square. Male Owl, who would stand a 1ft to 2ft outside of the square and toss its 10 x 10 cm pipe cleaners bent into a square. Then, scatter 80 beans (mice) all over the 4ft x 4ft square or hunting field. After that, the male and female owl should stand 1ft to 2ft away from your square or hunting field and toss the 10 x 10 cm square or the representation of the owl.
Remove any beans that the “owl” ate or that were in the 10 x 10 cm square, and also remove six more beans a day (to represent another limiting factor though this time it is biotic: the eastern gardener snake has greatly increased it population and the owls and the snakes are in direct competition for the mice).
Repeat. Each owl has two hunts a day so each owl should toss the square twice a day (this time do not account for births). The owls must eat 4 or more mice a day, so if ones owl eats fewer than 4 mice in a three day period it dies. Continue this until the ten days are up, one runs out of mice, or one dies.
Discussion and Conclusion
The hypothesis was correct on all of the investigations. Ones group preformed the experimentation very well and came out with some great results. The group should have learned very useful information about limiting factors, carrying capacity, and many others. In investigation 1 the owls survived and ate well, in investigation 2 the owls died on day 7 and 8, but ate well up to those days, in investigation 3 the owls survived only 8 days and never ate more than 4 mice in a day.
