Behavioral Cycles Among Different Organisms

1. Behavioral Cycles Among Different Organisms

2. Behavioral Cycles in Plants • Plant Dormancy • Is a temporary state of reduced rate or no internal activity (Scott Freeman, 2003, pg.898) . • Different chemicals (hormones) in the plant activate the plant to start growing and for it to go into dormancy.

3. Tree Dormancy • Both chlorophyll and carotenoids are present in the chloroplasts of leaf cells throughout the growing season. • During the growing season, chlorophyll is continually being produced and broken down and leaves appear green. • As night length increases in the autumn, chlorophyll production slows down and then stops and eventually all the chlorophyll is destroyed. • The carotenoids and anthocyanins that are present in the leaf are then unmasked and show their colors. • This is what causes leaves to change color and for trees to lose their leaves for the winter (dormant). http://www.na.fs.fed.us/fhp/pubs/leaves/leaves.shtm

4. Seed Dormancy • Seed dormancy is the state seeds are in before they start growing. • Seeds experience dormancy so they don’t start growing in conditions that won’t allow them to survive (drought, or winter). • Dormancy is broken when optimal growing conditions are present. • Water, sunlight, temperature are some ways to break dormancy (Scott Freeman, 2003, pg.926) .

5. Behavioral Cycles in Animals • Hibernation occurs when temperatures lower and winter conditions cause food to become scarce. • Animals (squirrels, voles, mice) must seek a well insulated shelter and reduce their internal activity (metabolic activity) which will lower their internal temperature (Scott Freeman, 2003, pg.948). • During hibernation (torpor) animals reduce their internal temperature, heart rate, oxygen intake. • This saves animals precious energy they need due to lack of resources.

6. How Organisms Migrate? • Migration is long-distance movement of a population associated with a change of seasons. (Scott Freeman, 2003, pg.1148). • Examples: • Arctic terns nest along the Atlantic coast of North America, fly south along the coast of Africa to Antarctica (total of 20,000 miles). • Monarch butterflies travel from all over the North to Central Mexico or southwest California. • Salmon when they hatch migrate to the ocean where after feeding and growing for several years return to where they spawn and then die.

7. How do Animals Migrate? • Piloting- Use familiar Landmarks where offspring follow their parents and memorize the routes. • Compass Orientation- Oriented in a specific direction based on the Sun during the day and the Stars at night. • True Navigation- Birds can detect magnetism by their visual system and have small particles of magnetic iron. • Changes in the positions of magnetic particles, in response to Earth’s magnetic field. (Scott Freeman, 2003, pg.1149).

8. References • Scott Freeman, S. (2003). Biological science. (2 ed., pp. 494-512). Upper Saddle River, New Jersey: Pearson Prentice Hall. • http://www.na.fs.fed.us/fhp/pubs/leaves/leaves.shtm