Darmancy

Dedicated to all Zoologist

1. Presented By : Shakeela Naz PRESENTATION TOPIC DORMANCY Submitted T o : Ms. Naila Gul Department of Zoology , KUST, Kohat

2. Dormancy  is a period in an  organism's   life cycle  when growth, development, and (in animals) physical activity are temporarily stopped. This minimizes  metabolic activity  and therefore helps an organism to conserve  energy . Dormancy tends to be closely associated with  environmental conditions . Organisms can synchronize entry to a dormant phase with their  environment  through predictive or consequential means. What is Dormancy?

3. Predictive dormancy  occurs when an organism enters a dormant phase  before  the onset of adverse conditions. For example,  photoperiod  and decreasing  temperature  are used by many  plants  to predict the onset of winter

4. Consequential dormancy  occurs when organisms enter a dormant phase  after adverse conditions have arisen. This is commonly found in areas with an unpredictable climate. While very sudden changes in conditions may lead to a high  mortality rate  among animals relying on consequential dormancy, its use can be advantageous, as organisms remain active longer and are therefore able to make greater use of available resources.

5. DORMANCY IN ANIMALS Hibernation Aestivation Diapause

6. Hibernation is a mechanism used by many mammals to reduce energy expenditure and survive food shortage over the winter. Hibernation is a time when some animals go to sleep, they sleep all of the way through the winter Hibernation

7. As the weather gets colder, leaves star falling from the trees and some animals start getting ready to hibernate. Hibernation occurs when an animal become inactive, or “sleeps” during the short, cold and harsh days of winter. Some hibernating animals include bears, pygmy possum, bats, frogs, snakes, lizards and snails.

8. Why do animals hibernate? Animals hibernate because in winter time there is not much food to eat and it is very cold. The animals make nice and warm places to sleep and have some food stored away for when they make up. When the animals wake up it will be spring time. The weather will be warmer and there will be plenty of food to eat.

9. Animals who hibernate do not eat and do not freeze All they do is sleep, until spring

10. AESTIVATION (SUMMER SLEEP OR SUMMER DORMANCY) Some animals have ability to remain dormant during unfavourable summer months when there is water scarcity or intense heat. Aestivation is shown by desert animals and variety of them like snail, ground squirrel etc.

11. Some animals show both aestivation and hibernation; For example Snail show hibernation and aestivation according to availability of water. Ground squirrel aestivate in summer and hibernate in winter.

12. Mammals like kangroo rat, pocket mouse aestivate when there is shortage of food. Whereas in white footed mouse aestivation occurs when there is shortage of water. In some birds like swift aestivation is due to scarcity of food.

13. DIAPAUSE Diapause is a predictive strategy that is predetermined by an animals genotype. Diapause is common in insects, allowing them to suspend development between autumn and spring , and mammals such as the roe deer ungulate with embryonic diapause, in which a delay in attachment of the embryo to the uterine lining ensures that offspring are born in spring, when condition are most favorable .