Migration - 2

1. Migration - 2 8 May 2012

2. Quick quiz • Wrybill has a uniquely ______ bill • Wrybill winter in the __________ island • Caribou migrate to _________in spring when calves are born • Migration is a r_________ activity • Migration involves p___________ • Animals are able to n_________ to find their way • Bar tailed godwit migrates to A______ to breed • Migration is costly in term of ___________ • Animals sense changes in the environment through s_______ cells • Sports question: What was the score for the Nuggets v Pirates at the weekend

3. Migrations are: • active... that is it’s not a passive decision • usually movements to a feeding/and or breeding area • usually two way trip • usually have regular timing • often long distance • often occur at a definitive stage in life cycle

4. Class definition Migration is the movement of a population to a new environment to better chances of survival, it occurs seasonally because it is routine and because it is genetically programmed within the organism

5. Migration - Definition • Migration is an active, regularlyrepeated movement in a particular direction by a populationof animals.

6. When to migrateHow do they know when to go? • Seasonal • Day length • Body clock – triggered by light response • Pituitary gland is stimulated • In birds part of the brain (the pineal) monitors day length Migrate when they receive environmental stimulus (i)

7. How do they find their way? • Some young hitch a lift with older animals who have made the journey before • Others have to make the trip without any prior knowledge • Animal compasses • Sun • Stars • Magnetic Often use more than one

8. Quick write • Discuss the significance of migration by describing and explaining. Elaborate your answer with an examples ( one each of bird, mammal) Key words • Navigation, Orientation (different types), migration, risks, benefits A = describe: M = explain using E = significance