Week 11 Overheads


Migration


What to Use to Know When to Go?

Light levels
Temperature
Food availability
Physiological changes
Endogenous clocks (circannual and circadian)

Advantages?
Disadvantages?

How to Know Where to Go?

Learned
Innate
Combination


Go the Distance

Time Metabolic energy consumption Optic flow

Landmarks


Photoperiod and Circannual Clock

Accelerate by short and long photoperiods
Birth time/age
Distance to travel
Species differences


Where to Go the First Time?

Learned Genetic


Features of Innate Vector Orientation

1. Geomagnetic field
2. Axis of celestial rotation

Energy Constraints

To refuel... ...or not to refuel...? Bird morphology and fuel load


Considerations for Migrating Birds

Open circles: energy/water constraint; Squares: navigational considerations; Triangle: correct seasonal timing

Considerations for Migrating Mammals

Can you think of some ways that the considerations of migration might be different for terrestrial mammals than for birds?


Return to 403 course page.