• Two way journey to breeding ground in spring and to the winter quarters in autumn.
• Regular, extensive, seasonal movements of birds between their breeding regions and their winter regions.
• Periodic to and from movements between nesting and winter quarters.

Types of Migration

• Daily / Local – resting sites to feeding areas
  • e.g. House sparrow – no long migration, colony to feeding
  • Disappearance of porudise flycatcher golden voiole & psitta, at regular internal due to local migration
• Seasonal
  • Response to seasonal change
  • Occur in beginning or end of worm season (tropical & subtropical areas)
  • On set of winter (temperate region)
  • e.g. Europe, N. America & Asia (N. Hemisphere) ducks, males and juvenile birds, known as moult migration
• Cyclic
  • Some seasonal others not a regular interval eg. Snowy owls in winters occurs in 3 to 5 yrs.
• Latitudinal
  • North to South or South to north migration
  • Most common migration
  • 5000 million or more birds fly 3200 km south to grassland, forests & lakes of central/southern Africa. Eg. Shore birds, Arctic tern 17,600km.
  • American Golden plever – Argentina
  • Siberian bird – Himalayas
• Altitudinal/Vertical migration
  • Species in mountain – winter – Lower altitude for food and shelter eg. Coiots of Anclas – Argentaina blue grouse – USA – Rocky Mountain
• Longitudinal
  • Birds – east to west / vice versa
  • Michigan – New England (California gulls)
  • Starting – East Europe or Asia to Atlantic coast.

Migratory Status – 4 major

1. Permanent residents
2. Summer migrate
3. Winter migrate
4. Transient migrant
5. Transient / Passage migrants

• Permanent residents
  • Throughout year and do not migrate from areas to another.
• Summer migrants
  • Summer e.g. S. America e.g. Summer migration esieals pied, cuckoo
• Winter - Winter migratory
  • Pintail, Goose shoveller
  • Palacortic or Eurasia – European starting, Winter migrants
  • Mongolia/Siberia – South India

Duration & Distance

• 500-17000km (one stretch or making stops)
• Short distances (Vespar Sparrow wordcock etc)
• Southern Canada to North America
• Night Hawk & Barn swallow 11,200km.
• Black headed bunting 6500km @ 40-80 kmp
• Majority of bird fly at night (small birds) and rest at day time.
• Blue geese fly 2720km @ 60 hours
• Most birds fly 800km non-stop

Altitude

• Some sea level, other near top of Mt. Everest
• Ducks & Geese 7400 ft and Vulture & lammergair 22,400ft
• Himalaya 17,280 ft, Himalayan Geese 29,500 ft.

Speed

• Small birds 32-64kmp
• Humming bird 32kmp
• Larger 40-96 kmp
• Sandpepers 90 kmp
• Geese 70-100 kmp

Causes

• Effect of Ice age
• Warm climate – northward for food
• Photoperiodism (length of day, triggers, effect, pituitary and pineal body in brain)

Advantages of Migration

• Better climate
• Exploiting two different habits
• Variety in birds diet
• Longer working hours
• Pressure of predation
• Parasites & infection of microorganism are reduced
• Promotes geographical dispersal
• Golden opportunity for men for watching bird

Methods of Studying Migration

• Observe movement across studying migration
• Radio-tracking
• Radar
• Tapes recording (bird call) (chip count)
• Collecting & studying dead
• Bonding or ringing nasaltags

Navigation

• Impointing (in born) Built in Compass (Magnetic field)
• Sun Compass orientation
• Butterflies – acute sense of taste
• Moth – acute sense of smell
• Bees - ultraviolet rays – discriminate polarized light
• Vit viper – can perceive heat of mammals
• Bacteria synttasize magnitude of compd. Of Fe & O₂ magnetic orientation in brain of pigeons & abdomen of bees.