White-Crowned Sparrow Migration Facts

Location/Distance

• The white-crowned sparrows live in Newfoundland, Aleutian Islands, northwest United States, southern Colorado, and southern Sierra Nevada in the summertime.

• They travel to the southern United States in the winter.

• Return to natal area in the summer.

• Most of their migratory routes stop in the continental United States.

• Populations in Dakotas and Manitoba go to south central Texas and Mexico.

• The Newfoundland population settles in New York.
  
  

Mating

• Northern Hemisphere's summer season is when mating begins.

• They mate in Western Oregon, northwestern Washington, southwestern British Columbia, and northwestern Canada.
  
  

Feeding

• They eat seeds of weeds and grasses, caterpillars, wasps, beetles, oats, wheat, barley, corn, elderberries, and blackberries.

• In autumn and winter they eat a lot. They feed occasionally during summer breeding when resources are available.
  
  

Migration Cues

• Hormones (Testosterone) give the birds cues.
  -High levels of testosterone helps suppress sickness (avoid decreased activity, anorexia, weight loss).
  -Low levels lead to low foraging, higher energy, desire to travel

• Weight Gain cues the birds to migrate.
  -Pre-migratory fattening increases body weight in approximately 50 days to sustain sparrows for migration
  -Sparrows that do not reach appropriate body weight will often not migrate on schedule

• Increase in snow depth and wind intensity let the birds know that it is time to migrate.
  
  

Navigational Mechanisms

• Innate Navigation - young birds are born equipped with ability to adjust to and use the earth's magnetic field

• Learned Navigation - they have a mental map; they also use celestial and olfactory cues