Unit1_Bird Migration

Many types of animals migrate, but bird migration in particular has

fas­cinated observers for centuries. 

What does "observer" mean?

• a priority; an urgent need

• a  person  who  watches something

• a difficult act or achievement

• movement from one place to another

Migration is the regular movement of animals between their breeding grounds and the areas that they inhabit during the rest of the  year.

What does "inhabit" mean?

• to make difficult to see

• to interest greatly

• to develop gradually

• to live in

The most common form of bird migration involves traveling to higher latitudes to breed during the warm season and then returning to lower latitudes during the nonbreeding period.

What does "migration" mean?

• type;  a  basic  group  in biological classification

• a priority; an urgent need

• a  person who  watches something

• movement from one place to another

Migration is an execellent example of how nature has responded to the biological imperative for species to evolve and spread out into all possible ecological niches that can provide the conditions necessary for species to breed and raise young.

What does "imperative" mean?

• unprotected from the wind

• a difficult act or achievement

• a priority; an urgent need

• a part or feature

What does "breed" mean?

• to live in

• to reproduce

• to live under difficult conditions

• to make difficult to see

This form of migration allows birds to breed in areas that provide optimal conditions for nesting and feeding their young.

What does "optimal" mean?

• active during the day

• best, most favorable

• to develop gradually

• active at night

Although most bird migration takes place between the lower and higher latitudes of the Northern Hemisphere, many species are transe­quatortal, living in the Northern Hemisphere during the breeding season and in the Southern Hemisphere during the remainder of the year.

What does "Hemisphere" mean?

• a priority; an urgent need

• movement from one place to another

• a difficult act or achievement

• one half of the Earth; also, one half of a sphere

Migration is an execellent example of how nature has responded to the biological imperative for species to evolve and spread out into all possible ecological niches that can provide the conditions necessary for species to breed and raise young.

What does "evolve" mean?

• to develop gradually

• to live in

• to leave the correct route; become separated from the group

• unprotected from the wind

No land  birds  are known to migrate into the higher latitudes of the Southern Hemisphere; only species of seabirds migrate to the Southern Hemisphere to breed.

What does "species" mean?

• best, most favorable

• type;  a  basic  group  in biological classification

• a difficult act or achievement

• a part or feature

Many rock ptarmigan never leave the high arctic tundra, spending their their breeding season atop windswept arctic peaks and the winter season in nearby valleys, enduring some of the coldest conditions on Earth.

What does "windswept" mean?

• to make difficult to see

• to live under difficult conditions

• active at night

• unprotected from the wind