But the eastern population has remained stable; the numbers on western side jump 10 to 20 percent each year.

The eastern North American population is declining and is considered endangered.

The eastern Mediterranean populations share not only the geographic position, but cuisine, some customs, and a very long history.

The primary causes of habitat loss directly cause the decline in eastern lowland populations.

However, it was recently found that the eastern populations actually represent a different species, W. morgani.

The western and eastern Atlantic populations may be isolated.

Their main problem was the alienation of the eastern population.

It is mostly a resident, although northern and eastern populations migrate south in winter.

The two forms most likely diverged when the eastern and western populations were separated in the last ice age.

The 2000s saw a rise in the foreign-born population, with the town now having a significant eastern European population.