- For several hundred thousand years, the Sahara has alternated between desert and savanna grassland in a 20,000-year cycle caused by the precession of Earth’s axis (about 26,000 years) as it rotates around the Sun, which changes the location of the North African monsoon.
- Cottonwood Island Wildlife Area Unit (wdfw.wa.gov)
The Cottonwood Island Unit is a unique forested property that is representative of a historic habitat type that would have been more widespread along the lower Skagit River Valley. It provides valuable mature cottonwood forest habitat for a variety of forest birds and raptors, primarily buteos and eagles. The remnant of Cottonwood Slough also provides off-channel habitat for salmonids during certain times of the year and has been evaluated for potential habitat restoration projects.
- Sahara (Wikipedia)
The Sahara (/səˈhɑːrə/, /səˈhɛrə/) is a desert spanning across North Africa. With an area of 9,200,000 square kilometres (3,600,000 sq mi), it is the largest hot desert in the world and the third-largest desert overall, smaller only than the deserts of Antarctica and the northern Arctic.