Explains biological soil crusts, organism-produced soil formations commonly found in semiarid and arid environments, with special reference to their biological composition, physical characteristics, and ecological significance.
Fact sheet on the need to protect biological soil crusts in the desert. These crusts are most of the soil surface in deserts not covered by green plants and are inhabited by cyanobacterium (blue-green algae) and other organisms useful to the ecosystem.
Bird banding is used to study the movement, survival and behavior of birds. The Bird Banding Laboratory Site has links to the value, procedure and history of bird banding, how to report bird bands (English & Spanish), and resources for birders.
Geographical access to multiple bird checklists developed by others that indicate the seasonal occurrence of birds in a given area. A Record Documentation Form to document supporting details of rare bird observations is also available.