index - a numerical scale used to compare variables with one another or with some reference number. 1  margin of error, margin of safety, safety margin - the margin required in order to insure safety; in engineering the margin of safety is the strength of the material minus the anticipated stress.
Nutty Ways to Celebrate Squirrel Appreciation Day This Year. SQUIRRELS! Whether you love them or loathe them, National Squirrel Appreciation Day, January 21st, is a great time to take a few moments and learn about these nutty animals. If you count flying squirrels we have 10 tree species in North America.
International Owl Awareness Day. Did you know thereâs actually an International Owl Awareness Day? Thatâs right, vultures arenât the only ones who get a day all to themselves! IOAD is August 4th, and we are celebrating in true owl fashion! Thursday, August 4th, weâre celebrating owls from 1:00-3:15 pm with crafts, activities, and a special keeper talks all about owls!