By Sara Amundson and Kitty Block
We learned last week about the outrageous killing of two iconic and rare “big tusker” male savanna elephants in an unpopulated corner of northern Botswana. “Big tusker” refers to an elephant with at least one tusk weighing 100 pounds but it effectively signifies an elephant who has survived for more than 50 years and whose knowledge and experience is irreplaceable to his herd.