David Moskowitz, a biologist, photographer, author and outdoor educator, will present his newest book, “Caribou Rainforest: From Heartbreak to Hope” on Tuesday.

The event will start at 6 p.m. at REI (1125 N. Monroe St.)

“Caribou are a great case study for how difficult conservation is,” said Mark Hebblewhite, a wildlife biologist at the University of Montana who has studied caribou for 20 years. “The notion that we can save everything and have a fully healthy, vibrant and continually growing economy is just being challenged. We have more species on the endangered species list all the time.