Marcelo H. Cassini is an Argentine biologist who began his studies of wildlife and its environments in the 1980s. Through his work, he has had the opportunity to experience nature in many corners of Argentina and various countries on every continent. Photography has always been a companion, but in the last decade, it has become a central activity in his encounters with nature. In this, his first book dedicated to photography, the author seeks to capture all the experience he has gained over these forty years of learning from wildlife.