A new study shows that losing a particular group of endangered animals — those that eat fruit and help disperse the seeds of trees and other plants — could severely disrupt seed-dispersal networks in the Atlantic Forest, a shrinking stretch of tropical forest and critical biodiversity hotspot on the coast of Brazil.A new study shows that losing a particular group of endangered animals — those that eat fruit and help disperse the seeds of trees and other plants — could severely disrupt seed-dispersal networks in the Atlantic Forest, a shrinking stretch of tropical forest and critical biodiversity hotspot on the coast of Brazil.