Migrating animals undergo perilous journeys every year. Humans make it more dangerous : Short Wave
Nearly half of the world's already threatened migratory species have declining populations, and more than a fifth of the 1,200 migratory species monitored by the U.N. are threatened with extinction.
The two greatest threats to migratory species are overexploitation and habitat loss from human activities. Invasive species, climate change, and pollution are also contributing factors.