Monarch butterflies descend upon Mexican forest during annual migration
- 9 years ago
ROUGH CUT (NO REPORTER NARRATION)
STORY: The 3,000-mile (4,800-km) mass migration of monarch butterflies in North America is one of the insect world's fantastic feats, with millions embarking on the arduous journey from as far north as Canada down into Mexico and the California coast each autumn.
The number of migrating monarchs has plummeted in recent years. Experts say that, while an estimated one billion monarch butterflies migrated to Mexico in 1996, the number stood at about 35 million this past winter.
Threats to the butterflies include habitat loss due to human activities, pesticides and climate change, experts say.
Experts say the arrival of the butterflies was delayed this past month because of cold fronts entering the northern continent.
While mainly a North American species, monarch populations also can be found in Central America, South America and elsewhere. Those outside North America do not migrate.
STORY: The 3,000-mile (4,800-km) mass migration of monarch butterflies in North America is one of the insect world's fantastic feats, with millions embarking on the arduous journey from as far north as Canada down into Mexico and the California coast each autumn.
The number of migrating monarchs has plummeted in recent years. Experts say that, while an estimated one billion monarch butterflies migrated to Mexico in 1996, the number stood at about 35 million this past winter.
Threats to the butterflies include habitat loss due to human activities, pesticides and climate change, experts say.
Experts say the arrival of the butterflies was delayed this past month because of cold fronts entering the northern continent.
While mainly a North American species, monarch populations also can be found in Central America, South America and elsewhere. Those outside North America do not migrate.