People and animals migrate but there is an extraordinary migration story of delicate creatures that weigh less than a postage stamp yet travel thousands of miles.
The great migration of monarch butterflies south in the fall and back north in the spring is an astonishing accomplishment.
Think about how many miles the tiny and delicate creatures must fly – from 50 to 100 miles per day! Every day for weeks. Making the journey south the monarchs fly from 2,000 to 3,000 miles in total.
Interestingly, on the way north it takes a few generations of monarchs to make the trip, whereas the journey south takes only one generation.
When I visited Carpinteria California I saw the monarchs over-wintering in Goleta, clustered in the trees, so amazing to see!
The monarch migration is fascinating and remarkable.
Where do Monarch Butterflies Live
Monarch butterflies live in much of the world, they can be found in Europe, Australia, New Zealand, and many Pacific Islands. In North America they exist in two separate populations: west of the Rocky Mountains and east of the Rockies.
The western population of monarchs spend winter in California and the eastern population flies down to Mexico for winter.
Monarch butterflies cluster on the trees in Goleta California
Why do Monarch Butterflies Migrate
Because the monarch butterflies cannot survive in cold winter weather conditions they migrate to warmer climates.
They begin the journey south in the late summer to early fall and return north in the late spring to early summer months.
Flowers attract the monarchs
Where do Monarch Butterflies Migrate
Western monarchs fly to the California coast and overwinter in pine, cypress, and eucalyptus trees.
While the eastern monarchs fly further south to Mexico and the oyamel fir forests in the mountains of the State of Michoacán and State of Mexico, about 2 hours driving distance west of Mexico City.
Their journey is an extraordinary insect migration.
Monarchs begin to move south from the end of August to October.
Monarchs cluster together over the winter months
Monarch Butterflies in California
You can find monarch butterflies around the coastal cities of California in Goleta (near Santa Barbara), Monterey, Pismo Beach, San Diego, and Santa Cruz.
Unfortunately, the population of monarch butterflies overwintering in California has greatly reduced in recent years.
As reported from the US National Park Service, in 2020 they counted fewer than 2,000 monarch in California. Compared to 1980 when an estimated 4.5 million monarchs spent the winter on the California coast.
The reduction is staggering, 99 percent fewer monarchs in a 40 year time span.
Fortunately, the eastern population of monarch butterflies is doing better.
California monarchs are in decline in recent years
Monarch Butterflies in Mexico
The place to see monarch butterflies in Mexico is at the border of Michoacán and State of Mexico at the Monarch Butterfly Biosphere Reserve. At this UNESCO World Heritage Site, the monarch butterflies and their habitat are protected.
Millions of butterflies overwinter in the mountainous region of Michoacán, with eight colonies of monarchs in the protected region of the biosphere reserve.
Watch this monarch video to experience a virtual visit to the monarch butterflies in Mexico.
How Monarch Butterflies Migrate
Scientists believe sunlight is what signals the monarch butterflies it’s time to migrate. And instinct is how the monarch butterflies find their way during migration.
It takes three to four generations of monarch butterflies to make the trip north to Canada. But it takes only one generation of monarch butterflies to migrate south to Mexico.
Why does it take only one generation for the monarchs to fly south but several generations to fly north?
Monarch butterflies born in Mexico will live 2 to 6 weeks. They begin the migration north and lay eggs (up to 400) before they die. Female monarchs lay 1 – 2 eggs on each leaf she lands on.
The next generations do the same, with the third or fourth generation arriving in their summer home of Canada or the United States.
Towards the end of summer, a super generation is born. This super generation of monarchs lives 6 to 9 months and makes the entire journey south in the fall.
It takes about two months for the monarch butterflies to fly from Canada to Mexico.
Monarch butterflies have distinctive orange and black wings
What do Monarch Butterflies Eat
The butterflies eat nectar from flowering plants, including milkweed. Monarch butterflies are attracted to Agastache ‘Ava’, Asters, Mexican Sunflowers, Zinnia, Verbena, Dwarf Butterfly Bushes, Bottlebrush, Lupine, and Milkweed.
During the caterpillar stage they eat only milkweed. They grow from a quarter inch to two inches long in two weeks.
Interestingly, milkweed contains toxins that make it taste yucky to birds, so this foul taste is passed on to the monarchs and helps protect them from predators.
The chrysalis stage lasts about ten days and during this time the caterpillar transforms into a butterfly. Adult butterflies eat nectar from flowers.
Monarch butterflies eat nectar from flowers
Monarch Butterflies Predators
Spiders, mice, praying mantis, fire ants, and birds such as orioles are the monarch’s predators.
Monarch butterflies develop protection from predators through the toxins in milkweed. Eating milkweed while in the caterpillar stage makes their skin poisonous to predators, plus it tastes bad, so it helps deter birds and insects from trying to eat them.
Can Monarch Butterflies Survive in Cold Weather?
Colder temperatures can cause monarch butterflies to die. The butterflies need warm temperatures to fly. Therefore, they migrate before it gets too cold in the northern regions of the United States and parts of Canada.
Monarchs cannot fly during high winds and rain storms either. In 2002 in Mexico a rainstorm combined with low temperatures killed up to 250 million monarchs. Approximately 80 percent of the monarchs did not survive at one of the monarch overwinter sanctuaries in Mexico.
Monarchs look like leaves on a tree from a distance
Monarch Butterfly Migration Facts
1. Monarch butterflies migrate from 2,000 to 3,000 miles
2. Migrating monarchs can fly up to 30 miles per hour
3. Monarchs fly around 50 – 100 miles per day during migration
4. There are two monarch populations: Western monarchs and eastern monarchs
5. Adult females have wider veins on their wings than males
6. Newly hatched monarchs must wait for its wings to stiffen before it can fly
7. As caterpillars grow larger, they shed their skin and grow a new skin to fit their size
8. Bright colors warn predators they are poisonous
9. Adult monarchs ingest nectar through a straw-like tongue, called a Proboscis
10. Monarch caterpillars get oxygen via holes in the sides of their bodies
11. Butterfly antennae and legs provide their sense of smell
12. Eastern monarchs spend winter in the Oyamel (oh-ya-mehl) Forest of Mexico
13. Female monarchs lead the other butterflies north from Mexico
14. Sunlight signals when the monarch butterflies need to begin migration
15. Instinct is how the monarch butterflies find their way during migration
16. It takes 3 to 4 generations of monarch butterflies to make the trip north
17. It takes only 1 generation of monarch butterflies to migrate to the south
18. The western population of monarchs spend winter in California while the eastern monarchs fly to Mexico
Various flowering plants attract butterflies
You can help the monarch butterflies by planting butterfly friendly flowering plants.
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