Thinking Citizen Blog — Monarch Butterflies — Beauty, Metamorphosis, Migration

Thinking Citizen Blog — Wednesday is Climate Change, the Environment, and Sustainability Day

Today’s Topic: Monarch Butterflies —Beauty, Metamorphosis, Migration

Is there anything more enchanting, more mesmerizing than a black and orange monarch flitting from flower to flower, doing its aerial dance to an unknown beat? Is there anything more implausible than the idea that such a fragile thing can make its way 2500 miles from New England to Mexico? Well, how about the metamorphosis of an egg into a caterpillar into a pupa into that magical winged long distance traveler? Today, a few more notes. Experts — please chime in. Correct, elaborate, elucidate.

THE FOUR GENERATIONS OF MIGRATION — Three generations to make it to New England, one “super generation” to return to Mexico

1. “But this grand migration is under threat. Climate change in both their winter hibernation grounds in Mexico and their summer breeding grounds in the US is having a considerable impact on the monarch migration. Deforestation in Mexican forests coupled with the conversion of grassland to farmland, the use of herbicides and pesticides, and a reduction of milkweed — the only plant in which the monarchs lay their eggs — across the butterfly’s flyways in the US, all come together to create the perfect storm of sorts for these tiny creatures.” (fifth link below)

2. “The overwintered population of those east of the Rockies may reach as far north as Texas and Oklahoma, during the spring migration. The second, third, and fourth generations return to their northern locations in the United States and Canada in the spring.” (first link)

3. “Captive-raised monarchs appear capable of migrating to overwintering sites in Mexico, though they have a much lower migratory success rate than do wild monarchs… Monarchs from the eastern US generally migrate longer distances than monarchs from the western US.”

NB: “Since the 1800s, monarchs have spread throughout the world, and there are now many non-migratory populations globally. Flight speeds of adults are around 9 km/h (6 mph).”

THE METAMORPHOSIS — from egg to larva (caterpillar) to pupa (chrysalis) to adult

1. “Monarchs transition from eggs to adults during warm summer temperatures in as little as 25 days, extending to as many as seven weeks during cool spring conditions.”

2. “During their development, both larvae and their milkweed hosts are vulnerable to weather extremes, predators, parasites, and diseases; commonly fewer than 10% of monarch eggs and caterpillars survive.”

3. “Monarch courtship occurs in two phases. During the aerial phase, a male pursues and often forces a female to the ground. During the ground phase, the butterflies copulate and remain attached for about 30 to 60 minutes. Only 30% of mating attempts end in copulation, suggesting that females may be able to avoid mating, though some have more success than others.”


1. Monarchs are “aposematic” — “warding off predators with a bright display of contrasting colors to warn potential predators of their undesirable taste and poisonous characteristics.” This is true in both butterfly and caterpillar phases.

2. “Monarchs are toxic and foul-tasting because of the presence of cardenolides in their bodies, which the caterpillars ingest as they feed on milkweed.”

3. Butterfly gardens: “In order to support and sustain butterfly populations, an ideal butterfly garden contains habitat for each life stage. “

NB: “Butterflies are ectothermic and rely on solar radiation for their metabolism. South-facing slopes are an ideal location for a butterfly garden, as they provide the most solar radiation.”

FOOTNOTE — LEPIDOPTERA — 10% of all described species

1. Butterflies are part of the order Lepidoptera which includes moths. Lepidos means “scales” and the bodies, wings, and proboscises of butterflies and moths are covered with them.

2. The order includes about 180,000 species, making Lepidoptera among “the four most speciose orders including hymenoptera (bees, wasps, ants), diptera (only one pair of wings, house flies, horse flies), and coleoptera (beetles, 25% of all described species). “God has an inordinate fondness for beetles.” (JBS Haldane)

3. The monarch is part of the subfamily, Danainae, which includes the Daniade or “milkweed butterflies.” The monarch’s Latin name is Danaus Plexippus. Weren’t you dying to know that?

Monarch butterfly — Wikipedia

Flight of the Butterflies — Wikipedia

Butterfly gardening — Wikipedia

Butterfly house — Wikipedia

The great monarch migration

Danainae — Wikipedia


PDF with headlines — Google Drive


#1 A graphic guide to justice (9 metaphors on one page).

#2 “39 Songs, Prayers, and Poems: the Keys to the Hearts of Seven Billion People” — Adams House Senior Common Room Presentation, 11/17/20


Please share the coolest thing you learned in the last week related to climate change or the environment. Or the coolest, most important thing you learned in your life related to climate change that the rest of us may have missed. Your favorite chart or table perhaps…

This is your chance to make some one’s day. Or to cement in your own mind something that you might otherwise forget. Or to think more deeply than otherwise about something dear to your heart.

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