Western Monarch Day
Witness the graceful dance of vibrant winged creatures as they flutter through the air, bringing a touch of enchantment to the natural world.
Get out your tiara…wait no! It’s not that day. It is Western Monarch Day. It is a day to celebrate the Western Monarch butterfly.
It travels from place to place but this day specifically we give thanks for their return to the central California coast. Why is this so important? It is important to watch and make sure that they do return. The monarch butterfly is facing a terrific decline in numbers.
Many conservation groups are calling for it to be protected as an endangered species and claim that the number of declines could be as high as 90%!
Western Monarch Day Timeline
1758
Linnaeus Officially Describes the Monarch Butterfly
Swedish naturalist Carl Linnaeus formally describes the monarch in the 10th edition of Systema Naturae, naming it Papilio plexippus and placing it within his new binomial system of classification.
1780
Monarch Becomes Type Species of Genus Danaus
Polish naturalist Jan Krzysztof Kluk establishes the genus Danaus and uses the monarch as its type species, helping fix the butterfly’s modern scientific name Danaus plexippus.
1874
Monarchs First Documented in New Zealand
Naturalists record monarch butterflies in New Zealand for the first time, early evidence of the species’ successful dispersal beyond its native North American range.
1937
Urquhart Begins Long-Term Monarch Migration Studiesd
Canadian zoologist Frederick Urquhart launches a decades‑long tagging program to track monarch movements, laying the groundwork for understanding their continent‑scale migration.
1975
Mexican Overwintering Sites for Eastern Monarchs Revealed
Working with volunteers led by Frederick and Norah Urquhart, Kenneth Brugger and Catalina Aguado locate massive monarch overwintering colonies in Mexico’s Trans‑Mexican Volcanic Belt.
1980s
California Counts Reveal Western Monarch Overwintering Strongholds
Systematic counts and research at coastal sites such as Pacific Grove, Pismo Beach, and Santa Cruz document hundreds of thousands of western monarchs clustering in winter groves.
2014
Genetic Study Traces Monarchs’ Migratory Origins
A large genomic analysis finds that monarch butterflies likely originated in North America as a migratory species, with non‑migratory tropical populations evolving later from migratory ancestors.
How to Celebrate Western Monarch Day
Did you know that if we all took a few simple actions we could help to save the Western Monarch Butterfly? Currently, three conservation groups are working to get endangered status and protection for this creature, but is it enough? No, it isn’t. So what can you do? Great question!
Plant a Monarch Friendly Garden
One way is to share a little bit of your yard with them. The main plant that they need is milkweed.
This plant is critical to their survival along the migration routes that they take. It provides nectar as well as the fact that it is the only plant in which the Monarch butterfly can lay their eggs in. In the Midwest of the United States of America, this plant is quickly disappearing as more and more land is being used for farming.
If you go to the Live Monarch website you can help by planting free seeds. Give the butterflies a rest in your garden and you can help to ensure their continued well-being.
When they come to feast and lay their eggs, you will be able to help document their numbers if you choose. But better yet you can enjoy their beauty knowing you have helped them!
History of Western Monarch Day
The Monarch butterfly is a stunning mix of grace and beauty. With rich tones of gold, red, yellow and orange they fly across the landscape and take over the job of pollination.
They somehow know when it is time to move. Their migration can be tracked from north and east to south and west, and then back again.
Amazingly each way of the migration takes four generations! Can you imagine? Taking into account how much they pollinate, and the fact that their migration takes such a toll on their population it is imperative to understand what their decline really means.
Can you picture the toll when I say the decline of Monarch population is near 90%? Let me share a visual with you. Let’s talk people instead of insects.
If we were to make a comparison, the loss to the butterfly would be as if all the people in the United States of America died except for those in Ohio and Florida. Stunning isn’t it?
With that picture in mind, can you now see why there is a Western Monarch Day? A day to bring awareness to this frightening decline? A day to find a way to make a difference!
Facts About Western Monarch Day
Monarchs Use an Internal “Sun Compass” to Navigate
Coastal California Groves Create Unique Overwintering Microclimates
Western and Eastern Monarchs Form Distinct Migratory Populations
Genetic and tagging studies show that eastern and western North American monarchs belong to one interbreeding species, Danaus plexippus, but form geographically distinct migratory populations, with western monarchs generally overwintering at coastal California sites while eastern monarchs concentrate in high-elevation oyamel fir forests in central Mexico.
Milkweed Chemistry Helps Monarchs Turn Toxic
Monarch caterpillars feed on milkweeds that contain cardiac glycosides (cardenolides), and specific amino acid substitutions in their sodium–potassium ATPase enzyme allow them to tolerate and sequester these toxins in their tissues, making both caterpillars and adults distasteful or poisonous to many vertebrate predators.
Western Monarch Numbers Have Crashed in Recent Decades
Monitoring of California overwintering sites indicates that the western monarch population has declined from an estimated 4–10 million butterflies in the 1980s to fewer than 2,000 individuals counted in winter 2020–2021, a collapse of over 99 percent that researchers link to loss of breeding and overwintering habitat, pesticide exposure, and climate-related stressors.
Small Urban Gardens Can Function as “Stepping-Stone” Habitat
Landscape ecology research finds that even small patches of milkweed and nectar plants in urban and suburban yards, parks, and transportation corridors can serve as “stepping-stone” habitat, offering breeding sites and refueling stops that help monarchs move across otherwise inhospitable agricultural and metropolitan regions.
Monarchs Are Widely Used as a Flagship Species for Insect Conservation
Because monarch butterflies are large, easily recognized, and culturally iconic, conservation planners often use them as a flagship species whose popularity helps mobilize public and political support for broader initiatives that reduce pesticide use and restore native host and nectar plants, indirectly benefiting many less conspicuous insect species.
Western Monarch Day FAQs
How is the western monarch butterfly different from the eastern monarch, and are they separate species?
Western and eastern monarchs are considered the same species (Danaus plexippus) but are managed as two regional populations that use different migratory routes and overwintering areas.
Eastern monarchs primarily migrate to high-elevation fir forests in central Mexico, while western monarchs generally migrate to coastal California and parts of the western U.S.; genetic studies show only minor differences, so they are treated as one species with distinct management units rather than separate species.
Why has the western monarch butterfly population dropped so sharply in recent decades?
Scientists and conservation groups point to a combination of habitat loss (especially the removal of native milkweed and nectar plants), widespread use of herbicides and insecticides, climate change, drought, and changes to overwintering groves as key drivers of the western monarch’s decline; long-term counts at California overwintering sites show drops of more than 95% from late‑1990s levels, illustrating how multiple human‑driven pressures can compound to affect a migratory insect.
What role do western monarch butterflies play in ecosystems beyond their visual appeal?
Western monarchs act as pollinators for a variety of wildflowers as they move across landscapes and also serve as prey for certain predators that have adapted to tolerate or avoid their toxicity, making them part of complex food webs; in addition, their sensitivity to habitat and climate changes makes them a useful indicator species for the health of broader pollinator communities and migratory corridors.
Why is planting “any” milkweed not always recommended for helping monarch butterflies?
Conservation organizations warn that planting non‑native or tropical milkweed species can disrupt monarchs’ natural migration and breeding cycles by encouraging them to breed year‑round in some regions and potentially increasing disease transmission; instead, experts recommend planting regionally native milkweed species and diverse, pesticide‑free nectar plants that bloom from spring through fall so gardens support monarchs without altering their life cycle.
How can everyday gardening practices unintentionally harm monarch butterflies?
Routine use of insecticides and some fungicides on lawns, ornamental plants, and even “pollinator gardens” can contaminate milkweed and nectar sources, killing monarch caterpillars and adults or weakening them so they are less likely to survive migration; mowing or clearing vegetation during breeding seasons can also remove eggs and larvae, so conservation guidance emphasizes reducing pesticide use, timing maintenance carefully, and leaving patches of native vegetation intact.
Are western monarchs currently protected as an endangered species, and how do agencies assess their status?
In recent assessments, U.S. federal wildlife agencies have found that migratory monarchs warrant conservation concern but have not granted them full endangered species protections, instead placing them in categories such as “warranted but precluded” while other higher‑priority species are addressed; these decisions rely on long‑term monitoring data, population modeling, and projections of future threats, and many NGOs continue to advocate for stronger legal protections for the western population in particular.
What kinds of community science projects focus on western monarch butterflies, and why do they matter?
Community science programs enlist volunteers to count monarchs at overwintering sites, report sightings of adults, eggs, and larvae, and track milkweed distribution across the West, providing large‑scale datasets that professional scientists could not gather alone; these standardized counts and observations are crucial for detecting population trends, evaluating conservation actions, and informing policy discussions about the status and management of western monarchs.
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