The 2026 Monarch Butterfly Crisis: Why Sacramento Bee Conservation Matters

The monarch butterfly endangered 2026 designation is no longer a hypothetical — it is the regulatory reality Sacramento pollinator advocates have been preparing for since the U.S. Fish & Wildlife Service announced its proposed Endangered Species Act listing in December 2024. Western monarchs, the population that overwinters along the California coast and spreads inland through the Sacramento Valley each spring, have collapsed to roughly 9,119 butterflies in the Xerces Society's 2024-2025 Western Monarch Count — a drop of more than 96% from the 2024 count and the second-lowest total on record. For Sacramento, that decline is not a faraway news story; it is happening to the same backyard pollinator network that local native bees, honey bees, and bumble bees depend on, and it changes what bee conservation has to look like in 2026.

This guide unpacks the 2026 crisis with the actual numbers — Xerces Western Monarch Count, USFWS listing decision, UC Davis breeding data, and Sacramento County pollinator records — and translates them into what residents, gardeners, and schools can do in the Central Valley right now. Monarchs and bees are not the same animal, but they share the same milkweed-poor, pesticide-loaded, drought-stressed landscape, and the interventions that help one almost always help the other.

TL;DR — The 2026 Monarch Crisis at a Glance

• The Xerces Society Western Monarch Count for 2024-2025 logged 9,119 butterflies across 256 overwintering sites — down from roughly 233,000 the prior year and the second-lowest count in the survey's 28-year history.
• In December 2024, the U.S. Fish & Wildlife Service formally proposed listing the monarch butterfly as Threatened under the Endangered Species Act, with a final rule expected in 2026.
• Western monarchs are below the 30,000-butterfly quasi-extinction threshold identified by Xerces Society scientists — the level below which scientists project a high risk of population collapse.
• Sacramento County sits inside the spring breeding corridor monarchs use as they leave coastal overwintering sites and spread inland; native milkweed and nectar plants in Sacramento yards directly support that corridor.
• The same drivers behind the monarch crash — habitat loss, pesticides, drought, climate stress — are the same drivers behind native Sacramento bee declines, which is why bee conservation and monarch conservation are now the same fight.

The Numbers — What the 2024-2025 Western Monarch Count Actually Shows

The Western Monarch Count is the longest-running citizen-science survey of overwintering monarchs in the Western United States. Coordinated by the Xerces Society with hundreds of volunteers, it counts butterflies clustering at coastal sites from Mendocino County south to Baja California during Thanksgiving and New Year's windows. The Thanksgiving Count is the headline figure; it is not a population estimate so much as a population pulse.

The 2024-2025 Thanksgiving total was 9,119 butterflies across 256 surveyed sites. That is roughly a 96% decline from the 2023-2024 count of approximately 233,000, and it is the second-lowest tally Xerces has recorded since 1997 — beaten only by the catastrophic 2020-2021 winter when fewer than 2,000 butterflies showed up at all known sites combined. For context, Western Monarch Counts in the late 1990s routinely cleared 1 million butterflies. The 1980s baseline, reconstructed from earlier surveys, was over 4 million.

Why does the 2024-2025 collapse matter so much when 2020-2021 was lower? Because 2020-2021 was supposed to be the bottom. The brief rebound to roughly 247,000 butterflies in 2021-2022, then around 335,000 in 2022-2023, then 233,000 in 2023-2024, suggested that western monarchs might recover toward the quasi-extinction threshold of 30,000 that Xerces Society biologists identified in their 2017 viability analysis. Falling back below 10,000 in a single year — without a single catastrophic event to point at — tells scientists the underlying habitat and stressor problems are still active and worsening.

The Quasi-Extinction Threshold, Explained

Quasi-extinction is the population level below which a species cannot reliably maintain itself even in good years. For western monarchs, Xerces and partner researchers calculated that threshold at 30,000 butterflies based on minimum cluster sizes, mate-finding probabilities, and the mathematical risk that a single bad winter wipes the population to zero. The 2024-2025 count is roughly 30% of that threshold. Scientifically, the western monarch is in a high-risk zone where one severe storm, fire, or pesticide event at a major overwintering grove could be unrecoverable.

The USFWS Listing Decision — What the 2026 Rule Actually Does

On December 10, 2024, the U.S. Fish & Wildlife Service published a proposed rule to list the monarch butterfly (Danaus plexippus plexippus) as Threatened under the Endangered Species Act, along with a proposed 4(d) rule defining what activities are prohibited and which are exempt. After a public comment period that closed in March 2025 and an extension period for stakeholder input, USFWS is expected to issue a final rule in 2026. Most observers expect the final rule to follow the proposed framework with modest adjustments.

Threatened status is one tier below Endangered. It triggers federal protections — including prohibitions on "take" of the species, mandatory consultation for federally permitted projects, and the eventual development of a recovery plan — while preserving more flexibility than full Endangered status. The proposed 4(d) rule for monarchs is unusually permissive compared to most listed species: routine agricultural activities, roadside mowing outside breeding windows, and incidental take during habitat restoration projects would generally be exempt. The intent is to encourage habitat work, not punish landowners.

What the listing does change, decisively, is the funding and policy environment. ESA-listed species qualify for Section 6 cooperative recovery grants to states, NRCS conservation program priority, and federal-agency duties to avoid jeopardy. For Sacramento, that means Caltrans roadside revegetation projects, federal building landscaping, and any construction with a federal nexus will need to consider monarch habitat. It also means California's existing State Wildlife Action Plan and the Western Monarch Conservation Plan move from voluntary frameworks to action items with federal backing.

Why Sacramento Is Inside the Crisis, Not Outside It

Sacramento is not a coastal overwintering site. The clustering groves are in Pacific Grove, Pismo Beach, Santa Cruz, and a string of eucalyptus and Monterey pine sites between Mendocino and San Diego. So why does the Western Monarch Count matter for Sacramento bee conservation? Because the butterflies counted on the coast in November are the parents of the monarchs that move inland in spring — and Sacramento sits inside their primary spring breeding corridor.

Western monarchs follow a multi-generational migration. The overwintering generation breaks diapause in February, mates, and disperses inland looking for the first emerging milkweed. In California, that first wave reaches the Sacramento Valley, the Delta, and the Sierra foothills between late February and April. Females lay eggs on early-season milkweed; the larvae develop, pupate, and emerge as a new generation that pushes north and east, into Oregon, Idaho, and the Great Basin. Sacramento is where the first inland generation gets made.

When the overwintering count crashes from 233,000 to 9,119, the number of breeding females reaching Sacramento drops by the same proportion. UC Davis monarch researchers have documented that Central Valley sightings in spring 2025 were down sharply from prior years, with multiple long-running breeding sites along the American River corridor producing zero confirmed eggs during the early-season window. The Conservatory's own native plant restoration sites — which historically host 5 to 15 monarch sightings between March and May — logged 2 sightings across all sites in spring 2025.

Why Bee Conservation Sits at the Center of the Monarch Response

Monarchs and bees are different animals — different orders, different life histories, different overwintering strategies. But the drivers that pushed western monarchs below the quasi-extinction threshold are the same drivers behind the steady erosion of California native bee diversity, and most of them play out at the property scale. Habitat loss, pesticide exposure, drought stress, and the thinning of native flowering plant communities show up in both crashes.

That overlap matters because Sacramento residents who plant for bees are almost always also planting for monarchs, and vice versa. Native milkweed (Asclepias fascicularis, narrowleaf milkweed; Asclepias speciosa, showy milkweed) is the only plant western monarchs lay eggs on, but its flowers also feed long-tongued bumble bees, leafcutter bees, and honey bees. California buckwheat, native asters, gum plant, and California fuchsia — all staples of a bee-friendly Sacramento yard — are also nectar sources for adult monarchs as they refuel between breeding sites. For more on the underlying plant list, see our guide to 10 native plants Sacramento bees love.

Sacramento's broader 2026 pollinator picture, covered in our 2026 bee crisis report, is dominated by the same forces. Native bee species richness in Sacramento County has trended downward in line with the same urbanization and climate drivers that hurt monarchs. The compounding effect of drought and heat on local bee populations hits monarch breeding habitat the same way: when native nectar plants skip blooming or compress their flowering window, both bees and butterflies lose food.

Tropical Milkweed: The Mistake to Avoid

One critical detail that separates well-meaning monarch gardening from helpful monarch gardening: native milkweed only. Tropical milkweed (Asclepias curassavica) is sold across Sacramento nurseries because it blooms long, looks lush, and survives the local climate. But it does not die back in winter the way native milkweeds do, and that single difference allows a parasitic protozoan called Ophryocystis elektroscirrha (OE) to build to dangerous levels on year-round leaves. Multiple Xerces Society and University of Georgia studies have documented sharply elevated OE infection rates in monarch populations breeding on tropical milkweed.

Worse, the persistent green leaves of tropical milkweed in California's Mediterranean climate can disrupt the migration cue itself — convincing some monarchs to break diapause, breed locally, and skip the trip to coastal overwintering sites. Researchers consider tropical milkweed a meaningful contributor to the western monarch decline. The fix is straightforward: plant native species (showy or narrowleaf milkweed for Sacramento), remove tropical milkweed, or at minimum cut tropical milkweed to the ground in October to mimic native dieback.

The Sacramento Action Plan — What Actually Helps in 2026

Conservation rhetoric is cheap. What follows is the short list of actions that Sacramento residents, schools, and businesses can do in 2026 that biologists and Xerces Society guidance support as having measurable population-level impact when adopted at neighborhood scale.

1. Plant Native Milkweed (Not Tropical)

Showy milkweed (Asclepias speciosa) and narrowleaf milkweed (Asclepias fascicularis) are the two species native to the Sacramento Valley. Both are available at Cornflower Farms, Elderberry Farms Native Plant Nursery, and most Sacramento native plant sales (the California Native Plant Society Sacramento Valley Chapter holds spring and fall sales each year). Plant in clusters of three or more — single plants are easy for arriving monarchs to miss.

2. Build a Continuous Bloom Calendar

Adult monarchs need nectar. Native bees need pollen and nectar. A yard that blooms in March, May, July, and September supports both. Pair milkweed with California buckwheat (Eriogonum fasciculatum), California aster (Symphyotrichum chilense), gum plant, and California fuchsia. Our guide to bee-friendly Sacramento gardens lays out a year-round bloom plan.

3. Stop Using Neonicotinoids

Neonicotinoid insecticides — imidacloprid, clothianidin, thiamethoxam — show up in big-box-store "systemic" pest control products and in pre-treated nursery plants. They are present in the pollen and nectar of treated plants for months and are documented contributors to both bee and butterfly declines. See our deeper analysis of neonicotinoids and Sacramento bees for the brand-level breakdown of what to avoid and what to ask nurseries about.

4. Report Sightings to Western Monarch Mystery Challenge and iNaturalist

Every documented Sacramento monarch sighting feeds the data scientists and policymakers use to write recovery plans. The Western Monarch Mystery Challenge runs each spring (February through April), explicitly soliciting sightings from interior California to map the inland breeding wave. iNaturalist's California Monarch Project does the same year-round. Both work well alongside the bee survey approaches in our Sacramento citizen-science guide.

5. Support Habitat at School and Public Property Scale

Yard-scale habitat helps. Schoolyard and park-scale habitat helps more. Sacramento City Unified School District and the City of Sacramento Department of Parks have both moved toward pollinator-friendly landscaping in recent years; resident voices in support of those programs accelerate them. Our walkthrough on starting a pollinator garden at a Sacramento school covers funding sources, plant lists, and curriculum hooks.

How the Bee Conservatory Is Responding to the 2026 Crisis

Our work has always been about pollinators broadly, not just bees. The 2026 monarch listing makes that overlap explicit. In response to the 2024-2025 count, we have expanded our restoration plant lists to require native milkweed at every Sacramento County site we work on; added monarch identification training to our volunteer onboarding; and partnered with the California Native Plant Society Sacramento Valley Chapter and the Sacramento Tree Foundation on a milkweed-distribution program for residents in low-pollinator-canopy ZIP codes.

We are also doing the smaller, less glamorous work that adds up: relocating bee swarms for free so households are not driven to exterminator-grade insecticides that drift into pollinator habitat, training Sacramento County volunteers to spot and document monarchs and listed bumble bees, and pushing for stronger neonicotinoid restrictions in city and county landscaping contracts. Read more about the operating philosophy in why we provide free bee removal.

Frequently Asked Questions

Is the monarch butterfly officially endangered in 2026?

The monarch butterfly was proposed for listing as Threatened (one tier below Endangered) under the U.S. Endangered Species Act in December 2024, with a final rule expected in 2026. Threatened status carries most of the same federal protections as Endangered status, including prohibitions on take and recovery-plan obligations. The western monarch population is also separately considered for state-level protection under the California Endangered Species Act.

How many western monarchs are left in 2025?

The Xerces Society's 2024-2025 Western Monarch Count logged 9,119 butterflies across 256 surveyed overwintering sites — a roughly 96% decline from the prior year's count of approximately 233,000. That puts the population well below the 30,000-butterfly quasi-extinction threshold scientists identified as the level required for reasonable population stability.

Do monarchs come through Sacramento?

Yes — Sacramento sits inside the western monarch's spring breeding corridor. Overwintering butterflies leave the California coast in February and March and disperse inland; the first inland breeding generation is produced in the Central Valley, including Sacramento County, between late February and May. Sacramento yards with native milkweed and nectar plants directly support that first generation.

What is the best milkweed to plant for Sacramento monarchs?

Plant native species: showy milkweed (Asclepias speciosa) and narrowleaf milkweed (Asclepias fascicularis). Avoid tropical milkweed (Asclepias curassavica), which can elevate parasite (OE) infection rates and disrupt the migration cue by staying green year-round in California's Mediterranean climate. Native milkweeds die back in winter, which is what monarchs evolved with.

What does the USFWS Threatened listing actually require of Sacramento residents?

Very little, directly. The proposed 4(d) rule for monarchs is permissive — routine yard care, agriculture, and roadside maintenance outside breeding windows are generally exempt. The listing primarily changes federal funding, agency consultation requirements, and the priority monarchs receive in conservation grant programs. For residents, the practical effect is more habitat funding flowing into California, not new yard-level prohibitions.

How can I help monarchs in Sacramento right now?

Plant native milkweed and nectar plants, eliminate neonicotinoid pesticide use, report sightings to iNaturalist or the Western Monarch Mystery Challenge, and support pollinator-friendly landscaping at your school, workplace, or local park. The Bee Conservatory offers free native planting consultations to Sacramento County residents — contact us to schedule one.

The Bottom Line

The monarch butterfly endangered 2026 listing is not a distant story for Sacramento. The 9,119 butterflies counted on the California coast last winter are the same population that should be reaching Sacramento Valley milkweed this spring, and the absence of those butterflies is showing up in real data on Conservatory restoration sites and along the American River corridor. The drivers behind their decline — habitat loss, pesticides, drought, climate stress — are the same drivers behind native Sacramento bee declines, which means the same yard-level actions move both populations.

We do not get a do-over on this one. Western monarchs are below the quasi-extinction threshold, and recovery requires a lot of small actions stacked across a lot of properties. Plant native milkweed. Skip the neonicotinoids. Document what you see. Support the schools, parks, and roadside programs that landscape with pollinators in mind. Sacramento bee conservation is monarch conservation in 2026, and the work happens one yard, one swarm, one school garden at a time.