[Pollinator] Xerces Society's Western Monarch Count: The Numbers are In!

Thu Jan 29 10:40:00 PST 2026

Western Monarch Numbers Remain at Historic Low

*Media Contacts: *
Isis Howard, Conservation Biologist, Xerces Society; 503-212-0546;
isis.howard at xerces.org
Sara Cuadra-Vargas, Conservation Biologist, Xerces Society; 562-625-0005;
sara.cuadra at xerces.org
Emma Pelton, Senior Conservation Biologist, Xerces Society; 503-212-0706;
emma.pelton at xerces.org

*SAN FRANCISCO; January 29, 2026 –* After surveys by hundreds of volunteers
and partners, results from the 29th annual Western Monarch Count
<https://westernmonarchcount.org/> led by the Xerces Society for
Invertebrate Conservation reveal another historically low population.
Approximately 12,260 monarchs were recorded
<http://westernmonarchcount.org/data> across 249 sites during the typical
peak overwintering period from late November through early December 2025,
when monarchs cluster together in groves of trees along California’s coast.

This is the third-lowest tally since the count began in 1997, following low
numbers last winter
<https://xerces.org/press/western-monarch-butterfly-population-declines-to-near-record-low>
and
a weak summer breeding season. The three lowest counts in the program’s
history have all occurred in recent years: 1,901 individual monarchs in
2020, 9,119 in 2024, and 12,260 in 2025. Western monarchs numbered in the
low millions regularly in the 1980s. The increasing frequency of record-low
years heightens ongoing concerns about the health and stability of the
western monarch migration.

“Western monarchs are in serious trouble. The migration is collapsing,”
said Emma Pelton, a senior conservation biologist with the Xerces Society.
“We must move quickly to safeguard existing monarch habitat and restore and
better manage the landscapes monarchs depend on, or else we risk losing one
of North America’s most incredible natural phenomena. Our window for action
is narrowing, and our conservation efforts must accelerate.”

Highest monarch count in Santa Cruz County

Despite low overall numbers, monarchs continued to roost in good numbers at
sites in Santa Cruz. Natural Bridges State Beach recorded the highest count
this season with 2,500 monarchs in early December. Xerces and partners deployed
ultralight radio tags
<https://xerces.org/press/new-ultralight-radio-tags-are-tracking-monarch-butterflies-in-santa-cruz>
in
Santa Cruz to better understand monarch movement during the overwintering
period, information that could improve how overwintering habitat is managed.

Mid-season counts at other well-known sites include:

   - Albany Hill, Alameda County: 221 butterflies
   - Skywest Golf Course, Hayward, Alameda County: 510 butterflies across
   two sites
   - Gill Tract Community Farm, Alameda County: 148 butterflies
   - Pacific Grove Monarch Sanctuary, Monterey County: 188 butterflies
   - Pismo State Beach Monarch Grove, San Luis Obispo County: 471
   butterflies
   - Ellwood Mesa, Santa Barbara County: 29 butterflies across nine sites
   - Gaviota State Beach, Santa Barbara County: 425 butterflies across two
   sites
   - Ocean Ave. Park, Ventura County: 178 butterflies

Development threatens remaining overwintering habitat

Experts say protecting and managing overwintering sites is vital to
maintain the monarch migration. Loss of overwintering habitat on the
California coast due to development remains a major threat to monarch
survival.

“Since tracking began, over 60 monarch overwintering sites have been
destroyed. In the last year alone, at least three active sites have been
significantly damaged by extensive, inappropriate tree removal,” said
Sarina Jepsen, director of the Xerces Society’s endangered species program.
“Without adequate places for monarchs to overwinter, we will lose the
migration.”

There are a number of active proposals to develop monarch groves. Local
advocates in Hayward, CA are working to protect two overwintering groves in
the Skywest Golf Course that are threatened by development plans
<https://www.spectator.news/local-activists-fight-for-haywards-open-space/> for
the Hayward Executive Airport. Overwintering habitat was also partially
lost at a documented site
<https://www.vcreporter.com/news/vista-del-mar-trees-cut-down-monarch-butterfly-habitat-removal-sparks-protest-in-ventura/article_3dff25ca-92c1-4910-97d5-e63b33cc0312.html>
in
Vista Del Mar, Ventura, before constituents rallied to temporarily stop an
order to remove additional eucalyptus trees to make way for a potential
development.

In contrast, some communities have demonstrated that development can
proceed while still protecting monarch overwintering habitat. At Gill Tract
Community Farm <https://www.gilltractfarm.org/> in Albany, CA,
collaboration among UC Berkeley, scientists, and community members
protected and enhanced an overwintering site while allowing nearby student
housing to move forward. Today, students and local partners steward the
grove and support monarch monitoring with the Xerces Society.

Low numbers driven by long and short term stressors

While annual fluctuations in monarch numbers draw attention, scientists say
the real concern is long-term decline of monarchs and other butterflies
<https://www.xerces.org/press/study-finds-that-us-butterfly-populations-are-severely-declining>
driven
by habitat loss, pesticides, and climate change. Research led by Drs.
Cheryl Schultz and Elizabeth Crone showed that western monarchs have
declined by approximately 10% per year since the 1980s
<https://westernmonarchcount.org/wp-content/uploads/2014/11/Western-monarch-PVA_Schultz-et-al.-2017.pdf>,
suggesting this year’s low numbers reflect an ongoing trend rather than a
sudden crash.

“When populations get this small, they become far more vulnerable to both
short-term stress and long-term pressures,” said Isis Howard, a
conservation biologist with the Xerces Society who coordinates the Western
Monarch Count. “With low overwintering numbers becoming more common,
monarchs have fewer chances to rebound from extreme weather or pesticide
exposure
<https://xerces.org/press/study-links-pesticides-to-monarch-butterfly-deaths-in-pacific-grove>
.”

A call to action to save the monarchs

“While another year of low numbers is bad news for western monarchs, the
good news is that everyone can play a role in bringing them back from the
brink,” said Pelton. “If we all do what we can, we can make a real and
lasting difference.”

The Xerces Society is inviting all Californians to make a tangible
difference this year through the Western Monarch Call to Action
<https://xerces.org/western-monarch-call-to-action>. Priority actions to
recover the population include:

   - Avoid using pesticides
   <https://xerces.org/bring-back-the-pollinators/avoid-pesticides>,
   especially insecticides, which threaten monarchs and other pollinators.
   - Create and maintain monarch habitat year-round by planting regionally
   appropriate native flowers
   <https://xerces.org/monarchs/monarch-nectar-plant-guides> and native
   milkweeds <https://xerces.org/milkweed/milkweed-guides>. Qualifying
   individuals can apply for a free habitat kit
   <https://xerces.org/pollinator-conservation/habitat-kits>.
   - Advocate for protection of overwintering sites
   <https://westernmonarchcount.org/map-of-overwintering-sites/>.
   -

   Participate in community science <https://xerces.org/community-science>.

###
Acknowledgments

The Western Monarch Count is made possible by hundreds of dedicated
volunteers and partners who collected data at overwintering sites, as well
as funding from: The California Wildlife Conservation Board, California
Association of Resource Conservation Districts, Cinco Hermanos Fund,
Elizabeth Weber, Maxwell/Hanrahan Foundation, Monarch Joint Venture,
Nature's Path Foods Inc., San Diego Zoo Wildlife Alliance, U.S. Forest
Service International Programs, and Xerces Society members.

Isis Howard (she/her)

Conservation Biologist

The Xerces Society for Invertebrate Conservation

503.212.0546 | isis.howard at xerces.org

xerces.org
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