AREA OF FOREST OCCUPIED BY THE COLONIES OF MONARCH BUTTERFLIES IN MEXICO, DURING THE 2023-2024 OVERWINTERING PERIOD

During the second half of December 2023, nine monarch butterfly colonies in Mexico occupied a total of 0.9 hectares of forest, representing a 59.3% decrease from the 2.21 hectares recorded in 2022. Five colonies (0.273 ha) were located within the Monarch Butterfly Biosphere Reserve, while four (0.627 ha) were outside. The largest colony was found in the San Antonio Albarranes ejido (0.346 ha) and the smallest on Federal Property (0.003 ha).

• In the second half of December 2023, nine monarch butterfly colonies were recorded across the state of Michoacán (four colonies) and the State of Mexico (five colonies), occupying a total forest area of 0.9 hectares.
• The 0.9 hectares of occupied forest in 2023 represents a 59.3% decrease compared to the 2.21 hectares recorded during the 2022 overwintering period.
• Of the nine colonies, five (covering 0.273 ha) were situated within the Monarch Butterfly Biosphere Reserve (MBBR), and four (covering 0.627 ha) were located outside the reserve.
• The largest recorded colony occupied 0.346 ha in the San Antonio Albarranes ejido (Palomas sanctuary), while the smallest occupied 0.003 ha on Federal Property (Sierra Chincua sanctuary).
• The report identifies three primary threats to monarch butterflies: climate change, land use change in North America and forest degradation in Mexico, and the decline of milkweed at breeding sites in the United States caused by herbicide use.

APA

E., R.-S., FERNÁNDEZ-ISLAS, A., CRUZ-PIÑA, M., MONDRAGÓN-CONTRERAS, G., & MARTÍNEZ-PACHECO, A. (n.d.). AREA OF FOREST OCCUPIED BY THE COLONIES OF MONARCH BUTTERFLIES IN MEXICO, DURING THE 2023-2024 OVERWINTERING PERIOD. WWF International. https://www.worldwildlife.org/documents/626/5wx7wlzzjm_Monarch_Butterfly_Survey_Report_Feb_7_2024_.pdf

Chicago

E., RENDÓN-SALINAS,, A. FERNÁNDEZ-ISLAS, M. CRUZ-PIÑA, G. MONDRAGÓN-CONTRERAS, and A. MARTÍNEZ-PACHECO. AREA OF FOREST OCCUPIED BY THE COLONIES OF MONARCH BUTTERFLIES IN MEXICO, DURING THE 2023-2024 OVERWINTERING PERIOD. WWF International, n.d. https://www.worldwildlife.org/documents/626/5wx7wlzzjm_Monarch_Butterfly_Survey_Report_Feb_7_2024_.pdf.

Wikipedia

{{cite report |last1=E. |first1=RENDÓN-SALINAS, |last2=FERNÁNDEZ-ISLAS |first2=A. |last3=CRUZ-PIÑA |first3=M. |last4=MONDRAGÓN-CONTRERAS |first4=G. |last5=MARTÍNEZ-PACHECO |first5=A. |title=AREA OF FOREST OCCUPIED BY THE COLONIES OF MONARCH BUTTERFLIES IN MEXICO, DURING THE 2023-2024 OVERWINTERING PERIOD |publisher=WWF International |url=https://www.worldwildlife.org/documents/626/5wx7wlzzjm_Monarch_Butterfly_Survey_Report_Feb_7_2024_.pdf |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{endarea, author = {E., RENDÓN-SALINAS, and FERNÁNDEZ-ISLAS, A. and CRUZ-PIÑA, M. and MONDRAGÓN-CONTRERAS, G. and MARTÍNEZ-PACHECO, A.}, title = {{AREA OF FOREST OCCUPIED BY THE COLONIES OF MONARCH BUTTERFLIES IN MEXICO, DURING THE 2023-2024 OVERWINTERING PERIOD}}, institution = {WWF International}, url = {https://www.worldwildlife.org/documents/626/5wx7wlzzjm_Monarch_Butterfly_Survey_Report_Feb_7_2024_.pdf}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }