AREA OF FOREST OCCUPIED BY THE COLONIES OF MONARCH BUTTERFLIES IN DURING THE HIBERNATION SEASON OF 2019-2020.

RENDÓN-SALINAS, E.1, F. MARTÍNEZ-MEZA2, M.A. MENDOZA-PÉREZ3, M. CRUZ-PIÑA3, G. MONDRAGÓN-CONTRERAS2 y A. MARTÍNEZ-PACHECO4.

1World Wildlife Fund-México, Jaime Torres Bodet No. 22, Col. Poetas, 61500, Zitácuaro, Michoacán 2Dirección de la Reserva de la Biosfera Mariposa Monarca, Cuauhtémoc Ote. No. 34, Esq. Manuel Altamirano, 61504, Zitácuaro, Michoacán 3Danaidas Conservación y Desarrollo Sustentable, A.C., Caoba 106 Mirador del Fresno II, Zitácuaro, Michoacán 4World Wildlife Fund- México, Av. México No. 51, Col. Hipódromo, 06100, Cd. de México

Abstract

During the second half of December 2019 we located and assessed 11 colonies of Monarch butterflies (3 in Michoacan and 8 in the ), in addition we located and assessed a new colony in El Potrero ejido1, Municipio de Amanalco de Becerra, State of Mexico. The colonies occupy a total of 6.99 acres (2.83 ha) of forest: 5 colonies occupying 6.08 acres (2.46 ha) are located inside of the Monarch Butterfly Biosphere Reserve (MBBR) and 6 colonies occupying 0.91 acres (0.37 ha) are located outside of it. This area represents a 53.22% decrease in respect to the area of 14.95 acres (6.05 ha) occupied in December of 2018. The colony of in the east of the State of Mexico covered 0.02 acres (0.01 ha) of forest.

Introduction

The Monarch Butterfly (Danaus plexippus) migrates each fall from the east of Canada and the United States to hibernate in Michoacan state and the State of Mexico (Fig. 1). The main threats to the Monarch butterfly are: i. the decrease of plants which the larvae eat throughout the reproduction sites located in the United States, ii. the historical degradation of forests in the hibernation zones in Mexico, and iii. climate change (Pleasants y Oberhauser, 2012; Vidal et al. 2013). The smallest area of forest occupied by the colonies was recorded in 2013-2014 with 1.66 acres (0.67 ha), meanwhile during the 2018-2019 season the area occupied by the colonies increased to 14.95 acres (6.05 ha) (Rendón-Salinas et al. 2005-2018; Vidal y Rendón-Salinas, 2014). Since the 2004-2005 season the Alliance WWF- TELMEX TELCEL Foundation, coordinated with the Direction of the Monarch Butterfly Biosphere Reserve (DMBBR) of Mexico’s National Commission of Natural Protected Areas (CONANP) in order to systematically monitor the hibernation of this species in Mexico. In this report we include the area of forest occupied by the Monarch butterfly colonies during the second half of December of 2019 and use it as an indirect indicator of the species abundance for the 2019-2020 season.

1 An Ejido is a form of communal land management in Mexico

Figure 1: Natural Protected Areas and Hibernation Sanctuaries in the "Monarch Region"

Methodology

Since the beginning of November we would visit the hibernation sanctuaries located in the “Monarch Region” twice a month to establish the presence or absence of the colonies; when a colony was located we would determine the location using a GPS Garmin® with UTM projection and with the WGS 84 data. We recorded the perimeter of the forest occupied by the butterflies starting at the tree located at the highest point of the slope and based on the direction and the distance between the trees outlying those occupied by the butterflies. The data collected was processed with the Geographic Information System ArcView 3.3 in order to establish the area occupied by the colonies (Vidal y Rendón-Salinas, 2014). Additionally, the colony located outside of the Monarch Region in Atlaulta was also measured.

Results

During the second half of December 2019, we located and assessed 11 colonies of Monarch butterflies (3 in Michoacan, 8 in the State of Mexico) which occupied 6.99 acres (2.826 ha), it was established that 5 colonies occupying 6.07 acres (2.458 ha) were located inside the MBBR and 6 colonies occupying 0.91 acres (0.368 ha) were located outside of it. This area represents a 53.22% decrease in comparison with the recorded area of 14.95 acres (6.05 ha) occupied in 2018-19 (Fig. 2). The largest Monarch colony which occupies 3.15 acres (1.274 ha) was recorded in El Rosario ejido (santuario Sierra Campanario) and the smallest colony which occupies 0.002 acres (0.001 ha) was recorded in El Potrero ejido (santuario Cerro de la Antena), this colony represents a new colony within the protected area of the Natural Resources Protected Forest Zone, , Malacatepec, Tilostoc and . For the second time a colony located in Ojo de Agua ejido was recorded to be 0.12 acres (0.049 ha) (Table 1). The colony of Atlautla bordered the National Park of Iztaccihuatl-Popocatepetl outside of the Monarch region occupying 0.02 acres (0.01 ha).

Table 1. Hibernation colonies and forest area occupied during the second half of December 2019. Location State Sanctuary Colonies (Agricultural Properties) Area (Acres) Area (Hectareas) E. El Capulín * * E. Mesas Altas de Xoconusco * * Cerro Pelón State of Mexico C.I. San Juan Xoconusco 0.694 0.281 B.C. San Pablo Malacatepec 1.082 0.438 Sierra Campanario E. La Mesa 0.470 0.190 Within the Monarch Cerro Altamirano E. Contepec * * Butterfly Biosphere Cerro Pelón E. Nicolás Romero * * Reserve (MBBR) Chivatí-Huacal C.I. Carpinteros * * Sierra Campanario E. El Rosario 3.148 1.274 Michoacán Propiedad Federal * * Sierra Chincua E. Cerro Prieto 0.680 0.275 E. El Calabozo Fracción 1 * * Lomas de Aparicio E. Crescencio Morales * * Area occupied within the Reserve 6.074 2.458 Cerro del Amparo E. San Francisco Oxtotilpan 0.072 0.029 Palomas E. San Antonio Albarranes 0.400 0.162 State of Mexico Piedra Herrada E. San Mateo Almomoloa 0.200 0.081 Outside the MBBR Peña Ahumada E. Ojo de Agua 0.121 0.049 Cerro de la Antena E. El Potrero 0.002 0.001 Los Azufres P.P. San Andrés 0.114 0.046 Michoacán Mil Cumbres E. Río de Parras * * Area occupied outside the reserve 0.909 0.368 Total occupied area 6.983 2.826 E= Ejido (Communal land management), C. I.= Comunidad Indígena (Idigenous Community), P. P.= Pequeña Propiedad (Small Property), B. C.= Bienes Comunales (Communal Properties), * No hubo colonia (No colony present)

Figure 2: Area of forest occupied by monarch butterflies hibernating in Mexico; 1993-1994 to 2019-2020 Acknowledgements

We would like to acknowledge Angélica Reyes-Ruiz for their support in the field and for producing the map, to the authorities and collaborators of the properties which were visited. To the staff of the Área de Protección de Flora y Fauna Nevado de , and of the Área de Protección de los Recursos Naturales Zona Protectora Forestal, Valle de Bravo, Malacatepec, Tilostoc, and Temascaltepec, as well as the Iztaccihuatl-Popocatepetl national park. We would like to especially acknowledge Gloria Tavera Alonso, Regional Director of the Centro y Eje Neovolcánico of the National Commission of Protected Areas (CONANP) for her support and coordination for the monitoring. This work was made possible thanks to the support of the Alianza WWF Fundación Telmex-Telcel (that forms part of the Alianza WWF-Fundación Carlos Slim) and CONANP, through the Direction of the Monarch Butterfly Biosphere Reserve.

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