7 important facts about the 2019-2020 season of the monarch butterfly in Mexico

11 Monarch butterfly colonies were recorded (3 in Michoacán and 8 in the State of Mexico), including a new colony record in the El Potrero ejido, Municipality of Amanalco de Becerra, Edomex.

During the 2019-2020 season, the Monarch butterfly population occupied a forest area of 2.83 hectares
During the 2019-2020 season, the Monarch butterfly population occupied a forest area of 2.83 hectares

During the 2019-2020 season, 11 colonies of Monarch butterflies were recorded (3 in Michoacan and 8 in the State of Mexico), occupying 2.82 ha, of which 5 colonies (2,458 ha) were located within the Monarch Butterfly Biosphere Reserve and 6 colonies (0). 36 ha) were established outside of it, which means a decrease of 53.22% with respect to the area (6.05 ha) occupied in December 2018, reported the National Commission of Natural Protected Areas (CONANP) and the WWF-Telmex Telcel Foundation Alliance.

The Monarch Butterfly Biosphere Reserve continues to be a key site for the Monarch's hibernation, where 87% of the total butterfly population was concentrated during this season. The colony of El Rosario ejido (Santuario Sierra Campanario), registered the largest forest area with 1.27 ha and the smallest (0.001 ha) was El Potrero ejido (Santuario Cerro de la Antena), this colony represents a new record within the Natural Resources Protection Area Zona Protectora Forestal, Valle de Bravo, Malacatepec, Tilostoc, and Temascaltepec. For the second time, we registered the colony of the ejido Ojo de Agua with 0.049 ha (Table 1). We measured the Atlautla colony in the area of influence of Iztaccihuatl-Popocatepetl National Park, with 0.01 ha.

Roberto Aviña Carlín, National Commissioner of Natural Protected Areas, mentioned that the effort being made to conserve this spectacular migratory phenomenon is the result of Mexico's coordination with the governments, academia and civil society of Canada and the United States since February 2014, when it was defined within the framework of the North American Leaders' Summit held in Toluca, State of Mexico, where a trilateral working group was established in view of the population decline registered in the 2013-2014 season, which was 0. 67 hectares of forest occupation of the Monarch butterfly colonies in their hibernation sanctuaries

"In the most recent hibernation seasons, it has been usual for the butterflies to occupy an average of about three hectares of forest. The previous season, 2018-2019, was very good, with 6.05 hectares of forest occupied, but certainly atypical, thanks to the fact that the first generation of butterflies in spring 2018 in Texas found favorable climatic conditions to repopulate all the breeding sites in North America," explained Jorge Rickards, General Director of WWF Mexico.

"The current reduction in the Monarcas population is not alarming, but we must remain vigilant to ensure that it is not a trend in the coming years. The conservation work is long term. In this sense, the WWF Telmex Telcel Foundation Alliance has more than 16 years measuring the area of forest occupied by the butterflies during their hibernation and 20 years monitoring the conditions of the forest in the Monarch Butterfly Biosphere Reserve, which reflects good conditions as a hibernation habitat with a very low illegal logging rate of 0.43 ha in the period of 2018-2019. We are committed to continuing to work hand in hand with all those involved on behalf of the species, its habitat, and the human communities that depend on it," concluded Rickards.

The Monarchs travel more than 4,000 kilometers from Canada and the United States to spend the winter in the Mexican forests, from November to March. The Monarch Butterfly Biosphere Reserve is also home to 132 species of birds, 56 mammals, 432 vascular plants and 211 fungi. These forests also infiltrate water into the Cutzamala System for more than 4.1 million people in Mexico City and its metropolitan area.

This extraordinary migratory phenomenon for its "Exceptional Universal Value", was designated in 2008 as World Heritage of Humanity.

The main threats to the monarch in North America are the reduction of reproductive habitat in the United States due to the decline of cottonseed due to indiscriminate herbicide use and land use change; forest degradation at wintering sites in Mexico due to historical illegal logging and weather-related tree felling; and extreme weather conditions in Canada, the United States and Mexico.

On Oct. 7, in Acuña, Coahuila, the first record of Monarch butterflies in Mexico for the 2019-2020 season was obtained, and this season they arrived punctually at their hibernation sites on the Day of the Dead.

Throughout the hibernation season, there were no extreme climatic conditions that put the butterfly population at risk. The only effect was the 32nd cold front associated with a mass of cold air between January 19 and 21, 2020, when a drop in temperature was recorded with rain and strong gusts of wind, and even ice in some parts of the region, but without major consequences for the colonies.

The first signs of butterfly reproduction were recorded during the last week of January 2020 and from the second week of February, thanks to citizen monitoring carried out by the Guanajuato State Government, the first Monarchs were observed migrating towards the north of Mexico and the south of the United States in search of feeding and oviposition areas. Currently, Monarch groups can be observed crossing the highways so it is requested that if Monarchs are seen flying they should slow down to 60 kilometers per hour.

The Royal Mail Program and the National Monarch Butterfly Monitoring Network have records of Monarchs since late February on their spring migration in the states of Guanajuato, San Luis Potosi, Nuevo Leon, Tamaulipas, Queretaro, Hidalgo, and Coahuila.

In May 2019, the Action Plan for the Conservation of the Monarch Butterfly in Mexico was published, which is the guiding instrument that defines 147 priority actions to be implemented in the 6 strategic lines identified in a participatory manner for the conservation of the migratory phenomenon both along the migratory route and in the wintering habitat of the Monarch butterfly in Mexico, such as 1) Economics of conservation, 2) Restoration and conservation, 3) Research and monitoring, 4) Inspection and surveillance, 5) Social participation, communication and culture for conservation, 6) Coordination and financing.

Some clusters and butterflies can still be seen scattered among the oyamel and pine trees in some public access sites with authorization for tourist visitation in the states of Mexico and Michoacán. Conanp invites you to continue enjoying this exceptional natural phenomenon, and at the same time to listen to the recommendations of the local guides so that the tourist's stay and experience is a pleasant one. The 2019 - 2020 tourist visitation ends on March 31, 2020.

Migratory route

1. Monarchs are found in the United States and Canada between April and August.

2. To survive the winter, they migrate to Mexico in September and October.

3. Although they have never been here, they are guided by the position of the sun.

4. They hibernate in Mexico from November to March, forming colonies in forests of pine-oak and oyamel, at an altitude of more than three thousand meters.

5. During February and March, they mate and then return to the United States, where they lay their eggs on the Asclepias.

More than 40% of the monarch butterfly that hibernates in Mexico is found in El Rosario

Of all the Monarch Butterfly that arrived at the forests of the country, to Michoacán and the State of Mexico, little more than 40% is concentrated in the El Rosario Sanctuary, which is located in the municipality of Ocampo, they assured in a press conference, Homero Gómez González and the Regional Delegate for Tourism, Georgina Herrera Tello.

This is because this lepidopteran is looking for nearby water and thick forest, and that is what El Rosario has; thanks to the reforestation actions and to which they brought water from a distance of eight kilometers. Also, unlike in past seasons, the Monarch is not found above the sanctuary, but 200 meters from the entrance is a huge colony, which begins to be seen in significant amounts from the parking area, commercial area and much to little distance.

Official data show that the current butterfly population increased 144% last year, so the figure is historical, it had never happened. "We have many people working to take care of it, from guides, and others who are responsible for making recommendations to tourists as they do not touch them, do not step on them, take pictures without flash, do not make noise, they also tell them that you can not take plants of the sanctuary, "said Gómez González. Currently, there are around 174 ejidatarios who are part of the administration of the sanctuary, and the instruction is to care for the monarch.

Homero Gómez González said that from November to date, more than 75,000 tourists have come to El Rosario, and it is expected that at the end of the season they will have 150,000 or more, both international and national. The current number of visitors may have been higher because in two weeks because of the shortage of gasoline, there were many who canceled their visit or postponed, but despite what happened the figures are good, and the population of the butterfly in this place is historic.

Georgina Herrera Tello said that these visits translate into an important economic spill for the eastern region, and added that it has had to do the promotion work by the agency that represents in this part of the state.

By Mexicanist Source CONANP