Recognizing that sound science is key to effective conservation, we support scientific research, including habitat and species assessments, with direct relevance to conservation in the overwintering sites. Our research funding supports scientists studying ecology and the conservation of monarchs in Mexico.
Dry Year in 2020-2021 Overwintering Season
Since monarchs began arriving in early November, the National Weather Service’s Drought Monitor in Mexico reported Moderate Drought in the region where the colonies are established. Drought (precipitation deficit, vegetation stress, low soil moisture, low water body level) increased and by February and March, it had already become a Severe Drought. At the Meteorological Station located in the Llano de las Papas in Sierra Chincua, at the same elevation as the butterfly colony and a scant three kilometers away, the average relative humidity for November was 53% and decreased to 26% in February. Additionally, only 11 millimeters (0.43 in.) of rain were recorded throughout the season between December and January.
The dry conditions prompted a lot of flight activity throughout the season, except on the few cold and cloudy days. Many butterflies were seen trying to hydrate in wet areas of nearby plains, streams and flowers. Early flowering of many shrub species and outbreaks of forest pests were also visible. In response, we need to continue climate and phenological monitoring, and take science-based action to mitigate the effects of climate change. Such actions include reforestation based on data obtained from assisted migration experiments and decreasing the emissions that are driving climate change.
Monitoring Restoration of Illegally Logged Area in S. Chincua (2021)
Dr. Arnulfo Blanco García and his students continued with their seed-scattering experiments to monitor natural regeneration in a 10-hectare area that was illegally logged. They made two field visits, in January and March, to verify the functionality of the perimeter fence and to check the seed traps that were previously installed. The fence was deemed adequate since no evidence was found of damage by livestock. Regarding the seed traps, a larger number of oyamel seeds were found in the traps placed in the forest compared to those placed in the logged areas. This year, production of cones and oyamel seeds increased significantly, but only in the forested areas.
These observations suggest that even in years when there are lots of seeds in the forest, the seed dispersal process is seriously compromised in logged areas. To increase sites that foster germination, Dr. García and his team are evaluating the possibility of manually dispersing oyamel seeds and preparing soil accordingly. Another option is to reforest part of the logged area since the natural regeneration process is slow. MBF will continue supporting this important research to seek optimal alternatives for the restoration of the forest. Below some photos of items found in the seed traps.
Oyamel seeds on moss
Oyamel seeds/monarch remains
Assisted Migration (2021)
Dr. Cuauhtémoc Sáenz Romero, his colleagues and students continue their experiments of reciprocal transplants of oyamel (Abies religiosa) at contrasting elevations. One and a half years after the current part of their experiment started, the sites where most of the seedlings were planted at a higher elevations than where they originated, i.e., 3400 m, continued to show very good survival rates (98% on average). Those planted at 2600 m, in a site chosen to mimic a warmer climate (between 2°C to 4 °C higher than the one where the seedlings originated), showed an average 30% survival rate.
A dry and warm March-May season 2021 is expected due to “La Niña” weather pattern in the Pacific creating conditions for forest fires. Therefore, spring 2021 will be extremely harsh for young seedlings of oyamels at the lower altitude limit from both natural regeneration and reforestation programs. Seedling recruitment will be challenging, especially with forest fires and pest outbreaks. Below photographs of the oyamel seeds at different elevations.