Authorities reported that the population of eastern monarch butterflies overwintering in Mexico this season is the second smallest on record, with a 59.3 percent decrease from last season. The lowest overwintering population was recorded ten years ago, and data from the last thirty years shows an overall downward trend. Particularly low numbers this season, however, means that eastern monarch butterfly sightings will be much rarer when the butterflies migrate back north in the summer.

 
According to Jorge Rickards, director of World Wildlife Fund M?(C)xico, drought and high-heat conditions have limited recent growth of plants eastern monarch butterflies rely on for food, creating greater gaps between flowering patches and less nectar available once the butterflies find it.
Despite the news, Dr. Emily Geest, postdoctoral fellow at the Oklahoma City Zoo and Botanical Garden, is hopeful. She reminds people that monarchs have experienced low numbers in the past but have rebounded due to increasing the number of nectar and milkweed plants. If homeowners and gardeners begin planting these vital plants now, the eastern monarch butterfly population has a good chance of coming back stronger than ever.
https://www.aza.org/connect-stories/stories/troubling-news-for-the-monarch-butterfly
https://www.telemundo.com/noticias/noticias-telemundo/medio-ambiente/video/migracion-de-mariposa-monarca-en-mexico-registra-su-segundo-nivel-mas-bajo-en-la-historia-tmvo12561305
https://monarchwatch.org/