Monarch Butterfly Numbers Rise Dramatically
After years of decline, a Texas A&M researcher and butterfly advocate says the total population of monarch butterflies appears to be increasing.
By Keith Randall, Texas A&M University Division of Marketing & Communications
College Station, March 18, 2019 — After several years of decline, the number of monarch butterflies appears to be up dramatically – perhaps as much as much as 144 percent – according to a Texas A&M University researcher and monarch butterfly advocate.
Craig Wilson, director of the USDA Future Scientists Program and senior research associate in the Center for Mathematics and Science Education at Texas A&M and a longtime butterfly enthusiast, says early figures show many more monarchs than had been expected for 2019. The figures are promising considering monarch numbers have been trending down for the past five years.
“Figures show the highest number of hectares covered since at least 2006,” Wilson said. “Monarch numbers are usually measured in hectares, so that’s means about 15 acres are being used for their breeding grounds in northern Mexico. That’s a really positive sign, especially since their numbers have been down in recent years. I believe the record low was in 2013-14 when only 0.65 hectares (about 1.65 acres) were covered. So it is very promising news.”
By estimating 50 million monarchs per hectare, it would mean a total population of about 300 million, said Wilson.
Wilson said that milkweed, the essential plant that monarchs rely on for food, is in fairly plentiful supply in Central Texas, noting that personnel around Easterwood Airport in College Station have agreed to delay grass mowing around areas of the airport where milkweed flourishes.
Wilson says that monarchs overwinter and breed in Mexico and then have three more generations as they travel north to Canada. “Texas is a crucial place for them – they have to pass through the state on their way north in the spring and lay eggs,” he points out. It is critical that monarchs have access to milkweed, the only type of plant that monarch caterpillars will digest as the multiple generational migration heads north.
“If Texas residents want to help, they can start asking local garden centers and feed stores to get in more supplies of milkweed now and plant them,” he said. He added that about 500 Texas A&M students are engaged in monarch community projects, such as planting milkweed in local parks and gardens.
