MISSION, Texas (Border Report) — The National Butterfly Center, with its serene grounds along the Rio Grande in South Texas, is always a big draw for tourists and locals living on the border.
Now, a four-fold increase in butterfly species recently recorded at the facility is drawing even larger crowds. But it has some environmentalists worried that rare butterflies migrating from Central and South America are coming farther north due to global climate change.
On New Year’s Day, there were a record-breaking 87 species of butterflies spotted at the center. That’s a 300% increase from the 20 to 25 species that normally flutter about this time of the year, National Butterfly Center Executive Director Marianna Treviño-Wright told Border Report.
“What we’re seeing in terms of the species diversity is we’re seeing more tropical butterflies,” Treviño-Wright said. “We’re seeing butterflies that are normally found in southern Mexico and Central America, which means human beings are not the only climate refugees. The butterflies are moving farther north.”
Human beings are not the only climate refugees. The butterflies are moving farther north.”Marianna Treviño-Wright, executive director of the National Butterfly Center
In the last days of 2021, the center logged in a variety of butterfly species from the interior of Mexico and beyond. This included the first documented sighting in the United States of a Lugubrious blue skipper on Dec. 28, according to a center report.
Some butterflies recently spotted here hadn’t been seen north of the Rio Grande for nearly 30 years, like the Goodson’s greenstreak, which was last photographed in the United States in 1994. Also spotted were the spread-winged skipper, the rare pale sicklewing, and the Orion cecropians and pale-spotted leafwings, which are commonly found in Central and South America, the center reports.
“Butterflies are a key indicator of climate change,” said Dr. Jeffrey Glassberg, president of the North American Butterfly Association, which founded the South Texas center in 2002.
“Not only are their numbers declining in North America as a result of increased aridity due to climate change, but we see butterfly species rapidly ranging northward in response to the increasing warmth, especially in the winter. The relationship between butterflies and a warming world should be of peculiar interest to scientists, evolutionary biologists and climatologists, alike,” Glassberg said in a statement.
Treviño-Wright said this part of the Rio Grande Valley is on the northernmost edge of the neotropics in North America. To witness so many butterflies travel thousands of miles from their homelands, she said, is a scary indicator that they are trying to escape dangerous warm weather that threatens their food and water sources.
“They’re trying to get away from the aridity, the dryness and the heat … the drought and the high temperatures that are wreaking havoc on Central and South America,” she said.
Like many species, a change in their habitat can affect their ability to reproduce and their overall numbers.
A study by the nonprofit World Wildlife Fund found that “monarchs are highly sensitive to weather and climate: They depend on environmental cues — temperature in particular — to trigger reproduction, migration, and hibernation.”
The butterfly species that have made it across the border to the Rio Grande Valley did so just as the region is green and lush after an exceptionally wet November when three times the average monthly rainfall fell. And it is several degrees warmer than normal right now.
“Rain and heat are perfect for breeding butterflies,” Treviño-Wright said.
But extreme weather could force them to keep moving farther north.
Last year the Rio Grande Valley experienced dramatic weather swings.
It began with a statewide freeze last February that in South Texas that killed thousands of plants and butterflies in various lifecycle stages.
The months of June and July were among the wettest on record, National Weather Service Meteorologist Barry Goldsmith told Border Report.
And they were followed by higher-than-normal temperatures that lasted from September through December and included several record-breaking days in the high 80s in 2021.
The center recorded 92 degrees on New Year’s Day, which is a record.
The average temperature for this time of year should be in the low 70s, according to the National Weather Service.
Sandra Sanchez can be reached at firstname.lastname@example.org.