For Gail Manning, an entomologist at the Fort Worth Botanic Garden, the fall monarch butterfly migration has almost been a no-show.
One day last week, Manning tagged 14 monarchs, down from the hundreds she found at the same time last year.
“The numbers I'm seeing are definitely down this year,” Manning said. “They may have diverted to more of a westward path. I’m kind of crossing my fingers for the cold fronts to move down and help push them through Texas.”
Each fall, the monarchs fly through Texas on their way to central Mexico, where they spend the winter before flying north in the spring and laying eggs. All the migratory population east of the Rockies flies through Texas on its journey to Mexico.
Monarchs migrate through Texas in the fall and overwinter in central Mexico.
Historically, the peak of the migration should be going through North Central Texas this week.
Not to worry, said Chip Taylor, founder and director of Monarch Watch at the University of Kansas. This is shaping up to be the best fall migration since 2011 — it’s just that the butterflies have largely bypassed Dallas-Fort Worth.
“It’s going to be at least twice the size of last year,” Taylor said.
He confirmed Manning’s suspicion that the lack of cold fronts in this unusually warm October have kept most of the butterflies west of the Metroplex.
The threat of El Niño
Despite the higher numbers in this fall’s migration, Taylor said the monarch population is still vulnerable.
With a strong El Niño expected to wreck havoc this winter, it could pose a problem for the monarchs’ home in central Mexico. While El Niño tends to bring wetter weather to Texas, the monarch’s overwintering site in Mexico is more likely to be in drought.
The number of monarchs that survived the trip to Mexico won’t be known until this winter when a count is conducted.
35 million: The estimated monarch population in the winter of 2013-14, down from an estimated 1 billion in the mid-’90s.
The monarch population reached an all-time low in the winter of 2013 with an estimated 35 million, a dramatic decline from nearly 1 billion in 1996.
That has prompted efforts to protect that monarch habitat along the entire migratory corridor, which stretches into the upper Midwest.
In Texas last week, former first lady Laura Bush announced the Texas Monarch and Native Pollinator Conservation Plan, a multiagency effort to have 225 million monarchs by 2020.
Breeding grounds lost
One example will be to establish four monarch gardens with the help of the Native Plant Society of Texas at the northbound and southbound rest areas in Hillsboro and Salado, both of which are operated by the Texas Department of Transportation.
You got to have food for that entire corridor or you miss a link in that chain.
Ben Hutchins, Texas Parks and Wildlife invertebrate biologist
Creating monarch corridors with milkweed and other native plants is seen as essential since much of the habitat has been lost to farming. There have been efforts to create monarch corridors along Interstate 35, including using medians and rights of way all the way to help build back the population.
About 165 million acres of summer breeding grounds, close to the size of Texas, have been lost.
Click here for monarch butterfly migration patterns and population numbers.
While the ideas are gaining traction, the programs will need help. Taylor, the founder of Monarch Watch, said it will take the federal government’s input to make the program go forward nationally.
“There's a lot of talk about the White House getting the Department of Transportation behind this,” Taylor said. “There has to be a lot of force coming toward this to make it happen. It’s do-able but it won’t be easy.”
This plant is essential for monarchs because it is where they lay eggs on their northern migration in the spring. For those that have milkweed in their gardens, it is important to cut back the plant in the fall so it is healthy for the spring migration. Tropical milkweed with yellow or orange flowers is the kind normally available at commercial nurseries.