Every year, millions of monarch butterflies fly from Mexico to Canada. But some don’t make it, and UT researchers are trying to figure out why.

Pictures of monarch butterflies on ships and oil rigs off the Gulf of Mexico have flooded Monarch Watch, an organization that promotes education, conservation and research about monarch butterflies. Tracy Villareal, a UT professor in the Department of Marine Science, said he wondered whether the butterflies were flying through the Gulf of Mexico as part of their usual migration from Mexico to Canada or if they were directed there by a storm.

To discover the answer to this question, Villareal developed an app called “Monarch Migration.” It was funded through the UT crowdfunding program HornRaiser, which is currently raising money for projects such as an electronic scoring machine for the Texas Taekwondo team and a neuroscience project to create mutant mice that can’t get drunk. Orley “Chip” Taylor, founder and director of Monarch Watch, also supported the Monarch Migration app and plans to eventually use the app to gather information about the monarchs’ entire migration route.

“The way scientists used to record butterfly sightings is by running behind them with a compass in their hand while trying to write down where they were and time of day,” Villareal said. “The app can do all this seamlessly.”

Monarch Migration is designed for oil rig workers who want to record monarch butterfly sightings in the midst of their hectic and often dangerous work. It is simple to use — once a user is registered, only one touch is necessary to record the time and location of the butterfly. The user can choose to report more information such as the number of butterflies, the angle at which they are flying or what direction they are going. The app was released in the spring of this year, and users have uploaded 75 reports so far.

“I want this to be a minimal distraction. I am very happy if even one person per platform reports,” Villareal said. “The app was designed to allow us to gather information that is distributed as widely as possible.”

Villareal said he eventually would like to expand the use of the app across the Pacific and Atlantic oceans. People have reported monarch sightings as far away as New Zealand, North Africa and the United Kingdom, where the butterflies are called “stormchasers” or “wanderers.”

This app will help scientists direct resources to the most effective efforts to conserve this internationally popular butterfly. The population has declined over the past 15 years, according to article in the journal Insect Conservation and Diversity. Scientists contribute the decline to several factors including declining winter habitats, depleted food sources and storms.

During the colder seasons, the monarchs live in evergreen forests in Mexico, which are often targeted by illegal logging. In the warmer months, the butterflies live in the United States, where they struggle to find enough milkweed, their favorite food. Farmers in the Midwest genetically modify their crops so they are resistant to herbicides that decimate the milkweed population ­— a technique that is effective for raising crops but not for helping butterflies. At any point during their migration, storms can blow the monarch butterflies off course.

Villareal’s app will help scientists understand how much the last factor is affecting the monarch butterflies’ migration.

“Independent of the research, I think monarch butterflies are cool. They do this iconic migration over thousands of miles and are visually appealing,” Villareal said. “It’s hard to imagine a world without monarch butterflies.”