U.S. Fish and Wildlife Service announced on Monday it would conduct a one-year status review of the monarch butterfly to determine if they are warranted protection under the Endangered Species Act.

The agency is requesting scientific and commercial data through a 60-day public information period and they are looking for data on the insects' biology, range and population trends, habitat requirements, genetics and taxonomy, distribution patterns, population levels, life history, thermos-tolerance, and conservation methods.

The review was in response to a petition from the Center for Biological Diversity, the Center for Food Safety, and the Xerces Society for Invertebrate Conservation to list the subspecies of monarch (Danaus plexippus plexippus), indicating the listing might be necessary.

The Center for Biological Diversity argues the decline is driven in part by the widespread planting of genetically engineered crops in the Midwest, where most monarchs are born. The vast majority of genetically engineered crops are made to be resistant to Monsanto's Roundup herbicide, a potent killer of milkweed, the monarch caterpillar's only food.

In the past 20 years, the Center estimates monarch butterflies may have lost more than 165 million acres of habitat -- an area about the size of Texas -- including nearly a third of their summer breeding grounds.

The Center for Biological Diversity said the population has declined from a recorded high of approximately 1 billion butterflies in the mid-1990s to only 35 million butterflies last winter, the lowest number ever recorded.

In addition to herbicide use with genetically engineered crops, they say, monarchs are also threatened by global climate change, drought and heat waves, other pesticides, urban sprawl and logging on their Mexican wintering grounds.

Scientists have predicted that the monarch's entire winter range in Mexico and large parts of its summer range in the states could become unsuitable due to these threats.

Monarch butterflies are found through the United States and many fly between the U.S., Mexico and Canada -- a journey of 3,000 miles. The journey, according to studies, has become more perilous for the butterflies because of threats along their migratory paths, their breeding grounds and wintering grounds. 

"We are extremely pleased that the federal agency in charge of protecting our nation's wildlife has recognized the dire situation of the monarch," said Sarina Jepsen, the Xerces Society's endangered species director. "Protection as a threatened species will enable extensive monarch habitat recovery on both public and private lands."

There are ways for the public to get involved in conservation efforts for monarch butterflies through the Xerces Society.