The monarch is a large orange butterfly. The wings have prominent dark veins and two rows of white spots at the edges, and the body is dark. The wingspread ranges from 89 to 105 millimeters (about 3.5 to 4 inches). Males are bigger than females and have a visible dark spot over a vein on their hind wings.
Where they Live:
Monarchs in northern states settle primarily in conifers and maple trees, while monarchs in the south commonly live in pecan and oak trees. Monarchs spend the winters in forests, forming clusters of butterflies in a state of diapause, which is like hibernation. The forests provide protection from wind and storms and exposure to dappled sunlight to keep the butterflies warm enough not to freeze but cool enough not to break diapause and deplete the fat reserves they need to survive the winter. In Mexico, monarchs spend the winters primarily in oyamel fir trees, and in California they cluster in gum, pine, cypress and sycamore trees.
Monarchs across North America have declined by more than 80 percent over the past 20 years. In the mid-1990s there were approximately 1 billion monarchs, but as of winter 2013-2014, the population had declined to 35 million. Monarchs are threatened by the loss of milkweed in the Midwest due to spraying of Roundup (glyphosate) on genetically modified crops that has nearly wiped out milkweed from the core of the butterfly's range. They are also threatened by sprawl, global climate change, pesticides, development of their overwintering groves in California, and logging of their overwintering grounds in Mexico.
The low monarch wintering numbers in 2013 and 2014 resulted in an April 2014 statement of shared concern by leaders of the United States, Mexico and Canada. The monarch butterfly was specifically included in the 2014 Presidential Memorandum on pollinator conservation. Additionally, the FWS is conducting a status review to determine if protection under the Endangered Species Act (ESA) is warranted for monarchs.