Who doesn’t marvel at the sight of a beautiful floating Monarch Butterfly? I still always gasp with delight when I see one. They are majestic. On top of that, they are awesome! Everyone (including me) seems a little confused about how Monarchs migrate- but I worked in a butterfly dome at Franklin Park Zoo in Boston, MA and found out once and for all! Not all Monarchs migrate, there are resident Monarchs that stay in one place and live and die there for about 1-2 months in the warmer spring and summer. Then, there are migrating Monarchs that emerge from their chrysalis (or cocoon) around September, just when it is getting cold in their Northern habitats all over North America (well, ok, only a little up into Canada). These migrating Monarchs can live up to 9 months! Pretty sweet for a butterfly. They overwinter as adults and start migrating back North at the start of spring, making it only part of the way before they lay eggs and die. The next couple generations make it back up to their Northern habitats.
Where do they go? Well, if they were born east of the Rocky Mountains, they go down to one of a few sites in Central Mexico. If they were born west of the Rocky Mountains, they come right here to Santa Cruz (or a few other places in California)!!! We are one of a few places in California that have overwintering Monarchs! At Natural Bridges State Beach in Santa Cruz they have a “Welcome Back Monarchs” day in October every year. I went to it my first fall in Santa Cruz. What an amazing sight!
My digital pictures are unfortunately lost, but here is one taken at Santa Cruz, CA Natural Bridges State Beach from a great Nature Photography blog The Nature of Things. The sight of thousands upon thousands of Monarch butterflies all aggregated on the same tree is an incredible and once-in-a-lifetime must see.
Yet, this natural wonder is threatened. In California, they overwinter along the beautiful, sweeping California Coastline- an area many people would like to live. Thus, Monarch habitat constantly faces pressure from housing construction. This threat was somewhat relieved when Californians passed a $2 million bond to buy and conserve Monarch habitat. Because this conservation effort is patchy with many city ordinances and management plans, the Monarch Joint Venture is working to provide comprehensive Monarch conservation.
In Mexico, the Monarch Butterfly Biosphere Reserve, a UNESCO World Heritage site, was set up to conserve Monarch overwintering habitat. This Monarch habitat is also threatened, however, from illegal logging. In Mexico, Monarchs flock to the Oyamel fir-pine forests. A study by Brower et al. in 2002 viewed photographs of the forests from 1971 to 1999 and found an alarming rate of forest destruction via legal and illegal logging (in the Reserve). In particular, by 1999 44% of the forest was degraded and the largest patch of forest reduced to 5827 ha from 27,000 ha. Tourism, however, has been a saving grace, causing Mexican President Felipe Calderon to pledge $4 million in 2007 to protect the migrating Monarchs and their tourist-attracting abilities.