The Monarchs Are Here!!!

An extraordinary and fascinating 4,000-mile journey is about to get underway, originating in a humble terrarium in Solar One’s East River building and ending against odds about three months later in the Yucatan peninsula of Mexico.

Each year for the past three years, Solar One has raised monarchs on its premises, eventually releasing the full-grown butterflies into Stuyvesant Cove Park during the latter half of the summer, just in time for their epic flight. Visitors to Solar One can witness the development of these remarkable creatures, from cream-colored globular eggs resembling beads of sap on the backs of milkweed leaves, to the large wrinkled, multi-colored caterpillars and the dusty-green-and-gold-foil chrysales from which they eventually unfurl like bright orange-and-black banners.

In addition to raising the butterflies, this year Solar One has also been certified as waystation #2356 for migrating monarchs, providing the travelers with much-needed resources for their herculean peregrination and collecting valuable conservation research. Check back here in the coming weeks for more information about possible monarch-related events, such as talks and tagging demonstrations.

Now for some monarch trivia:

– The North American monarch migration usually begins mid-way through the month of September and continues for four-to-six weeks, when up to 100 million butterflies arrive at any of a few dozen winter colonies in California (for monarches located west of the Rockies), Mexico, Texas and Florida. The most celebrated roosts are typically in the Sierra Madre foothills or on the Yucatan peninsula.

Though most adult monarchs normally live only two-to-six weeks, the generation that migrates south lives anywhere from six-to-eight months thanks to a process of metabolic dormancy known as diapause. After emerging from this state in February or March and beginning the journey northward, this super-generation mates and lays its eggs along the way, dying soon after. Upon adulthood, their progeny continue the journey north, though these too may lay eggs and die before reaching their eventual summer homes. No single butterfly makes it all the way to their winter home and back.

– As larvae, monarchs feed exclusively on milkweed plants. The bitter sap supposedly provides them with an effective defense against predation throughout their lives, imbuing them with a mild toxicity that makes them unpalatable to most birds and small mammals. Given their dramatic appearance, its no surprise they need such a defense. Most other butterflies are able to evade detection, either through their small size or cryptic coloration. On the other hand, the monarch’s conspicuous costume may also serve as a warning to the hungry.

– The link between bT corn and the decline of monarch populations is still unresolved. A particular form of transgenic, or gentically modified, maize, bT corn incorporates natural pesticides into the crop’s genome to help curb pest populations, but can affect other non-targeted organisms as well. Though bT corn (most familiar via Monsanto’s Roundup Ready brand) is grown almost exclusively in segregated fields, windborne pollen can often end up dusting milkweed plants or mating with wild corn species, releasing the genes into the larger ecosystem. One of the potential repercussions of such ecological tampering may be the diminution of monarch populations. Various studies in recent years have yielded conflicting and inconclusive results (See “Impact of bT corn pollen on monarch butterfly populations: a risk assessment” and “bt_corn_and_the_monarch“; also, click here to read the original Cornell University report that raised concerns).

– Another unresolved controversy about monarchs is their ecological relationship with viceroy butterflies. As viceroys closely resemble monarchs and occupy overlapping niches, ecologists have long suspected that some kind of mimicry may be at work. Since viceroys do not feed primarily on milkweed and were believed to be non-toxic, their similarity to monarchs had once been considered a textbook example of Batesian mimicry, a secondary and passive form of defense by which an otherwise defenseless organism evolves to resemble and exploit the appearance of another organism within its niche that does possess an active defense strategy. Viceroys, therefore, were thought to be mistaken for bitter-tasting monarchs and thus avoided by predators.

Some ecologists now suspect, however, that the relationship between the two may be of an entirely different form known as Muellerian mimicry, an additive form of mimicry in which different species with similar defenses evolve to resemble each other as a way of reinforcing their warnings to deter predation. Recent evidence does in fact suggest that viceroys may possess similar bitter-tasting toxins as the monarch. Therefore, a negative experience with an individual of one species would promote avoidance of the other, establishing something of a symbiotic relationship. This form of mimicry stands in direct contrast to Batesian mimicry, which superficially resembles parasitism.

Another classic example of Muellerian mimicry is the poisonous frogs of various tropical rainforests, which collectively exhibit similar warning coloration.

– See Monarch Watch for more information on the monarch butterfly life cycle and conservation.

Sources: Monarch Watch;“Fly Away Home”, The New York Times; “Diapause In Insects”, 8e.devbio.com; “Transgenic Maize”, “Muellerian Mimicry”, Wikipedia; “Monsanto and the Roundup Ready Controversy”, SourceWatch; “Monarchs and bT corn: questions and answers”, Integrated Crop Management; “Impact of Bt corn pollen on monarch butterfly populations: a risk assessment”, The Proceedings of the National Academy of Sciences; “Bt Corn and the Monarch Butterfly”, Council for Biotechnology Information; “Toxic pollen from widely planted, genetically modified corn can kill monarch butterflies, Cornell study shows”, Cornell News; “Monarch Viceroy Puzzle”, International Society for Complexity, Information and Design; “The Arts of Deception: Mimicry and Camouflage”, mongabay.com; “Mullerian mimicry in Dendrobates frogs near Tarapoto, Peru”, Proceedings of the Royal Society of London B; “Larva and Caterpillar”, www.monarchlab.org; “Monarch Chrysales on Our Porch”, www.xanga.com/joylily514; www.teachingwithmonarchs.com


Posted on Wednesday, July 30th, 2008 at 8:03 am | Tagged in Native Plants, Solar One, Stuyvesant Cove Park | posted by Bill

AddThis Social Bookmark Button   Print Print   Email Email