Time of the Monarch
Nov 14th, 2009 by farmstandmarfa
PART II TIME OF THE MONARCH
Señora Rocío Treviño, founder of Mexico’s Monarch migration-tracking program, Correo Real, is thrilling butterfly trackers with her recent report of October 20 from Saltillo, Coahuila:
Today monarch butterflies adorned the sky and fields across Coahuila like we haven’t seen for years. From Cuatro Cienegas to Saltillo people reported thousands of butterflies. I went out into my garden this morning and counted an average of 60 per minute for nearly two hours. This evening, I took my granddaughters to a stream in the “Boca de Leon” canyon to search for roosts. At last, there were clusters of some three thousand butterflies and something incredible that I have never encountered in all my years–a monarch with a tag!
Vladimir Nabokov would have understood this ecstatic declaration of the butterfly counter in northeastern Mexico. “My pleasures are the most intense known to man:” Nabokov revealed, “writing and butterfly hunting,” the novelist revealed.
Though Nabokov mentioned one butterfly or another in just about everything he wrote, he reserved his most obsessive passion for the blues in the Lycaenid family. For most ordinary mortals, the butterfly that captures our imagination is the monarch. True, the butterfly is rather large with a 3-5 inch wingspan, making it easy to spot. And its orange wings – thickly veined in black and edged in white polka dots – give off quite a show. But it is the story of the monarch’s nearly 3000-mile migration that tugs at our hearts and bolsters our spirits with imaginings of how the tiniest amongst us can overcome an unthinkable challenge.
Butterflies and moths belong to the Lepidoptera order of insects, the scaly-winged ones. The butterfly might be a moth that left its night-bound life behind for a daylight existence to co-evolve with flowers during the Cretaceous Period. The monarch, Danaus plexippus, is one of the brush-footed milkweed butterflies in the Nymphalidae family. Their small brushy forelegs are kept tucked up under their thorax. These lovelies are tropical butterflies. As glaciers retreated after the Ice Age, they traveled further and further north following their host plant, the milkweed, as far as Canada.
The only plant the monarch larvae feed on is the milkweed. The females lay their eggs on the underside of the plant’s leaves. Its common name comes from the milky latex sap it oozes when a leaf is broken off. An ancient medicinal plant, milkweed takes its scientific name, Asklepius, from the Greek god of healing.
The cardiac glycosides in the milkweed, used by plant medicine makers to reduce the inflammation of mucous membranes and to treat heart ailments, are found stored in the bodies of the monarch caterpillar and butterfly. These chemicals give the insects a noxious taste and protect them from most predators. The bright pumpkin color of the butterfly might be a warning to a hungry hunter saying, “You don’t want to eat me. I’ll make you sick.”
When the summer milkweeds yellow and tufts of their silky seeds parachute through the increasingly cool air, the last monarch of the year to metamorphose splits open its chrysalid. Clinging to the transparent remnants of the chrysalis, the butterfly inflates its crumpled wet wings, pumping them full of hemolymph, then hangs upside down for several hours waiting for the wings to dry and harden before taking flight. Unlike the monarchs of spring and summer, the fall brood will not mature sexually right away but will remain pre-pubescent during the grueling migration south and the months spent in the wintering grounds.
The eastern population of fall migrating monarchs spend their winters in the fir-covered volcanic mountains of central Mexico. Sixty-foot tall forests of the oyamel fir, moist and cool from mountain top clouds, shelter the butterfly clusters. As the coldest months of the year pass into warmer ones millions of monarchs fully wake from their torpid state more sexually developed. In his book, Chasing Monarchs, the naturalist Robert Michael Pyle writes intriguingly, “the ‘courtship’ following the winter dormancy can only be considered as ravishment.”
“The male simply attacks the female on the wing, drives her to the ground, and wrestles with her. He will maneuver the female onto her back, wings spread, and cover her – a face-to-face embrace I’ve never seen among other butterflies. In a couple of minutes he will achieve copulation by enfolding the tip of her abdomen within the handlike claspers of his own rear end, and inserting his aedeagus. Then he will fly straight up, carrying her in a postnuptial flight, while she remains closed and inert, into a tree. There they will remain in coitus for an hour, two, or all night long, while he passes his seed packet (the spermatophore) to her bursa copulatrix.
The sexually mature hibernates celebrate the spring equinox for 3-5 weeks before the last of them departs for their northern summer breeding grounds by the first week in April.
The female nectars along the way from a variety of flowers but is genetically driven to reach the first emerging milkweed of spring as quickly as possible. The male follows, claspers ready for grabbing and more mating. Besides the transfer of sperm he delivers nutrients to her that give her the strength to support her inexhaustible search for milkweed hosts and to reproduce. The migrants are already 8 or 9 months old, having hatched, molted, pupated and emerged from the chrysalid the fall before near the Great Lakes or even Quebec.
During the early weeks of the northern migration, the female might find her first host plant in northern Mexico, but she is likely to have to fly to southern Texas or coastal Louisiana, before she can begin to lay her eggs. The discovery of an unfolding milkweed kindles her investigation. Using all six legs she drums the leaves to assess the suitability of the plant. Too much moisture on a leaf would rot the egg. She tests the toxicity of the plant. If she has a choice, she flies from one plant to the next, before finding a milkweed she will accept.
Once satisfied, she lays her first dome-shaped egg singly on the hairy underside of the leaf. Seconds later she is in the air, exploring the terrain for another perfect milkweed leaf on which to lay her next pale yellow egg. She could lay up to 400 hundred eggs before dying.
Each hatched egg produces an insatiable leaf-eating larva that molts five times and becomes increasingly larger. The fifth instar, a plump two-inch long dazzling yellow and black and white striped caterpillar, urgently searches for a discreet green haven in which to hide the final transformation. Here the caterpillar spins a silk pad and attaches it securely to a stem or the underside of a leaf.
Hooking into the silk pad, it lets itself hang upside down.
Before long the caterpillar begins to shed its exoskeleton. A chrysalid takes its place and hardens into a thing of beauty- a spring green capsule. The chrysalid is dotted here and there with metallic gold spots. Near the top a half necklace of gold forms along the crest. Inside the capsule the secret of life takes place as the liquefied caterpillar forms organs and body parts.
Within 35 days of the egg laying the first monarch broods are mature enough to continue the migration north, staying east of the Rockies. The females search for milkweed and lay eggs along the way. These multiple generations increase the population and protect against species loss during the migration and the long overwintering. The males move north too but linger longer in the milkweed meadows of summer staking out territory and patrolling for females.
Three or four generations of monarchs migrate as far as southern and eastern Canada until the shortening daylight of late August produces the last generation of the year. This fall brood of monarchs will read the sun and follow it south to the wintering colonies concentrated in a belt of volcanic mountain ranges and valleys in the states of Michoacan and Mexico.
Is the female a daughter of Danaus, a mythological king, fleeing her cousin Plexippus who her father’s twin determined she was to marry? On sight she is distinguishable from the male by having wider black veins. Besides thinner veining, the male exhibits a black spot on each hind wing, a pheromone scent pouch.
They will glide on thermals like migrating birds, resting when the wind is unfavorable or cold, to conserve their stores of fat. They will nectar along the way on the flowers of fall – goldenrod, aster, Joe Pye weed, gayfeather and the eastern groundsel bush. In Texas they will find frostweed and cowpen daisies in bloom. During their journey they will visit fields of blooming clover and alfalfa and stands of sunflowers.
Their ability to see ultraviolet light allows them to read a flower and see where its nectar is concentrated. The butterfly lands and tiptoes over the petals. When the toes of its back legs taste sugar, the proboscis, rolled up tight, uncoils to suck the high-energy nectar, sweeter than soft drinks. Stored as fat the nectar from the flora in the flyway will keep the butterflies alive during the winter and start them on their way in the spring. By November they will have reached their winter home.
For a number of years scientists have known how the monarch is guided by a circadian clock in its brain that interacts with a sun compass also located in the brain. The findings of an astounding experiment focused on the navigational skills of the Monarch have just been published in the September 2009 issue of Science.
In a report on the website Science Daily Steven M. Reppert, MD, professor and chair of neurobiology and senior author of the study, said, “We’ve known that the insect antenna is a remarkable organ, responsible for sensing not only olfactory cues but wind direction and even sound vibration.” Reppert and his colleagues studied the antenna more closely and found that the monarch also has an antennal clock. This second antennal clock communicates with the one in its brain to keep the monarch on its migratory path.
Reppert’s team experimented on the monarch’s antennae in three ways. First, they surgically removed the antennae to determine that this disabled the butterfly’s navigational ability altogether. Second, they dipped the antennae in black paint and discovered that the butterfly could not navigate. Last, they covered the antennae with clear paint and found that the butterfly could fly where it intended.
This description might sound like a simple experiment any high school student could try, but Reppert and his scientists are cutting edge. They are mapping the monarch’s genome.
The monarchs’ bi-annual migration is an unfolding mystery. We now understand that their sense of direction is an interaction between their two clocks and their sun compass. And we comprehend generally that they know where to winter-over because this inherited behavior is embedded in their genetic chemistry. But we don’t know how it works. Until the mid-70s we didn’t know where the eastern monarchs were going every fall.
AT LAST, THE WINTER COLONY
As early as 1857 entomologists, beginning with the Canadian, W. S. M. D’Urban, began to make notes about the monarch: “such vast numbers as to darken the air by clouds of them.”
C. V. Riley, Missouri’s first State entomologist suggested in 1878 that monarchs migrated like birds.
“Almost past belief… millions is but feebly expressive … miles of them is no exaggeration,” is how J. Hamilton described the Monarch migration at Brigantine, New Jersey in the fall of 1885.
Ancient peoples in Mexico have known for millennia where the monarchs spend their winters. The indigenous Mazahua speak of the monarch as seperito, “the butterfly that passes in October and November.” The winter monarch colonies were a long kept secret amongst the forest people.
In the late 1930s Frederick Urquhart, a Canadian biologist, and his wife, Norah began to tag monarchs. By 1972 they knew that the Monarchs followed a northeast to southwest migration pattern. Norah placed notices in Mexican newspapers asking for volunteers to tag the butterflies. Another husband and wife team, Ken and Catalina (Cathy) Brugger, living in Mexico, undertook the Urquhart’s challenge. They tracked the butterflies in and around the plains and mountains of eastern Michoacan. Though they felt they were getting closer to uncovering the secret, their trail kept running cold. Near the village of Donata Guerra an older man agreed to show them where the butterflies congregated. They were led 10,000 feet high first to a colony of millions on Cerro Pelon and then to another one on Cerro Chincua. When the sun shown through the clouds whole colonies of monarchs lifted into the air. Color-blind Ken Brugger missed the fireworks but witnessed the experience of his life.
The Urquharts arrived the following year in 1976 to realize their dream and climbed the butterfly mountain. They found a monarch wearing one of the little gummed tags that had been issued to a volunteer. The tag read: “Send back to the University of Toronto Zoology.”
Later that year, the Urquharts released their scientific discovery in the August issue of The National Geographic. “Found At Last: The Monarchs’ Winter Home,” the article triumphantly announced. Urquhart added this poetic description to the annals of monarch history: They “filled the air with their sun-shot wings, shimmering against the blue mountain sky and drifting across our vision in blizzard flakes of orange and black.”
The cover of the magazine taken by the photographer Albert Moldavy showed Catalina (Cathy) Brugger as a grown up flower child, sitting between pillars of monarchs. She wore a broad dimpled smile. Her hair pulled up ballerina-like in a tight bun was decorated with butterflies, wings spread wide. Brugger’s outstretched hands, delicately lifted were dotted with the salt-seeking insects.
This announcement marked the beginning of a new chapter in the story of monarch that includes the conservation of the butterfly’s winter habitat, flyway and summer breeding grounds. The work of tagging the monarch has expanded and is now presided over by Dr. Orley R. “Chip” Taylor at Monarch Watch, a citizen’s scientist effort to collect data for research.
The latest report about this year’s migration has recently been posted by Journey North on November 6, 2009:
The monarchs arrived in large numbers yesterday at Mexico’s winter sanctuary region.
The news was announced by biologist Eduardo Rendon, who heads World Wildlife Fund-Mexico’s Monarch Butterfly Program.
“Today, all of the roads that lead to the Monarch Reserve are full of butterflies,” he reported yesterday. Evidently the monarchs began to arrive on Sunday and Monday, when the first trees containing clusters were found in the Sierra Chincua and El Rosario sanctuaries. Yesterday was the first day with such a clear, massive arrival.
You can read Eduardo Rendon’s announcement below in Spanish.
Llegada de las Mariposas!
5 de noviembre de 2009
Estimados todos,
El domingo y lunes inició el la llegada de mariposas a los santuarios de hibernación. Los primeros árboles con mariposas fueron encontrados en la Sierra Chincua y en Sierra Campanario. Mientras que solo fueron vistas mariposas en el Cerro Pelón.
Hoy por todas las carreteras que confluyen a la Reserva están llegando las mariposas. Mi impresión es que se trata del primer día con esta cantidad de mariposas llegando. Acerca del tiempo de llegada, habrá que decir y considerar que fue con 10 días de retraso.
Gracias,
Eduardo Rendón Salinas
Coordinador de Programa Mariposa Monarca
World Wildlife Fund (WWF) México
Read Rocio Treviño’s Oct. 20 report in Spanish:
http://www.learner.org/jnorth/monarch/fall2009/CorreoReal102209_Esp.html
Journey North Follow the monarch’s migration
http://www.learner.org/jnorth/monarch/
Visit Correo Real’s website
http://www.profauna.org.mx/monarca/
SOURCES
Monarch Watch http://monarchwatch.org/
Journey North http://www.learner.org/jnorth/
North American Conservation Plan
http://www.cec.org/pubs_docs/documents/index.cfm?varlan=ENGLISH&ID=2300
Science Daily
http://www.sciencedaily.com/releases/2009/09/090924141736.htm
Dispatches From a Vanishing World by Alex Shoumatoff’
http://www.dispatchesfromthevanishingworld.com/pastdispatches/monarch/monarch1.html
Chasing Monarchs by Robert Michael Pyle
(The Farm Stand Marfa newsletter is written and published by Sandra Harper in Marfa, Texas each week during the growing season. Send comments, inquiries, or requests for free subscriptions to farmstandmarfa@gmail.com.)



















