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Septmeber 3, 1961 - The Monarch ButterflyMIGRATING MONARCH BUTTERFLIES Exclusive Sunday Review Sketch by Dennis Puleston of Brookhaven Focus on Nature "It surely makes an interest- ing column when ever we can get our sketch and text done by the same person. When you read the following article con- cerning one of our common butterflies, you will realize what I mean." ... ... ... ... —p.s. THE MONARCH BUTTERFLY By Dennis Puleston, Brookhaven In my youthful beginnings as a naturalist, when I collected but- terflies around my home in Eng- land, I can recall the many 'hours I spent examining the color plates in my insect books, dreaming of the rarities I hoped to catch. There was one in particular that attracted me, a large, handsome, orange and black creature known as the Milkweed Butterfly. Upon reading the descriptive text, how- ever, I realized how slight were my chances of capturing t h is fine species, for it was a native of America, rarely seen in Eng- land. Little did I know that I Would some day live in an area where this insect wound be actual- ly common, for this Milkweed Butterfly of England is n o n e other than the Monarch, so fam- War to us all on Long Island. Yet my early thrill over pic- tures of this species, common as it is in these parts, has never quite left me, and when I learned more of its remarkable life his- tory my interest in it has been enhanced. The Monarch is a great wanderer; it had found its way from the Hawaiian Islands, where fit was introduced, to such remote Pacific areas as Formosa and New Zealand. In the Atlantic, it appears regularly in the Azores and Cape Verde Islands. Most probably, it is from these islands that the British visitors wander. A few are seen there a l m o s t every year; yet the species can never establish itself, since its caterpillars feed only on milk-1 weed, and this plant does not grow in Europe. So every Milk- weed Butterfly found there has crossed hundreds, and perhaps thousands, of miles of ocean to reach its destination. It is dif- ficult to imagine how such an apparently fragile creature, weighing only a small fraction of an ounce, could make such a journey, yet it certainly does. While its occurrence in these far places can be considered ac- cidental, the Monarch is one of the, few butterflies in this country to make a regular migration every year. This southward move- ment takes place in the I a t e er and early fall, and one of its favored routes is along the dunes and beaches of Long Island's south shore. At this sea- son, on a favorable day, Mon- archs can be seen passing by in hundreds, headed purposefully westward towards the New Jersey shore, which they also follow. Oc- casionaiiy they will stop to feed on nectar from the goldenrod blos- soms, thereby fortifying them- selves for the long journey to the Gulf States land the Caribbean, where they winter. The flight of this butterfly is seemingly effortless; after a few flaps of the powerful wings it sails steadily with the momentum it has thus gained. It takes par - ticular advantage of the strong northerly winds that occur at this time of year; on such days the Monarch traffic is markedly heavy. Sometimes many thou- sands will cluster for the night in a grove of trees, until the branches are covered with them. In the spring, the northward movement is a more leisurely affair; some individuals stop en route to mate, lay their eggs, and die. Their offspring continue the journey, even far into Canada, where, in turn, they breed. The eggs are pale green, cone - shaped, and ribbed. The cater - pillar, tiny when hatched, grows rapidly as it e a t s milkweed leaves almost continuously. When it has reached full size a f t e r several weeks of voracious feed- ing, it is a handsome creature, banded with rich yellow and creamy white, the bands divided by transverse black stripes which give it a tigerish appearance. Near the front end of the body, two peculiar black filaments pro- purpose of these adornments is not fully understood. The milkweed foliage on which the Monarch feeds has given it a valuable defense against the birds which prey on many other insects. Apparently the plant gives a bitter taste to this butterfly, rendering it unattractive as a food source. So successful is this defense that another species bene- fi -ts from it; although the Viceroy Butterfly does not feed on milk- weed, birds ignore it because of its striking similarity in appear- ance to the Monarch. Examples of such imitative coloration, which is known as protective mimicry, can be found throughout th e world of Nature. When the caterpillar is ready to pupate, or turn into a chrysalis, it climbs to the underside of a .leaf and suspends itself, h e a d down, by a strong thread. Slowly the skin splits down the back, to reveal the pale green chry- salis underneath. In this i n e r t stage, the insect remains f or several weeks, but in the mean- time, a miraculous transforma- tion is taking place inside the creature. Gradually it turns dark- er, until the black - veined, orange wings of the butterfly can be clearly seen, although they are still shrunken and deformed. Then a split 'appears at the lower end of the shell, and painfully the butterfly emerges, to cling to the empty case while its wings dry and expand. Within an hour, the butterfly is ready to take flight and complete the life c y c l e through which -the species must pass, in order that it can con- tinue to enrich our gardens,