Nature Notes: On the Trail of the Monarch

Two Wednesdays ago I was back at Crooked Pond south of Sag Harbor, this time with Victoria Bustamante and Arthur Goldberg, both of whom were new to the pond. The exposed flats, with their wonderful array of rare and opportunistic sedges, grasses, and flowers were still thriving. I say “opportunistic” because they only appear in odd droughty years when the pond level is way down.

The tupelos were turning red. Autumn was on its way. White water lilies covered the pond. A pair of painted turtles were sunning on a glacial erratic. Frogs jumped into the shallows here and there. Whirligig beetles churned the water’s surface. Tree swallows and purple martens were overhead, calling and hawking insects. A lone (of course!) solitary sandpiper was skipping from lily pad to lily pad, having the place all to itself.

During the past three weeks monarch butterfly adult and larval observations have been dribbling in by phone or email, but one tiger swallowtail, a spicebush swallowtail, and a few cabbage whites represented the day’s butterfly population at Crooked Pond. Even though it was already the season for them, we did not spy a single monarch butterfly. There were some milkweeds around, but no monarchs.

Yet, already this year, there have been more monarch reports than last year at this time, maybe because they have become like the bald eagle, osprey, coyote — objects of everyday fascination in the world of nature.

When I was growing up in Mattituck across the bay, I probably saw a monarch now and then, but among the butterflies I only remember the swallowtails. They had those distinctive trailing edges. However, when I dropped out of college for the second time, enlisted in the Army, and ended up studying Russian at the Army Language School in Monterey, Calif., in 1958, my knowledge of butterflies hit a growth spurt.

Pacific Grove, where I made my residence after leaving the barracks life, was home to a grove of buttetfly-gathering trees famous in California. What did the butterfly trees gather every fall and winter? Half of the West Coast monarch population! People came from up and down the coast just to see the pines and eucalyptus with their bundles of quiescent monarchs coloring the green needles and leaves orange. So did I.

Then in 1964, I not only observed monarchs, but began studying them closely while a graduate student at the University of California, Santa Barbara, north of Los Angeles, well south of Monterey. I started my study by reading the late McGill University professor Fred Urquart’s treatise on migrating monarchs. He and his wife, Norah, a zoologist, had been studying, even raising and tagging them, since 1938. They knew by following the trail of their tags every year that they flew south starting in late summer, a few ending up in Texas, 1,500 miles away. But Urquart didn’t know until 1975 — long after I left the study of monarchs, became an ichthyologist, and landed a teaching job at Southampton College — that they flew all the way to the state of Michoacan in the mountains of central Mexico, almost 2,500 miles from their starting point in Ontario.

It turns out that monarchs, which only fly during the day, can cover 80 miles a day. Ours fly westerly along the ocean dunes when they arrive from the north, then turn south when they hit New Jersey. They seem to like to fly into early fall’s preponderant southwesterlies, but some other meteorological and/or cosmological factors must be at work in guiding them along. Apparently, it’s in their genes. Come the end of summer, they head south, even though they sprung from larvae hatched from eggs by a third or fourth generation adult reaching the north in the late spring.

Why all the way to central Mexico? Apparently they like the peace and stillness of the pine and fir groves there, just as the West Coast ones seek out the Monterey pines each year. And it has worked for generations upon generations up until recent decades. Thereafter the population began to suffer greatly. There is mounting evidence that commercial weed killers genetically infixed in corn, soybeans, and other Midwestern crops have practically eliminated the milkweed species that monarch larvae feed on. It’s the same foodstuff that gives them the toxic glycosides that make them unpalatable to most would-be predators.

Orioles and grosbeaks can tolerate the poison stored in the wings of the emerging adults more than most other birds, but they take only a handful of the flying adults, as these birds have raised their young and fledged them by the time the monarchs are emerging from their pupae.

Ill-placed and ill-timed storms can take their toll. According to recent genetic studies, monarchs wouldn’t be able to fly such long distances without a special gene that enlarges and strengthens their wing muscles.

A look-alike, the viceroy, takes advantage of its similar coloration and escapes considerable predation even though it does not have chemicals that make it unpalatable to most predators that feed on butterflies.

So we shall see. There is a petition circulating in Washington, D.C., to list the monarch as an endangered species. Mexico is very proud of its monarch “biosphere” and its worldwide listing among heritage sites, but it will take more than Mexico’s watchfulness to keep the population going. Even the West Coast population is diminishing, the cause of which is not being investigated.

Locally, a friend and professional geologist-hydrogeologist, Peter Dermody, is a longstanding monarch tagger, one among many operating across the country. Sadly, however, he wasn’t able to tag a single Long Island monarch last year. Let’s see how the fall pans out.

There’s a healthy crop of goldenrods and asters springing into bloom, not to mention the myriad nectar-producing ornamentals flowering locally. Will this be the year that the monarch population begins to make a comeback, following in the tracks of the eagle, osprey, piping plover, peregrine falcon, and the rest of them?

Maybe, maybe not.

Larry Penny can be reached via email at [email protected].