New Jersey butterflies don’t know it, but on certain days, especially around the Fourth of July, they are under surveillance, their movements scrutinized by an earthbound fan club of dedicated butterfly lovers affiliated with the North American Butterfly Association (NABA).
During the Morristown-based organization’s major early-summer census period, counters like the husband-and-wife team of Sharon and Wade Wander spend six or more hours at a stretch prowling through sometimes rough terrain for the butterflies, whose coloration, speedy flight or unusual food sources can make them elusive.
The counters—some professional naturalists, some amateurs—are not just out to enjoy the beauty of the butterflies. The insects also can give us clues about the state of the environment. Butterfly populations respond to climate and habitat changes—just like populations of snow leopards, penguins or polar bears. A sharp decline in the number of butterfly sightings in a specific area may mean that a food source has been destroyed, either by extreme weather or land development. Conversely, a sudden increase in the number of butterflies—particularly a species normally associated with a more southerly region—may be the by-product of warmer-than-normal temperatures.
On a sunny morning last July, the Wanders led a small group into a designated 15-mile-wide section of the Delaware Water Gap National Recreation Area for what is called the Springdale count. The Wanders, independent environmental consultants who founded the count 20 years ago, were accompanied by veteran counters John Lampkin, a composer and music teacher; his wife, Jane, a jewelry designer; and graphic artist Tomas Gonzales. Despite the warm weather, they wore high rubber boots or pants tucked into socks to deter disease-carrying ticks. They traveled in two cars and came armed with the tools of the butterfly counter’s trade: close-focus binoculars (which let you focus within four to five feet of an object), digital cameras, water bottles and hearty sack lunches. Previous generations of New Jersey butterfly hunters netted their prey, often killing it for their collections; their modern counterparts capture only photos.
Butterflies congregate at food plants the way New Jerseyans meet at diners. Experience has taught the Wander group where to find these culinary hot spots. Once in the recreation area, the cars moved slowly along Crater Lake Road in search of nectar-rich milkweed, the most popular butterfly food plant of early summer. “If milkweed isn’t blooming, we see fewer butterflies,” said Sharon. Luckily the flowers were open, and the first milkweed clump was alive with dozens of small skippers, a family of butterflies that move in quick, darting patterns.
As the morning progressed, some roadside stops were relatively brief; others involved excursions on foot into open meadows. “Not many flowers grow in the shade,” said Sharon, “so the butterflies are usually in sunny spots.” The insects are easiest to identify while feeding, but veterans can categorize fast-flying species like fritillaries by their flight patterns.
The Springdale counters were hoping to spot the giant swallowtail, a large black butterfly with a distinctive X pattern of yellow spots on its upper wings. Giant swallowtails have been on the increase in northwestern New Jersey, but the insects are still rare in the Springdale count area. A sighting would be a high point of the outing.
The Springdale count is one of about 12 similar annual counts throughout the Garden State, from Cape May to Sussex County. New Jersey counters are part of a larger international effort that includes members of the society’s 25-plus U.S. chapters. Canadian and Mexican counters also submit annual tallies.
The 2011 Springdale count group was relatively large—27 people, divided into six parties. The separate parties moved within assigned areas throughout the six-hour counting day, keeping within sight of each other to avoid duplication in counting. The mood was collaborative, rather than competitive, and newcomers were paired with veterans. (To get involved, contact the New Jersey chapter of NABA through its website, naba.org.)
The Wander party kept a sharp lookout for butterfly motion and mud puddles.The puddles attract crowds of male butterflies, lured by the promise of moisture and nutrients. Puddling, explained Sharon, is strictly a single-sex activity. Females receive nutrients from the mud puddles secondhand during mating. At a well-known wet spot near Big Flatbrook, the group discovered a congregation of butterflies that included Eastern commas, known for the silvery comma-like markings on the underside of their wings.
On other early July days, similar counting parties were circulating through other areas. (Whatever the exact day, their cumulative work is called the Fourth of July count.) The long-established Raritan Canal count takes place largely on public lands near a portion of the historic Raritan Canal and includes counters with backgrounds in the arts, engineering, science and biomedical research. Its leader, Michael Gochfeld, is a professor of environmental and occupational medicine at the UMDNJ-Robert Wood Johnson Medical School and author with his wife, Joanna Burger, of Butterflies of New Jersey. A nature lover since childhood, Gochfeld has led the Raritan Canal count for 23 years; 7 years ago he also began leading a count at Duke Farms in Hillsborough.
Many butterfly enthusiasts, including Gochfeld and Sharon and Wade Wander, started out as amateur bird watchers, another hobby that requires patience, a love of the outdoors and keen powers of observation. “It’s one of the greatest things we’ve gotten into,” said Wade Wander.
That camaraderie was evident when the Wander group called it a day at about 4 pm and headed back to join the rest of the Springdale counters at the Wanders’ house, about half an hour away. After a barbecue, the counters compiled their tallies. Despite diligent searching, no giant swallowtails were sighted. That disappointment was tempered by elation over some 20-year record-high numbers: 45 pale-blue summer azures, 30 question marks and 98 small, brown northern broken dashes. After two years with no sightings, counters also tallied three American snout butterflies, named for their elongated mouth parts.
The final total for 2011 was 2,719 individual insects from 46 species, up just over 100 butterflies and one species from the 2010 count, but significantly below the record high of 5,090 butterflies in 2007 and the 20-year species high of 61 in 2008. Weather variations, which can affect the bloom time of food plants, survival of larva, and the emergence of adult butterflies, are a major determinant of butterfly numbers, Sharon explained.
As the Wanders and their colleagues wander out for this month’s count, they’ll be curious to see how the recent mild winter affects their 2012 data. Higher-than-normal temperatures might have increased survival rates for overwintering butterfly eggs and larvae, resulting in larger numbers in July. On the other hand, said Sharon, species that emerge earlier than usual may be gone by counting day. “It’s a source of endless speculation,” she added.
Already, mild weather has lured large numbers of red admirals from their usual southern states to New Jersey and other northeastern states. The butterflies, with their distinctive red-orange wing bands, arrived en masse in early May. Sharon said some of the adult red admirals and their offspring might still be flying and feeding in the Springdale count area in July, leading to higher counts.
However, butterflies have been known to defy expectations. “It’s hard to believe,” said Wade, “but one species—the checkered white—is most plentiful right by Newark Airport.”
Elisabeth Ginsburg is a freelance writer and garden consultant. She counts butterflies from her back porch in Glen Ridge.