The Appalachian Trail was socked in by clouds the morning Glenn Taylor went looking for the spruce-fir moss spider.
Just north of Clingmans Dome, he stopped to inspect a north-facing boulder covered in bright green moss.
A biologist with the Great Smoky Mountains National Park, Taylor happened to be trying out a brand-new pair of contact lenses that day. Around his neck hung a 10-power hand lens, and in his pocket he carried a lighted magnifying pencil.
“These spiders are tiny, but they’re out there,” Taylor said. “You have to know where to look.”
Measuring less than oneeighth of an inch in length, the spruce-fir moss spider is one of the world’s smallest tarantulas. The species, which lives almost exclusively in high-elevation spruce-fir forests, was discovered on North Carolina’s Mount Mitchell in 1923 and first found in the Smokies on Mount LeConte in 1926.
In 1995, the spider was added to the federal endangered species list after the balsam woolly adelgid wiped out much of the Fraser fir trees in the Southern Appalachians.
This summer Taylor began surveying the spruce-fir moss spider in the Smokies, mostly by revisiting sites previously identified by Fred Coyle, a spider expert from Western Carolina University who has documented the species’ status throughout its range in the Southern Appalachians.
Like the proverbial needle in the haystack, the spruce-fir moss spider does not lend itself to easy discovery. After five days of hard looking, Taylor had found just six spiders. Last week, he and Jennie Bradbury, a forestry technician for the park, found one more.
Using a GPS unit, they stopped at a site where Coyle previously had located one of the elusive spiders. Taylor explained that spruce-fir moss spiders make their homes beneath moss mats attached to north-facing rocks, not moss-covered logs.
Carefully peeling a patch of moss off the rock, Taylor found what he was looking for. Immediately apparent on the dark underside of the moss was the spider’s tubeshaped web. A closer inspection revealed the spider itself. Using a hand lens, its spinneret and the fine hairs on its body were visible. The spider was mostly gray, and only when it moved was it easy to see with the naked eye.
“They’re not shy or anything,” Taylor said. “They just have very specific habitat needs.”
Biologists believe the spruce-fir moss spider uses its web more for shelter than to catch food. Its diet consists of springtails, a small, wingless insect found in the moss mats.
After taking photographs, Taylor carefully positioned the moss back on the rock. The elevation was 6,314 feet, and the forest type was spruce-fir, the spider’s preferred habitat.
Because the Smokies contain 74 percent of the spruce-fir forests in the Southern Appalachians, the park represents an important stronghold for the endangered spider.
Researchers are hoping the park’s second-generation fir forests that have reclaimed stands hit by the initial balsam woolly adelgid attack will provide new habitat for the spruce-fir moss spider.
They’re also going to see if new moss can be coaxed into growing on bare boulders to expand the spider’s habitat.
In addition to surveying known spruce-fir moss spider sites, Taylor will investigate new locations that might support the tiny tarantula.
“Most of the sites that have been mapped are along the Appalachian Trail and easy to get to, but they could be anywhere,” he said.