City Wilds

Daddy longlegs moves across snowy trail on Anchorage’s Hillside





On a late October walk with Jan and the dogs, slushy snow covering the Hillside’s Spencer Loop Trail, we noticed a surprising abundance of bugs crawling atop the snowy ground or hovering above it. Among the biggest surprises was the presence of several daddy longlegs, their familiar forms revealed by eight long and spindly legs.

As faithful City Wilds readers will recall, it’s my habit to document insects and arachnids—which I informally group together as “bugs”—throughout the year while passing through Anchorage’s parks and greenbelts. Though I regularly find spiders even in mid-winter, I rarely if ever see their arachnid relatives, daddy longlegs. The latter’s notable presence on the snowy October landscape got me wondering: how do daddy longlegs survive the winter?

Well, subsequent online research has revealed that most of them don’t survive winter, at least in colder climes like ours. Their eggs do quite well though, when deposited in spots that offer insulation from the cold—burial in the soil apparently being a favorite choice—and hatch the following spring to produce a new generation of daddy longlegs. 

Mating, I’ll add, reportedly occurs from late summer into fall, which might help to explain why I tend to see (or notice) daddy longlegs more often then on local trails; perhaps they’re moving widely about in search of partners.

Because they don’t tolerate cold well, daddy longlegs will sometimes gather in large masses when they find a sufficiently warm spot in dropping temperatures. A few years ago, two different discoveries of such arachnid “clumps” were reported in Alaska. The one that gained the most notoriety occurred beneath the windowsill of a National Park Service building in Glacier Bay National Park. 

When park staff noticed the furry, beardlike mass formed by the bodies of hundreds, if not thousands, of daddy longlegs shortly before Halloween, they posted images on Facebook and Twitter. That in turn gained the attention of several media outlets, including The New York Times, which reported the phenomenon in a story headlined, “Did this Building Grow a Beard? Nope. Those Are legs.”

Even more impressive to me was a discovery made by Thomas Glass in Dillingham, later reported by KTUU. The Anchorage TV station played a video made by Glass that showed him brushing a hand along a mass of daddy longlegs that had congregated around a heating vent. As he did so, hundreds of the arachnids detached themselves from the “bundle” surrounding the vent and scrambled—or dropped—to the ground below.

 Glass noted that “Dipdooly is what they are called out here,” adding “At night you could see them migrating across the ground everywhere looking for somewhere to warm up. They show up every fall when it turns cold, but I haven’t seen this many before.” 

Those who’d like to see the furry bundles of daddy longlegs can do an online search for “daddy longlegs in Alaska.” That’s what worked for me.

I’ll note here that such clumps of daddy longlegs have been found in many different places around the world, including caves and forests in regions considerably warmer—and drier—than Alaska. 

Scientists admit they don’t know why daddy longlegs bunch up, though several theories have been offered: to keep from drying out in arid climates, as defense mechanisms against predators, and yes, to stay warm in cooling temperatures. Though most of the arachnid clumps are groups of less than 100 daddy longlegs, one discovered in China reportedly included more than 300,000 individuals. Try imagining that.

 While videos of the daddy longlegs’ hairy clumps—and their sometimes-explosive scattering when disturbed—have gained the most attention, there’s an amazing amount of online information about these unusual creatures and other equally remarkable aspects of their lives. Before sharing a sampling of what I’ve learned, I’ll present something of a daddy longlegs primer.

First, as their name suggests, daddy longlegs have exceptionally lengthy legs when compared to the size of their small, oval body. At first glance, this is their most defining trait and it’s the one aspect of these creatures that most of us humans notice. As I’ve already suggested, they belong to a group of invertebrates known as arachnids, whose members (among other characteristics) have four pairs of legs. Insects, you’ll recall, have three pairs.

 Scientists estimate that as many as 10,000 species of daddy longlegs inhabit the Earth and they’re found on every continent except Antarctica. To date, between 6,000 and 7,000 species have been described. In scientific nomenclature, all of these different kinds of daddy longlegs belong to the order “opiliones.” In Alaska, thirteen different species have been discovered. Wherever they happen to reside, they seem to prefer more humid areas and (like many forms of life) are most diverse in tropical areas. 

Though best known as daddy longlegs in English-speaking parts of the world, they’ve been given a variety of other names, including harvestmen and shepherd spiders, which not surprisingly seem especially popular in rural farming and herding areas. 

I’ve so far only found one Alaska Native name for the creature: according to Kodiak’s Alutiiq Museum, Native residents who live along the state’s southwestern coastal areas know daddy longlegs as “sukunuuk.”

Though many people assume they’re a type of spider, the daddy longlegs people most commonly see crawling along the ground or on the outside walls of their homes are NOT spiders (though to confuse matters there is a spider sometimes called daddy longlegs, better known as the cellar spider). 

Daddy longlegs are in fact more closely related to another type of arachnid, scorpions, than they are to spiders, which went down their own evolutionary path hundreds of millions of years ago. Which brings up another point. Scientists say that a daddy longlegs fossil discovered in Scotland is at least 400 million years old. So they’ve been around a long time.

One way to distinguish daddy longlegs from spiders is that they have a single “fused” body (that looks a bit like a brownish pea), while spiders have a narrow “waist” between their front and back ends. Besides that, daddy longlegs have only two eyes, while spiders have eight. Of course counting eyes requires you get pretty close to them, something most people have no desire to do. 

A few other things distinguish daddy longlegs from spiders. For one, they don’t produce silk, so they don’t make webs. Neither do they have fangs or produce venom. They do however have two small, arm-like appendages near their mouth, which enable them to grab and hold tiny insects and other small bits of food. 

In short (it seems this point is emphasized in every daddy longlegs story), they present no danger to people.

Here’s another difference from spiders: the second pair of legs that extend from the small oval body of daddy longlegs act as sensing devices, much like the antennae of other organisms. More than their eyes, these specially adapted limbs help daddy longlegs “see” (or sense) what’s going on around them.

There’s something else about the limbs of a daddy longlegs that amazes even the people who study them: they have the ability to drop a leg if it’s been grabbed, say by a predator. Or a researcher. 

This voluntary release of a body part is called “autotomy,” and scientists say it’s a survival mechanism. Better to lose a leg than one’s life, after all. (Or, in the case of some lizards, a tail.) For those who are wondering, the legs do not grow back. But they are apparently “programmed” to twitch for a few seconds after dropping from the body, which may help a daddy longlegs escape from a predator, and how amazing is that?

As you might suppose, researchers have studied this ability of daddy longlegs to not only sacrifice a leg or two (or more), but to adapt their walking style to accommodate the loss. Researchers insist they’re not pulling the legs off the daddy longlegs, but they’re certainly providing the stimulus that causes the dropped limb. According to a PBS report, “Whether (the limb loss) hurts is up for debate, but most scientists think not, give the automatic nature of the defense mechanism.”

 Easy enough for us humans to say. 

For those who’d like to know more about the “voluntary” limb loss and the way daddy longlegs adapt, I’d suggest doing an online search for PBS/KQED Science and the title “Daddy longlegs risk life, and especially limb, to survive.”

The scientists in that report have also somehow determined that daddy longlegs “have a 60 percent probability of losing a leg during their lifetime.” How they know this, I can’t say, but it suggests to me that they’ve been encouraging way too many daddy longlegs to lose their legs. Though the information gained may be remarkable, a guy like me has to wonder: isn’t this a form of wildlife harassment in the name of science? That’s a topic for another time I suppose (and one that I’ve reflected upon with other animal “research,” even sorts considered largely benign.)

Besides dropping a leg or three when necessary, daddy longlegs have other defense mechanisms to save themselves from predators (which in Alaska may include birds, shrews, and frogs): first, they emit “foul-smelling” chemical excretions that are not easily detected by humans, but may keep smaller predators away; second, they’re really good at “playing dead.” Being earth-toned in color, they blend with lots of the debris that covers the ground. When sensing a threat, daddy longlegs will sometimes simply “curl up” and remain still for up to several minutes. Apparently, it can be quite effective.

Lots more has been learned about these common—and to repeat, harmless to humans—creatures. But I’ll end here and refer interested readers to the many online videos, images, and stories that offer further insights into the nature of daddy longlegs, yet another life form that we humans too easily overlook, underestimate, or even worse, do harm to, when in fact they are, in their own way, quite wondrous creatures.

 

Anchorage nature writer and wildlands/wildlife advocate Bill Sherwonit is a widely published essayist and the author of more than a dozen books, including “Living with Wildness: An Alaskan Odyssey” and “Animal Stories: Encounters with Alaska’s Wildlife.” Readers wishing to send comments or questions directly to Bill may do so at akgriz@hotmail.com

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