PACIFIC NORTHWEST MOTHS

Guest blog post from Merrill Peterson, of Western Washington University and Carol Kaesuk Yoon, science writer for the New York Times, extolling the virtues of moths and the fantastic web resource, Pacific Northwest Moths,

We here in the Pacific Northwest are lucky for many reasons - towering Mount Rainier, schools of delicious salmon, summer harvests of raspberries - and, though not too many people know this, an abundance of beautiful and fascinating moth species. To help people study, better understand and enjoy these species, a group of lepidopterists (people who study butterflies and moths) worked for the last three years to create a new website called Pacific Northwest Moths. So far, there are just over 1,200 species on the site, with ultra high resolution photographs of each one (you can zoom in to see individual wing scales), range maps, detailed species accounts, and even an easy-to-use interactive identification key.

So what's in the region and on our site?

There are moths that hardly seem to be moths at all! Like many other insect species, some species of moths have evolved to look like much tougher, more intimidating and potentially dangerous insects, like wasps or bees. This Hemaris thetis is a bumblebee-mimicking moth that can be found in our region. This chubby clear-winged moth can be found hovering over flowers in broad daylight, sipping nectar. 

Others have evolved to look equally unattractive, but for different reasons - like the species that mimic bird poops, including Tarache knowltoni, which, when it is at rest with only the front wings showing, is easy to mistake for bird droppings.

Some moth species in the region are hard at work, attempting to do what human hands and tools have been unable to accomplish, for example, controlling invasive weeds. The weed known as Tansy Ragwort can be deadly to livestock, and can even harm humans when cattle eat the weed and produce contaminated milk. Tansy Ragwort even produces toxic pollen which can create tainted honey if it's anywhere within two miles of a hive. But this noxious weed is now being challenged by Tyria jacobaeae, a moth species whose caterpillars enjoy munching down this invasive species. 

In addition to having pictures of species of these species and more, the site has maps showing where and when they have been found. In this way, researchers can use the website to track and record any moth species that come within our region, including the odd stray tropical species that wanders up, like this Black Witch Moth. This impressively huge tropical species did exactly that this summer, turning up in July at Priest Lake, Idaho.

Because each species account shows all known sightings of a species, it gives everyone, including scientists, a chance to see how the fauna of our region has changed and continues to change over time. It also allows us to see phenomena such as the massive outbreaks of western tent caterpillar moths, Malacosoma californicum, such as have plagued Island and Whatcom Counties in Washington State this summer.

There are some groups of moths that are interesting, simply for their incredible diversity. For example, one group in our region that is very species-rich, and a real headache for taxonomists, is the genus Euxoa. If you look at the site, you'll find more than 120 species, many of which are extremely difficult to distinguish. 

Moths can also be very important as a food source to bats, birds, spiders, and even foraging bears. Take for example, one of our moth species known as the army cutworm moth or Euxoa auxiliaris. A study in Yellowstone found that grizzly bears eat aggregations of these moths in rock screes, where the bears sit and patiently turn over rock after rock to find the moths hidden on the underside. The moths turn out to be more energy-rich sources of food than blueberries, trout, nuts, or deer meat, and represent 34% of the bears' diet in late summer, when they are fattening up for winter. A single bear can eat up to 40,000 moths per day at their peak!

We envision Pacific Northwest Moths as not only a repository of data already known, but as a place where people can continue to report new sightings, a never-ending citizen science project that can help us understand the ever changing story of the moths of our region.

DRAGONFLIES LIVE FOR SEX

Well, don't we all? By "all," I mean all living things that reproduce sexually. When you think of it mechanistically, an organism's adaptations are primarily directed toward getting its genes into the next generation. Eat, sleep, avoid predators, grow up and reproduce—what else is there? Well, besides keeping in touch through Facebook.

For dragonflies, it's a long larval life in the water, as they eat and try to avoid being eaten. Then the magic of metamorphosis when they leave the water to become an adult winged insect. After that, more feeding and predator avoidance and, most of all, attempting to reproduce.

Male dragonflies spend much of their time at the water. Think of a singles bar, where the males are hanging around in hopes of meeting someone of the opposite sex. That's why those males head for the water. As the larvae are aquatic, the females have to lay their eggs in the water. Because the females have to come to the water to do this, males have a better chance of meeting one there.

Because so many males are at the water, the sex ratio can be extremely skewed there, with dozens to even hundreds of males for every female. Thus for a male there can be extreme competition for mates, and some males never mate in their lifetime. One way to alleviate that is for a male to defend a territory large enough, keeping other males out of his air space, so that he has access to any female that approaches. Many kinds of dragonflies do just this.

When a male damselfly sees a female, he immediately attempts to grab her for mating. He flies up to her, lands on her head and bends his abdomen forward to clasp her "neck" (prothorax) in two pairs of clasping appendages at the end of the abdomen. As soon as he has a good grip, he brings his abdomen forward and transfers sperm from the tip of his abdomen, where they are produced, to a storage chamber called a seminal vesicle in his second segment. From there, the spermatozoa can be transferred to his copulatory organ.

He then signals the female his readiness to mate by swinging her forward. The tip of her abdomen contacts his second segment, and structures on both of them form a firm connection. His genital ligula (penis) then transfers the sperm to the female's vagina, where it is moved to the spermatheca, another storage organ.

They then disconnect from that point, and she is ready to lay eggs. Her eggs travel from her ovary down her oviduct and are fertilized as they pass the spermatheca. She then can insert them into plant tissue with a specialized ovipositor, and the cycle begins again.

Dragonflies do about the same thing as damselflies, but the male fills his seminal vesicle before mating, and he clasps the female's head with three clasping appendages. The majority of dragonflies lay their eggs directly into the water rather than inserting them into plant tissue. See Odonate Oviposition, November 3, 2011, on this blog site.

Dennis Paulson

PACIFIC NORTHWEST TURTLES

There are two native freshwater turtles in the Pacific Northwest. One is very common, the other quite uncommon. The common one is the Painted Turtle (Chrysemys picta), found all over the interior of the region south to northern Oregon and locally in western Washington and the Willamette Valley. Painted Turtles are seen in great numbers basking on logs and rocks in warm lakes in the summer, but they are shy and quickly slide into the water when approached.

These turtles are all omnivores, with a wide diet including water plants, insects, crayfish, fish, tadpoles, and dead animals. In some species, mating takes place in the fall, but the sperms don't approach the eggs until spring. This is called delayed fertilization and is common in temperate-zone reptiles. The females then come ashore in summer and dig a hole in the sand in which to lay their clutches of round, white eggs. The eggs may overwinter or hatch in fall, in that case the young turtles usually overwintering in the nest and emerging the following spring.

The other native freshwater turtle is the Western Pond Turtle (Actinemys marmorata). This species, once widespread in western Washington and Oregon, has disappeared from much of its range north of the Columbia River. Considered a species of special concern, much conservation effort has been expended on it. Biologists hatch turtle eggs in captivity, then release the young when they are large enough to be less vulnerable to predation. This very successful program has been going on for two decades at Seattle's Woodland Park Zoo and has resulted in a present population of around 1500 turtles in the wild in Washington.

The most frequently observed turtle in much of western Washington is not one of these natives but is the introduced Red-eared Slider (Trachemys scripta). This species, the most common turtle in the pet trade, has been introduced all over the world. People keep the cute babies for a while, then tire of them and toss them in the nearest lake. This may be humane treatment, but it's not good for the environment, as these invasive turtles compete with native turtles and transmit diseases to them.

Two other species have turned up in Lake Washington and elsewhere, the Snapping Turtle (Chelydra serpentina) and Spiny Softshell (Apalone spinifera). These very distinctive turtles also are native to eastern North America. Both get quite large, and they live a long time and keep on growing, so there are probably a few monsters out there. They are also aggressive species that will bite fiercely, so caution is advised!

Any account of Pacific Northwest turtles should mention the marine turtles that show up in our waters. Leatherback Turtles (Dermochelys coriacea) are regular off the Washington coast. Although sea turtles are basically tropical, this is the species that ventures into colder water than the others. When seen from a pelagic birding trip, Leatherbacks usually show up as a blob in the water, only the head visible. At closer range the big ridges down the shell can often be seen. Other sea turtles, including Green (Chelonia mydas), Loggerhead (Caretta caretta) and Pacific Ridley (Lepidochelys olivacea) are much rarer, but a few have been found washed up on northwest beaches.

Dennis Paulson

Microplastics in Northern Fulmars as an indicator of marine plastic debris in the North Pacific

(Results in press as of 8 Jul 2012 at http://www.sciencedirect.com/science/article/pii/S0025326X12001828, pdf available upon request.)

Marine plastic debris is an increasing problem in ocean ecosystems. Plastic degrades slowly on land, but in the ocean it persists even longer – if left to its own devices, potentially for hundreds or thousands of years. Also, because plastic is light, it floats or is suspended in the water column and can be carried long distances from its origin by ocean currents. To see just how big of a problem this has become, you need only look a little to the west of our own coastline at the “Great Pacific Garbage Patch” – a mass of trash larger than Texas accumulating at the center of a current system called the Northern Pacific Gyre.

Plastic in marine ecosystems can be extremely harmful to wildlife. Animals can not only become entangled in the debris, but they can also eat the tiny “microplastic” particles that are the result of plastic trash being broken apart in the ocean. Seabirds in particular are known to suffer a great deal from plastic ingestion, which can have serious negative consequences to their health as plastic can accumulate in the gut, reducing stomach capacity, obstructing digestion and causing starvation and reduced growth.

The only good side to this situation is that we can use some seabird species as indicators of marine plastic debris in the environment. Not all seabirds eat or accumulate a lot of plastic – some dive for their food and manage to bypass the surface realms of floating plastic. Some are not so lucky. Procellariids, or “tube-noses” including birds such as albatrosses, petrels, and fulmars, are some of the most extreme accumulators of plastic. This is primarily because they are surface-feeders and are more likely to swallow floating microplastics – presumably as a result of confusing them with food.

Northern Fulmars (Fulmarus glacialis) in particular have been accepted as the best indicator species for marine plastic debris in the northern hemisphere. This is mostly due to their extremely wide range and distribution – they can be found in the North Pacific, North Atlantic, and the High and Low Arctic. They can therefore be used as an international standard indicator of marine plastics. Monitoring projects focusing on microplastics in Fulmars in the Arctic and Atlantic are fairly wide-spread and well-established. However, data for the North Pacific is lacking and outdated since the 1990s. This fall, I made a first attempt at rectifying this lack of monitoring in the Pacific Northwest. I examined the stomach contents of 20 Fulmars: five from Washington (salvaged from the beach in fall 2009) and fifteen from Oregon (supplied by Sharnelle Fee at the Wildife Center of the North Coast: http://www.coastwildlife.org/Home.html).


I found that 90% of specimens contained plastic, with an average of 21 plastic items and 0.34 grams of plastic per bird. Likely due to the high human population density of our area, this is notably more than in the Canadian high arctic, where studies report only 33% of Fulmars containing plastic (Mallory 2008). However, our study showed similar amounts of plastic to recent studies in the North Atlantic – in 2003, researchers reported 95% of Fulmars as having an average of 29 items and about 0.35 grams of plastic (van Franeker et al. 2003).


While a third of a gram of plastic might not sound like a lot to us, who can hold as much in the palm of our hand, this can be a huge burden for birds the size of Fulmars. There aren’t any established standards or goals yet for the United States, but the Oslo & Paris Convention in Europe has established a goal to reach less than 2% of Fulmars in monitoring surveys containing more than ten plastic pieces. 45% percent of Fulmars in my study and 56% in the North Atlantic in 2003 (van Franeker et al. 2003) contained more than ten items. In short, neither the status of marine plastic debris in the Pacific nor the Atlantic is anywhere near a level considered to be manageable and healthy for marine life.


I also found that 95% of plastic items in the Fulmars were user plastics – things like fragments from consumer products, Styrofoam, and the occasional bit of sheet plastic from a grocery bag. Only 5% were pre-production industrial plastics – round pellets usually of white, beige, or brown color that haven’t yet hit the factories. This is similar to recently reported trends in Northern Canada (Mallory 2008), but opposite of trends reported for the North Pacific in the 1990’s, which found primarily industrial plastics in Fulmars and other seabirds (Robards et al. 1995; Blight & Burger 1997). This could either mean that consumer plastic debris has increased in the Pacific, or that industrial plastics have decreased. It seems likely that both may be the case, as increased regulation on shipping companies may have decreased industrial plastic spills while increased human population and consumerism may be causing increased input of litter into the ocean.

Most of the plastic particles in these Fulmar specimens were neutral colors, such as white and beige. This suggests that Fulmars eat plastics that may resemble food items, such as fish, squid, or crustaceans. However, no data is available regarding the color composition of marine plastic debris in the environment, so we can't really tell whether the high proportion of these neutrally-colored plastics in Fulmars are a result of selection by the Fulmars or just a representative sample of what's available in the environment.


In terms of differences in plastic accumulation within my sample, I found that juveniles from Oregon contained significantly more microplastics than the adults (P=0.033). This is consistent with findings of other researchers (van Franeker et al. 2003), and likely a result of the fact that parents regurgitate food to their offspring, probably transferring plastic along with it. Alternatively, the juveniles might be less selective than adults in "prey" selection. The accumulation in juveniles is highly concerning because plastic accumulation is thought to contribute to reduced growth and could have future implications for recruitment of adults in Fulmar populations.


The last variable I looked at was the difference in plastic accumulation between the sexes. I didn’t expect to see any difference, since males and females are a similar size, both contribute to feeding offspring, and presumably have the same feeding habits. Overall, my expectations were confirmed and there was no significant difference (P=0.27). However, when I compared only the contents of the ventriculi, or the bottom portion of the stomach responsible for mechanical digestion, males contained notably (although not quite significantly) more plastic (P=0.095). Further investigation will hopefully clarify this trend, but for now, we are left in some uncertainty and confusion as to why females might accumulate less microplastics than males.

This project was only a first effort to use Northern Fulmars for microplastic monitoring in the Pacific Northwest. Already, other students at the University of Puget Sound are planning to continue this research in the future, which will hopefully lend additional significance and applicability to these results. Most of all, the results of this study will become vastly more useful with continued monitoring in an effort to better understand trends in environmental levels and composition of marine plastic debris and its potential effect on wildlife.

References:
Blight L.K. & Burger A.E. 1997. Occurrence of plastic particles in sea-birds from the Eastern North Pacific. Marine Pollution Bulletin 34: 323-325
Mallory M.L. 2008. Marine plastic debris in Northern Fulmars from the Canadian high Arctic. Marine Pollution Bulletin 56: 1501-1504
Robards M.D., Piatt J.F. & Wohl K.D. 1995.Increasing frequency of plastic particles ingested by seabirds in the subarctic North Pacific . Marine Pollution Bulletin 30:151.157.
van Franeker J.A., Meijboom A. & de Jong, M.L. 2003. Marine litter monitoring by Northern Fulmars in the Netherlands 1982-2003. Wageningen, Alterra, Alterra-rapport 1093

Lydia Kleine, Curatorial Assistant, Slater Museum

Bio of the author: A biology student at the University of Puget Sound, I have worked as an assistant at Slater Museum for a year. This was a final project for a marine biology class. I will be graduating this month and looking for a job.

Result in press as of 8 Jul 2012 at http://www.sciencedirect.com/science/article/pii/S0025326X12001828

GARTER SNAKES

No, they're not "gardner snakes" or "garden snakes." They are garter snakes, named after the striped garters that embellished many a lady's leg in the distant Twentieth Century. A snake that bites, thrashes around, and emits a foul-smelling fluid when handled probably wouldn't make a very good garter, however.

The first stage of predator avoidance is to flee, and snakes—notwithstanding their lack of legs—are superb at that. If not entirely out in the open, as for example when they cross roads, they quickly disappear into the vegetation when disturbed. If captured, the larger ones have no hesitation about biting to defend themselves. A bite from the many sharp teeth of just about any snake will bring out a series of four-letter Anglo-Saxon words such as "ouch" and "rats."

Whether they bite or not, some snakes are sure to wind their body around the captor (or the captor's arm, in the case of a human) and discharge a smelly fluid consisting of mixed feces and urine and a musk produced in the cloaca. If you must catch one, securing the tail is just as important as grabbing the head.

Most garter snakes have a middorsal pale stripe and a pale stripe low on either side. No other common northwestern snakes share that pattern. Although the scales on their underside are smooth, garter snakes have keeled dorsal scales, which gives them a rough appearance and feel. They are rarely more than three feet in length, and most are much smaller.

There are three common species of garter snakes in the Pacific Northwest, but there is sufficient variation in all of them that identification is not always easy.  The Common Garter Snake (Thamnophis sirtalis) occurs all across North America. The ground color is dark, with the typical light stripes. Our populations usually have red spots along the sides, but the darkest individuals can show very little red; look closely. In western Oregon and southwestern Washington, the head is largely reddish.

Western Terrestrial Garter Snakes (Thamnophis elegans), widespread in the West, never show any red markings. Populations in our region characteristically show a series of alternating dark spots in a checkerboard pattern on a lighter ground color, still with the normal three stripes. There are melanistic populations in the Puget Sound region, some individuals almost entirely black.

Northwestern Garter Snakes (Thamnophis ordinoides) are restricted to the Pacific Northwest, mostly west of the Cascades. They are smaller than the other two species, with a relatively smaller head. The head is somewhat lighter than the body, with a contrasting dark stripe through the eye. This species is very variable, from very dark with contrasty yellow stripes to a lighter color with dark markings not so different from those of a Western Terrestrial. Some individuals have a red dorsal stripe or are largely reddish above, unique to this species.

Common and Western Terrestrial Garter Snakes eat mostly vertebrate prey, especially fishes and amphibians, but both may take any other small animals that they come upon. Because of their primary diet, they are commonly found around water, even in it (notwithstanding "Terrestrial" in the name). Northwestern Garter Snakes are invertebrate feeders, capturing mostly slugs and earthworms. This correlates with their smaller head and mouth and entirely terrestrial existence.

Garter snakes are common throughout the warmer parts of the year. They disappear by October, sheltering underground where possible. Sometimes numerous individuals den together, perhaps conserving body heat by being tightly packed. They are often the first snakes to appear in spring, sunning themselves in exposed places near where they spent the winter in dormancy. Like all reptiles, they use the sun for thermoregulation.

Garter snakes are the only common snakes in the wetter parts of the Pacific Northwest, and they are often found in suburban parks with natural habitats remaining. Their continued presence is a great reason to preserve those habitats.

Dennis Paulson

LIZARDS ARE COOLER WHERE IT'S HOT

We have lizards in the Pacific Northwest, but like all other reptile groups, they become more common and diverse as you travel lower in latitude. In the southwestern deserts, lizards often dominate the landscape, if you exclude the ever-present and noisy birds.

Lizards seem among the most heat tolerant of any vertebrates. You walk around in the desert when it's so hot you really shouldn't be out there, and you find lizards running ahead of you across the burning sand. Most of them are long-legged, and they hold their body above the substrate as they move. The really fast Zebra-tailed Lizard (Callisaurus draconoides) can run bipedally, using only its hind legs for a slightly greater speed. They have been clocked at four meters per second, and they seem to blur as they run. As your eyes follow them, you may not see that they stop.

The long legs and toes, especially the hind ones, are what furnish the combination of speed and sand traction that these lizards need to move about. All of their needs are met by high speed: predator escape, prey capture, and quick moves from shade to shade. Try chasing one down. None of the lizards shown here does much climbing except the Lesser Earless Lizard (Holbrookia maculata), which moves around on rock faces or up in low shrubs.

One adaptation shared by all these lizards to avoid the hot desert sand is to contact it as little as possible. One way of doing this is to rest on their heels and flex their toes upward. Perhaps their toes are especially heat-sensitive. And if you keep watch, you'll see that these lizards usually head for shade in the middle of the day. They're not that heat tolerant!

Earless lizards are unique in lacking external ear openings, perhaps an adaptation to keep sand out of the ear. Oddly, the closely related Zebra-tailed Lizard and fringe-toed lizards (Uma) have ear openings, yet they spend even more time on the sand. Maybe earless lizards just like silence!

The heads of the Zebra-tailed and Lesser Earless lizards are somewhat scoop-shaped, widest at the mouth. They push their head into the sand and, by digging with alternate strokes of the legs, bury themselves very quickly to avoid predators or spend the night.

Most of the lizards of the desert eat arthropods, with two rather different modes of foraging for them. The common mode is as a sit-and-wait predator. The lizard remains in one spot and watches around it. If it sees an insect or spider, it runs and grabs it. The Leopard Lizard (Gambelia wislizenii) is large enough to take other lizards as prey.

The other mode is as an active searcher. This characterizes the whiptail lizards of the genus Aspidoscelis (formerly Cnemidophorus). They move slowly along, digging in the soil with alternate front legs, and scare up or unearth their prey. They are just as fast on the go as the other types, though. The striped pattern helps them disappear when they move into dense cover. As in striped snakes, the animal doesn't seem to move when you see only part of it.

One of the lizards shown here, the Desert Iguana (Dipsosaurus dorsalis), is a herbivore. Typically it takes leaves, flowers and fruits of the low shrubs that are common in its arid habitat. Note its blunt head, not so different from the big green iguanas of the tropics.

Check out the southwestern desert in summer, the lizard season, but be sure to bring water!

Dennis Paulson

THE RINGED TAIL TALE

The Ring-tailed Lemur of Madagascar.

At our recent event, Exotic Species Night, visitors of all ages had the opportunity to see, touch, smell, and experience the museum's strangest, most exotic natural history artifacts. One booth in particular received a great deal of attention -- the "Odd Objects and Curious Artifacts" table. This table was a hands-on, touch-everything station with a collection of mystery "stuff" ranging from Mastodon teeth and whale earbones to Pencil Urchin spines and giant Tusk Snails. One object was particularly intriguing to some of our younger visitors -- a long, bushy, black-and-white striped tail. Nearly everyone correctly identified the original owner of the tail as none other than the Madagascan Ring-tailed Lemur. But one particularly inquisitive 4th-grader wasn't convinced.

"But couldn't it also be a raccoon's tail?" she asked. "Raccoons have striped tails too! How do you know it's  not a raccoon tail?" After reassuring her that I personally had seen the lemur before it became tail-less (which truthfully was not all that reassuring), I explained that raccoons typically have shorter, rounder, more bushy tails than Ring-tailed Lemurs. "Cacomistles and coatis on the other hand," I continued, "have tails that are quite similar in length and shape to a lemur's. They would be very hard to identify if I didn't know where they were from!"

And then came the big question.

"Why do they all look the same?"

The Ringtail, or Ring-tailed Cat, can be found
in the Southwestern United States. It has a
relative farther south known as the Cacomistle.
Both are not actually cats, but are more
closely related to raccoons and coatis.

Many species of coati, a Central and South American
relative of raccoons, also have ringed tails.

Raccoons are the best local representative with the ringed-
tail color pattern.

Without even knowing what a coati or cacomistle was, this curious ten-year-old girl knew that something interesting was going on here. In fact, this question has intrigued mammalogists and evolutionary biologists for nearly two centuries and we're still not entirely sure why so many animal tails have converged on this color pattern. Coatis, cacomistles, raccoons and Ring-tailed Lemurs aren't the only ones. This "ringed tail" business is far more widely distributed than you'd imagine. Excluding the bears (Ursidae) and the seals (Pinnipedia), more than half of the families in the order Carnivora have ringed tails. That includes things like the Red Panda, raccoons, cacomistles, coatis, and ring-tailed cats (not actually a cat), as well as civets, linsangs, genets, and most true cats like Tigers, Leopards and Cheetahs. Recent paleontological evidence suggests that even some dinosaurs had black-and-white striped tails!

Cheetahs have partially ringed tails used mostly for camouflage.

Clouded Leopards also have ringed tails.

The Tiger's ringed tail is probably used for camouflage too.

Sinosauropteryx was a the first dinosaur to show distinct color patterns
 in its fossil remains. Paleontologists believe that it had a ringed tail just
like many modern day mammals.

The Spotted Genet and many other
members of its family have ringed tails
which they use for communication.

In spite of this relatively high rate of ringed-tailed-ness in Carnivorans, evolutionary biologists believe that the first Carnivores probably had uniform tails. The fancy tail patternings most likely evolved later in arboreal, nocturnal species as a means to visually communicate with other animals at night (the contrasting bands are easy to see in darkness). But why only in arboreal species? How could a striped tail make you a better tree-climber? Well, it doesn't, but having a long tail does. Animals that live in the trees use their long tails for balance and support as they move along branches. These long tails are rather conspicuous -- sometimes they make up more than half of the animal's body-length -- the perfect place to put up a billboard! A long bushy tail is essentially a blank canvas on which an animal can place valuable visual cues and signs for other individuals. For most Carnivorans, these visual cues take the form of ringed tails.

There are, of course, some exceptions and odd balls. The Cheetah for example, has a partially striped tail despite it's very terrestrial lifestyle. As do Tigers. In some of these cases, terrestrial species have evolved a spotted or striped coat for camouflage, and these stripes/spots simply continue down the length of the tail. But according to the evolutionary biologists, most ringed tails evolved entirely independently from patterns on the rest of the body -- meaning ringed tails used for camouflage are the exception to the rule.

As for the ringed tail of the Ring-tailed Lemur (a Primate, not a Carnivore), the same rules probably apply. A long tail for arboreal locomotion is a great place to put some valuable visual cues regardless of whether you are nocturnal or not. We know that lemurs are very social, so it makes sense that they would utilize their tail to communicate. And Ring-tailed Lemurs do in fact use their beautiful tails for unique displays such as scent displays and aggressive interactions between rival individuals.

So, long story short, black-and-white striped tails are an excellent example of convergent evolution among relatively unrelated animal groups (raccoons to lemurs to dinosaurs) and are used for communication, especially in arboreal and/or nocturnal species. If you'd like more information regarding color patterns in the Carnivora order, check out Alessia Ortolani's scientific paper from 1998 titled "Spots, stripes, tail tips, and dark eyes: Predicting the function of carnivore color patterns using the comparative method." PDF here.

Stay curious!
-Robert Niese
Education and Outreach Coordinator