Hops-itality

pacific tree frog (photo: jacki dougan, creative commons license)

[Reprint from April 2012]

Fifty years ago, Rachel Carson asked the world to consider a simple question: imagine springtime without birdsong.

Silent Spring was an unlikely subject to become a best-selling book—the effect of DDT and other pesticides that persist in body tissue, becoming more and more concentrated as they move up the food chain (a process known as biomagnification). Yet nearly everyone could easily understand that their own quality of life would be diminished should they step outside one sunny May morning to find the dawn chorus had been replaced with a deafening stillness.green treefrog (Photo: sarowen, Creative Commons license)Thanks to Carson’s courageous stand—and the subsequent public outcry—songbirds and other avian species dodged a bullet.* Now there’s another set of wild voices in the spring choir who could use a hand—the amphibians.

More specifically, frogs.

There are now over 1,800 threatened amphibian species. At least 168 species have gone extinct in the last two decades due to factors such as habitat loss, water pollution, disease, climate change, and invasive species. Additionally, many areas in North America, Europe, and southern Africa have recently experienced severe drought.

Many frog species depend on ephemeral (temporary) water sources for breeding since they don’t support fish that would eat the eggs and tadpoles. If the ephemeral pools dry up before the young amphibians have time to metamorphose, or if there isn’t enough rain to create pools in the first place, it can result in a missed generation… and a fragile future for frogs.Poison Dart Frog Sitting on a Leaf (Photo: MoleSon2, Creative Commons license)Kermit the Frog spoke from experience—it isn’t easy being green… or yellow, or red, or black, or blue.

Frogs are essential to the health of wetland, riparian, and coastal ecosystems. Tadpoles feed on algae, preventing blooms that can reduce oxygen levels. Frogs consume millions of insects each year, including mosquitoes and ticks carrying diseases that threaten the health of humans, their companion animals, and livestock. A wide variety of wild mammals (raccoons, opossums), birds (herons, hawks, geese), and reptiles (snakes) rely on frogs as part of their diet.

April 28th is the 10th Annual Save the Frogs Day, established to raise awareness and funds for amphibian conservation. Since many frog species are comfortable living in cities and suburbs, I thought I would pass along suggestions for homeowners who would like to offer some hoppin’ hospitality, courtesy of the event organizers:A Wet Welcome Mat

Fall and spring are the best times to create a permanent oasis for frogs. Kits are available at many garden and home improvement stores, or simply use a container or dig a hole that is deep enough (at least 1 foot at one end) and line it with sand or a flexible plastic liner before adding water.  Keep in mind, you must provide a sloped ramp so the frogs can get out easily.  Slope the liner or build one out of rocks to gradually allow the frogs to get to ground level or out of the pond. (Some nurseries also have floating devices for swimming pools that can allow amphibians who might jump in a way out.)

Don’t clean the water. In fact, add floating plants such as lily pads or leaves to provide cover. Refill slowly and carefully if water levels get low.

Don’t put fish in your pond, as they will munch on your tadpoles and frogs.

Shade & Shelter

Place your pond in a shady spot, preferably surrounded with native plants to attract a tasty bug feast of ladybugs, bumblebees, and other pollinators to also help beautify your yard. You can stack some rocks or turn over a half of a flowerpot beside the rim of the pond to give your frogs a place to sit and eat their lunch as it flies or crawls by.glass frog (Photo: Josiah Townsend, Creative Commons license)Go Organic

Don’t use pesticides or weed killers. Amphibians absorb water—and any chemicals in it—through their skin. Pesticides and weed killers can run off from land into water and can be lethal to amphibians. Certain weed killers also can alter hormones, changing male frogs into females and reducing the potential of frogs to perpetuate thriving populations.

Patience, Grasshopper

Don’t be tempted to relocate frogs from other areas or stock your pond from pet stores. You may introduce diseases or invasive species and domestically raised frogs will not necessarily adapt to wild habitats. If you build it, frogs will come.

Look & Listen

Become a frog watcher. You will appreciate these wonderful animals more if you can see them in action, and you can help their conservation in the process. There are a number of citizen scientist projects centered on these jumpy amphibians, including FrogWatch USA  and the USGS North American Amphibian Monitoring Program. Learn more about the wetlands in your community and collect data that will help monitor wild population health.

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* Although the focus of this post is frogs, wild birds still face many challenges and threats to their long-term survival. You can check out one such hazard here. Others will be addressed in upcoming NDN posts.

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© 2012 Next-Door Nature—no reprints without written permission from the author (I’d love for you to share my work; all you have to do is ask). Thanks to these photographers for making their work available through a Creative Commons license: [from top to bottom] Jackie Dougan (Pacific tree frog in rose); sarowen (green treefrog); Sascha Gebhardt (poison dart frog); ucumari (bullfrog); Josiah Townsend (glass frog).

Froggy goes a-courtin’

wood frog

.[Reprint from February 2011]

My mole Tboy (mole as in spy, not insectivore) tells me Valentine’s Day has its intended effect on the wood frog population in southwestern Virginia. Mid-February is when the first early-bird males usually appeared at area ponds, floating patiently in anticipation. Within a few days the gene pool is getting crowded, and the boys are warming up for karaoke and the start of happy hour. Once the ladies arrive and joint be jumpin’!

The watering holes have been silent for the last few months. Winter is a time for amphibians to lie low. Really low. Aquatic frogs hibernate on or partially submerge in the mud at the bottom of ponds and lakes. Terrestrial frogs, including the wood frog, hibernate on land. Some burrow down below the frost line, but wood frogs are not adept diggers so they seek out crevices in rocks, crawl beneath a log, or just huddle in the leaf litter.  Their hibernacula don’t always make for cozy inglenooks. When the temperatures drop below freezing, so do the wood frogs. But not to worry—wood frogs have what it takes to best Old Man Winter.

Antifreeze.

No, I’m not talking about well drinks. A high concentration of glucose keeps a frog’s vital organs from freezing, so even though the animal may stop breathing and doesn’t have a heartbeat, it’s not dead. As soon as things heat up again, the frog thaws and life goes on.

wood frogs in amplexis

Wood frogs in amplexis—male is on top (Photo: Richard Bonnett, Creative Commons license)

The wood frog club scene is cool. That’s because it usually begins in late winter, sometimes before the ice has disappeared from vernal reproduction pools. The whole rave lasts for about two weeks. A female steps onto the dance floor—I mean into the water—and a male grabs her and holds on tight. The process is called amplexis. That’s Latin for embrace. Yeah… kind of like the way sumo wrestlers embrace.  Because once the male has her in his arms, he’s not letting go without a lot of… persuasion. Sometimes not even then.

The process is highly competitive and not without hazards. “Satellite” males hang out beyond the water’s edge so they can grab a gal while she’s in transit. In this way, he avoids jostling with the boys at the pool while also scoring a ride to the party. Male wood frogs are stimulated by movement so they;re not always discriminating about who they grab. Sometimes it’s the wrong species of frog, and sometimes several males will grab the same female, which can cause her to be squeezed to death or drown. Club life has its ugly side, too.
wood frog egg masses
But, assuming there aren’t any bar brawls, the female will lay large masses of 1500+ eggs, choosing a site where they receive sunlight and protection from predators. When she releases her eggs, the male—who has been waiting for this opportunity and is now in the perfect position—fertilizes them with a sperm-containing fluid and soon the eggs begin to develop.wood frog metamorphosing

Eventually, the tadpoles hatch and begin their metamorphosis, absorbing the nutrient reserves in their tails to fuel their makeover.wood frog metamorphosingTime to head for the forest and get on with the serious business of making a living. Last call! (Until next year, that is).

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© 2011 Next-Door Nature— no reprints without written permission from the author. Cover photo by Garrett and Kitty Wilkin; egg mass photo by Richard Bonnett; metamorphose photos by Brian Gatwicke. Thanks to all these photographers for making their photos available for use under a Creative Commons license.

Prodigal sons (and daughters)

next-door nature, mountain lion, cougar, dispersal, Midwest

Cougars are one of several predator species returning to historic ranges, even when they include highly developed areas (Photo: Wayne Dumbleton, Creative Commons license)

[Reprint from 2012]

Midwesterners are welcoming the return of some long-absent natives.

On second thought, “welcoming” is probably an overstatement… because just as in the famous biblical parable, not everyone is thrilled about this reunion.

A rigorous statistical study to be published in a 2012 issue of the Journal of Wildlife Management confirmed the presence of 178 cougars (Puma concolor) in the Midwestern U.S. states of Missouri (10), Nebraska (67), North Dakota (31), Oklahoma (12), South Dakota (11), and Texas (12). Single incident reports were documented in Arkansas, Illinois, Iowa, Kansas, Louisiana, Michigan, Minnesota, and Wisconsin.next-door nature, cougar, mountain lion, historic photo, market huntingOnce found throughout North America, from the Canadian Yukon south to the Chilean Patagonia and all 48 contiguous United States, cougar populations dropped precipitously over most of their historic range following European colonization of the continent. The 19th and early 20th centuries, in particular, were hard times for all wild predators. Eradication programs aimed at protecting livestock interests were common. Bounties for cougar pelts, combined with sport hunting and a reduced prey base, lead to extirpation of the species east of the Rockies, with the exception of a small subspecies population in Florida (the Florida panther, Puma concolor corryi).

You’ve heard of a coat of many colors? How about a cat of many names? Cougars are almost interchangeably known as mountain lions and pumas, but regional variants include catamount, panther, painter, ghost cat, screamer… and that’s just the English nomenclature.The cougar has had more than it’s share of scientific names, too. Originally considered the largest member of the Felis clan, a genus that includes both the domestic cat (F. catus) and the somewhat larger jungle cat (F. chaus), in 1993 taxonomists created a new Puma group based on similar genetic structure and composed of two members—P. concolor and P. yagouaroundi, the much smaller jaguarondi, found in Central and South America. Another homecoming of sorts, I guess you could say, although whether the members are happy about their new blended family is anyone’s guess.

As the forth largest of all the world’s cats, adult cougars reach shoulder heights of between 24-35 inches (60-90 cm), nose-to-tail lengths of between 6.5-8 ft (2-2.4 m, females and males, respectively), and average weights of 100-150 lbs (42-62 kg; females and males, respectively).  It’s interesting to note that the closer a cougar lives to the equator the smaller it will likely be; the largest cougars are those found closest to the poles.

The species gets its name from the Latin word for “plain” or “one color” and that’s generally true for individual animals (as long as you ignore the lighter belly, throat and chin). At the population level there’s significant color variation, from golden to silvery-grey or even coppery-red. Cougar kittens don’t start out concolor—they are spotted with ringed tails but these markings fade as the youngsters mature.next-door nature, cougar, mountain lion, dispersal, historic range, midwestAdult cougars have a sleek but muscular physique and are able climbers and strong swimmers, with exceptional leaping and powerful sprinting skills. Despite their speed, these cats are typically ambush predators that quietly stalk and then, if possible, drop silently down onto prey from above, breaking the neck or delivering a suffocating bite.

Cougars are obligate carnivores, which means to survive most of their calories must come from meat. What’s less important is whether the main course is mouse, squirrel, rabbit or raccoon, mutton, venison or veal. This failure to discriminate between wild game and domestic livestock has resulted in a long and bitter feud with ranchers that continues to this day.

The 1960s, however, were witness to a sea change in American attitudes toward the environment in general and predators specifically—at least in the urban and suburban areas that were rapidly becoming home to a majority of citizens. Public pressure to change management policies created greater legal protection for cougars and their numbers began to increase. Over subsequent decades, pressure to disperse has obviously increased as well, as western cougar habitat reaches carrying capacity.

Which brings us right back to where we started, with cougars recolonizing the center of the continent. They use what researchers call a “stepping stone” pattern. Young animals say goodbye to Mom (male cougars are absentee dads) and go looking for adventure. Travel the highways and byways, stop at an interesting locale, scout out dating and dining options then move along. Sometimes quite far along… as was the case with a male cougar who made it to Connecticut before being hit and killed by a vehicle.  Leaving home is what most young mammals, including humans, are programmed to do. I’m as good an example as any, having dispersed from Missouri at 21 to explore all three North American coasts and beyond.
next-door nature, cougar, mountain lion, dispersal, midwest
Cougars may have returned to their old stomping grounds but don’t expect fireworks or any other hoopla. As a native who left the area and has returned many times (although never to stay) I can assure you this homecoming will be a low-key affair.

We Midwesterners don’t like to call attention to ourselves, you know.

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© 2012 Next-Door Nature—no reprints without written permission from the author (I’d love for you to share my work. Just ask first.). Thanks to these photographers for making their work available through a Creative Commons license:  Wayne Dumbleton (cover); USFWS/Public Domain (historic photo of a market cougar hunter); Anthonut (profile); Susan Shepard (climbing down); NaturesFan1226 (sharpening claws).

When a Mess is a Nest

Gray squirrel on a tree branch.

[Reprint from November 2010]

Winter winds have blown nearly all the remaining leaves to the ground. They lie tossed and trampled on the ground like post-holiday parade confetti. The hyperbole of autumn reds and oranges and yellows is long gone, replaced by browns, taupes, and grays.

But bare boughs and blue skies offer the perfect opportunity to pull back that leafy curtain for a peek “behind the scenes.” All you need to do is step outside… and make the leap from two dimensions into 3D.

Sure, we all know it’s a three-dimensional world, but with the exception of a flight of stairs now and then human days are usually spent in a forward-backward-left-right routine. Skeptical? Spend even a few minutes watching a gray or fox squirrel ricochet between branches and you’re guaranteed to feel like your days are spent in Flatland.

Unlike many mammals, squirrels make it easy for wildlife watchers. They’re not shy, they’re active during the day, and much of their activity occurs within the visual field between our feet and our face. Of course, while we keep our feet planted firmly on the ground squirrels do not, and when they bolt up the bole into dense foliage they seem to disappear like a Santa up a chimney. What good does it do to look up?

Dreys in a silver maple

Two dreys in a silver maple (Photo: KJ Lindsey, CCL 2.0)

In parts of the country that have both squirrels and seasons when trees go au naturel, craning one’s neck can be more rewarding during the winter months. That’s why I’m trying to cultivate a new habit during walks with my terrier-boy, Dash. Whenever I catch myself contemplating my shoes, which is often, I lift my eyes and scan the trees, starting at about the same level as the roof of a two-story house. Try it yourself. See those seemingly accidental wads of leaves and twigs, about the size of a football, caught in the gutters formed by branches? Those are squirrel nests, also known as dreys.

Squirrels aren’t as famous for their engineering skills as are beavers but maybe they should be.  It can’t be easy to build 20 feet or more above the ground on a foundation that sways with every breeze. Construction begins with a platform of woven twigs, followed by a spherical framework secured to the base. Leaves, paper, and moss are used to fill in the gaps and create a snug, weatherproof abode with two doorways—a main entrance and a hidden escape hatch. The exterior may look a little rustic but the interior décor is luxurious. Lined with fur, feathers, and other cozy furnishings, it’s the perfect cocoon for a cold winter’s night.

Closeup of a drey

Close up of a drey (© N. Hawekotte, used with permission)

Squirrels don’t hibernate but they do lie low during inclement weather. When the mercury drops or the snow starts to fly, a group of females may crowd into a single drey, kind of like a slumber party without the pajamas, pizza, and prank phone calls.

As spring approaches, the dreys serve a dual purpose as nurseries for the new crop of infants. I realize not everyone is a tree squirrel fan, but if you’re an aficionado and want the scoop on where to enjoy watching for youngsters when they venture out to explore the world and learn how to navigate in every direction, now’s the time to make note of which trees are littered with messy nests.

Just think 3D… without the funny glasses.

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© 2010 Next-Door Nature — no reprints without written permission from the author.

Hide and seek

meadow vole by manual crank

Meadow voles are sometimes referred to as mice and moles, but there is a difference (photo: Leo Papandreou, Creative Commons license)

[I’m attending a faculty retreat in a remote location this week so I decided to run this reprint from 2011. I’ll be back with new Next-Door Nature soon!]

Winter weekend mornings are perfect for catching a little extra shut-eye, but my fur-covered drill sergeant thinks it’s important to rise and shine on schedule, seven days a week. I can’t seem to dissuade him from this mindset.

There’s a snooze button on clock radios and even on my iPhone, but wire-haired fox terriers don’t come with that feature, as either standard or optional equipment. Snug in my blanket burrow, my sympathy for small, ground-dwelling creatures is renewed every time Dash excavates me from beneath the covers and insists, “GET UP! It’s time to OPEN YOUR EYES!!”

Once we’re wrapped in an appropriate number of layers and out the door he begins to search in earnest for that one perfect piece of real estate on which to make his mark. This takes some time—Dash has strong feelings about the importance of a job well-done. As we mosey along I often find myself absent-mindedly scanning the terrain as well (although I use my eyes instead of my nose, and with a different objective).

We had slightly warmer temperatures in southwestern Virginia this past weekend so there was more wildlife activity than when the mercury huddled near zero, and I noticed etchings in the dun-colored grass near our usual pathway.

meadow vole surface runway system 1

At first I thought the scribbles were the result of melting ice, but somehow that didn’t feel right. I took a closer look…

close up of meadow vole surface runway system

…and began to develop a hypothesis:  meadow voles. But if a vole was the engineer behind this winding road, where was the signature grassy-igloo nest?

meadow vole nestAha—I knew it! And not just one… there was a second nest.  I could read what had happened as if a book lay open before me. A blanket of white stuff builds up in the shadows and becomes a snowy fortress for an intrepid rodent willing to do a little mining. Food and building materials close at hand, there’s no need to venture out into the outside world of hungry predators.

Meadow voles (Microtus pennsylvanicus) claim many an alias: meadow mice, field mice, round moles, meadow moles. They are neither moles nor mice, but they are more closely related to the latter than the former. Moles are insectivores. Mice and voles are rodents. Unsurprisingly, then, there are physical similarities. Voles have shorter legs and tails than mice, but it’s dentition—their teeth—that caused mammalogists to set them apart from others gnawers. The upper cheek tooth row is relatively long compared to other rodents, and the third premolar has some distinguishing characteristics. Yeah, I realize that’s an observation that borders on nit-picking but taxonomists are a crowd that believes the key to life is in the details.

As soon as Dash finished his business, I dropped him off back home so I could take a closer look—you can’t sneak up on a rodent with an inquisitive terrier in tow. Smartphone in hand, I examined the carefully arranged, perfectly spherical, palm-sized mound of dried grass and wondered… had the nest become a nursery? Had the vole family tree added another branch? I listened carefully, but if a creature was stirring it wasn’t loud enough to register against my eardrums. The weather forecast calls for a general warming trend but I wondered… would the nest prove warm enough without its outer ice-cave shell?

meadow vole runway and nest Who was I kidding? I’m a woman of the natural world and I could see the writing on the sod. What had once been a well-camouflaged hideaway now looked like a treasure map for predators. If the other companion canines in our neighborhood overlooked these nests while on their quest for bladder relief, it’s unlikely the raccoons, opossums, and even tree squirrels in the woods just beyond the pavement would be so clueless.

I’m a tender-hearted soul, I’ll admit. I’m also a biologist and, therefore, an equal-opportunity empathizer. I hate to think of vulnerable pink babies being gobbled down, but I wouldn’t like to see a starving raccoon either. Some creatures die so other may live. It’s the way of this world.

But while they are alive, in the course of going about the business of living, voles make a unique if fleeting mark on the world that can be discovered and appreciated by anyone who will open her eyes.

Thank you, Drill Sergeant Dash, sir!

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© 2011 Next-Door Nature— no reprints without written permission from the author.

Urban development

Raccoons by John Biehler, Creative Commons license

Just hangin’ on the corner with the homies… smart, bored, and looking for trouble (Photo: John Biehler, Creative Commons license)

[Another reprint, this one from February 2012. I’ve been traveling over the holidays and due to some family-related changes to the itinerary I haven’t had much time to write. New stuff is coming, though. I promise. And is there a better way to start a new year than with raccoons? I think not!]

World War II had barely ended when researchers began to notice a major migration under way in North America, from undeveloped and agricultural areas to cities and suburbs.  Now, in the early 21st Century, the urban population is over 20 times that of the early-1940s—in some places, more than 50% higher than the surrounding rural landscape. With growth has come all the problems that naturally occur as a community becomes overcrowded: housing shortages and squatting; dumpster diving; increases in theft and property damage; sanitation-related public health concerns. sometimes, we all need a little help getting through the day... by jmtimages, creative commons licenseAll of this has a tendency to make established residents less tolerant of immigrants, even when the new neighbors are clever, ambitious, hard-working, good parents, and undeniably cute as all get-out.

Raccoons (Procyon lotor) may be new to the urban scene, but… oh, you probably thought I was talking about people, right?

That’s understandable, I suppose. Just about everything I’ve said to this point could apply to humans as well. There’s no denying that Homo sapiens is now an urban species. The tipping point (>50% of humans living in areas of high population density) came around 2007. Each year, more of us are lured by the promise of better-paying jobs, more housing options, access to social services and chain restaurants, bigger shopping malls, a larger dating pool, and high-speed Internet connections. In other cases, concrete tentacles sprawl past the city limit signs to grab up and devour surrounding countryside, forcing rural residents to choose between relocating to land that hasn’t yet caught developers’ eyes and becoming accidental townies.

urban raccoons by liz west ccThe “built environment” is intended to meet the wants and needs of our own kind, but raccoons may be better suited for what we’ve constructed than the target real estate market.

Raccoon Nation, a documentary that aired in the U.S. on the PBS “Nature” series, and in Canada on the CBC News Network series “The Nature of Things with David Suzuki,” makes a strong case in support of that thesis.* As filmmakers follow the furry urbanites in their native North America (including Chicago and Toronto—known as the “raccoon capital of the world”), as well as in Germany and Japan (where they were intentionally introduced), it’s hard not to notice the similarities between those who construct cities and those who exploit them and their work.

How alike are we? Let’s build this case from the ground up.

raccoon paw and human handFeet—humans and raccoons are both plantigrade. In other words, we walk with the entire foot planted firmly on the dirt… make that asphalt. There are other examples (elephants, kangaroos, and pandas come to mind), but the majority of mammals walk on their tippy toes (more on this in a future blog post).

Hands—okay, technically raccoons don’t have hands, they have two more feet. Or you could say they do have hands but they just happen to use theirs for walking. That’s all semantics, though. Look closely and you’ll see one reason it’s so hard to invent a raccoon-proof container—a paw that looks a lot like a palm and a digit that’s as close to the functionality of an opposable thumb as it gets for non-primates.

dumpster raccoons by zeetz jones ccStomachs—the best way to avoid starvation long enough to pass your genes along to the next generation is to cultivate the ability to eat anything and everything you can cram in your mouth that contains a calorie. The human diet is astonishingly diverse, and urban raccoons gobble up everything we leave on our plates and toss in the trash… plus a lot of stuff we would rather not eat. Some researchers suggest that omnivory played a crucial role in human development—by providing a more consistent and more nutritious diet, and because finding potential new foods, determining whether they are edible, and figuring out how to eat them pushed our brains to create new neural pathways. Which brings us to…

Brains—raccoons and people also share a high level of behavioral plasticity, a term that implies the ability to change. Flexibility, adaptability, and life-long learning (well… we both have that capacity; whether we use it or not is another issue). With no email to check, no AYSO games to attend, no need to commute, and only one significant predator (those commuting automobiles), raccoons have plenty of time for learning. Each day is devoted to DIY personal growth, lifestyle enhancement, and honing useful skills, such as…

  • how to turn a garbage can or dumpster into a convenience store;
  • how to tight-rope walk a fence (great for avoiding the neighbor’s dog);
  • how to shimmy down a tree branch onto a rooftop;
  • how to turn a loose shingle on that roof into an attic entrance;
  • how to turn that attic into a cozy, rent-free nursery.

Whether you find these critters endearing or exasperating, it’s never fun to clean up refuse that’s strewn across your yard, and there’s no denying they can and do cause damage to property. Ironically, our attempts to outwit them are molding these savvy metropolitan mammals to better fit the world we built for ourselves. And here’s the other reason I will never invest my hard-earned money in some inventor’s guaranteed raccoon-proof fill-in-the-blank: because no human being will ever have as much time to devote to keeping a raccoon out of something as raccoons, often working in teams, are willing and able to devote to cracking the code. By trying to thwart them, we’re simply selecting for the traits that make a more worthy opponent and a better urban animal. An über-coon, if you like.

bipedal raccoons by David~O ccBefore you know it, they’ll be standing upright in line right beside us at Starbucks, waiting for a Venti Caramel Macchiato to help them wake up for the night shift.

Urban raccoons share another, disturbing commonality with their human neighbors—the toll exacted by easy access to a plentiful, high fat, high sugar, high calorie diet. Diabetes, hypertension, and cardiovascular disease may do more to limit their numbers, in the long run, than all the Hav-A-Heart trap-toting home and business owners, urban wildlife biologists, and nuisance wildlife control operators combined. Cleverness and dexterity are no match for the fearful symmetry of a predatory heart attack or kidney failure.

No wonder they call it the urban jungle.

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© 2012 Next-Door Nature—no reprints without written permission from the author (I’d love for you to share my work; all you have to do is ask). Thanks to these photographers for making their work available through a Creative Commons license: John Biehler (3 sepia raccoons); jmtimages (mother & child); Liz West (supper club); Stuti Sakhalkar (human handprint); Jon Stogner (raccoon pawprint); Zeetz Jones (dumpster ); David~O (bipedal).

Nutcracker suite

cardinal-grosbeak-crossbill

No, not Tchaikovsky. These are avian nutcrackers (left to right): northern cardinal, rose-breasted grosbeak, and red crossbill. (Photos: ehpien, Conrad Kulper, and Eugene Beckes, Creative Commons licenses)

[A seasonally appropriate reprint from December 2011. New posts are coming for the new year, I promise.]

Ever wonder why hens’ teeth (and any other kind of avian teeth for that matter) are rare? It’s because teeth are heavy. That’s a problem if you live life on the wing but can’t use a knife and fork to cut your meals up into easy-to-swallow morsels.  A bird’s beak (aka bill) is an adaptation to flight that serves most of the same functions choppers handle in Earth-bound creatures… but without the high metabolic cost of carrying around a set of pearly whites.

Bird Beaks by Shyamal and Jeff Dahl, CC

Figure A. Beak shape and size offers a clue as to what the owner likes to eat.

The beak is a sheath of tough skin on the upper and lower mandibles. Wild birds exploit a wide array of feeding resources and niches, and they are aided in this task by a startling diversity of beak morphology (see Figure A). For example, nectarivores (nectar-eaters), including hummingbirds, usually have long, straw-like beaks that reach deep into flowers. Insectivores (insect-eaters) tend to have narrow, slightly curved beaks that can reach into the small crevices where their prey try to stay out of sight. Piscivores (fish-eaters) have a sharp hook, serrated edges, or both, that help them hold on to their slippery supper. Some of the most distinctive beaks, though, belong to nutcrackers.

The northern cardinal (Cardinalis cardinalis) is a familiar and popular resident of cities and suburbs, possibly because it’s so easy to spot and identify. It’s so popular, in fact, that seven U.S. state legislatures have chosen this species to be their avian poster child.  At  8½—9” (21—23 cm) from jaunty crest to tail tip, it’s a medium-sized songbird with ahim and her cardinals by Steve Wall cc stereotypic nut- and seed-busting beak—short, stout, and cone-shaped. I like cardinals as much as the next person—I’m from St. Louis, after all, where you can walk down any street in the whole town and know you’ll see someone wearing a shirt adorned with a bright crimson bird perched on a baseball bat. But my affection is somewhat tempered by the fact that their beaks work equally well at crushing seeds and human skin, as I can personally attest. Who would guess you could have empathy for a sunflower seed?

The rose-breasted grosbeak (RBG, Pheucticus ludovicianus) is slightly smaller than a cardinal (7—7½” or 18—21 cm) with a pale, conical but more zaftig bill… a chestnut to the redbird’s hazelnut. Of course, it’s natural for kin to resemble one another, and the RBG is, in fact, one of 17 species known as the “cardinal-grosbeaks.”* Grosbeak—from the French grosbec (gros thick + bec beak) is a bit of a misnomer for this striking black and white bird with a cherry cravat (the females prefer a more sedate, sparrow-like wardrobe). Compared to the schnozzes sported by some members of the Cardinalidae clan, the RBG has a proud but modest snoot.

Although not as common as its stop-light colored cousin, human development—and the fire suppression policies that accompany it—have caused forests to sprout where once only grasses grew, allowing the RBG to expand its breeding and migration range westward (although the Rocky Mountains have proven to be a tough habitat nut to crack).  They’ve become a more frequent visitor to backyard bird bistros, where they like to snack on safflower, cracked corn, and black-striped sunflower seed. Insects and fruit are part of their diet as well, but seeds account for the majority of their calorie intake, especially during winter months.

As the name suggests, red crossbills (Loxia curvirostra) are true specialists. At first glance you might think this is a bird in dire need of an orthodontist, but that oddly shaped bill allows them to force open conifer cones and extract the tasty nutmeat inside. The muscles that allow birds to bite down are stronger than the ones used to open their beaks. But unlike cardinals and grosbeaks, who can clamp down with great force on tough-hulled sunflower seeds (and tender, well-meaning human hands), the crossbill can wedge the slightly opened tips of its bill between the scales of a tightly closed pinecone and then bite down, pushing the scale up to expose the kernel.

The red crossbill is extremely dependent on conifer seeds—wildlife biologists refer to animals whose very existence depends on a narrowly-defined habitat or food sources as obligate species. Most granivores (seed-eaters) start their lives eating protein-rich insects, making a dietary change once they reach adulthood, but crossbills feed on seeds from nest-cradle to grave. Of course, there are risks associated with being a specialist… we’ve all been warned against “putting all your eggs in one basket.” But as long as long red crossbill by eugene beckes ccas you follow the advice of Mark Twain and “watch that basket!” there are benefits as well. For example, red crossbills can raise young any time of the year—even during winter—as long as the cone crop is abundant. I guess some nutty looking adaptations are really quite useful.

The Clark’s nutcracker (Nucifraga columbiana) has also used the reliable conifer nut to expand its breeding season. But this member of the Corvidae family (jays and crows) takes the idea even further. It is a hoarder, storing surplus pine, spruce, and hazelnuts. They actually have a special pouch under their tongues which they use to clark's nutcracker by Jamie Chavez cccarry seeds over long distances. A single Clark’s can hide as many as 300,000 pine nuts over the course of a year, and they use this cache crop to feed themselves and their nestlings. Research has shown they have a phenomenal memory and can find most of the seeds they’ve stashed, even months later.

Most… but not all; some of the hidden seeds germinate, re-establishing the bird’s favorite trees in areas cleared by fires or logging operations. It’s a sustainable harvest practice, however accidental, and a form of basket-watching that would make Samuel Clemens proud.

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* The grosbeak taxa is a conglomerate of distantly related songbirds known as a polyphyletic (“of many races”) group that we’ll explore in greater detail in future NDN posts.

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© 2011 Next-Door Nature—no reprints without written permission from the author. Thanks to the following photographers for making their work available for use through a Creative Commons license: ehpien (northern cardinal); Conrad Kulper (rose-breasted grosbeak); Eugene Beckes (red crossbill); Steve Wall (male and female cardinals); Trisha Shears (2nd red-breasted grosbeak); Eugene Beckes (2nd red crossbill);and Jamie Chavez (Clark’s nutcracker).  Figure A was made available through WikiMedia by Shyamal and Jeff Dahl.  Bird song mp3s files are in the public domain.

Stick in the mud

red-eared slider by Charles Lam cc

[This reprint was originally published on January 14, 2012.] 

Shorter days and Jack Frost nipping at your nose means it’s the start of the serious season, filled with snowplows, tire chains, and 10-pound sacks of clay litter that will never feel a kitty’s caress.  In many parts of the northern hemisphere, it’s a long slog through snow, sleet, and freezing rain to get from December to daffodils.

Understandably, we look to Nature for role models. Native people aren’t unique in their ability to draw a connection between human and non-human animals—Madison Avenue is especially canny at choosing charismatic creatures to impersonate our enviable and endearing (or at least humorous) characteristics.  Particularly at this time of year, when mercury can’t seem to bootstrap its way past 32°F, you’ll find a lot of furry sales reps pitching warm and cozy wares in magazines and newspapers, on television and online. I assume the general idea behind this trend is that raw, gray days bring out the hibernator in all of us mammals.

Not to split hairs, but that’s not technically correct. Humans don’t hibernate, but we do go through some behavioral changes at this time of year, at least so far as jobs, school, and the other routines and rituals of modern life allow. times square blizzard by Asterio Tecson ccFunny, how those cold weather coping strategies make humans look strangely reptilian. Just watch—next time the Weather Channel predicts a cold front, with or without a “wintery mix,” check out all the necks and heads tucked back into Gortex shells, peeking out from fleece hoodies, swaths of scarves, and turned up coat collars as they hunch toward the warmth of home. Do you think they look more like bears, or turtles?

Now, there’s a bit of Class warfare at play here because homeothermic (body temperature largely uninfluenced by the surrounding environmental) hominid mammals aren’t often flattered by comparisons to scaly, poikilothermic (body temperature influence by the surrounding environment) cold-bloods. Knowing this, and well aware that you, dear reader, will read my claim with considerable skepticism, I’ve got an example ready to back me up: a familiar and easily identifiable semi-aquatic turtle called the red-eared slider (Trachemys scripta elegans).Even nature neophytes will immediately recognize this species, a common resident of lakes and ponds in urban and suburban parks, as well as pet stores. Shell, legs, head and tail are inscribed with stripes and nested ovals of green and yellow, the “elegant script” referenced in its Latin name (although the vibrant colors do tend to fade somewhat with age and a thick coat of algae).

The red “ear” on either side of the head distinguishes the slider from all other North American turtle species and allows for a quick and definitive ID as they sunbathe on stones and logs. “Quick” being the operative word here; sliders don’t hear well, but they are very sensitive to vibrations that alert them to the presence of potential predators, and they can slip back into the safety of the water with surprising speed.

In the wild, the slider’s life cycle begins with courtship and mating as early as March or as late as July, depending on the region and the weather. Subsequently, the female heads for dry land to deposit a clutch of eggs, excavating with her hind legs to create a nest in the soil. Then she turns for home with nary a backward glance, and the turtles-to-be she leaves behind are on their own from that point forward. Two or three months later, depending on the average ambient temperature, hatchlings emerge from the nest and set out to conquer the world.

Most of them don’t make it past the first year—such is Testudine life… and death. Those who live to see their 2nd birthday, however, can reasonably expect a couple decades of celebrations, getting bigger with each passing year (females reach 10-13 in (25-33 cm), while males max out at 8-10 in (20-25 cm)).

In addition to predation, freezing temperatures are one of the biggest barriers to longevity that young turtles must navigate in the wild (HA! I’ll bet you thought I’d lost my original train of thought on winter and hibernation, didn’t you?).  No one expects to see a slider in a snowstorm, so it’s natural to assume they use sleep as a survival strategy.  Hey, it works for two of the most diverse Orders on Earth—Chiroptera (bats) and Rodentia (rodents)—so why not?sunning r-eared sliders by Alan Vernon ccBut reptiles take a different road.

Brumation is a period of decreased activity, but it doesn’t involve the extreme metabolic changes that occur during hibernation. ‘Round about October, as temperatures dip below 50°F, sliders begin to settle in at the bottom of their preferred body of water, or in some cases under stream banks and tree stumps, and just… hang out. They’re less social, they move a little more slowly, sleep a little later, watch more television (I’m sure there must be a turtle equivalent), and generally feel lethargic and unmotivated. On warmer days, they’ll drag themselves up from the depths to stretch their limbs, have some lunch, and catch some rays with a few friends… but as soon as old Sol goes into hiding they follow suit, retreating into their shells to become stick-in-the-muds until spring.

Social commentators have come up with any number of marketable catch phrases to describe the human desire to turn our backs on a less than hospitable world—cocooning, burrowing, vegging out, even hibernating. The admen (and women) may argue that it doesn’t have the same sizzle, but what we’re really talking about here is brumating.

Sound like anyone you know?

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© 2012 Next-Door Nature—no reprints without written permission from the author (I’d love for you to share my work; all you have to do is ask). Thanks to these photographers for making their work available through a Creative Commons license: Charles Lam, Asterio Tecson, Jim, the PhotographerAlan Vernon, and Jack Wolf.