City Creatures Guest Post

Looking for even more Next-Door Nature? Check out my guest post on the Center for Humans & Nature blog:

Hungry

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Terrier-boy transformed into a velociraptor before my very eyes!

We were walking along, minding our own business, when a momentary ruffling of leaves on the side of the pavement captured Dash’s attention and instinct took over…

head periscopes right…

ears swivel forward, nostrils flare…

field of vision narrows, eyes become lasers…

muscles tense into compressed springs…

in the pause between two heartbeats the chase is on!

 

AND…ended just as quickly by that damned ever-present leash. Grrrr.

 

Initially, I assumed Dash’s prey response had been triggered by a mouse or vole, maybe a chipmunk. Holding him back by the harness, I leaned in for a closer look without really expecting to see anything but fern and wood violet leaves; small rodents usually dive for cover when a predator is on patrol. They don’t risk a backward glance.

So I was surprised and delighted to see small, dark-bright eyes staring back at me from beneath an impromptu stone roof.  Not a rodent after all, but an insectivore. A northern short-tailed shrew (Blarina brevicauda) standing his ground against monsters (Dash and me) larger, in relative size, than a T-rex. Fearless!

Or maybe just hungry.

Thanks to an extremely high metabolic rate, the northern short-tailed shrew (let’s go with NSTS for the sake of brevity) has to eat every 2-3 hours to avoid starvation. That makes for a mighty motivated and efficient predator. I’ll bet you if an NSTS was invited to a screening of Jurassic Park, and saw how much time the velociraptors waste stalking kids in the kitchen, he’d be thinking, “Sheesh… amateurs!” Or maybe he doesn’t need to see the movie. According to the fossil record, shrew-like mammals arrived in time to observe real dinosaurs stomping around on planet Earth. Not this particular shrew of course, but it could be buried deep in his genetic memory.

Finding, catching, and eating earthworms, snails and slugs, spiders, insects, frogs and salamanders, mice and voles, along with some seeds and fungi, is a shrew’s full-time 24/7/365 job. Sometimes they even eat each other. All those meals add up to a daily grocery tab of three times the NSTS’s weight. Think of it this way: if Dash were a shrew, he’d need to eat nearly 65 lbs of food every 24 hours, and if I were a shrew I’d need to eat… well, it’s none of your business how much I’d need to eat.

This voracious consumer tips the scales, barely, at 15-30g (0.53-1.06 oz) but he and his kind are literally red in tooth (and only figuratively of claw). Unlike rodents, a shrew’s teeth do not grow continuously. One set of choppers has to last for their entire life, but red-toothed shrews (Soricinae) have helpful iron deposits that provide additional strength to the surfaces most subjected to wear and tear.

Insectivores are one of only three known living mammal Orders with member species that produce venom. The saliva of a NSTS can paralyze or kill prey, even some animals larger than itself. Nothing as large as a human or a dog, mind you, although the pain of a bite can last several days.

Toxic spit certainly comes in handy when it’s time to appease that insatiable hunger. But before you can bite your dinner, to immobilize or eat it, you have to find it. Often in low- or no-light conditions. Lucky for the NSTS, there’s this thing called echolocation. You would think, given how many terrestrial mammals live at least a partially subterranean life, echolocating would be a pretty common talent. You would be wrong. Only rats, the tenrecs of Madagascar, the solenodons, and three species of shrews, including the NSTS, are known to have this ability. Unlike bats (which, because they can fly, are not technically classified as terrestrial mammals), shrews use low-amplitude, multi-harmonic sounds rather than clicks. It appears these calls are used primarily to collect information about their habitat rather than to zero-in on a food source. Still, you can’t find your way to prey if you can’t find your way.

Even with venom and ultrasonic squeaks, life isn’t a picnic. NSTSs (and shrews in general) have a high mortality rate. Winter is particularly brutal, especially if the shrew in question doesn’t have enough cached food to carry it through the lean times, when mercury itself remains huddled in a bulb-burrow. Summer brings its own set of challenges; temperatures above 95°F (35°C) are deadly for shrews, causing the animals to shift their periods of above-ground activity, interfering with their ability to find their 8-12 square meals per day.

It goes without saying (but here I am saying it anyway) that even fierce predators are often prey as well. Shrews are no exception. Despite spending much of their lives hidden in subsurface tunnels, under leaves, leaf litter, and snow, NSTS become a meal, or part of a meal, for many species of fish, reptiles, birds, and mammals.

It’s a predator-eat-predator world out there and size isn’t everything. You’ve got to stay hungry. As the saying goes, it’s not the size of the dog in the fight that counts, it’s the size of the fight in the dog. Or the shrew. They’re still around, still hungry, and the only dinosaurs to be found are computer generated and animatronic.

I guess that settles any argument over who ruled on Isla Nublar, and who got voted off the island.

 

[Thanks to the following photographers for making their work available through the Creative Commons license: Gilles Gonthier, Goran tek-en, and snapp3r.  © 2017 Next-Door Nature. Reprints welcomed with written permission from the author.]

Slender in the Grass

[photo: josh more, ccl]

But never met this Fellow, Attended or alone, Without a tighter Breathing, and Zero at the Bone.

 

Unlike Emily Dickinson, ophiophobia isn’t an issue for me. I like snakes and know them to be upstanding ecosystem citizens… umm, ok, upstanding probably isn’t the best descriptor for creatures without legs but you get my drift.

Of course, I offer an extra measure of obeisance for any and all animals who engage in chemical warfare but their numbers are relatively few here in North America. Of the over 125 snake species endemic to my home continent, for example, only 21 are venomous. All 18 of the vipers have a distinctive triangular head, and the 16 rattlesnakes in this group are armed with an unmistakable warning system. The 2 coral snakes species found in the U.S. wear a color pattern that’s easy to recognize from further than arm’s-length, and since Blacksburg, Virginia, isn’t anywhere near the western coast of Mexico I don’t have to watch out for yellowbelly sea snakes.

[photo: greg schechter, ccl]

So if I happen upon a small garden hose that unexpectedly untangles and slips into the lawn I’m not chilled to the marrow. On the contrary — when I spot a green grass snake (Opheodrys spp.) passing by I’m likely to lean in cordially and say, “Well, hello gorgeous!”

And what comely creatures these colubrids are, with large, round eyes and a red tongue tipped in black.  Bright, nearly neon green above, accented with sunny yellow and ivory below, their color scheme is positively tropical despite the fact that they’re only found well above the equator.  Both the smooth (O. vernalis) and rough (O. aestivus) are slight and lithe. For this genus “rough” refers raised scale keels along the back and sides but, like all snakes, the skin of both grass snake species is satiny, not slimy.

Contrary to what the name implies, grass snakes don’t limit themselves to turf and terra firma. They are great climbers, moving with grace and prudence as they stalk insects and small amphibians through brambles, bushes, and trees. The many regional names given to this species testify to this fact, including: magnolia snake, huckleberry snake, vine snake, bush snake, and green tree snake. Grass snakes are also known to mimic small breeze-blown branches to blend into the surroundings while waiting for prey, or while attempting to avoid becoming prey to birds, mammals, and other snakes, including the eastern racer (Coluber constrictor) and the eastern king snake (Lampropeltis getula).

Grass snakes are good swimmers who are often found near water, in and around moist meadows and marshes, in riparian habitat as well as open forests and woodlands, as well as cities and suburbs.

Their willingness to live in developed areas puts grass snakes at risk of being persecuted by house cats, run over by cars and mowers, and they appear to be susceptible to pesticides as well.  These docile beauties haven’t gone unnoticed by the pet trade, sadly. Although Smooths are protected in some places, few states in the U.S. regulate reptile harvest.  Hundreds, perhaps thousands, of grass snakes are collected from the wild each year, making them one of North America’s most exploited snakes. This practice is particularly tough on Roughs because they are easily stressed and don’t do well in captivity.

Seems to me Emily’s reaction to spotting a snake is more appropriate and understandable from that narrow fellow’s point of view… don’t you?

[photo: greg schechter, ccl]

© 2017 Next-Door Nature. Reprints welcomed with written permission from the author.

 

Baby Blues

Fledgling blue jays begging Dad to make a pizza run [photo: christian lanctot, ccl]

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Identifying songbirds by their calls is not my forte.

Sure, I can distinguish most common backyard residents with distinctive voices, including mourning doves (Coo…. coo, coo), Carolina chickadees (Fee-bee-fee-bay or chickadee-dee-dee), American robins (Cheerily, cheer-up, cheer-up! Cheerily, cheer-up!!), red-winged blackbirds (Conk-la-ree!), and the northern cardinal (Birdie, birdie, birdie! Cheer, cheer, cheer! — no wonder the St. Louis baseball club chose this mascot). I can usually tell when a mockingbird is singing a cover tune because I realize the familiar song has a new arrangement.

The further afield I stray from my audio comfort zone, or the built environment, though, the more I rely on my eyes for ID.  That said, I have a niche talent, developed in the late 990s while I was running a large wildlife rehabilitation center in Houston, Texas: I can easily identify a wide range of bird species by the sounds their nestlings and fledglings make when a parent (biological or a stand-in human) arrives with food.

[photo: smilla4, ccl]

That’s how I found out it’s baby blue jay season here in southwest Virginia. I haven’t done hands-on rehab for a long while but as soon as I heard those competitively pitiful “Feed ME! Feed ME!” cries, I knew. Young blue jays used to come into the center by the shoebox-full so that particular call for attention is burned on my brain.

Adult blue jays aren’t the most popular wild neighbors. Jay parents will actively, even aggressively, defend their offspring and, well, there are always people eager to criticize the way others raise their children. Jays also have a reputation for eating the eggs and nestlings of other birds… true, but relatively rare. An extensive study observed this behavior in only 1% of jays. They certainly aren’t the only feathered folk who will help themselves to a snack from an unattended nest but jays, with their signature sapphire, white, black, and gray plumage plus that jaunty crest, are so recognizable they receive more blame than is warranted.

What’s less well-known is that blue jays are always on sentry duty, and when they spot a predator or other threat they shout an alarm call the whole avian neighborhood understands.

[photo: duluoz cats, ccl]

Mom and Dad have PR problems but their offspring are undeniably endearing. Jays are an example of true co-parenting. The female incubates a clutch of eggs for 17-18 days, and during this time and for the first 8-12 days after the nestlings hatch, the male provides all of the family meals. Blue jays can carry food in their gular pouch, an area in the throat and upper esophagus. Acorns are a favorite (which makes my throat hurt just to think of it!).  Once ambient temperatures are warm enough, and the kids are old enough to thermoregulate, the female will join her mate on grocery runs.

Every summer, young jays arrive in wildlife rehabilitation centers, veterinary offices, kitchens, and grade school classrooms across the species’ range. They’re an abundant urban bird so it isn’t surprising blue jays would account for a large number of rehab intakes, but there are other factors at play as well. Nestling jays often venture out of the nest and onto nearby branches several days before they fledge (take their first flight). Sometimes a storm or strong breeze will give gravity a helping hand and the branchers end up on the ground sooner than expected.

Mom and Dad aren’t going to give up on Junior just because s/he made an ill-advised decision. They’ll continue to feed and monitor their children — both the wanders and the cautious ones who wait for their feathers to grow a bit longer before taking the plunge — for up to 2 months after the nest is empty. While the fledglings learn to fly they’ll be left alone at times, albeit usually within watching distances of their keen-eyed supervisors. The young ‘uns don’t mind but well-intentioned humans may find it harder to accept. One of the downside of looking winsome is that when people see you sitting on the ground or perched on a low branch, seemingly abandoned, they really, really want to help.

You’ve may have heard this Good Samaritan tune before but I’ll sing it again…

First, do no harm.

If you find a baby bird and think it might have been abandoned:

  • Wait and watch for the parents to return. In the case of a blue jay, an adult may actually dive bomb before you get very close to their precious child but not all species or individuals are that confident so be sure to give everyone plenty of room to feel safe.
  • If the bambino is well-feathered, bright-eyed, and looking around curiously, give the parents at least 60-90 minutes to return.
  • However, if the little one is clearly injured, or very young (naked or barely feathered, eyes closed), then it’s time to take action.

[photo: katrina j houdek, ccl]

Permitted wildlife rehabilitators will never be able to match the skills of a wild parent but they are trained to provide the proper nutrition and environment wild kids need to grow up healthy and strong, knowing they are blue jays (or Cooper’s hawks, or squirrels, or deer, or whatever they are) instead of people, and capable of living in the wild once they’ve been released.

The International Wildlife Rehabilitation Council website can help you access assistance, and if you’re based in the U.S. there’s a free app for iPhone and Android called Animal Help Now. You don’t even know be able to identify the bird, by sight or by sound, to make the call.

 

© 2017 Next-Door Nature—no reprints without written permission from the author (I’d love for you to share my work  but please ask).

Near and Distant

[Photo: Steven Crane, CCL]

African elephants (Loxodonta africana) aren’t usually considered an urban wildlife species but I’d come a long way and wanted to see them while I was in South Africa. The built environment just doesn’t have the amenities Earth’s largest living terrestrial mammal needs to feel at home.  Africa’s elephants prefer dense forests, woodlands, deserts, and even the transition zones between these biomes to urban canyons and suburban savannah. Lucky for me, this study abroad excursion included several days at the Shamwari Game Reserve near Port Elizabeth in the Eastern Cape.

[© Gil Sinclair 2013, used with permission]

I also had the good luck to meet some relatives of the elephant while in Cape Town.  The rock hyrax (Procavia capensis) has found it much easier to adapt to city living than its country cousin.  I suppose concrete looks pretty familiar when boulders are your preferred abode. It also helps when you look much less threatening to the human neighbors throughout the hyrax’s Middle Eastern, sub-Saharan, and southern African range than their towering relatives.

Up on Table Mountain, which overlooks the city, hyraxes were everywhere: scampering along the pathways, basking on benches, happily whistling to one another, and enjoying the sunset from rocky precipices. Ignoring humans while living alongside them can be a good survival strategy for urban wildlife, and the hyraxes showed little interest in the two-footed visitors… unless some tourist with a camera decided to force the issue. Attempts to get the affable-looking creatures to pose were met with low “bug off!” grunts.

[© Gil Sinclair 2013, used with permission]

The family resemblance certainly isn’t obvious at first sight but keep in mind that the genealogical tree branched out millions of years ago.  Let’s start with stature:   adult elephants stand 10-13 ft (3-4 m) tall at the shoulder and may weigh over 8 tons, while an adult hyrax measures up at about 8-12 in (20-30 cm) and tips the scales at a whopping 8-9 lbs (4 kg).

Elephants have very little hair while hyraxes are covered in short taupe fur and long guard hairs that function like a cat’s whiskers.  With their small round ears it’s easy to see how they could be mistaken for a large guinea pig (rodent) or pika (cousin to rabbits and hares). Maybe that’s why they have so many aliases; in South Africa they are called dassie (Dutch for badger) or klipdas (Afrikaans for rock badger), Swahili speakers know them as pimbi, and in the King James Bible they’re referred to as coney (Middle English and Anglo-French). Even “hyrax” is misleading, originating from the Greek word “hyrak” or shrewmouse.

Taxonomists know you shouldn’t judge a book, or a beast, by it’s cover. Look beneath the binding and you’ll find a different tail. Make that tale.  For example:

  • [Photo: Andy Withers, CCL]

    Hyraxes don’t have trunks but they do have small pointed tusks and can deliver a ferocious bite when cornered.
  • Like elephants, hyraxes have flat, hoof-like toenails rather than curved claws.
  • Both are social mammals; elephants live in herds of up to 100 individuals, hyrax colonies can have up to 50 members.
  • Both have long gestation periods (22 months for elephants, 7-8 months for hyraxes) and offspring are slow to reach maturity.
  • Elephant and hyrax newborns are precocial, relatively mature and mobile shortly after birth.
  • Both species employ cooperative care for raising young. Elephant calves are tended from birth by both their mothers and other females in the herd; and hyrax pups are greeted and sniffed by the entire colony the day after they’re born.
  • Females stay with the group their entire life; males disperse.
  • Male elephants and hyraxes don’t have a scrotum; their testes remain in the abdomen even after sexual maturity.

The differences between elephants and hyraxes are more than skin deep, too.

  • Elephants must drink up to 50 gallons of water per day; rock hyraxes can survive for long periods on just the water they obtain through their food (although they dehydrate quickly in direct sunlight).
  • Neither animal is a ruminant, but hyraxes have a complex three-chambered stomach; elephants have a simpler but less efficient digestive system.
  • Hyrax stomaches are filled with symbiotic bacteria that help break down plant material; elephants have to consume up to 300 lbs of food per day, in part because they aren’t able to extract much nutritional value from what they eat.
  • [Photo: Abri du Plessis, CCL]

    An elephant spends a good portion of each day filling its stomach with food and water; rock hyraxes are world-class loafers who are inactive 95% of the time.
  • Hyraxes have poorly developed thermoregulation compared to other mammals so they need to sunbathe for several hours each morning to warm up and won’t venture out of their shelters on cold or rainy days. Elephants have to work at staying cool; they don’t sweat or pant but their large ears help to dissipate heat and they’ve developed a temperature regulation strategy that involves storing heat during the day and releasing it at night, similar to camels and desert rodents.
  • Elephants have a sixth “toe” and their feet have large subcutaneous cushions that distribute weight and absorb mechanical forces; hyraxes have a more flexible foot with a rubbery pad in the center that can be raised to create a suction-cup for clinging to rocks and moving across slick surfaces without slipping.
  • African elephants have no natural predators as adults (they have a decided size advantage) but their calves are vulnerable to attack by lions, crocodiles, leopards, and hyenas. Hyraxes have many predators and, as such, they feed in a circle formation, heads facing outward, eyes scanning for danger.

I’m told that most tourists who have a safari on their bucket list focus on the iconic African Big Five — elephant, rhinoceros, Cape buffalo, lion, and leopard.  I’d be the first to agree they’re all worth seeing in their natural environment, with no bars or moats to limit your view. Or theirs. 

But I find celebrity tours less interesting than exploring on my own.  I like to switch to hyrax-time, wander through neighborhood, sit at a sidewalk cafe or bask on a park bench and watch the residents, human and non-human alike, go about their day. Taking note of what makes us different and all the ways we’re related, despite the distance. 

© 2017 Next-Door Nature—no reprints without written permission from the author (I’d love for you to share my work  but please ask).

Town Crier

Hartlaub’s gull [photo: Paul Barnard Fotografie ccl]

My flight into Cape Town landed early last night, just before 9p. That was fine by me since, by that point, I’d been on the plane about 11.5 hours, and in transit from Blacksburg for about 31 hours.  For the next 10 days I’ll be co-leading an international field experience for some of my students in Virginia Tech’s Master of Natural Resources program.

The shuttle pulled up to the hotel and I stepped out into a well-lit courtyard. Then, less than one hour into my first trip to the continent, I had my first encounter with the urban wildlife of South Africa.

I could hear but not see birds overhead. Lots of them.  It sounded like some kind of Corvid, squawking as if they’d just spotted treasure in the form of an untapped dumpster or fresh roadkill.

I checked in at the front desk and headed up to my room on the third floor with every intention of proceeding directly from the door to under the covers. Actually, I detoured to the shower, then bed.  I wasn’t expecting to continue hearing an avian play-by-play going on outside the window but, of course, now I was closer to the commentators’ booth. Still, tired as I was, I knew a few birds weren’t going to keep me awake. I figured the din would die down as soon as everyone settled in to dine.

Boy, did I flub that call.

The birds were still going strong when I woke up this morning so I decided to see for myself who had stayed up all night talking.  Not crows or ravens, as I’d thought. Gulls.  I’d forgotten that the hotel overlooks Table Bay.

[photo: Harvey Barriston, ccl]

Gulls are notoriously difficult to identify to species. They often have several years of varying adolescent plumage before they reach adulthood and stop trying out different looks. For that reason I wasn’t expecting to get a definitive answer when I did a little research on the gulls of South Africa, even though I could see some of them quite well  as they stood preening in the morning sunshine on the roof across the courtyard. Identification turned out to be a snap, though, as there aren’t that many different kinds of gulls here. The urban birds who welcomed me to Cape Town under cover of darkness were Hartlaub’s gulls (Chroicocephalus hartlaubii).

The Hartlaub is a small, non-migratory gull found along the coasts and estuaries of South Africa and Namibia.  Also known as the king gull, and once considered a subspecies of the silver gull (C. novaehollandiae), this urban homebody doesn’t stray far from land, and nearly half of the species’ total population rarely leaves the Cape Town area.

Primarly white with a gray back and black-tipped gray wings, the usually white head is hooded in very pale lavender gray during breeding seasons. The traditional chick-rearing colony is Robben Island, infamous as the place where former South African President and Nobel Laureate Nelson Mandela spent 18 of the 27 years he was imprisoned prior to the abolishment of apartheid.

[photo: Derek Keats, ccl]

Common in its range, the Hartlaub is nonetheless a relatively rare species in the global gull panoply. They’re known for being quite social and talkative in the fall and winter months–that’s right now in the Southern Hemisphere (I can vouch for that assessment). I’ll admit, I felt exonerated for making a faulty ID last night when I read that this gull’s call has been described as “crow-like.”

Hartlaub’s gulls readily habituate to the presence of humans and have learned to exploit our built environment so well they’re considered a nuisance in Cape Town, and a hazard at the local airports (I could have easily waited to learn that nugget of information until after I’m back home).

© 2017 Next-Door Nature—no reprints without written permission from the author (I’d love for you to share my work  but please ask).

Runner-up

Two male turkeys audition but fail to impress the judge (Photo: Teddy Llovet, Creative Commons license)

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I don’t know what American grade school kids are being taught these days—I left Oakville Elementary a couple of decades ago (okay, fine—several decades ago) and since I haven’t had kids of my own I don’t have access to 21st century homework assignments. But I’ll go out on a limb here and bet that most of them know the bald eagle (Haliaeetus leucocephalus) won the 1782 version of American Idol, and that it did so by edging out celebrity judge Benjamin Franklin’s favorite contestant, the wild turkey (Meleagris gallopavo).

That long-ago contest had little in common with the popular modern day version of reality TV. For one thing, neither bird has great pipes. Citizens were never asked to call or text in their votes. Also, the bald eagle has held on to national fame longer than fellow white-headed winner Taylor Hicks, while the turkey hasn’t exactly proven the voters wrong by, say, winning an Academy Award, Jennifer Hudson-style.

On the other hand, we don’t set aside a day each November (or any month, for that matter) on which the eagle takes center stage.  So in honor of Thanksgiving, I’d like to briefly sing the praises of the runner-up… and not just as the star performer at a holiday dinner.

Shortly after Congress immortalized the eagle on the Great Seal of the United States, Franklin shared his disappointment and misgivings over their choice in a letter to his daughter. Given the sparse pelt on his own pate, one might expect ol’ Ben would view the bald eagle as a kindred spirit, or at least harbor a bit of sympathy. Instead, his criticism was as harsh as any doled out by Simon Cowell, describing our new national symbol as “a Bird of bad moral character” who “does not get his Living honestly,” preferring to sup on rotting fish or, worse yet, stealing fresh seafood from more industrious raptors like the osprey (Pandion haliaetus). What’s more, Ben argued the eagle is cowardly, evidenced by how easily it can be driven away by much smaller birds defending their nests and offspring. Not exactly the role model image our fledgling country hoped to cultivate.

The turkey, according to Franklin, is “in Comparison a much more respectable bird,” a “true original Native of America” and a “Bird of Courage” who “would not hesitate to attack” any invader and defend his home turf.

This description might not square with your expectations after years of holiday stories featuring dim-witted, less than inspiring  Butterballs-to-be but the domestic turkey is but a pale and passive imitation of the real-deal.

Wild tom turkeys (as the males are called) will most definitely defend their breeding territory against potential rivals. Large and heavy, they are unexpectedly agile flyers, aggressive fighters, social, sometimes playful, intelligent, and adaptive.  To my knowledge they’ve never been accused of theft or caught dining on carrion (their omnivorous diet consists primarily of acorns and other nuts, seeds, fruit, buds and leaves, insects and the occasional small reptile or amphibian).

As far as moral character goes… well, you know rock stars. Toms strut their stuff in a flamboyant palette of iridescent red, green, purple, copper, bronze, and gold feathers worthy of Adam Lambert. No piercings or tattoos, but oozing cool with a Beat-worthy statement beard of stiff bristles starting just above the wishbone, wattles (flesh hanging from the head and/or neck), caruncles (fleshy growths on the head), snoods (long fleshy object draped across a tom’s beak), spurs and other body art. Their ladies, in keeping with general avian fashion trends, tend to be more conservatively dressed but they can strut like a runway model  when warranted, complete with long legs and outlandish makeup. Out of the spotlight, turkey hens are attentive mothers to their precocial offspring, in contrast to the menfolk, who are polygamous absentee fathers.

(Male bald eagles, it must be said, are actively involved in their children’s upbringing; given his own reputation, Ben might have been well served to heed the old saying about people who live in glass houses before he cast the first stone.)

Like the bald eagle, wild turkeys experienced a perilous decline in their numbers during in the last century, due to overhunting and habitat loss (rather than DDT exposure, as was the case for so many of our birds of prey).  Game agencies took action to protect the species and have been successful in helping the population rebound. So much so, in fact, that turkeys have not only returned to rural fields, pastures, and woodlands but have begun to tour in many major metropolitan areas as well.  In some parts of the country spotting a flock of wild turkeys foraging near a highway, hanging out downtown, or feasting at a backyard bird feeder is no longer a novelty.

That means a growing number of Americans now have a ticket to see  this national treasure up close and personal more than once a year, and at venues other than a serving platter.

For that, I am thankful.

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love-earthThis blog, like so many activities that foster support and appreciation of the natural world, is a labor of love. If you’ve enjoyed learning about the creatures who share our built environment, consider becoming an NDN Benefactor with a donation of any amount you’re inspired to give. If you’d like to find a little Next-Door Nature surprise in your inbox just click the Subscribe!  button in the upper right-hand corner of this page and receive notifications of new posts!

© 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: Teddy Llovet (cover); keeva999 (turkey in flight); Mic Stolz (plumage); Peter Patau (men).

Size matters

Next-Door Nature, toucan, song sparrow, beak size

When you’re trying to stay cool without air conditioning, it helps to carry a radiator on your face, large or small (Photos: Ame Otoko and Cephas, Creative Commons license).

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A scientists’ work is never done.

That’s because there’s always another layer to peel away, another stone to turn, another angle from which to view the situation.  Case in point—nearly 200 years ago, Charles Darwin made the connection between the size and shape of a finch’s beak and the availability of the seeds they eat; to this very day, no one has been able to produce evidence that undermines his observation and the conclusions he drew from them.

But what if there’s more to a beak than meets the eye?

That’s the question raised by Russell Greenberg of the Smithsonian Conservation Biology Institute. His theory—that beak size may also be an adaptation to temperature regulation and water conservation—has been bolstered by data from two recently published studies.  [Data collected, in part, by a newly minted PhD named Ray Danner. Ray just happens to be a member of my own adopted extended family, and if that name sounds vaguely familiar… well, regular NDN readers may remember that not too long ago I was bragging about another member of this ornithological power couple, Ray’s wife, Dr. Julie Danner.]

black-tailed jackrabbitSome years back, Greenberg noticed a difference in size between the beaks of sparrows living in salt marshes and those of sparrows settled just a kilometer or two further inland. Then a paper published in 2009 reported toco toucans (Ramphastos toco) may lose as much as 60% of their body heat through their long bills, based on thermal imaging and similar to the role played by the large ears of both elephants (Elephantidae) and jackrabbits (Lepus spp.). While many ecologists assumed toucans were a special case, Greenberg wondered—might other birds have evolved larger or smaller beaks to discharge or conserve heat as well?

He chose to test his hypothesis by applying thermal imaging to a subject with a much less prominent proboscis—the song sparrow (Melospiza melodia).  Native to North America, everything about these feathered minstrels is miniature compared to their South American kin. The toucan weighs in at 1-2 pounds (the large bill doesn’t actually tip the scale as much as you might think since it’s mostly hollow) while at 0.4—1.9 ounces the song sparrow is definitely a featherweight.

In the first study, two subspecies were examined. On average, the beak of an Atlantic song sparrow was found to have 17% more surface area than that of the eastern song sparrow, although both birds have similarly sized bodies. Based on the Greenberg team’s calculations, the Atlantic sparrow loses 33% more heat than it’s inland neighbor. The finding suggests beaks may play a role in thermoregulation for a wide variety of bird species.

The ability to stay cool when the ambient temperature rises is critical to survival, but how one gets rid of the excess heat is just as important.  Birds don’t sweat—they pant… and lose not just heat but water in the process. This summer, residents across the U.S. have been reminded just what a precious resource water can be, and never more so than for all the creatures without easy access to a faucet.  Greenberg and his colleagues suggest that a bird’s beak can function like a radiator, releasing heat without losing water. The Atlantic sparrow’s larger bill saves the bird about 8% more water than the smaller beaked eastern sparrow. That may not sound like much but during a hot, dry summer it could be a significant survival advantage.

The second study examined museum specimens of song sparrows collected on the other side of the continent, along the California coast. Sure enough, as maximum temperatures increase, so did beak size… with one caveat.  When the maximum temperature was higher than 98°F (37°C) beaks got smaller… just as was predicted by the original hypothesis. You see, if you took a song sparrow’s temperature the thermometer would read about 105°F (41°C). When the air temperature exceeds the bird’s own temperature, as it does in some regions, a larger beak could actually begin to absorb heat.

While the Smithsonian group has demonstrated a connection between climate and beak size, there’s still plenty of work to be done. For the new hypothesis to garner support, scientists need to see data that ties survival of wild birds to beak size-related heat dissipation.

Meanwhile, the fact that diet influences beak size and shape hasn’t changed—Darwin can continue to rest in peace. But as so often is the case, the more we discover the more we realize just how rich and complex this world and its inhabitants are … even an Earthling as seemingly plain and simple as a sparrow.

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love-earthThis blog, like so many activities that foster support and appreciation of the natural world, is a labor of love. If you’ve enjoyed learning about the creatures who share our built environment, consider becoming an NDN Benefactor with a donation of any amount you’re inspired to give. If you’d like to find a little Next-Door Nature surprise in your inbox just click the Subscribe!  button in the upper right-hand corner of this page and receive notifications of new 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 the top] Ame Otoko (toco toucan); Cephas (song sparrow); James Marvin Phelps (black-tailed jackrabbit); Mr. T in DC (house sparrow on drinking fountain); David Craig (song sparrow in hand).