Category Archives: mammals

Track & Field

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cottontail leaping

Back to school, and to early morning practice before class – hop to it!

[Students are returning to my university town for the start of another academic year… so in honor of college athletics I’m offering a slightly-edited instant replay of this post about cottontail rabbits that originally ran back in April 2011.]

On your mark…. Get set… HOP!

An article I read while eating breakfast had me thinking about track meets as the terrier-boy and I set off for our morning walk.  That piece may be why I noticed, for the first time, how runners imitate the posture of a rabbit as they settle into their starting blocks. Human runners have to fold themselves up to gain the potential energy advantage of a crouching leg, but rabbits are always ready for the starting gun.

sprinters

In 2009, Usain Bolt set a record of just over 23 mph in both the 100- and 200-meter, but he’s an exception even among world-class athletes. It’s nothing out of the ordinary for Sylvilagus floridanus to reach speeds of 18 mph, and they can maintain that speed for close to 800 meters… while zig-zagging to change direction every few strides. Let’s see Bolt try that!

racing cottontailsMost sprinters are specialists, but cottontails and other Lagomorphs, with the exception of pikas (Ochotona princeps), also excel at hurdles, steeplechase, and in some field events. Okay, they can’t throw a javelin or a shot-put, but they leap to the top of the score board when it comes to jumping.

leaping cottontails

Longing to see a long jump? At first glance, a cottontail’s 4.8 m (15 ft) may not sound too impressive when compared to current world record holder Mike Powell’s 8.95 m (29.4 ft), set in 1991. But consider this: a 4.8 m leap is 10x the average length of an adult cottontail’s body; 9 m is barely 5x the average height of an adult American male.

How high can they flycottontail courtship? The men’s high jump record stands at 2.45 m (8 ft), set in 1993 by Javier Sotomayor of Cuba. That’s only 1.4x the average height of Olympic jumpers. While courting, both buck (male) and doe (female) cottontails will jump 0.6 m (2 ft), nearly twice their height, to demonstrate worthiness. By that standard, not even elite human athletes would be able to find a mate.

cottontail courtship 2Once the mating ritual (which also includes a little boxing, just to keep things interesting) is complete, 1-12 kits are born approximately 28 days later. A doe will often mate again within hours of giving birth—what a woman! Admittedly, she’ll only visit the nursery when it’s time to feed the kids so she’s not going to win any “most attentive mother” awards. But, to be fair, compared to her baby-daddy she’s a doting parent, and staying away keeps predators from getting wise to the location of the nest. It will take her 3 weeks to wean one set of youngsters, then she’s got about 1 week to recuperate before the stork arrives again.

Still not impressed? She may have up to 7 litters in a single year.  Now, I call that a marathon.

[Thanks to the following photographers for making their work available through the Creative Commons license: Porsupah Ree, Rob Helfman, and Michale Connell.  © 2011 Next-Door Nature. Reprints welcomed with written permission from the author.]

Street Creatures – August 25, 2017

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Last week of Ocean Life Appreciation Month at NDN… and who better to represent life in the seas than a bottlenose dolphin, enjoying the beats near Deep Ellum in Dallas, Texas, USA (photo: matt griffin, cc by-sa 2.0)

Oddly Normal

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I don’t live far from the eclipse’s Path of Totality, but I decided to stay put just the same. I didn’t even order eclipse glasses. I know there will be plenty of great video to watch throughout the day, and since my sweetheart is a talented professional videographer, I feel like I’ve got that angle covered.  I want to focus on what’s going on down under, here on Earth.

In anticipation, I’ve been reading stories about how the event will impact wildlife. Every single one of these reports has focused on the “strange” animal behavior we can expect to witness as the day goes dark… and I find that very strange indeed.

What these experts are calling odd is considered completely normal activity when it happens each evening. And from the descriptions I’ve read about what to expect, assuming night is nigh would be a perfectly reasonable assumption for any creature—human or non-human—who doesn’t have a television or an Internet connection and, therefore, doesn’t know that the sun will be playing hide-and-seek with the moon for a little while today.

Humans tend to be less familiar with nocturnal species than the ones who are active during regular business hours. I think the eclipse is going to offer a chance to get to know our neighbors who work the night shift… kind of like a rerun of the National Night Out that took place earlier this month.

As the light begins to dim, creatures who are active during the day may start their usual bedtime routines.  Some diurnal birds will sing one last serenade to the daylight as faux-evening falls…

…some will hurry back to nests of eggs or chicks…

…others will congregate for mutual protection, as they do at the end of every day.

Birds who love the night life will wake, possibly feeling less than rested but still ready to boogie in search of an early breakfast (or late dinner, depending how you look at it).

Some wild mammals are active and visible during the day, including a fair number of rodents such as tree squirrels, groundhogs, prairie dogs, and chipmunks. I’m expecting the eclipse to be a great time to see mammals who are usually waking up just as I’m starting to wind down…

Insect musicians will surely want to set the mood with a tune or two.

Fireflies know a little night music calls for romantic lighting…

…and amphibians aren’t about to let the invertebrates steal the limelight!

As the skies brighten we’re also likely to have a second dawn chorus… but without needing to get up before sunrise! So don’t despair just because the eclipse will pass your part of North America by, or because you don’t know how to make and use a pin-hole camera (even after you Google’d instructions). There should be some amazing wildlife sights to see, right here on good ol’ terra firma.

 

[Thanks to the following photographers for making their work available through the Creative Commons license: Eric Kilby, Dan Dzurisin, Ingrid Taylar, Pat Gaines, Rachel Kramer, Will Wilson, Tony Oldroyd, Michael Eisen, Elizabeth Nicodemus, USFWS, tsaiian, David Huth, and Ingrid Taylar.  © 2017 Next-Door Nature. Reprints welcomed with written permission from the author.]

King of the Road

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[Here’s an oldie but goodie from back in 2010, with minor updates.]

There’s a wonderful word—one of my favorites— to describe creatures that are active at dawn and dusk. Crepuscular. It’s a popular time of day for many species, so the great outdoors gets lively when the light is low, and it’s a great time to see wildlife.

That is, unless you’re in a car.

Challenging light conditions can conceal an animal near the road and reduce a driver’s response time when something darts out. While driving at twilight, it’s important to scan the shoulders for movement or for the telltale shine of eyes reflecting headlights. Vehicles are a constant threat to wildlife, and my time running a large urban rehabilitation center provided more than enough evidence to support that claim.

Of course, I should know better. But, lost in thought on my way to the mall, I didn’t see the striped skunk (Mephitis mephitis) until he had sauntered into the middle of my lane. It wasn’t a major thoroughfare so I had the road to myself and, luckily, I wasn’t going very fast. I had time to cede the right of way. Good thing, too, because I knew better than to expect this black-and-white tough guy to blink. Fact is, he stopped and turned to stare down my Subaru.

The great horned owl is a striped skunk’s only one serious predator. Everyone else makes a wide detour, at least after being sprayed the first time. Since this particular crossing guard was a kit, the whole world has maintained a respectful distance—why wouldn’t he expect an automobile to follow suit?

If there’s enough time, skunks will usually give those who cross their path fair warning. According to mephitologist (skunk scientist) Jerry Dragoo of the University of New Mexico, a whole series of threat behaviors may occur before Pepe le Pew resorts to firing the big gun. Striped skunks will stomp both front feet, charge forward a few steps and then stamp, or back up while dragging their front feet before spraying the object of their wrath. They can discharge their weapon while looking you in the eye, using an over-the-shoulder stance or even a handstand.

I’ve heard stories in which a skunk was taking his or her time crossing the road, or was dining on some previously flattened wildlife, and clearly saw the car coming. Drivers have reported observing the kind of threat posturing described by Dr. Dragoo, although they did not recognize it as such. As their vehicle drew closer and closer, they wonder why the animal just stands there. Surely it will scurry off the road… any second now!

Instead, the skunk holds its ground, takes aim, and fires… and in the process becomes another scavenger’s meal.  Gone, but not forgotten.  Not until the fragrance fades, at least.

I’ve got good skunk karma, I guess. Either that, or this particular stinker was feeling mellow. Thirty seconds of holding my breath… then he decided to continue on his way and I escaped getting doused. My luck ran out a few minutes later at the mall, though. Still thinking about my skunk encounter, I swear I never saw that perfume saleswoman stamp her feet.

 

[Thanks to the following photographers for making their work available through the Creative Commons license: Desert Museum, TJ Gehling, and USFWS Mountain-Prairie.  © 2017 Next-Door Nature. Reprints welcomed with written permission from the author.]

Street Creatures – August 4, 2017

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As a counterpoint to last month’s Shark Week race between a Great White and former Olympian Michael Phelps, August is Ocean Life Appreciation Month here at Next-Door Nature.  Decidedly less jump-the-shark melodramatic… this week, we pay tribute to the endangered North Atlantic Right Whale. There are less than 400 remaining, not counting this individual who is receiving some love as s/he sails through Brighton, UK (photo: duncan c, cc by-nc 2.0)

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.]