Saturday morning I was biking with the Twins in St. George. No, we weren’t mountain biking; St. George, and neighboring Santa Clara have a wonderful networks of paved bike paths running all over the place. They pass through neighborhoods and pretty open spaces featuring slickrock outcrops, lava fields and shrubland, and are perfect for a parent who wants to bike with his kids while not worrying about traffic.
Here’s a quick clip of a typical stretch of path. Most of the shrubs along here are Thread Snakeweed, Gutierrezia microcephala (also called “Matchweed), Winterfat, Ceratoides lanata (also called “White Sage”), or Spiny Hopsage, Grayia spinosa.
Early on in the ride we spotted this- a Roadrunner* (pic below, right).
*They move fast and don’t sit still for long. As such, only this photo is mine.
We got a good look at him zipping about, and the early wildlife sighting got the ride off to a good start. Now, when we spot wildlife as a family, I always try to tell the kids something interesting about whatever it is we’re seeing. With Bird Whisperer this is getting tough; it’s likely he already knows more about any bird or mammal we see than I do. But with the Twins I can still usually manage to impart a new factoid or two. So I thought about Roadrunners and what I knew about them, and as I did so realized that I knew the following “facts”, all of which I had gleaned from watching ‘Roadrunner” cartoons in my formative years:
1- Roadrunners have 3 toes per foot, 2 facing forward, 1 backward (see pic right).
2- Roadrunner run faster than coyotes.
3- Roadrunners cannot fly.
4- Roadrunners are herbivorous, subsisting primarily on birdseed.
5- Roadrunners say, “Meep! Meep!”
6- Roadrunners inhabit Monument Valley, Canyonlands National Park, and other areas of the Colorado Plateau Semi-Desert, as evidenced by the numerous and frequent sandstone monoliths appearing in the cartoons*.
*And which frequently play a role in the demise of the pursuing coyote.
So as you can see, I knew quite a bit about Roadrunners. Unfortunately, every single one of those “facts” is flat-out wrong.
Tangent: Was anybody else besides me rooting for the coyote? I never sought out the cartoon; it was one of several packed into the “Loony Tunes” hour I watched religiously every Saturday morning growing up. When a Roadrunner segment would come on I’d wince. Because I knew what was going to happen: the coyote would never catch him, and would die- and apparently be reincarnated*- like 10 times while trying, and the roadrunner would never get caught and he would always be all smug and snarky-like about it. And it wasn’t like the coyote wasn’t trying; he’d get some big box delivered from Acme, Inc. and he’d be all excited, the way I am when a box of bike parts shows up in the mail, and he’d come up with some catapult or rocket or giant spring but it just never worked out- usually for no good reason. As a perennial mechanical hack, my sympathies were firmly with the coyote**.
*Really, what was up with that? Was the coyote supposed to be a metaphor for Jesus or something? Or maybe he was just a precursor to Kenny in South Park…
**And still are, despite that biting incident.
But I could never look away. It always turned out the same, but each time, some little voice inside my 10 year-old head would say, “Maybe, just maybe, he’ll catch him this time! I can’t break away to pee or get another bowl of Quisp now- this could be it! I might miss it!” But of course it never turned out any different, and I think another little piece of my fragile 10 year-old soul died with each episode. Man, I hated that f$@#ing bird.
Wow, I started this tangent thinking it would be all light and whimsical, but it turned out kind of Nietzsche-meets-Janis-Joplin. That’s the thing with tangents- when I start them I really have no idea where they’re going.
All About Roadrunners
But I know where this post is going. The Greater Roadrunner, Geococcyx californianus (pic right, not mine), is common to the Southwestern US and Northern Mexico. It’s actually a Cuckoo, or more specifically, one of the 142 species of bird comprising Cuculidae, the Cuckoo Family. There are cuckoos of one sort or another all over the world, on every continent except Antarctica. If you know anything about Cuckoos you probably may be familiar with them as brood parasites, sneakily laying their eggs in the nests of other species, but most of the cuckoos involved in that monkey business are Old World Cuckoos*. Geococcyx is one of 4 genera in the subfamily Neomorphinae, or New World ground-cuckoos, and the Greater Roadrunner is the only member of this subfamily found in the US.
*The common avian brood parasite around here is the Brown-Headed Cowbird, which is not a cuckoo at all and which we checked out during Bird Feeder Week last January.
Side Note: The Lesser Roadrunner, G. velox, looks almost identical but a little smaller. It lives down in Mexico in a couple different areas, including the Yucatan Peninsula. So if you go to Cancun and do a day-trip to Chichen Itza, keep an eye out while driving that (phenomenally boring*) toll road to get there.
*The Northern Yucatan is flat as a pancake and covered in dry, view-obscuring, scrub forest. Driving solo across the peninsula in a VW Bug without radio or CD player- as I did several years ago- is mind-numbingly dull…
This brings us to the first bad “fact”. Roadrunners don’t have 3 toes; they have 4. The inner 2 toes face forward, while the outer 2 face back. This arrangement, called Zygodactly, is common to all members of the Cuckoo family but is not (quite) unique to them. It also occurs in parrots, woodpeckers and owls and seems to be an effective foot-form for grasping trunks, branches and twigs.
With roadrunners it’s been adapted to running, and, true to the cartoon, that’s what roadrunners do, usually preferring a sprint to flying.
Where the cartoon gets it wrong on the running part is around the bird’s relation to coyotes, or predators in general. Roadrunners (pic left, not mine) can sprint up to 18 – 20 MPH, but a sprinting coyote can beat 30MPH. So the scenes you see in the cartoon of the coyote closing in on the roadrunner, then the roadrunner saying “Meep! Meep!” and then kicking in the afterburners and leaving Wile E. behind are bunch of baloney. In the real world, a roadrunner being chased by a coyote will just fly away. Roadrunners aren’t great flyers; they don’t do it well or far, but they can get airborne for a few minutes, which is often all it takes to evade an oncoming canine.
But roadrunners overwhelmingly run (or jump) (vs. fly) to hunt. And this brings us to the fourth bad “fact”: Roadrunners are omnivores, and aggressive, skilled hunters. They routinely hunt small rodents, scorpions, tarantulas and small reptiles, including- get this- rattlesnakes! No, they’re not immune to the venom, just fast. And clever. Roadrunners are usually solitary birds, but they’ll often pair up to take on a rattler. One will feint and distract the snake while the other goes in and nabs it behind the head with its beak.
Once caught, the roadrunner dispatches its prey by repeatedly bashing its head in against a rock. Not quite like the cartoon, eh?
Roadrunners also regularly hunt at or around suburban bird feeders, preying upon smaller birds like swifts and swallows. They’ve even been observed leaping up out of hiding and nabbing low-flying birds in mid-air!
Also unlike the cartoon is their call, which not only is not “Meep! Meep!”, but is not anything remotely like it. It’s a repeated “cooing” on a declining scale, reminiscent of a Mourning Dove, but with a sort of gurgling undertone, like it needs to clear its throat. You can listen to it here if you’re curious.
Side Note: Speaking of Mourning Doves, I got this nice shot of one down in St. George. Someday I’m doing a post on them.
OK, so that’s 5 “facts” down. The last “fact” is its range. I’m pretty sure you will never see a roadrunner zipping through Monument Valley or Arches NP, or pretty much any of the places depicted in the cartoon*. The roadrunner is a bird of hot deserts- the Mojave, Sonoran and Chihuahuan. As I mentioned in last Thanksgiving’s series on the amazing botany of St. George, Southwest Utah is completely unlike the rest of the state in that it dips down into the Northernmost reaches of the Mojave and that’s why it’s full of cool stuff you don’t see anywhere else in the state- stuff like creosote and Joshua trees and desert tortoises and several species of rattlesnake that don’t occur elsewhere in Utah. The Greater Roadrunner is another “Mojave Indicator”; you generally won’t see it outside of this area in the state. Occasionally one will be sighted just a bit out of its typical range; they sometimes show up in or around Cedar City or even Parowan and in 1932 a decomposing one was found outside of Provo(!), but they never breed so far North. Roadrunners are territorial, so it may be territory/population pressure that pushes them Northward every once in a while.
*In fairness, Saguaro cacti also frequently appeared in the cartoon. And though they don’t occur in the Southern-Utah-type canyonlands so often depicted in the cartoon, they are endemic to the Sonoran desert, where roadrunners do in fact live.
Side Note: The first roadrunner I ever saw was down in the Chihuahuan, driving across West Texas in the spring of 1990. It was crossing the highway. Less than 5 minutes later, a coyote ran across the highway, in the same direction. I thought, “Wow- just like the cartoon! I’m in the real West now!”
Yeah, so everything I “knew” about roadrunners was wrong. But if anything, they’re cooler than the cartoon- Roadrunners are fast, mean, clever, bold desert hunters. And there’s another thing that fascinates me about them: they’re an “in-between” thing.
When we think about other animals, we tend to categorize them. We think of animals as herbivores or carnivores, as little timid creatures, or big lumbering ones, or means and scary ones. And certainly we think of birds in different categories: waterfowl, raptors, little brown birds at our feeders, etc. But probably the biggest mental division we make among birds is between those who fly and those who don’t. We’re of course familiar with all sorts of birds that fly, and even if we don’t see them every day, we’re at least conceptually familiar with birds that don’t, such as ostriches and emus. But a roadrunner is in-between. We know of other in-between birds of course- chickens and quail and grouse and pheasants, but we tend to think of them as well, sort of lame. Like they would certainly want to fly, right? They just can’t seem to get it together… But a roadrunner- a fast, resourceful desert killer- clearly has its act together; there’s no way it’s “lame”. It’s not like other birds. It’s an in-between.
We think of in-betweens as transitional because we know that animals who live in environments and ways very different from their ancestral environments must have passed through such in-between stages in their evolutionary past. Here’s an example: whales. We know that whales and hippos shared a common ancestor sometime in the last 50-60 million years. And we know that that common ancestor was a 4-legged mammal that walked around on the land. But in-between that proto-hippo and modern whales there must have been some “in-between” ancestors. What would be an example? Well, maybe something like a seal or a sea lion. And what would be in between a seal and a whale? Well, maybe something like a manatee, or dugong.
What about the other way? What’s in-between a seal and something that walks around on land, like a dog or a cat or a rabbit? Maybe an otter? Or a beaver?
As it turns out, even though you can line them up along a spectrum of in-between-ness, none of these things- whale, seal, otter, manatee, are particularly closely-related to one another. But here they all are in front of us, appearing to fill out an almost continuous march to the sea.
But they’re not a continuum, and from their own perspectives, none of them is in-between anything. Some pinnipeds may someday evolve into more whale/fish-like forms, or maybe they’ll evolve the other way, back toward land-living. Or maybe they’ll keep on living like they do till the end of the world.
The animal world* is full of these kinds of in-betweens, with flying squirrels and loons (which can barely walk on land) and mud-skippers and amphibians. Ostriches descended from birds which evolved flight and then lost it, Vampire bats descended from flying mammals that evolved sonar and then lost the high-frequency component, and apes descended from reptiles who lost color vision and then re-evolved it. Evolution isn’t a continuous line; it’s a meandering, endless soap opera.
*So is the plant world, but that’s another post. So is fungi, a great example being yeast, who’ve apparently “lost” the multi-cellularity their ancestors evolved.
In the big picture, nothing’s really an in-between, because everything is. Certainly we- hairless, giant-headed, crazy-breeding, bipedal chimpanzees- are in no position to call anything an in-between.
Back To The Point I Was Trying To Make But Got Distracted From By Trying To Draw A Seal
So back to the roadrunner. It often strikes people as intuitively odd that birds would ever “give up” flight. If you could fly, why wouldn’t you keep flying? Many examples- most now sadly extinct- come from islands, where birds, lacking land-based predators, no longer needed to fly, resulting in such creatures as the Dodo, Raphus cucullatus, of Mauritius. Dodos (pic left, not mine) were part of Columbidae, the same family as pigeons and doves, and presumably evolved flightless-ness after some number of their flying ancestors wound up on the island. But other examples, such as the ratites- a group which includes ostriches, emus, cassowaries and rheas- apparently evolved flightless-ness on a continental landmass*. For whatever reason, running and greater size worked out to be a better deal for them than retaining flight capability.
*Which would be… yes, that’s right, Gondwanaland! I am telling you, that place was rocking!
Side Note: A bit of a head-scratcher for me are “island ratites”, such as the kiwi and now extinct moas of New Zealand and Elephant birds of Madagascar. These are/were ratites, and so presumably evolved flightless-ness prior to the break-up of Gondwanaland. (It’s pretty certain, from both fossil and modern physiological evidence*, that ratites were already flightless before the Southern supercontinent broke up.) But you have to wonder if, having wound up on island-sized Gondwanan fragments with an absence of predators, was the Dodo-effect then also at play in their continued evolution?
*Specifically, ratites lack a keel on their sternum upon which to anchor large wing muscles. So even if somehow an ostrich or an emu was endowed with giant wings and wing-muscles, its skeleton couldn’t support them.
Ratites are impressive birds, but none of the living species in the group are anywhere near carnivorous as roadrunners. And it makes you wonder, if we do think of the roadrunner as an in-between, what exactly is it in between? On one end of the spectrum are its cuckoo-cousins, but what lies on the other end of the spectrum of possibilities for a running avian carnivore?
Just a couple million- and maybe as recently as 15,000*- years ago, a 300+ lb carnivorous flightless running bird, Titanis walleri, roamed North America (drawing right, not mine). At 8’ tall, this was a top of the line carnivore- no coyote was chasing him around on rocket roller-skates. And T. Walleri wasn’t the first time a bird of that form and scale appeared. ~50 million years earlier, several Diatryma species (genus = Gastornis), at 6’ tall, appears to have led a similar lifestyle.
*How recently it became extinct is debatable.
Side Note: I mentioned both these birds back last January during Bird Feeder Week. (Man, was that a great week or what?)
So we know that 6’+ flightless avian carnivores evolved at least twice in North America. Though not at all closely-related to either of these prehistoric horrors, G. californianius is, to the best of my knowledge, the modern day North American bird closest in form and lifestyle to them. Makes you think twice about that cute little fella in the cartoon. Now maybe I know why I was rooting for the coyote.
13 comments:
Watcher,
I am now a little bummed that all my notions about roadrunners based on the cartoon have been debunked. But I'm OK with that because I learned some really cool new factoids. Next thing you'll tell us is that the Flintstones could not stop their cars with their feet.
Yes, I also wished that someday the perfect box would come from Acme, Inc. that would allow the coyote to catch the roadrunner, but deep down knew that it never would really happen (just like Sylvester would never actually get to eat Tweety).
Cool action graphics. Don't feel bad about the seal and otter - there were probably in-betweeners that looked just like them.
I must be too young to have eaten Quake cereal, but I loved Quisp. Doing further research, I discovered Quake cereal pieces were shaped like small gears with holes in the center, and that Quake was described in commercials as "bustin' with earthquake power." The cartoon even wore a mining hard hat! Quake is undoubtedly the closest thing to a geology-cereal as there will ever be. I'm going to start a movement to bring it back!
Roadrunners are cool, even without Looney Toons. I've seen them a few times and was fascinated as I watched them move. And thanks to this post I know know more about them.
OK, I know this was just a typo, but it amused me anyway: "... and seems to be an effective foot-form for grasping trucks".
Jube, if you like Quake you may also like Quarry:
http://www.youtube.com/watch?v=j5kE0MY4nYs
Quarry! Mmm, gotta get me some o' that. I can then stop taking my mineral supplements, too.
Also, I like the new banner image. It is new, right? (Knowing me it's probably been up for weeks and I'm just now noticing.)
The sight line, the "going fast" streaks, the secret Watcher society symbol, and I assume that's a map you're thinking about.
I haven't changed the banner for my blog in ages, maybe it's time.
Kris- thanks for the typo catch- fixed it.
And yes, new banner. Actually I put that banner up last week, then added the bling last night. The diagram in the thought-cloud is the S-curves/ Counter-steering graphic from the post I did after our 1-day Hurricane trip last Spring.
I like to change the banner every month or so, but yours is pretty cool.
cmsparks- You know, I think deep down that's everyone's secret fantasy- that someday their perfect box will come from Acme. Nice way to phrase it.
Jube- Hey maybe I'll come up with a breakfast cereal. It'd be little WTWWU logos, but it would taste like Quisp. Or maybe peanutbutter Cap'n Crunch. And the commericals would have happy-looking people tucking into bowls of WTWWU-O's as the sun breaks over the horizon, with a narrator saying, "Watch the World Wake up the right way..."
I might need to leave the eye out of the logo-cereal pieces though; that might creep people out.
It occurs to me that evolutionary in-betweens are more a human perception than anything. We like neat and tidy, but nature isn't so picky - as long as the organism stays alive and reproduces it's successful.
These in-betweeners also offend our sensibilities. If I knew my great-great-great-great-grandfather could fly, but since then the family line lost that ability, I'd be crushed. But the Roadrunner is OK with mostly running and only occasionally flying - it is what it is. We're such an egotistical species; always anthropomorphizing.
(A) No, we don't know from fossil evidence that ratites became flightless before dispersing to their current distributions. The early fossil record for ratites borders on the non-existent.
(B) Bats also lack a large keel on the sternum. They fly just fine.
(C) New Zealand was far from predator-free; in fact, New Zealand birds were exposed to some pretty terrifying predators (the world's largest eagle, for starters). The thing is, though, all the major New Zealand predators were other birds, and flying isn't so hot as an escape mechanism when what you're escaping from can fly as well (similarly, while ground-nesting is a disaster when mammalian predators are about, it's quite effective when it comes to hiding nests from aerial predators).
Christopher- great input, thanks! Couple comments in return, (following your enumeration):
A)Following up, my ratite evolution summary looks to be a year and a half out of date. The old story (which I believe I initially picked up from one of David Quammen's books in the mid-90's) was a monophyletic group with a flightless common ancestor. The new story (as of 2008) is that they’re probably paraphyletic, unless grouped together with tinamous, which do fly (if not particularly well), and now it looks as though ratites lost flight capability at least 3 times independently.
(I have to wonder though, is it fair to call the ratite fossil record “non-existent”? A quick search pulled up pretty specific examples of ratite fossils here, here and here…)
B)I think your example- birds & bats- is a bit of a case of apples & oranges. In birds the upstroke of the “flap” is powered by the supracoracoideus muscle, which is attached to the sternum along the base of the keel, underneath and surrounded by the pectoralis muscle, which is attached to the (same) keel above and around it. Hence the need for the large keel. (Nice little diagram here.) In bats, the upstroke is powered by the deltoids, which are anchored on the back side, (and so don't need to be packed under the pectoralis and anchored to the same spot) and so they do fine without an expanded keel. For an ostrich to regain flight without (re-?) expanding the keel, the musculature would have to be pretty dramatically re-routed. Maybe there are good examples of keel-less flying birds I'm not aware of, but bats aren't it.
C)Quite right. I should have qualified “predators” with “mammalian.” Thanks for piping up.
Roadrunners are cool. Period. Always worth a stop, look and gander. They are fierce hunters that remind me of the raptors in Jurassic Park. Interestingly, Robins also stimulate this thought.
We have them and we are not hot desert although we are near the Sonoran, at 5k feet, it is a different zone.
One of your graphics (the one with the swift) did not load for me, but I could click the link.
Nevermind, graphic loaded on refresh.
I said "early fossil record" - the examples you found are all Neogene. The moa and emu examples well postdate the divergence of the modern groups (the dromornithids which appear in the same paper as the emu are no longer regarded as ratites - more like giant flightless ducks). The egg taxon I wouldn't know enough to comment on.
There are a few older potential fossil ratites out there (e.g. Eleutherornis, Remiornis) but unfortunately we just lack the knowledge to feel confident about how they fit in. Alternatively, some authors have supported origins of particular subgroups of ratites from fossil flying birds such as lithornithids and Palaeotis, but again there is little agreement.
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