If you are a fan of dinosaurs, probably know what sound accompanies this image.
Watching Jurassic Park for the first time (and several times after that) introduced us to what Tyrannosaurus rex would be like, in their movements, behaviors, and sounds. This scene is never, ever going to get old. It was also perfect that my first viewing of Jurassic Park was at a drive-in during a rainstorm.
Hollywood is no stranger to using odd things to recreate visual and audio effects of sights and sounds with which we are familiar…or have no familiarity with at all because they haven’t been invented yet (lightsaber swooshes), or because we don’t regularly stab people in the shower (chocolate syrup was used for blood in the original Psycho), or because the sound is so far in the past that no human has ever heard anything like it.
Hollywood gave us something terrible, awesome-sounding, and not-at-all-subtle for Tyrannosaurus rex because we, as human beings living in a time dominated by large fuzzy roaring mammals (lions and tigers and bears, oh my!), expect our large predators to roar, snarl, and bellow. Most of the animals used to create the classic sounds of the Jurassic Park Tyrannosaurus rex are large mammals.
Extant Phylogenetic Bracketing and the Sounds of Tyrannosaurus rex
Figuring out how an extinct mammoth sounds, or how an extinct species of large cat sounds, is not that difficult because we have large pachyderms and large felids around to use as examples. We use large mammals as a comparison against large dinosaurs because hey, that’s what we have to work with. However, dinosaurs are not mammals. Dinosaurs belong to a group of animals called archosaurs. Archosaurs took a completely different evolutionary path from our group, the synapsids (mammals and mammal-like reptiles.) The archosaur group and the mammal-like reptile group have been doing their own things, evolutionary-speaking, for over 250 million years.
Our present-day representatives of archosaurs are the crocodiles and the small theropods (a.k.a. birds). These animals are much closer to large non-avian dinosaurs in terms of evolutionary history, anatomy, and behavior than are large mammals. Crocodiles evolved before large non-avian dinosaurs, and small present-day theropods (birds) became specialized after large non-avian theropods evolved. We have the beginning of the story (crocodiles) and the end of the story (present-day theropods), with large non-avian dinosaurs landing in the middle.
Using crocodiles and present-day birds to test hypotheses (questions) about extinct dinosaurs is called Extant Phylogenetic Bracketing. The present-day examples (crocodiles and birds) give us examples of what is possible for extinct animals (large theropods) that are also part of their group (archosaurs). A lot of the information we have on theropod dinosaur behavior comes from comparisons to the behavior of present-day birds, such as parental care and egg clutch sizes (Varricchio et al., 2008; Varricchio and Jackson, 2016) and potential courtship behaviors (Lockley et al., 2016).
Enter Dr. Julia Clarke, professor of vertebrate palaeontology at the University of Texas. She used extant phylogenetic bracketing to take two unsettling sounds (crocodile vocalizations and the booming call of the Eurasian Bittern), scaled them up to what they would sound like coming from a Tyrannosaurus rex-sized critter, and….dang.
Was that not completely eerie? What if you were in the forest and heard – or felt like the host mentioned – that sound behind you? I guarantee you’d have a case of the freakies: I know I would.
Humans have (when compared to the rest of the animal kingdom) a rather limited range of hearing. Humans, in general, can hear sounds between 20 Hz and 20 kHz. Sounds below 20 Hz are typically referred to as infrasound. Our species doesn’t really hear infrasound all that well. Check out this link from the Cornell Lab’s Elephant Listening Project. There are three sound clips at 10 Hz, 20 Hz, and 30 Hz. Can you hear the sound?
I could not hear any of the clips (I did feel pressure in my ears) but that’s not surprising: I have not evolved to communicate using low-frequency sounds, unlike elephants and some birds (the link goes to a recording of a cassowary).
However, just because we as a species can’t hear infrasound doesn’t mean that some of us may not sense it in other ways. I felt a pressure in my ears when listening to the clips, and afterward I felt a low-grade headache. There have been studies done that suggest infrasound may induce feelings of unease in humans. One such study was the Purcell Room Concert of May 31, 2003. The audience listened to the music, into which infrasound was inserted at specific times (the audience didn’t know.) The audience was then asked to fill out a questionnaire detailing their experiences during the concert. To quote the webpage:
“During our concert, infrasound boosted the number of strange experiences reported among the audience, even among those who were unaware of its presence. Unusual reports included a sense of coldness, anxiety, and shivers down the spine. On average, infrasound boosted the number of strange experiences by around 22 percent. It also increased the intensity of any feelings reported.”
Do these experiences sound like any unexplained phenomena you’ve heard of? Turn down the sound for this clip: it’s a little loud.
Here’s a chilling thought: if Tyrannosaurus rex had part of its vocalizations in the low frequency or infrasound range, not only would we hear that menacing gurgle, but the vocalization would likely trigger an anxiety reaction during the encounter.
I’ll leave you with this lovely clip of a vocalizing American Alligator. Have a Creepy October!
Here is another post going into the highlights of one of our more recent papers dealing with dinosaur ichnology: the study of foot injuries in the fossil record!
Have you ever stubbed your toe? Pulled a muscle in your leg? Walked anywhere with a rock in your shoe? It doesn’t take major discomfort to figure out that foot and leg injuries can result in you walking “funny.” Perhaps you had to hop around on one foot for a bit. Maybe you could only take a certain length of step using your injured leg. All of the compensations that you make to avoid further or greater discomfort or pain have a good chance of being seen in your trackway. These modifications due to pelvic limb injuries also have a good chance of being preserved in the fossil record.
Tread Carefully Of course, we have to be careful when looking at a fossilized trackway and seeing something “odd” about, for example, the gait of an animal. One aspect that can confuse people about vertebrate ichnology is that there is a HUGE amount of variation in how footprints are preserved and in how the animals themselves moved. All of that variation is perfectly normal. Dinosaurs (and any other vertebrate ambling over the landscape) are not metronomes. They are not robots. They will absolutely not take a step that is EXACTLY 345 cm long each and every time they step, or place their feet EXACTLY the same way every time. Some oddities in trackways are just that: oddities that are due to the natural variation in how a living, breathing, complex animal interacts with its environment as it moves from Point A to Point B.
In other words, when we look for phenomena that we can call pathologies, we are looking for repeated abnormalities in footprint shape and movement. This is the framework we used to review reports of fossilized footprints that preserve oddities that cannot be explained by poor preservation or an animal being an animal.
What Is An Ichnopathology? When we discuss pathologies, or in this case ichnopathologies, we’re talking about trauma (bone or soft tissue) that would result in an animal walking differently than it would be expected to walk. A pathology of the foot would result in direct preservation of the soft tissue and/or skeletal trauma that the foot experienced, such as a dislocated, broken, or amputated toe. A pathology of the lower (tibia and fibula, and muscles) and/or upper leg (femur and muscles) would result in a pace (a footstep) and stride (how the animal moves from right footprint to right footprint, or the “right-left-right” sequence of the trackway) that is different, such as a limp, shuffle, or foot drag, while the footprint itself may (but not always) look completely normal.
What Is Not An Ichnopathology? There are footprint phenomena that are not ichnopathologies, no matter how strange they may look. Here are a couple of examples.
A. Missing Toes versus Natural Morphology Here’s the danger of looking at isolated, singleton footprints. Let’s say you see a single footprint with a missing digit II (inner toe). Is this footprint the result of an injury, or is it the footprint of a dromaeosaur? It may be easy to see that the toe is missing, but looking at the trackway is essential in making an accurate interpretation of why that inner toe is “missing”.
Compare these two images:
The top image from Abel (1935) shows a large theropod trackway with a toe missing on only the right footprint. The bottom image from Xing et al. (2012) shows that there is a toe “missing” on both left and right footprints. Both trackways show this as a repeated occurrence. When we see a toe repeatedly missing from one foot only, that is a likely candidate for a pathology. When we see a toe missing repeatedly on both feet, it was likely never there to begin with, as is the case with dromaeosaurs. In fact, a consistently missing digit II is one of the synapomorphy-based characters we can use to confidently identify a trackway as belonging to a member of Paraves.
We have also observed dinosaur trackways where only one footprint shows a missing toe, while all of the other toes are more or less impressed. Those occurrences are most easily explained by preservation, rather than injury or anatomy: not every footprint within a trackway is going to be beautifully preserved.
B. Limping versus Laterality Remember before when I said that animals aren’t metronomes? It is not uncommon for perfectly healthy animals to favor one limb over the other. This might result in a trackway that looks like it preserves a limp. However, “limping” is a loaded term: it implies that there was an injury or defect that caused the animal to walk the way it does. Data collected from emus (Dromaius novaehollandiae) shows that emus may take longer paces when stepping off with their right foot than if they step off with their left foot (McCrea et al., 2015). In other words, emus are right-handed, or right-footed. Ostriches have also been observed to be a bit right-footed (Bachiodonna et al., 2010). These irregular walking patterns aren’t the cause of injury, but rather because of laterality.
C. Anatomical Anomalies
I have a few bizarre requests for the Universe in terms of cool fossils to be found. One is polydactyly in dinosaurs, or even in a fossil felid trackway. When I was a child my family adopted a polydactyl cat (also known as a Hemmingway cat). Charlie’s hands sported two extra digits each, while his feet each had one extra digit. If Past Me had known Present Me was going to be this much of an ichnology geek, Past Me would have taken pictures of his footprints. No matter how many toes a cat has, there are still features on the foot (and the footprint) that would make it easy to identify it as a cat footprint, like the tri-lobed metatarsophalangeal pad.
Polydactyly is not as uncommon as one might think in the fossil record. Early tetrapods, specifically the early amphibians, that first started making their appearance on land in the Carboniferous had more than five fingers and toes on their hands and feet.
Let’s fast forward to the Mesozoic. Would we necessarily recognize polydactyly in the footprint of a more derived, specialized tetrapod, like a theropod? There are four-toed footprints that are attributed to theropods. Saurexallopus is interpreted to be the footprint of a theropod with four functional toes. The trackmaker was possibly an oviraptorosaur, such as Chirostenotes (Gierlinski and Lockley, 2013). Having a more well-developed digit I compared to other theropods that were running around at the same time (Late Cretaceous) was normal for Chirostenotes and close relatives, so this is a case of anatomy rather than polydactyly.
There are other trackway phenomena that can give the appearance of polydactyly. One of these is a really busy track surface. Busy track surfaces often show animals walking over the footprints of other animals. This often results in dinosaur (and bird) footprints that have the appearance of extra toes, when the simplest explanation is that the footprint is actually one footprint stepping on a different footprint. Another example is when a theropod (usually three-toed) sinks into a substrate deep enough that the hallux and the metatarsus will impress – it gives the appearance of a theropod print with “extra” toes. We see this at the Flatbed Creek Dinosaur Track Site in northeastern British Columbia, where these theropod footprints look like they have five toes instead of the usual three. One toe is indeed a toe – digit I (equivalent to our big toe) – but we don’t usually see that in non-avian theropod footprints. The other “toe” is the impression of the tarsometatarsus.
You’ve seen some examples of what are not ichnopathologies. Now you get to be rewarded with the really painful-looking footprints and trackways…the ones that you look at and cringe because there is no way those injuries were not extremely uncomfortable. Here I will show the recent additions to the owie-ichnology literature. All of our examples come from non-avian theropods. Much like our modern hawks and eagles, Cretaceous theropods likely used their feet for much more than walking: the feet were also a means of prey capture and restraint (Tanke and Currie, 2000). Theropods led hard, fast lives, and that wear-and-tear showed up on their feet.
Despite all that foot use, wild modern birds of prey have a low occurrence of foot injuries: Bedrosian and St. Pierre (2007) documented a 14% pelvic limb injury rate in Red-tailed Hawks and American Kestrels. Like our modern birds of prey, foot-related injuries are not common in non-avian theropods. The percentage of injured theropod feet is small: Rothschild et al. (2001) observed that healed stress fractures in foot elements range from 0.3% to 6% in large theropods. Other injuries to theropod feet include bony growths that likely resulted from infection/osteomyelitis. So, as these injuries are uncommon in theropod foot bones, we can extrapolate that the resulting footprints from injured feet are uncommon. When we see an ichnopathology, we’re lucky (the trackmaker, however, was less fortunate).
1. Trackway Ichnopathology
A trackway of a large theropod (cf. Irenesauripus mclearni) from the Early Cretaceous Gates Formation was reported to us. At first, we thought it might be one theropod following right behind another theropod because the steps the animal was taking were WAY too short.
We looked at the substate: it was firm when the animal walked on it, so it wasn’t simply having a tough time slogging through the muck. Then we noticed that the right foot was turned in much more than we usually see in large theropods: non-avian theropods tend to walk with their middle toes pointed roughly straight ahead, or in parallel with the trackway. This theropod was waddling. More specifically, this theropod was using a Pigeon-toed Waddling Gait. It’s hard to say if this gait was the result of an injury to the foot or leg, or if this was a developmental anomaly.
2. Swellings and Dislocations
The most “showy” injuries are those that involve swelling and/or dislocation of a toe. Theropods had no way to reset a dislocated toe, so it would have to walk around with that injury.
Here is a dislocation and swelling-related ichnopathology from the Dakota Group (late Early to early Late Cretaceous) in Colorado.
The second most striking dislocation injury I’ve ever seen in a footprint is this large theropod footprint from the Late Cretaceous (approximately 97 million years ago) Kaskapau Formation in northeast British Columbia. Not only is the middle toe (digit III) severely dislocated, but the outer two toes have seemed to compensate for this injury by spreading way out. Unfortunately, the Kaskapau and the Dakota Group pathological footprints were found as singletons. The good news is that, if these animals’ footprints are preserved elsewhere, we have a good chance of linking the footprints to their trackmakers.
Footprint swellings like these are also seen in modern birds. Here is a Canada Goose trackway that I collected a couple of years ago. At the time I made the replica, the toe swelling was hidden by the muddy sediment, but it came out beautifully in the plaster replica.
As painful as these two footprints look, they were a mere inconvenience compared to what this next trackmaker must have suffered. Check out this large theropod footprint (first reported by coauthor Darren Tanke) from the Late Cretaceous Wapiti Formation in northwest Alberta.
Yes, you are seeing that correctly: the animal, likely a tyrannosaur (based on the size, and shape of the toe claw, or ungual) stepped on its own toe. Check out how narrow the impression is right before the claw. This could be a trick of the preservation, or it could be that the tissue around the claw was necrotic and beginning to atrophy – this leads to the next level of ichnopathology, also related to tyrannosaurs.
In 2011 a large theropod trackway consisting of three footprints was reported to us from the B.C. Wapiti Formation. On documenting the trackway, we noticed something peculiar: the inner toe on the left footprints was far too short, while the inner toe on the right footprint was a normal length. Not only did we have the first tyrannosaur trackway preserved, we had one with a rather nasty pathology – a missing toe!
An Ichnopathology Pain Scale
Everyone is familiar with the pain scale used in hospitals. Hospitals are like not allowed to use my favorite pain scale, courtesy of Hyperbole and a Half. Both these pain scales and all of these foot injuries made me ask “What would a theropod pain scale look like?”
So I dusted off my pencils, Googled horrible foot injuries in animals (there are things that I can’t unsee), and used the Bellatoripes fredlundi trackway and all of those horrible swellings and dislocations as inspiration for The Theropod Pain Scale.
There are two reasons I am immensely proud of this image. First, looking at it made all of my staff simultaneously laugh and cringe in empathy pain for the poor afflicted theropod: apparently the lip quiver did them in (yes, I know the presence of lips is debated in archosaurs – the image was meant to have a touch of comedy in it). Second, it was published! The coauthors liked it, but that didn’t guarantee that the reviewers or the editor would have liked it. I’m glad they did – I do my best teaching and interpretation with humor.
The study of ichnopathologies, just like the study of tracks and traces, gives us a closer look at the complex biological lives of these now-extinct large theropods. Fossilized evidence of injuries reminds us of the fragility and vulnerability of animals often portrayed to the public as rough, tough, indestructible eating machines. Even the most fearsome predator has off days and oopsies. Ichnopathology research also demands that we make use of our living laboratory – outside – as an opportunity to look more closely at the common animal trackways we might take for granted. Each one is an opportunity to learn how an animal’s life is reflected in its footprints.
Abel O (1935) Vorzeitliche lebensspuren. Gustav Fisher, Jena.
Baciodonna L, Zucca P, Tommasi L (2010) Posture in ovo as a precursor of footedness in ostriches (Struthio camelus). Behavioural Processes, 83, 130–133.
Bedrosian BE, St. Pierre AM (2007) Frequency of injuries in three raptor species wintering in northeastern Arkansas. Wilson Journal of Ornithology, 119(2), 296–298.
Gierlinski G, Lockley MG (2013) A trackmaker for Saurexallopus: ichnological evidence for oviraptosaurian tracks from the Upper Cretaceous of western North America, p. 526-529 in Titus AL, Loewen MA (eds.) A the top of the Grand Staircase: the Late Cretaceous of southern Utah. Indiana University Press.
Niedzwiedzki G, Szrek P, Narkiewicz K, Narkiewicz M, Ahlberg PE (2010) Tetrapod trackways from the early Middle Devonian period of Poland. Nature 463: doi:10.1038/nature08623
Rothschild BM, Tanke DH, Ford TL (2001) Theropod stress fractures and avulsions as a clue to activity, p. 331–336 in Tanke DH, Carpenter K (eds.). Mesozoic vertebrate life: new research inspired by the paleontology of Philip J. Currie. University of Indiana Press.
Tanke DH, Currie PJ (2000) Head-biting in theropods: paleopathological evidence, in Perez-Moreno BP, Holtz Jr., T, Sanz JL, Moratalla J (eds.). Aspects of theropod paleobiology. Gaia, 15:167–184.
Xing L, Li D, Harris JD, Bell PR, Azuma Y, Fujita M, Lee Y−N, Currie PJ (2013) A new deinonychosaurian track from the Lower Cretaceous Hekou Group, Gansu Province, China. Acta Palaeontologica Polonica 58(4), 723–730.
This is a repost from my old blog site from April 2016 when, I swear to the Great Grey Owl, a marketing company tried to recruit me for what is a plot from a Simpson’s episode…except they were dead serious.
April Fools’ Day is tomorrow, and I am waiting with mild trepidation over what faux science gags I am going to see on the Internet. What I was not prepared for was to have someone actively try to recruit me to deceive the public in a pretty rotten way.
Let’s be clear right from the start, Dear Reader: I love a good prank. I’ve been on the receiving end of many a gag courtesy of my colleagues. The most recent prank was having my office filled with toy spiders – we refer to it as The Spidering…this happened over a year ago, and I’m still finding spiders (NOTE: This happened 7 years ago, and I am STILL FINDING PLASTIC SPIDERS IN MY THINGS. That’s OK: I got Rich back. He will be finding cat pictures in his books FOR YEARS. ) What I REFUSE to do is to actively deceive the public with regards to fossil discoveries, fossil heritage appreciation, and fossil conservation.
Enter my phone conversation from Tuesday afternoon.
I’m out of town, picking up some supplies for the up-coming field season. My cellphone interrupts my browsing. It’s a phone number from British Columbia. NOTE: As technologically slow as I am, I am pretty good at Googling phone numbers – I know exactly which organization made this call.
I will refer to the person on the other end as Skippy. Skippy was all excited to tell me of their great idea. There is a project that is going ahead somewhere in British Columbia (not in my neck of the woods), and those involved thought that a great way to get publicity would be to announce a fake dinosaur skeleton discovery as a result of said project. This plan was considered a good idea because, well, April Fools’ Day. Skippy continued: they even wanted to get the public involved in submitting names for their new fake dinosaur find. Skippy was wondering if they could use our former institution’s name to lend their April Fools’ prank credibility.
Dear Readers, guess how I responded. I think I was quite polite under the circumstances.
The first words out of my mouth were “Absolutely not!” I went on to say a version of this:
There is already a culture of mistrust in the general public towards science and scientists. The public is also deeply interested in fossil discoveries and news, and trusts that when such news is announced, it’s for real. Faking a fossil discovery in British Columbia and using the name of an institution would only serve to fuel such public distrust of scientists. There is no way that we could in good conscience take part in such a scheme.
I ended the conversation with Skippy by saying “And I had better not see our names anywhere near anything that you publicize.” Skippy’s response was “You won’t be included,” wording that makes me think that they are actually still planning to go ahead with this Scicomm Wrong.
Half-assed publicity stunts such as these give me nothing but anger and frustration. This is nothing more than manipulating people’s natural curiosity about dinosaurs and fossils for a project that will do absolutely nothing to further their appreciation of their province’s fossil heritage. There is no way that this can be spun as a scicomm opportunity: had our name been associated with this scheme, we would have lied to the public – April Fools’ Day or no – and given them a reason to get excited about dinosaurs in British Columbia. People trust us, whether they consciously recognize that trust or no, to give them trustworthy and factual information about the fossil heritage in British Columbia.
I will not apologize for this: I respect and greatly appreciate the public’s natural interest in their fossil heritage. We will never abuse that interest for the sake of tacky publicity.
British Columbia is only just starting to develop a cultural appreciation and respect for the province’s fossil heritage, and still has work to do towards viewing fossils as irreplaceable heritage and not just a get-rich-quick means to marketing. The idea that the public has a sense of ownership and pride over their province’s heritage is not yet at the levels we see in Alberta (an even better example is South Korea), where fossils have been part of the cultural identity for decades. Science education institutions rely on the goodwill of the public to be supportive of fossil heritage protection and conservation. We will not lightly throw that hard-earned trust away for the sake of a “joke”.
Public Service Science Announcement (PSScA): there is indeed such as thing as bad publicity, especially when it deliberately exploits people’s science curiosity for the sake of clicks or views.
UPDATE: Indeed, Dear Readers, I did scour the Internet for a week after this phone call to ensure that a) no “dinosaur” discovery was announced and b) anyone’s name that I knew wasn’t associated with it. I saw nothing, so maybe they took the hint.
Over the holidays (December 2017) I was at home, minding my own business – drinking tea, working on retooling the last publishable chapter from my dissertation, watching bad paranormal TV, and acting as a heated mattress for the kitty – when there was a knock on my front door.
Lo and behold, it was a door-to-door religious solicitor! Nowadays they are fairly high-tech: rather than try to hand me a pamphlet, his opening line was presenting his tablet/iPad and saying “Now watch this video and I’m sure it will help you answer some of Life’s questions.”
My grandparents had a sign taped to their door that read “No solicitors, religious or otherwise. We have no time, patience, or money.” Needless to say, they taught me well.
My response to these types of solicitations is polite but direct: I’m an evolutionary biologist, and my questions are already answered. I caught a very brief change flicker over the guy’s face – something akin to a flare of anger – but he wisely turned around and left.
Naturally, I shared my experience with my Twitter friends.
I let my mind free-associate a bit after that. I briefly thought about how funny it would be if, rather than having religious solicitors, we had science solicitors, going door-to-door spreading the Science. Of course my brain immediately jumped to “Science doesn’t preach: science provides learning opportunities.”
The more my brain played with the idea, the more my brain liked it.
I have completed one pamphlet* for what I’m calling Science Tracks: purely science communication pamphlets that can be used for any opportunity that arises for spreading the good word about all the awesome science that’s out there. I may have been a little optimistic about getting more than one completed over the holidays. One big reason is that I don’t want to use other people’s photos for this without permission, and the only pamphlet I could complete using my own photos was OMFG* BIRDS! (no one who follows me is surprised), but it is a start of something that I would like to continue. *Oh My Feathery Goodness.
The other time was a planned overnight in October with all of the right gear.
One adventure was more enjoyable than the other. I’ll let you guess which one.
A well-planned tent-less camping trip is a fun adventure! There are many tent-less camping systems, like tarps and camping hammocks. I have yet to try these systems, so I’ll talk about what we used on our trip.
There are key pieces of equipment you will need for your tent-less camping trip. You won’t be spending money on anything special: you’ll use all of this gear for tent camping!
The Sleeping Pad
Sleeping outdoors means carrying a sleeping pad. There are a lot of options for backpacking sleeping pads. If you’ve stayed over at someone’s house, you’ve likely used an inflatable air mattress. They can be comfy, but your standard air mattress is just too big and too heavy to bring with you on a backpacking trip.
Think of a sleeping pad as the minimalist air mattress. Sleeping pads aren’t just for a cushy sleep. Sleeping pads keep your body off of the cold-sucking ground while trapping warm air from your body heat between you and the ground.
How warm is your sleeping pad? Check the R-value. The R-value tells you the sleeping pad’s ability to resist heat loss. This means YOUR heat loss. Low R-values (2 and lower) are for warmer climates and summer camping, while medium R-values (3 – 4) are great for three-season camping. If you’re winter camping (or are a cold sleeper) definitely go for a sleeping pad with a 4.5 R-value or higher. A general rule is that the higher the R-value, the thicker and heavier the sleeping pad will be. Don’t despair! We’re talking about a difference in between one and two kilograms, not dozens.
There are different types of sleeping pads: self-inflating, manual-inflating, and closed-cell foam pads. I’ll talk about what I know, which are self-inflating pads.
Self-inflating sleeping pads have a foam core. You can fold them in half lengthwise and then roll them up into a tight roll. When you roll up your sleeping pad for travel (and put it in the stuff sack), you squeeze all of the air out of the foam cells. When you unroll the pad, the empty foam cells expand and suck in air through the inflation valve. All you have to do then is breathe into the valve to get your sleeping pad just the right firmness, close the valve, and you’re set!
Pro-tip: Get yourself a silicone bag, like the MEC Pack Rat Silicone Stuff Sack, for packing your sleeping pad. Silicone bags, like a non-stick pan, glide easily over the rolled-up sleeping pad. This means you can pack and unpack quickly (and without frustration!)
I’ve always used a self-inflating sleeping pad. I’ve never had one deflate on me overnight (if you’ve slept on a standard air mattress you know the feeling). My absolute favorite is the Therma-Rest Prolite Plus Women’s Sleeping Pad. This pad has been with me for ten years. TEN YEARS. Its R-value is 3.9 so it’s great for three-season camping. I’ve used this pad in the sub-alpine where the temperatures dropped to -5 C at night in August (yup, it gets cold up there!) and I didn’t feel the ground sucking my life-energy from my soul.
Air pads* are extremely light and pack down quite small. You need to manually inflate them, but the air pump is actually a lightweight bag pump. They come in a range of R-values and pack down super-duper small. As with self-inflating pads, air pads with higher R-values tend to be a bit more spendy.
The Sleeping Bag
Idyllic as it may seem, sleeping under the stars wrapped in your cloak like a hobbit off to visit the Lonely Mountain is not going to cut it, comfort-wise.
You’ll want a sleeping bag. Look, I’ve made due with a fire, a guide tarp, and a pile of leaves. OK, maybe not a pile of leaves, but that was an … unexpected journey.
Not all sleeping bags are created equal. Sleeping bags, like sleeping pads, have ratings. Sleeping bag ratings are given in temperatures. A -10 C rated sleeping bag is going to be a lot warmer than a sleeping bag rated at +5 C. For three-season tent-less camping in temperate climates, you’ll want a sleeping bag that is rated for below freezing temperatures.
Pro-Tip: The temperature rating on a sleeping bag doesn’t mean that you will be snug as a bug in a rug using the bag at that temperature. It means that you will SURVIVE at that temperature. It’s a country mile between comfy and surviving.
Personally, I like a down sleeping bag. They compress down beautifully in a compression stuff sack for stowing in your pack. Down is crazy warm for its weight. Down is also very durable: a well-cared for down sleeping bag will last over a decade. My old MEC Raven -7 C Mummy Bag is still going after fifteen years.
Down sleeping bags have their drawbacks. One, they’re a little heavier than a synthetic bag. Two, once it gets wet, it’s game over for warmth, and they take a long time to dry out. You have to think like a duck to get the most out of your down bag. A duck has its down feathers right up against its body, protected by the water- and wind-repellent layer of their contour feathers. The contour feathers also keep all of those toasty little air pockets trapped within the down close to the body.
So how do you keep either your down (or your synthetic) bag warm and dry when you camp without a tent? You need layers over your down, my duckies!
Ducks keep wet out of their down feathers by preening: they rub oil over their outer feathers which repels moisture…like water off of a duck’s back (c’mon, I had to!) We’re not about to slather our sleeping bags with butter, so we need a fabric option.
An overbag acts like the contour feathers on a duck: it keeps the wind and external moisture off of the bag. It also helps to trap in your body heat. You can add another 5 C to 10 C degrees to your sleeping bag’s rating with a wind-stopping overbag. I have a MEC Emperor Penguin Windstopper Overbag (no longer available).
If I needed to pick up a new overbag, I’d be interested to try out either the North Face Ocelot Overbag* or the MEC Talon Overbag*. They are comparable in price and both do what overbags are supposed to do: keep condensation away from your body and your main sleeping bag while repelling external water.
I had my sleeping pad, my sleeping bag, and my overbag, but what if it got really chilly at night?
The Sleeping Bag Liner
You can add even more warmth to your sleeping system by adding an inner layer! You can get fancy-shmancy with wool and silk liners, but I went for the least expensive one I could find, my MEC Fleece Sleeping Bag Liner (no longer available).
The polyester fleece wicks away sweat, adds a bit more warmth to your bag, and keeps the inside of your main bag a bit cleaner (it’s so much easier to wash the fleece liner than a down sleeping bag). If I needed a new bag liner, sign me up for the Big Agnes Fleece Sleeping Bag Liner*.
It’s made of Polartek recycled fleece and adds another 5 C – 10 C to your sleeping bag. Oh, and can I say that snuggling up in a cozy fleece blankie at the end of the day feels like luxury? Because it does!
What if you’re worried about all of your gear directly touching the wet ground? Or WHAT IF IT RAINS ON YOU AND YOUR GEAR?
Siltarps are basically a piece of nylon that is impregnated with silicone. They’re very light and waterproof. My very first paleontology survey in the alpine demonstrated the necessity of a backpack tarp. It was a gorgeous August day, but when we reached the summit of a mountain the weather turned FAST. We were caught in a freak snowstorm. One of our group pulled out this teeny package from their back, unfurled it, and lo! A giant tarp covered us and our gear, keeping us dry. Staying dry meant we stayed warm, and staying warm means avoiding hypothermia.
I picked up a backpacking tarp immediately after returning from this trip. The Rab Guides Siltarp 1 is very similar to the tarp I have.
Siltarps weigh less than a 1-liter water bottle and take up very little room in your pack. My siltarp is a must-have for every paleontology survey or hike. When we did our tent-less camping trip, we put our sleeping gear on one guide tarp, and used the second guide tarp as an emergency rain shelter. Thankfully it didn’t rain!
You can definitely get away with using a regular polytarp (those blue tarps that make loud crinkle noises) that you can find at your local hardware store, but they won’t pack up as small and won’t be as light. Siltarps are also less expensive than tarp shelters. You can turn your siltarp into a shelter by hooking the side loops over your hiking pole (the subject of a future post!) or running nylon cord through the loops.
I consistently use all of the gear in this post. When I camp in my bivy sack in the sub-alpine, I don’t even bring my sleeping bag: I use my sleeping bag liner and my overbag (and wear warm undies, which I would bring regardless.)
One piece of tent-less camping gear I am extremely eager to try is the camping hammock! Hammocks that hook up to trees would not work well in the sub-alpine or the alpine: the trees are just too teeny. I would use a hammock for lower elevation forest camping. Camping hammocks vary in price: this depends on whether the hammock comes with a rain fly. Since I already have a siltarp that I would use as a rain fly, I would love to try out the MEC Double Hammock with Tree Straps*!
I’d still want to use my sleeping pad, overbag, and sleeping bag liner when sleeping in a hammock. There would be cold night air underneath me, so insulation would be a must.
Have you ever gone tent-less camping? What sort of gear did you use? Did you ever have an unexpected tent-less camping trip? Tell me about your adventure!