tag:blogger.com,1999:blog-7443075087825368900.post2572191323210651376..comments2024-01-04T05:26:02.451-07:00Comments on Life is short, but snakes are long: Do snakes sleep?Andrew Dursohttp://www.blogger.com/profile/04720822623046554913noreply@blogger.comBlogger14125tag:blogger.com,1999:blog-7443075087825368900.post-47958730818845844792021-04-19T14:32:57.346-06:002021-04-19T14:32:57.346-06:00Nice summary regarding sleep in snakes, Andrew. He...Nice summary regarding sleep in snakes, Andrew. Here is a paper that defines what a venom is and distinguishes it from poisons and toxungens: https://tinyurl.com/yexrsd86. - Bill HayesBillhttps://www.blogger.com/profile/03820091128186600073noreply@blogger.comtag:blogger.com,1999:blog-7443075087825368900.post-91254650319973484932017-04-18T10:49:01.704-06:002017-04-18T10:49:01.704-06:00Definitely. Good idea—that's possible, and tes...Definitely. Good idea—that's possible, and testable. Hopefully someday someone will take it on.Andrew Dursohttps://www.blogger.com/profile/04720822623046554913noreply@blogger.comtag:blogger.com,1999:blog-7443075087825368900.post-52455423630845805222017-04-18T10:26:10.745-06:002017-04-18T10:26:10.745-06:00Seems like an interesting project for someone. I ...Seems like an interesting project for someone. I wonder how tongue-flicks figure into this? Can you assume that no flicks for a certain time period = sleep state?<br /><br />-Mike<br /><br />Mike Pingletonhttps://www.blogger.com/profile/04240429148701800796noreply@blogger.comtag:blogger.com,1999:blog-7443075087825368900.post-9992893713930073382017-03-25T02:29:17.308-06:002017-03-25T02:29:17.308-06:00Thank you again Tim for your thoughtful comments.
...Thank you again Tim for your thoughtful comments.<br /><br />1. My aim in pointing out that hibernation and brumation are not so different is not to suggest that there are no physiological/behavioral differences between reptiles & mammals. Rather, I wanted to emphasize that reptilian hibernation and mammalian hibernation are not two distinct categories but rather part of an evolutionary continuum of deep-sleep strategies used by vertebrates, one that is intimately tied to the ectothermy-endothermy spectrum. For instance, <a href="http://eprints.utas.edu.au/8530/" rel="nofollow">hibernating echidnas have periods of arousal, during which they often move to other locations</a>. Probably monotreme hibernation is the closest we can get to a living organism with similar physiology to that of the common ancestors of all amniotes.<br /><br />Regardless of what I or any etymological or biological expert says, "brumation" will continue to be used for herps and "hibernation" for mammals, and there's nothing wrong with that. But simplifying the biological world into mutually-exclusive categories often denies us the true complexity of the underlying reality, and gives the misleading impression that reptilian and mammalian physiology/behavior were independently created in isolation from one another, when in fact they were not.<br /><br />2. Your point about the similarity between the terms "hibernation/brumation" and "poisonous/venomous" is a good one, and a good example of how term use can change over time. Again I would argue that toxin injection has evolved numerous times and there are grey areas (such as the delivery of skin gland toxins by the pointed ribs of <i>Pleurodeles waltl</i> and other salamandrids). But, again, the distinction is useful and will continue.<br /><br />3. I don't think that anyone uses the color of snake oral secretions as a useful way to classify them as venom or not venom. I think anyone would agree that the chemical composition and function are more important characteristics than the color. I looked into it and evidently <a href="https://books.google.de/books?id=7hfLBAAAQBAJ&lpg=PA211&ots=2ahY_ttG07&dq=colorless%20snake%20venom&lr&pg=PA211#v=onepage&q=colorless&f=false" rel="nofollow">the venom of many vipers is colorless when they are first born, and the venom of some adult Asian cobras is colorless as well</a>. I suspect you'll agree that these colorless secretions are still venom. The differences between the composition of <i>Heterodon</i> venom and that of other snakes are no greater than would be expected given their evolutionary distance from those other snakes. Once more, the distinction between "true venom" and "whatever non-front-fanged colubroid snakes have" is A. only a matter of degree, not mutually-exclusive categories, and B. categorized primarily, if not solely, by the life-threatening potential towards humans (and, again, this distinction is useful; in fact I think that describing snakes that don't pose medically-significant threats to humans as "venomous" is misleading and confusing, which is why I often try to point out that venomous/non-venomous is also an evolutionary continuum).<br /><br />4. Regarding the sequestration of toxins into nuchal glands, we have conclusive evidence only that <i>Rhabdophis tigrinus</i> sequesters bufadienolides into its nuchal glands. We have every reason to believe that other <i>Rhabdophis</i>, and the two closely-related genera <i>Macropisthodon</i> and <i>Balanophis</i>, also use their nuchal/nucho-dorsal glands for this purpose (although the toxins may vary). Fourth, there is evidence that <i>Thamnophis</i> retain tetrodotoxin in their livers for up to two months. But as far as I know, to date this is the extent of our knowledge of the diversity of non-injected chemical defenses in snakes.<br /><br />5. Sorry about not being able to edit comments; it's one of the several drawbacks of using the Blogger platform.<br /><br />Thanks for reading and writing!Andrew Dursohttps://www.blogger.com/profile/04720822623046554913noreply@blogger.comtag:blogger.com,1999:blog-7443075087825368900.post-70167043391226992072017-03-24T22:27:51.776-06:002017-03-24T22:27:51.776-06:00three (3) years* of Latin [forgot a word, sorry, a...three (3) years* of Latin [forgot a word, sorry, and evidently cannot Edit comments...?] :PAnonymoushttps://www.blogger.com/profile/06852503143923610783noreply@blogger.comtag:blogger.com,1999:blog-7443075087825368900.post-54352812347333635822017-03-24T22:24:19.600-06:002017-03-24T22:24:19.600-06:00Sure enough, researching the etymology of the two ...Sure enough, researching the etymology of the two terms: <i>brumation</i> and <i>hibernation</i> reveals no specification/difference between them in regards to the physiological/behavioural nature of reptiles (or any creature for that matter) over Winter. But there <i>is</i> a physiological/behavioural difference between reptiles and mammals in that the former does <i>not</i> undergo a coma-like sleep and will instead be sluggishly active, occasionally drinking and even basking at the opening of their hibernaculum on warm spells.<br /><br />And this is where semantics must've been put aside for simplicity sake however long ago, to use simple terms in distinguishing a (physiological/behavioural) difference between reptiles and mammals in their overwintering nature irrespective of the literal, etymological meaning of the terms. Perhaps it is similar to old-timers (still) interchangeably using <i>poisonous</i> and <i>venomous</i> for the physiological process of inJECting venom. NOTE: It is important to specify 'physiological process of inJECting' since it <i>has</i> been recently discovered that at least five (5) genera of serpents are poisonous (and coincidentally all five are venomous to some degree, or inject toxins*), in which the physiological process of poisonous is inGESting. But old-timers weren't/aren't referring to toxins sequestered in the nuchal glands when using "poisonous", haha; they were/are referring to serpents' fangs and venom glands.<br /><br />In conclusion: if not "brumation", the so-called "experts" need to find (or create) a term that identifies and distinguishes reptiles from mammals in their overwintering physiology/behaviour...there <i>is</i> a difference obviously, and I want a word to describe it!<br /><br />Thank You for the follow-up comment and link, though; I am big into linguistics and quite the etymological prick actually LOL, so I like learning facts like this! Admittedly/shamefully for this 'linguistic connoisseur' who took three (3) of Latin, haha, I don't think I ever rooted out/researched the etymology of either term, at least too long ago for me to recall (and obviously forgot), and therefore never realized <i>brumation</i> technically doesn't distinguish anything, HA!<br /><br />*Prepare for a digression-of-an-asterisk note completely irrelevant to this topic LOL:<br /><br /><i>Heterodon platyrhinos</i> at least, if not the entire genus <i>Heterodon</i> is actually <i>not</i> mildly venomous, but rather mildly <b>toxic</b> since the colour of their secretions is clear whereas venom is always some shade of yellow, not to mention significant composition differences. An excerpt of greater elaboration, from Linda Krulikowski's amazing book: Snakes of New England (with the amazing Harvey B. Lillywhite contributing):<br /><br />"The [Duvernoy's] gland is composed of branched tubules rather than simple groupings of cells, and is situated immediately under the skin, above and near the angle of the jaw. It is derived from the same tissue as tooth enamel. The Duvernoy's gland opens by a duct at the base of the posterior, enlarged teeth. The secretions from the glands flow down the enlarged, rear teeth and into the prey, by the chewing motions of the snake. The secretions are introduced slowly into the victim, by indirect pressure from the nearby jaw-closing muscles (Green. 1997: 78-95). The secretions of Duvernoy's glands are colorless, whereas true venom glands secretions are typically some shade of yellow. These clear secretions immobilize the victim and help the snakes digest the prey."Anonymoushttps://www.blogger.com/profile/06852503143923610783noreply@blogger.comtag:blogger.com,1999:blog-7443075087825368900.post-42976613728234047002016-10-01T14:51:47.317-06:002016-10-01T14:51:47.317-06:00A good article arguing that the distinction betwee...A good article arguing that the distinction between the terms 'hibernation' and 'brumation' is hazy at best and unnecessarily jargon-y:<br /><br />http://theobligatescientist.blogspot.com/2010/11/do-reptiles-hibernate-or-brumate.html?m=1Andrew Dursohttps://www.blogger.com/profile/04720822623046554913noreply@blogger.comtag:blogger.com,1999:blog-7443075087825368900.post-81149920791046337112016-04-07T13:57:16.063-06:002016-04-07T13:57:16.063-06:00And it's good to be so excited and passionate ...And it's good to be so excited and passionate about something! :) Welcome, and thank You for the great articles.Anonymoushttps://www.blogger.com/profile/06852503143923610783noreply@blogger.comtag:blogger.com,1999:blog-7443075087825368900.post-56649666963542168232016-04-04T20:32:07.414-06:002016-04-04T20:32:07.414-06:00Tim, it's certainly true that there are a myri...Tim, it's certainly true that there are a myriad of wonderful exceptions to and twists on every "rule" in nature—my favorite thing about biology is those exceptions! I can be pretty excited about pointing them out. Thanks again for the thoughtful comments.Andrew Dursohttps://www.blogger.com/profile/04720822623046554913noreply@blogger.comtag:blogger.com,1999:blog-7443075087825368900.post-22864340059883528002016-03-31T20:16:47.435-06:002016-03-31T20:16:47.435-06:00And I thank You for Your thoughtful, insightful re...And I thank You for Your thoughtful, insightful response, Andrew. :) Indeed; relying too much on common sense and intuition can become 'cloudy', and it was not my intention to convey the notion that science should be based on common sense and intuition exclusively. Technology definitely has its benefits, not least to show Us physiological aspects that We cannot see (on the outside).<br /><br />I suppose when I stated 'every animal sleeps, period', I admittedly was not thinking of, and therefore not including insects. It's not that I put insects below vertebrates, I was just simply ignorant LOL (or perhaps too tired). It was probably also--perhaps subconsciously--the connotation of "animal" growing up which drew a line between certain groups/types/kinds of animals, perhaps between vertebrates and insects (not invertebrates in general, just insects); this is obviously wrong, for insects are a part of Kingdom: <b>Animalia</b>.<br /><br />So; Antarctic insects that hibernate but don't sleep...I still didn't know about them either way, so You got me there! But would it be more like a reptilian <i>brum</i>ation then, not hibernation? ...which is not a coma-like sleep like hibernation is. And my use of 'sleep' is actually more broad, incorporating, say, 'autopilot' mode which is <b>not</b> completely unconscious, or in the case of these pelagic birds and mammals: on 'standby' mode so to speak. I should have specified.<br /><br />Lastly, I'm not surprised about these pelagic birds and mammals sleeping half of their brain at a time; this would explain the Albatross (a pelagic bird) sleeping while flying...rather; the source of that ol' fact I learned years ago probably didn't realize it was only sleeping half of its brain at a time (because it definitely hadn't specified this...it was a sign at the Forest Park Zoo in Springfield, MA)...I sure as heck didn't realize it till Your comment just now, but it makes sense. And yeah, something like pelagic birds flying way above the ocean can't be discerned to be sleeping or not--how can You see and even <i>think</i> of the possibility/ability which would sound absurd to most people initially, until proof tells them--and only technology was able to furnish the proof.Anonymoushttps://www.blogger.com/profile/06852503143923610783noreply@blogger.comtag:blogger.com,1999:blog-7443075087825368900.post-37575061824390693832016-03-27T12:10:46.160-06:002016-03-27T12:10:46.160-06:00Thanks for your thoughtful comment, Tim. I would a...Thanks for your thoughtful comment, Tim. I would add that, although in general I agree with you that we shouldn't use technology just because we can and that we should always be making observations and thinking about how they can suggest clever experiments to test hypotheses, we do need technology and physiological experiments, and sometimes, "common sense" and "intuition" can lead us astray. It's certainly been shown that snakes sleep. But, I challenge your assumption that "every animal sleeps, period". For instance, I recently learned about some Antarctic insects that hibernate for most of the year, but don't sleep or have a circadian rhythm during the short Antarctic summer during which they are active 24 hours a day. Also, without technology, we wouldn't know about pelagic birds and mammals that sleep half their brains at a time, seeming behaviorally never to sleep.<br /><br />Kobelkova, A., S. G. Goto, J. T. Peyton, T. Ikeno, R. E. Lee, and D. L. Denlinger. 2015. Continuous activity and no cycling of clock genes in the Antarctic midge during the polar summer. Journal of Insect Physiology 81:90-96.Andrew Dursohttps://www.blogger.com/profile/04720822623046554913noreply@blogger.comtag:blogger.com,1999:blog-7443075087825368900.post-21000686947902425412016-03-26T22:35:59.434-06:002016-03-26T22:35:59.434-06:00Studying brain waves is nice and all, but have We ...Studying brain waves is nice and all, but have We become so advanced ("advanced", perhaps) that We have forgotten the base of Science: observation? Also; applying logic, common sense, analytical thought, and intuition?<br /><br />Id est; serpents sleep, and it is indicative via their pupils 'dropping' as though facing down, and appearing to be in total autopilot mode, looking nothing like when they're moving about, foraging, eating or drinking. When stimulated or simply awakened, the pupils rise to normal-appearing mode, and the serpent slightly lifts its head as though becoming attentive. This is the observation part of it, and I've watched for 24 years.<br /><br />The logical, common sensed, analytical and intuitive part is simply that every animal sleeps, period. We don't need concrete proof of this, such as via technology. As with humans, rest is just as essential as keeping active and fit, as rain is to sunshine, and as war is to peace. Id est; it is the essential balance of Nature and of Life.<br /><br />Dreaming? That's a tougher one to discern, and if it can be figured out not just in serpents but all animals, it may distinguish just how differently animals sleep.<br /><br />On a final note, I found the <i>smell</i> stimuli interesting, as I have had otherwise nocturnal species (<i>exempli gratia, Boiga dendrophila</i>) eat in early-mid afternoon when I knew they were asleep in their caves below. Granted, opening the enclosure could have woken them, and <i>this</i> is where brain wave equipment would be necessary - to see if anything changes from opening to closing the cage, or does nothing change until a certain time passes where it can be almost guaranteed the smell of food woke and brought the animal(s) out?<br /><br />Thoughts?Anonymoushttps://www.blogger.com/profile/06852503143923610783noreply@blogger.comtag:blogger.com,1999:blog-7443075087825368900.post-74174686137311828622015-10-20T09:37:34.865-06:002015-10-20T09:37:34.865-06:00Good point! Do they ever sleep?Good point! Do they ever sleep?Andrew Dursohttps://www.blogger.com/profile/04720822623046554913noreply@blogger.comtag:blogger.com,1999:blog-7443075087825368900.post-22564076556985884812015-08-31T11:43:06.795-06:002015-08-31T11:43:06.795-06:00And the situation with night snakes (Hypsiglena) i...And the situation with night snakes (Hypsiglena) is complicated as well--they surely do rarely at most move about during the day outside of cover, but available evidence shows they mainly capture prey by day, ambushing diurnal lizards from hiding.<br />Anonymoushttps://www.blogger.com/profile/02793902539569917116noreply@blogger.com