Yes, several lizards can play dead! Death-feigning (also known as thanatosis -from the Greek noun θανάτωσις, meaning “putting to death”; and Thanatos, meaning catalepsy, or tonic immobility) is a state of immobility assumed in response to external stimuli.
It can be for various reasons, such as a prey evading a predator, a predator trying to lure potential prey closer, or even a male trying to mate with a female.
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The French biologist Georges Pasteur classifies this behavior as a form of self-mimesis, a form of camouflage or mimicry in which the “mimic” imitates itself in a dead state.
Predation is the major reason for this behavior. The mechanism of “playing dead” is efficient in that it limits the ability of predators to detect, recognize, and subdue their prey.
As explained by the Somersby Animal Hospital several predators need the vibration or sounds of movement to detect where the lizard is, and so becoming entirely rigid can be an effective way for lizards to disappear from the menu of the predator.
The most-reported defensive behavior of lizards is tail loss (also known as autotomy) and locomotor escape (Greene 1988, Robert et al. 1998, Rocha-Barbosa et al. 2008). However, the third major defense mechanism is “playing dead”.
This behavior is not exclusive to lizards but is shared by mammals (e.g., Francq 1969), birds (e.g., Sargeant & Eberhardt 1975), fish (e.g., Howe 1991), amphibians (e.g., Gargaglioni et al. 2001, Bertoluci et al. 2007), insects (e.g., Acheampong & Mitchell 1997) and of course reptiles (e.g., Greene 1988).
How do lizards “play dead”?
In most cases, lizards “play dead” by maintaining a rigid posture or by simulating fully relaxed muscles (e.g. fainting; Greene 1988).
According to the site Healthy Pets by Dr. Karen Becker the western leaf lizard is patterned to look like a dead leaf, and it will even dart a short distance then stop, blending in with the forest floor, and hiding in plain sight.
Tonic immobility is considered to be a fear-potentiated response induced by physical restraint and characterized by reduced responsiveness to external stimulation.
The efficiency of this defensive behavior
While efficiency in this defensive behavior has been poorly tested, its occurrence in several vertebrate groups suggests a favorable evolutionary pressure toward its maintenance (Miyatake et al. 2004).
Immobility might discourage sequential attacks, allowing escape, as demonstrated in experiments using invertebrates (Miyatake et al. 2004).
Which lizard species play dead?
Death-feigning has been reported for several different families, such as Anelytropsidae (Torres-Cervantes et al. 2004), Crotaphytidae (Gluesing 1983), and Scincidae (Langkilde et al. 2003).
Among tropidurid lizards, this behavior has been observed in Eurolophosaurus nanuzae Rodrigues, 1981 (Galdino & Pereira 2002), E. divaricatus Rodrigues, 1984 (Gomes et al. 2004, Kohlsdorf et al. 2004). Previously in Tropidurus nanuzae and T. divaricatus (Frost et al. 2001), T. torquatus Wied, 1820, and T. hispidus Spix, 1825 (Bertoluci et al. 2006).
Bertoluci et al. (2006) have also reported anecdotal records for several other species in the tropidurid family. Among Liolaemidae, this behavior has been reported only in Liolaemus lutzae Mertens, 1938 (Rocha 1993).
This family consists of 229 species (including subspecies) belonging to the genera Ctenoblepharys, Phymaturus, and Liolaemus. The latter comprises most of the species of the family, with 200 species (Pincheira-Donoso et al. 2008a).
The South American Liolaemus lizards occur in Argentina, Bolivia, Brazil, Chile, Paraguay, Peru, and Uruguay, which represents the widest range of environments occupied by a single lizard genus.
Dos Santos et al report observations of the defensive behavior of L.occipitalis in nature and the first record of death-feigning in this species (data collected between November 2009 and January 2010).
The death-feigning behavior observed in this study was similar to that described in Tropidurus species by Bertoluci et al. (2006). During handling, L. occipitalis lizards exhibited very relaxed muscles, remained immobile in the observer’s hand, and maintained this posture when placed on the ground.
During death-feigning, simultaneous slow and lateral tail movements and intermittent movements of opening and closing the eyes were observed.
Lizard Playing Dead In Action – Video
Is my lizard dead or playing dead?
As previously explained, lizards are notorious for playing dead. Therefore, before considering your lizard dead, try poking it. And get a real good look to see if it’s breathing.
Another thing you can do is to put a tiny mirror near its nose and check carefully to see if the mirror fogs up, or see behind its front legs for a pulse under the skin.
Additional Links With Info
BEUX DOS SANTOS et al, “Playing dead to stay alive: death-feigning in Liolaemus occipitalis (Squamata: Liolaemidae)”, Biota Neotrop. Vol.10 no.4 Campinas Oct./Dec.2010, https://www.scielo.br/scielo.php?pid=S1676-06032010000400043&script=sci_arttext
BERTOLUCI, J., CASSIMIRO, J. & RODRIGUES, M.T. 2006. Tropiduridae (tropiduridae lizards). Death-feigning. Herpetol. Rev. 37(4):472-473.
BERTOLUCI, J., BRASSALOTI, R.A., SAWAKUCHI, H.O., RIBEIRO JR., J.W. & WOEHL, G. 2007. Defensive behavior with stiff-legged posture in the Brazilian tree toads Dendrophryniscus brevipollicatus and D. leucomystax (Anura, Bufonidae). Alytes 25(1-2):38-44. https://www.researchgate.net/publication/235617009_Defensive_behaviour_with_stiff-legged_posture_in_the_Brazilian_tree_toads_Dendrophryniscus_brevipollicatus_and_D_leucomystax_Anura_Bufonidae
ENDLER, J.A. 1986. Defense against predators. In Predator-Prey Relationships. Perspectives and approaches from the study of lower vertebrates (M. Feder & G. Lauder, eds). The Univ. Chicago Press, Chicago, IL, p. 109-134. https://www.researchgate.net/publication/312970811_Defense_against_predators
GREENE, H.W. 1988. Antipredator mechanisms in reptiles. In Biology of the reptilia (C. Gans & R.B. Huey, eds.). Alan R. Liss, New York, vol.16, p.1-152. https://es.scribd.com/doc/136673394/GREENE-H-W-1988-Antipredator-Mechanisms-in-Reptiles-in-Biology-of-the-Reptilian-C-Gans-R-B-Huey-Eds-Alan-R-Liss-New-York-p-1-152-v
HOWE, J.C. 1991. Field observations of death feigning in the convict tang, Acanthurus triostegus (Linnaeus), with comments on the nocturnal color pattern in juvenile specimens. J. Aquaricult. Aquat. Sci. 6(4):13-15. https://eurekamag.com/research/007/349/007349723.php
MIYATAKE, T., KATAYAMA, K., TAKEDA, Y., NAKASHIMA, A., SUGITA, A. & MIZUMOTO, M. 2004. Is death-feigning adaptive? Heritable variation in fitness difference of death-feigning behavior. Proc. R. Soc. B. 271:2293-2296. https://royalsocietypublishing.org/doi/10.1098/rspb.2004.2858
Have you ever seen a lizard playing dead? Please, share your experience with us below in the comments!
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