The Regal Horned Lizard (Phrynosoma solare) is found in Sonora desert and Sinoloa of Mexico and Arizona of United States. This species of lizard tends to choose dry, hot and sandy environment as their habitat. It has one row of lateral abdominal fringe scales accompanied with a crown of ten horns over its head, four large occipital horns and six temporal horns.
In BBC’s “Life in Cold Blood” series, it was mentioned that the lizard is able to control the supply of blood to its head where it collates the blood in a cavity behind the eyes. In the morning, the lizard will only exposed its head from the underground and heats up the pool of blood collated in its head via sunbathing before releasing them to the rest of the body so that the whole body can get warmed up, recovering from hibernation. As a cold blooded animal, this is crucial to its survival due to the fact that its predators are warm blooded and are already active in the morning while it needs time to get warmed up.
However, this ability to control the blood flow to the head has another amazing function which helps increase the lizard’s chances of surviving out in the wild desert.
When under attack or being pursued, the Regal Horned Lizard can squirt a jet of blood at its predator from its eye in order to scare them away. Basically what it does is that it traps the blood beneath a series of thin tissues within its eye sockets. The rapidly increasing blood pressures will then tear open the tissues, forcing out a jet-like squirt of blood at the predator. This jet of blood is capable of shooting up to a height of 4feet. It is also believed that the released blood contains a distasteful substance, which elimates the appetite of the predator for the lizard.
One may think that the lizard will be only be able to squirt once in a while as the losing of blood is not desirable for all animals. However, Dr. Wade C Sherbrooke of the American Museum of Natural History found out that this tactic can be used by the lizard for multiple times if it is under continuous irritation. Furthermore, it is also able to “quickly recover from the experience without obvious ill effects”, contradictory to the biology observed in most animals.
- “Horned Lizards,” by Eric R. Pianka and Wendy L. Hodges. University of Texas, URL: http://www.zo.utexas.edu/faculty/pianka/phryno.html (accessed on 01 Apr 2013)
- ” Horned Lizards (Phrynosoma): Life as Predator and Prey”, by Sonoran Herpetologist, 15 May 2007, URL: http://tucsonherpsociety.org/20%20(5)_49-60.pdf (accessed on 01 Apr 2013)
- K.P.N., Shuker, 2001. The Hidden Powers of Animals: Uncovering the Secrets of Nature. London: Marshall Editions Ltd: p.128
- “Sneaky sunbathers,” by David Attenborough. BBC One, 15 Jan 2010, URL: http://www.bbc.co.uk/programmes/p0060tnq (accessed on 01 Apr 2013)
- W.C. Sherbrooke, Introduction to horned lizards of North America, California Nature History Guides No. 64: p.126