Greater Short-Horned Lizard

Nicole DollBlog, Education

Greater Short-Horned Lizard
  • Scientific Name: Phrynosoma hernandesi 
  • SARA Status: Endangered (Under consideration for)
  • COSEWIC Status: Special Concern
  • COSEWIC Range: Alberta, Saskatchewan  

The Greater Short-horned lizard is the most northerly occurring iguanid lizard species in the world, with its northern limits reaching southern Alberta and Saskatchewan. Here, it is restricted to four distinct regions in southeastern Alberta, and two distinct regions in southwestern Saskatchewan. It is the only species of lizard found in both these provinces. 

Greater Short-horned lizards are small and flat-bodied with unique ‘horns’ that protrude from their head, as their name suggests. Their colouration can vary depending on their environment in order to better blend in, making them a very cryptic species. This, coupled with their ability to remain completely motionless allows them to be masters at camouflage, which is important to avoid predators and to hunt prey.  

The range of Greater Short-horned lizards spans across North America, with the most northern extent in southern Alberta and Saskatchewan and the most southern extent in Mexico. Within Canada, they prefer sparsely vegetated areas on south-facing slopes with minimal disturbance. They rely on loose, well-drained soils, which are important for burrowing during winter for thermal protection.

To avoid freezing temperatures, they burrow about 10 cm deep in the ground and remain inactive throughout the winter months. If they are unable to find suitable burrows they become very vulnerable during hibernation. Their diet consists of various insects and arthropods, such as crickets, beetles, spiders, and ants.  

Threats: 70% of Canada’s population of Greater Short-horned lizards live in Grassland National Park. Here, their habitat is protected but they are still threatened by the spreading of invasive plant species and inclement and extreme weather conditions. Summer droughts and winter freeze/thaw cycles cause mortality. These threats are expected to worsen with climate change.  

Subpopulations outside of Grassland National Park and within southern Alberta are subject to additional threats that impact habitat. This includes agriculture, industrial development, road construction which all result in habitat loss, as well as dam and irrigation projects that lead to habitat degradation.  

What’s being done: More research is needed to understand population sizes and trends of the Greater Short-horned Lizards. However, since the locations of the remaining populations in Canada are known and are generally small, it is critical that these areas are protected from development. The lizard is protected both provincially and federally, however it is not protected in the U.S or Mexico.  

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