Population Size and Trends
The estimated population of the Greater Short-Horned Lizard in Alberta in 2001-2002 is about 2,651 – 16,060 mature lizards (Government of Canada, 2014). This population estimate is very broad because of uncertainties of the proportion of suitable habitat which is occupied by the lizard, and the actual densities of lizards within the suitable habitat. These uncertainties come from the small proportion of apparently suitable habitat which has been searched for appearance and behavior of the lizards, resulting in an unknown of the presence of lizards during the survey that took place in 2001-2002 (Government of Canada, 2014). After giving the Greater Short-Horned Lizard the title as being endangered it is estimated that the population of the lizard is either stable or slightly declining in Alberta (Government of Canada, 2014).
The estimated population of the Greater Short-Horned Lizard in Saskatchewan in 2008-2011 is estimated to be about 5,200 – 8,320 mature lizards. Again this is a broad estimate as the information is also very limited (Government of Canada, 2014).
It is predicted that the Greater Short-Horned Lizard population will never be stable in Canada, and that they will likely always be rare and highly localized in Alberta and Saskatchewan, as these two places contain the lizards habitat requirements (Government of Canada, 2014).
The estimated population of the Greater Short-Horned Lizard in Saskatchewan in 2008-2011 is estimated to be about 5,200 – 8,320 mature lizards. Again this is a broad estimate as the information is also very limited (Government of Canada, 2014).
It is predicted that the Greater Short-Horned Lizard population will never be stable in Canada, and that they will likely always be rare and highly localized in Alberta and Saskatchewan, as these two places contain the lizards habitat requirements (Government of Canada, 2014).
Factors Limiting the Population Growth
Carrying Capacity: Currently there are only 8 known spots where the species can be located in Alberta and Saskatchewan (Government of Canada, 2014). Between Alberta and Saskatchewan it is calculated that there is only an area of 132 Kilometers squared of space that is occupied by the Greater Short-Horned Lizard (Government of Canada, 2014).
Fecundity: The mating period for the Greater Short-Horned Lizards is in between May and June, so the babies will be born in the warmer season, as the gestation period for the lizard is about 3 months (Greater Short Horned Lizard, 2015). It is estimated that a female lizard will give birth to 5-30 lizards in one pregnancy (Greater Short Horned Lizard, 2015). However, the mothers tend to leave their babies shortly after they are born able to function on their own, however, when they are only young the lizard does not have short horns, this makes them vulnerable to predators and the surrounding environment (Greater Short Horned Lizard, 2015). Density: The Greater Short-Horned Lizard is a scattered species, as there are only 8 known spots in Canada, in Alberta and Saskatchewan, where the lizard is located (Greater Short Horned Lizard, 2015). However, within these 8 spots that the lizard exists the population is fairly dense, in relation to the population size, as there are only a select number of places in Canada these lizards can survive (Greater Short-Horned Lizard, 2015). Predation: The primary food source for the Greater Short-Horned Lizard are ants, which there is a sufficient amount of (Government of Canada, 2014). However, the lizard itself has a lot more predators above them on the food chain (Government of Canada, 2014). Therefore, the Greater Short-Horned Lizard has a couple natural defense mechanisms, which include: camouflage skin color, ability to inflate itself and the ability to squirt blood out of its eyes (Government of Canada, 2014). The lizard is either a yellowish colour, reddish brown or gray colour, depending on their surrounding environment (Government of Canada, 2014). This species can also inflate itself to twice its original size to try to scare of predators (Government of Canada, 2015). Finally, the Greater Short-Horned Lizard can squirt blood through the ducts in the corner of their eyes to scare off predators (Government of Canada, 2015). |
http://www.huffingtonpost.ca/2013/07/24/greater-short-horned-lizard-blood-eyes_n_3642490.html
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