Introduction

Here you will find lots of information on Collared Lizards.  Please feel free to have a look around...

Just to give you a little info about me:  I am a British keeper of several species of Collared Lizards.  The first are Texan and New Mexico Collareds (both colour locales of the common or Eastern Collared lizard), Auriceps (Yellow Headed Collared Lizards), and the third are Western Collareds (Crotaphytus Bicinctores pictured above).   

I hope that this site will help you to learn a bit more about collareds both in the wild and in the vivarium, personally I have struggled to find more than a handful of informative sites authored by experienced owners.  There are a few brilliant sites out there, written by keepers with priceless experience and total dedication to the animals they keep, and I am pleased to call them my friends (Links at the top of the page). I just wanted to make a little contribution based on my own experiences, because if my fellow enthusiasts weren't online I'd have been stumped. The general idea was to help keepers learn like others helped me.  At the time this site was created, it was (I believe) the only collared lizard site created by a British author.  Now, lucky for you, there are more folk who have shared their knowledge online, and I'm pretty sure just about anything you could wish to know about the species can be answered by one or more of the authors within the sites listed on the links page. Many Thanks, and happy reading :o)


Basic Information

Latin Name:  Crotaphytus Collaris:

Origins: Northern American desert regions through to Mexico.

Size: 9 to 15 inches

Colouration:  Males are brightly coloured in variations of green, blue, brown and yellow, Females are duller in colour varying from grayish green-blue to beige.

Home for these beautiful and increasingly popular creatures is the arid rocky desert land of America, ranging from as far north as Nevada and Colorado, further south into Oklahoma and Texas, and even further as far as eastern New Mexico.  There are many different Species of Collared Lizards, the most widespread and readily available being the "Eastern" or Common Collared Lizard.  There are many other species, whose habitats range further to the North and South of the Common Collared, these species will be described later, however as these are not generally available in the UK, and are not often kept as pets I will focus for now on the Eastern Collared Lizard (Crotaphytus Collaris Collaris) and the Western Collared Lizard (Crotaphytus Bicinctores).

They live amongst the rocks and shrubs of the desert, and are incredibly variable in their colour, pattern, and even personality.  Eastern Collared lizards are green/blue in colour, often with yellow markings, the males being brightly coloured and the females invariably duller greyish green/beige/grey.  Both have mottled spots (usually pale cream/white) across their backs and have a pale tummy.

The Bicinctores are entirely different, being primarily brown in colour, they also have mottled spots in cream or white across their backs, but have longer faces, a chunky tail, and males have blackish blue pigmentation to the their tummies and throat (sometimes called a gular or dewlap).  The pictures here highlight just how different the two species are, although I believe they are both equally stunning:


I plan to draw a family tree at some point, so if this sounds confusing, check back I'll add it in soon.

Males are known for their territorial displays of aggression. It is worth noting that in their natural habitat one male will have a large territory, and will protect the females living within his boundaries.  Should another male cross his path he will arch his back, blow out his sides in an effort to make himself look bigger and bob his head rapidly.  This is followed by a series of push-ups.  I am not sure what exactly he is trying to achieve by such a display, but apparently it works.... usually.  If this fails he will try to chase the intruder away.  Collared lizards have powerful back legs that enable them to sprint at great speeds.  They can run in an upright position, using only their back legs to propel them.  At full speed their stride is approx 3 times the length of their body.  This is also a trick that helps them to escape from birds, snakes and other unwelcome predators.
 

When they are not defending their territory they can be found basking on warm rocks under the sun, and hunting for insects.  They will also eat smaller lizards and arachnids, and have no qualms about eating their own young.

Winter in the Wild

Hibernation will come into play during August or September depending on temperature, and will last through until spring.  During this time sleep is induced by the reduction in body temperature.  Being cold blooded, they regulate their temperature by basking in the sun.  When the summer is nearing its end and the temperature is not so warm, instinct tells them that before it gets too cold for them to function they must find somewhere to spend the winter.   At this point they will dig a hole or find a suitable crevice where they will not be exposed to the elements, or preyed upon by other animals.  They also stop eating in order to empty their gut of all contents.  There is no point hibernating if the food in your belly is going to rot there for 6 months and make you sick, and if you have no way of warming up to dispel the rotting food in your tummy, it is eventually going to win, and take your life.  Thus hibernation is important, and they have to get it right in order to guarantee they wake up in the spring. During this dormant period the body releases chemicals that allow the lizards to reproduce.  Again instinct is what makes this happen to a degree.  Spring time is the ideal time to lay eggs, because by the time they hatch, the bugs will also be in abundance so the chances of survival are greater. 

Once they have woken from their sleep, they have all the right hormones to kick start the new generation.  Within a few weeks the females will develop brightly coloured stripes and/or spots across her neck and sides.


Paragraph.

 

These are orange to red in colour and vary in pattern and intensity. 

Interestingly, most young collared lizards also develop these colours, male and female.  It is believed that this is developed in young males to prevent aggressive attacks from mature males defending their territories.  Young males are submissive and will not display territorial behaviour until they mature in their second year, thus allowing them to roam without being bullied by bigger males until they establish their own territory.


Reproduction

In correspondence with the females developing their gravid (this is reptilian terminology for pregnant) coloration the males will also begin to develop enlarged testes.  The mating ritual begins with the male bobbing his head rapidly at the female, in much the same way as he does when competing with males.  He will drag his belly and hips in circles on the floor, often the female will bob her head back in retaliation.  He will bite the back of her neck and climb on her back to her to pin her down.  If the female is not ready to mate she will arch her back like a cat to prevent his advances, or even climb on his back.  When she is ready she will accept his advances and allow him to attempt to mate with her. Eggs are usually laid and buried 21 to 28 days later in dark, damp burrows and take between 45 and 65 days to hatch, these times vary particularly with different species.  The development rate is also dependent on temperature.

Once she has laid her eggs the female will bury them in sand/soil.  Some mums will straight away go about their business as usual and others, maybe because they aren't so sure nobody is going to dig them up and eat them will  often for several days guard their clutch, though once they leave the eggs they will not return.  The average clutch size is 5 or 6 but they have been know to lay up to a dozen.Once her eggs are laid she will feed aggressively, eggs take up a lot of space inside her tummy, so in the final days/week she probably hasnt been able to eat much, and will need to replace the goodness that went into the eggs as well as fill the gap in her very empty tummy. Collared lizards are capable of retaining sperm for long periods of time, and as such three or four clutches can be produced in a season without them breeding again.  When they begin to develop new eggs their gravid coloration will return and the cycle is repeated. 

When the new generation begins to hatch they will feed on their egg sac for several days before emerging from their place of refuge to forage for insects.  They are aggressive feeders and will eat anything small enough. Babies grow quickly and by the end of the summer will be comparatively large.  Their orange and red coloration will usually develop as they grow in order to protect them from adult males and they will eat lots, in order to grow and store fat in preparation for the winter. 

When the following spring arrives the females are usually sexually mature.  Female yearlings will reproduce, and whilst the young males might attempt to mate the females will usually reject their advances in favour of more mature adults.  Female Collared Lizards grow slowly throughout their lifetime, although males will usually be fully grown by about the age of 3.  Their lifespan in the wild is subject to debate, though keepers have recorded captive collared lizards reaching 10 to 15 years.