EVENING NEWS (Edinburgh, UK) 26 February 05 Cold-blooded killers hatch mass breakout (Gareth Edwards)
Its poisonous bite can kill a human, its powerful jaws are almost impossible to prise apart - and it is famously bad-tempered.
So the arrival of five more Mexican beaded lizards might not seem like something to celebrate at Edinburgh Zoo.
But zoo staff are delighted after hatching five babies of the deadly species which are threatened with extinction in the wild.
The rare breed - one of only two species of venomous lizard in the world - rarely breeds successfully in captivity.
The team at the zoo’s reptile house have been watching over a clutch of large lizard eggs for months, keeping them at a constant temperature in a specially-adapted incubator.
The young were bred from a pair of adult lizards that came to Edinburgh when Glasgow Zoo closed in 2003, and they finally mated last spring.
Originally the female lizard laid 11 eggs, of which only six were fertile. There was some concern when one of the fertile eggs failed to develop.
But the five healthy babies hatched earlier this month.
Reptile keeper Ross Poulter said: "We’re really pleased that this unique lizard has successfully bred here, as it is an extremely rare occurrence for this species.
"This production will greatly improve the genetic stock in the Mexican beaded lizard captive breeding pool and help to further the knowledge of this species significantly."
A close relation of the more common venomous gila monster, the Mexican beaded lizard, or Heloderma horridum, can grow to about 30 inches long. It lives mainly on insects, rodents and birds.
Its Latin name means "horrible studded lizard", a name it acquired because of the distinctive bead-like black and yellow scales which cover its entire body.
These are called ostioderms, and each one contains a tiny piece of bone that gives the creature an almost armour-plated skin.
Beaded lizards are well-known among reptile experts for being short tempered. The tank which houses the two adults is plastered with warnings to staff not to become complacent around them.
The animal’s powerful jaws can lock on to a victim so tightly that the only way to remove the creature is to burn it off.
Its venom is highly poisonous and potentially fatal to man in extreme cases because there is no known antidote.
Even though the animals can appear sluggish, they are able to move rapidly when provoked, and produce a hissing sound to warn off intruders.
Once found throughout Western Mexico, the animal is now nearly extinct and is protected under the Convention on International Trade in Endangered Species. The animals’ population has dropped because of man encroaching on their habitat, and they are frequently killed in the wild in Mexico because they are seen as dangerous.
Since the animals were hatched, Mr Poulter has been acting as a surrogate mother to ensure the survival of the baby lizards.
A Zoo spokeswoman said: "The keepers removed the eggs from the mother as soon as they were laid to make sure the eggs were incubated in the perfect conditions for hatching.
"Their survival is very important and keepers could not take the risk of the female lizard being neglectful.
"It seems the mothering instinct in the female was quite strong though, as after the eggs were removed, she kept returning to the nest site to look for the eggs."
The baby lizards will remain at the zoo until they have grown to a size where they are likely to survive and are in good health. Then they will leave Edinburgh to join other breeding groups around Europe.
http://news.scotsman.com/scitech.cfm?id=218332005
