The Blue Lacerta

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The reproduction of the blue lacerta~

Male and female blue lacertas are fully mature at around 1500 years of age, meaning that they are able to reproduce at the same time. The breeding season occurs during early winter to late spring and usually lasts for about 3 - 6 months. During this time, females who have not reproduced for fifty years will produce one egg cell, however females that have recently reproduced (say, in the last 10 years or so) will not. 

Blue lacertas will bond, pair, and mate for life with the same partner for the rest of their lives. A blue lacerta can select a mate anytime of the year, although the most popular time is during the breeding season. During this time, matured males will begin to start showing off to females either by flashing or flaring their fins, or showing off their aquatic expertise by leaping, diving and twirling in the water. Males may also begin to be more aggressive with each other as the breeding season nears. 

Females may also become increasingly grouchy and picky with other females, especially with younger or newer females to an area. Nipping and slapping is common, especially when there are other males in the vicinity. 

Once a suitable mate has been selected, both blue lacertas will follow each other about, hunting together, sleeping near each other, nuzzling and occasionally soft-tackling. They will spend almost everyday with each other, bonding and becoming used to one another as the breeding season approaches. After days of bonding, the female will then start producing a single egg cell, (providing she has not reproduced in the last fifty years) and will begin releasing pheromones. The male will then sense her chemical messages through the air, and shortly afterwards, both will begin to travel further and further away from their small territory, in search for the best site for building a nest for the female to lay her single egg in. Nest mounds made in planted areas (close to water), river banks, and ocean shores are perfect for blue lacerta eggs, providing they are very close to water and have plenty of air. Mound nests are also efficient for blue lacerta eggs, as they build up useful amounts of moisture, creating the perfect environment for developing and hatching. Moisture is very important for eggs as not only will it be useful for developing, but if there is not enough moisture in the air when hatching, the shell membrane will dry out, consequently causing the young hatchling to stick to its' tough shell. 

After a suitable nesting spot has been selected, a small yolk would have been formed within the female, ready for fertilization. Mating always takes place in shallow water, usually on ocean shores, or upon shallow river banks. Beforehand, the male will court her, nuzzling and nudging her as he walks around her, clicking gently. The female will then stand still, occasionally clicking as she awaits the male's next move. The male will then approach her side, before mounting her and sliding his paddle shaped tail beneath hers, so both cloacas are touching. He will grip onto her scaled sides with his small claws, holding himself in position for a few minutes, until he eventually slides off. The female will usually remain still directly after mating, whilst the male will plod out of the water, leaving her alone for a few minutes. After a minute or so after lying still in the water, the female will then plod off, before joining her mate once more. Mating may commence more than once between a pair, to achieve effective fertilization.  

After the yolk is fertilized, the egg will then pass throughout the female, layers of shell encasing the yolk. Inner and outer shell membranes, mineral salts, and water are added first, before albumen (the 'whites' of the egg) is secreted and layered around the soft yolk as well as more water, and then finally layers of hard shell encase the yolk (the shell is mainly made of calcium carbonate). This whole process takes an average of around a week, before the egg passes through the cloaca. 

Around a week or two after being mated, a slight bulge will be just noticeable around the abdominal area on the female. At this stage, the egg is nearly ready to be laid, and the pair will be off again, travelling back to their chosen nest site. Once arrived, the female will begin to make herself comfortable, creating a large mound nest on either soil, amongst foliage, or sand. Both parents will forage around for branches, twigs, leaves, bark, and even mud or sand, to make a suitable mound for the egg to be laid in. The mound will be draught proof (as quick icy changes can kill a developing embryo), as well as reasonably hidden amongst other vegetation so predators cannot easily spot and consume an egg. The mound nest will also be quite close to water, (at least a metre or two away) as it is important for the hatchling to get to the water quickly, so they do not die of either predators, lack of food, or protection. 

After a suitable mound nest has been created, the egg forming throughout the female should be ready to be laid. The female will then crouch over the nest, making sure there is an opening in the mound where the egg can slip into easily. The male will stand a little way from the female, guarding the two until the egg has been laid. 

She will then begin to push the egg out, her back slightly arched in the process. She may emit several distressed clicks, as egg laying can be a painful process for first time females. After a few minutes of pushing, the egg will eventually slip out from the cloaca, landing into the mound nest. The egg is grey-blue in colour, and is around 30cm long. The female may take a few moments to recover, before she and her mate will cover the egg with a thin layer of leaves, sand and dirt, before covering the whole nest completely. 

After the egg laying process is complete and the mound nest is suitable, both parents will leave the egg to hatch by itself. The blue lacerta pair will return back to their daily lives, hunting, sleeping, and interacting with each other, just like before. Reproduction is complete for both blue lacertas, although the egg is still yet to form and grow.. 

Male courting the female - female left, male right. 

A male blue lacerta approaching a female after courting.  - female left, male right. 

The Growing Egg~ 

After the parents have abandoned or left the egg in the mound, the egg will start to grow as soon as it receives ongoing heat. Because the egg is situated in a mound, during the day the mound will heat up, producing warmth for the egg. The conditions will be stable within the mound, with the proper amount of heat, and humidity needed to grow. Incubation of the egg lasts for a single year, and during that time the egg faces many obstacles. Weather, predators, and the changing environment are only a few, which means survival rates are fairly low. However, during thousands of years, blue lacertas have adapted to their environment, their eggs included. Blue lacerta eggs are encased with a particularly hard shell, the outer shell itself as thick as a centimetre in width. This provides much protection from too much or too little heat, and some predators. The thick outer shell also provides protection from other hungry blue lacerta hatchlings, and also stops too much water entering the egg, which could drown the growing embryo. 

There are many stages of development during the incubation of a blue lacerta egg. During the first three months, 'blood islands' will begin to form within the egg, linking with one another - creating a circulatory system whilst a heart is being formed elsewhere. Soon, the vascular systems will join and the heart will begin to beat for the first time. Small veins will begin to form and sprout out from there, and a small embryo will become visible. After the first five months of incubation, the embryo will continue to grow, limb buds forming, and the tail growing. After eight months of incubation, the embryo should fill up more than half the egg, with little digits forming upon it's small limbs. After three more months of incubation, the toes have been formed, and the webbing, scales and finnage begins to form. By this stage, the embryo has nearly filled the whole of the egg. And finally, during it's large month of incubation, the embryo would have filled up the whole of the egg - scales, fins, body, and even an egg tooth has been formed. 

After a total of twelve months of incubation, the embryo is ready to hatch. With a strong egg tooth firmly planted in between its' nostrils on it's upper jaw, the hatchling is able to make its' way out. The hatchling does not click or emit any other noises during hatching, as there are no parents around to help release them from the tight confinements. Providing the conditions are right for hatching, (humidity, heat.. etc) the hatchling will begin to tap at the shell. Hatching can take anywhere from five hours, to twenty five hours, it depends on the health of the hatchling, and the conditions at the time. As the hatchling continues to tap at the thick shell, a small hole or crack should appear, making it easier for the hatchling to continue. Unlike most reptiles, blue lacertas act like birds as they hatch, by tapping and 'zipping' their way around, until they are able to crawl out. After a couple of hours during the hatching process, the young hatchling should have made a small hole/crack in the shell and begin 'zipping' their way around, by tapping around the shell until a large crack appears and the shell splits in two. 
After many long hours of hatching, the hatchling should have tapped and zipped, the shell eventually splitting in two. After much tiresome work, the hatchling may take a few more minutes to crawl out of the shell completely. Newly hatched hatchlings usually recover in the small mound for a few more hours, before venturing out into the world for the first time. Hatchlings do not need to be fed during the first 24 - 48 hours of their life, as they are still absorbing their yolk sacs from the egg. Some hatchlings may accidentally hatch prematurely, and may even be still attached to their eggs by multiple veins. It is important they stay in the mound until these veins are absorbed into the body (via the cloaca) or else if the veins are damaged they may bleed to death. 

After many hours of recovering in the mound, the young blue lacerta hatchling is ready to crawl out, and venture into the world. Hatchlings may scrape, dig, or tunnel their way out, before instinctively scampering quickly towards the water. Like crocodiles, turtles, or any other water dwelling/mound building creature, this time is probably the most dangerous time of their lives. They must reach the water before being picked out for prey, which is common for young blue lacerta hatchlings. Once reaching the water, hatchlings instinctively know how to swim, (they may be slightly clumsy at first!) and usually head towards cover or a suitable shelter to dwell in. This can be anywhere from submerged rocks, logs, or coral beds, or even densely planted areas. These areas all have to be underwater, so the hatchling is reasonably safe, and can feed easily. Hatchlings will live like this, dwelling in water close to where they hatched and almost never venturing onto land, or straying into deeper water. Many hatchlings may group and cluster together, meaning more protection and safety. Young blue lacertas will life like this until they reach five hundred years old. During that time, hatchlings will continue to grow slowly, reaching about five metres in length by the time they are five hundred years old. 

Hatchlings will continue to grow and develop over the years, by the time they reach over five hundred years, they are ready to venture on land, and venture into deeper waters. Their diet will consist of more animal organisms than plant organisms, and will grow over ten metres in length by the time they reach one thousand years. At this stage, they are not considered as 'hatchlings' anymore, and in another five hundred years, the reproduction cycle starts again.. 

A hatchling nearly ready to squeeze out of the shell

A hatchling nearly completely free of its tigh confines of its shell