4. Reproduction of reptiles
Many species of reptiles can produce offspring in captivity. For their successful breeding in terrariums, it is necessary to provide close to natural conditions, suitable temperature and humidity. In order for young growth to develop normally, it is necessary to monitor its diet and be sure to give vitamins and mineral top dressing.
Turtles lay eggs, from which, after a certain period, the young hatch. Newborn turtles do not need parental care and are able to take care of themselves.
Turtles in captivity breed quite rarely. Breeding turtles is a painstaking and responsible work that only experienced specialists can do. However, the first to achieve good results was an amateur who devoted many years to his work, so you should not despair if you do not immediately get offspring.
One of the keys to success in breeding reptiles will be patience.
In order for the turtles kept at home to breed, you need to provide them with the proper conditions: proper nutrition, hibernation, a suitable habitat and relative freedom of movement.
For successful breeding, in addition to observing all conditions of detention, it is desirable to place several individuals of the same species in one pen or terrarium. When forming a group, the correct ratio of the number of females and males is important, which contributes to the manifestation of elements of mating behavior in these animals. In freshwater turtles, this ratio is approximately 2: 1, and in terrestrial in most cases – 3: 1.
In addition, when choosing animals, you need to take into account their age – you should select sexually mature, but not old individuals, which you must first check with your veterinarian. Sick or weakened animals are unlikely to produce offspring.
Trachemys can mate throughout the year. In terrarium conditions, the mating season usually falls at the beginning of spring; the female lays eggs from July to September.
For a while, a group of selected turtles needs to be carefully watched to determine how ready they are for mating games and breeding. If a relationship has been established between heterogeneous individuals, the remaining turtles need to be moved to another place.
It is interesting to watch the mating games of turtles both in vivo and at home. Both terrestrial and terrestrial turtles often manifest themselves in a completely different direction during the breeding season than in ordinary life.
Males of land species often fight among themselves, seeking the favor of their chosen female. They push around, trying to pry each other with a shell to flip onto their backs. Female turtles do not always prefer those males who won the fight. They can choose both the defeated and the male, who did not participate in the battle.
Turtles, like other reptiles, after building a nest and laying eggs do not care about offspring at all, and small turtles appear already completely ready for independent life.
In nature, water turtles lay their eggs in coastal sand, burying them near the pond. Land turtles dig masonry into a hole dug in the ground. Under natural conditions, mating in most species of turtles occurs in April-May, and offspring is born next spring.
In preparation for breeding in food for turtles, it is necessary to add products containing vitamin E. In nature, in most species of turtles, the breeding period begins immediately after hibernation, so it is recommended that animals be put into hibernation for several months.
Small turtles that have just hatched from eggs already see well and are guided mainly by sight. Under natural conditions, young water turtles in a few minutes after birth independently get to the water, being guided most likely by the level of illumination of water, which is higher than the illumination of land, even at night.
During the breeding season, turtles need to create comfortable conditions: do not disturb them, exclude all extraneous noise and vibration, try to touch animals as little as possible. At home, if you decide to breed, you must take care of the place where the eggs will be located in advance.
For freshwater turtles to start mating, the water temperature in the terrarium or aquarium should be 22–26 ° C. On land, you should prepare a place where the female will lay her eggs. You can dig a small depression in the sand or soil and place a container with sphagnum moss there so that it is on par with land. After the female lays eggs, the container should be removed and placed in an incubator. The temperature in the incubator should be maintained at 28-30 ° C.
After 2-3 months, depending on the type of turtle, small turtles will appear from the eggs. They must be immediately placed in the aquaterrarium or aquarium. They feed almost the same way as adult turtles, with the exception of plant foods.
The birth of a baby Balkan tortoise
Newborn baby turtles, like other reptiles, have the remains of the yolk sac, which disappear a few days after birth, as well as a special egg tooth with which they dissect the shell. In addition, in the first days after leaving the eggs at the turtles on the plastron, you can see the transverse fold – a consequence of the bent position of the cub inside the egg.
Land tortoise eggs should be placed in a sand container and kept in an incubator at a temperature of 28–32 ° C. If you do not have an incubator, you can use a regular glass jar or aquarium filled with sand, which should be regularly moistened. Such an incubator can be heated using a conventional incandescent lamp. You can put the incubator next to the central heating battery.
The eggs of turtles have a calcareous, sometimes leathery, oval shape. Their sizes vary depending on the type of animal. The number of eggs in a clutch can be from 2 to 8 pieces in a Mediterranean and up to 70 pieces in a Far Eastern tortoise.
Eggs laid by turtles are far from always fertilized. In order not to keep empty eggs in the incubator for several months, they need to be checked. To do this, you can build a primitive ovoscope: put a small light bulb in a small cardboard box, for example from a flashlight, and cover the box with a lid in which an egg-shaped hole is cut, but a little smaller. To test an egg, you need to put it, without turning over, into the hole and turn on the light bulb. Darkening will be noticeable in the middle of the fertilized egg, and the empty one will transmit light evenly. When checking, you should remember that the longer the maturity of the eggs, the more accurate the result.
The eggs of land and water turtles, unlike birds, cannot be turned over in any case, therefore, they should be transferred very carefully to the incubator.
After the female lays eggs, she should be kept away from other animals for some time. Female nutrition for several weeks should be enhanced, since during this period the immunity of turtles is weakened and they are more susceptible to various diseases.
If turtles appeared, you need to try to save them all. In no case should they be placed in the same paddock or terrarium with adult turtles, as these reptiles have no maternal instinct and can harm cubs.
Reproduction of all types of snakes occurs through sexual contact. The courtship process is known as the “snake dance”: the male pursues the female, tries to stop, presses her head to the ground, wraps her tail around it.
Snake eggs laid after mating usually have a parchment shell. There are oviparous and viviparous species of snakes.
With egg production, the embryo develops in the egg, laid in the environment.
With oviparous birth, the embryo develops inside the mother’s body, but at the expense of food reserves in the egg. With this type of reproduction, the cubs appear enclosed in a shell, from which they are subsequently released.
Live birth – the appearance of a fully formed young in a transparent leathery shell, which immediately breaks.
Under natural conditions, the mating season in snakes is preceded by a long wintering, which takes place in rodent burrows and other shelters. Some species of snakes, such as Amur snakes, adhere to individual sites that have been preserved for several years.
Formed mating couples return from wintering to their usual place where females lay their eggs.
Under natural conditions, the reproduction of snakes is usually seasonal in nature. So, the period of activity of snakes is March-April, October-November. Mating time lasts from March to May. During the mating season, several dozen snakes accumulate in a certain place, forming a tangle. After mating, the males creep, and the females remain in place, bearing eggs. An ordinary snake female can lay up to 50 eggs. There are cases when up to 1200 snake eggs were found in one nest. In such places, the eggs are often glued together and look like one large masonry. Unlike other types of snakes, snake eggs can tolerate significant fluctuations in ambient temperature without compromising embryo development.
Some species of snakes are able to lay fertilized eggs 2-3 years after mating, since the sperm inside the female remains viable for a long time.
Garter snakes are viviparous. After several months of pregnancy, females are born from 40 to 70 cubs.
The duration of pregnancy of snakes is different: in Amur and Aesculapius snakes – 33–45 days, in patterned – 60–70, in other representatives of the family of snakes – 48, in various species of pythons – 60-110.
When the pregnancy comes to an end, snakes build a nest from leaves and branches, arrange it in the hollows of low trees and under fallen trunks, in burrows of rodents and anthills. In the clutch of reptiles, there can be from 3 to 40 oval or elongated eggs, differing in size depending on the type of animal. Curling up around the masonry, the snake warms the eggs with the help of muscle contractions. Some snakes just bury their eggs in the ground, a bunch of vegetable debris. Most snakes do not show further concern for offspring. But some species, such as the four-lane snake, king cobra and silt snake, protect the masonry until the young.
Snakes grown in captivity to start mating games need not deep hibernation. Enough separate content, a slight drop in temperature during the month and termination of feeding during this period. A month after wintering, the females are planted with males for mating. Joining a pair of snakes can be carried out at any time of the year, but usually the terms remain the same as when breeding in the wild – February-March.
To breed reptiles in captivity, you need to pick up a pair. The sex of the reptile is determined by the peculiarities of color: the females are painted less brightly. In addition, males have a longer tail and there is a thickening in the lower row of scales in the anus. The sexual maturity of snakes depends on their age and body length. The length of the female should be at least 60 cm, the male – 50 cm.
During the breeding period and the first time after it, the content of snakes requires increased attention. The elimination of noise, the creation of comfortable conditions in the terrarium is necessary to increase the sexual activity of snakes. In the diet of animals feed with a high content of vitamins, phosphorus, calcium. However, many females refuse to eat during the period of gestation and laying of eggs.
The female royal python can do without food for 8 months, from the moment of mating until the birth of offspring.
If the female takes care of the offspring, hatches the masonry, then incubation in vivo is possible. At this time, you can not disturb the snake, you should carefully monitor its behavior to ensure normal conditions for the appearance of offspring. It is important to systematically monitor how the snake is located on the masonry, in order to avoid its partial opening and temporary removal from it. This contributes to the rapid cooling of the eggs and can lead to impaired embryo development.
It is interesting to observe the behavior of snakes during natural incubation. So, the female green python lays up to 40 eggs and protects the clutch for about 50 days. Curling up around it, the reptile is able to regulate temperature and humidity, either completely covering the masonry with the rings of its body, or partially opening it for ventilation.
Maturation of green python eggs can successfully take place in an incubator. A prerequisite for this is maintaining a high level of humidity.
The duration of the incubation period depends on the type of snake. Under terrarium conditions, it usually takes place at a temperature of 27–30 ° C and an air humidity of 90%. A similar regime is especially important for the red-backed snake, whose young appear in translucent egg membranes.
In order to ensure the safety of young animals during natural incubation, it is desirable to place shelters for newborns in the terrarium, into which adult snakes could not penetrate. Such precautions reduce the potential for parents to eat offspring.
In cases where natural incubation is not possible for a number of reasons, remove eggs from the terrarium in a timely manner. This is especially important for clutches consisting of a large number of large eggs that tend to stick together. Subsequently, this may cause difficulties in transferring them to the incubator.
In order not to damage the eggs of snakes, you should handle them very carefully. When moving eggs, you cannot change their position, turn over, as this can adversely affect the further development of embryos. This factor is most important for large snakes. For species that lay small eggs, such as common snake, it is not critical.
Artificial incubation is carried out in special incubators consisting of a container, heating and humidity maintenance systems in sawdust, peat, moistened moss. A container can be a box of glass, plexiglass, plywood.
An incubator is a container designed for keeping eggs and breeding young reptiles. When equipping the incubator, the temperature and humidity are taken into account at which the development of animals will occur properly.
The temperature regulator and incandescent lamp are elements of a temperature control and maintenance system. A moisture source, which can be used as a wide pan with water, and a device that controls its level, a psychrometer, are components of a device for maintaining and controlling air humidity, increased for eggs with a shell shell and lowered with parchment.
More closely monitor the masonry from the moment the first cut appears on the egg. Often young snakes do not immediately leave the egg, but remain in it throughout the day. It is important to remember that artificial extraction of snakes is unacceptable, as it leads to injuries, the death of a newborn animal.
Amur runner masonry
Young snakes about 12–20 cm long appear in a month. A week after the birth of the snake begin to catch small insects, frogs, in the same period the first molt passes. When feeding young animals, it should be borne in mind that they need more food than adults, and they should be given 2 times more often. Then, as it grows, the volume of food and the frequency of its intake are gradually reduced, bringing it to a level sufficient for an adult snake of a particular species.
The offspring grows rapidly: by 6 months the mass of snakes reaches 70 g, by the year 100 g, length exceeds 50 cm. Signs of sexual activity appear after a year, at 18 months reptiles reach puberty and are ready for reproduction.
The reproduction of lizards occurs mainly through sexual contact, with the exception of some species that reproduce by parthenogenesis. In this case, the offspring develops from the egg without its preliminary fertilization by the male.
Lizards are oviparous animals. They lay eggshells that develop for several weeks outside the mother’s body before they hatch. However, in some species of lizards, oviposition has formed. Their eggs are not covered by shells and remain in the female’s oviducts until the completion of embryonic development. Subsequently, already hatched cubs are born.
In South American skinks, eggs are devoid of yolk and develop in the oviducts, receiving nutrition from the mother through the placenta. Placenta in lizards is a special temporary formation on the wall of the oviduct, in which the capillaries of the mother and embryo come close enough to each other so that the latter receives oxygen and nutrients from her blood.
The number of eggs or calves in the brood can vary from 1-2 in large iguanas, skinks, and some geckos to 50 in other species.
Puberty in lizards usually depends on body size. In small species, it lasts less than a year, in large – several years. In some small forms, most adults die by laying eggs.
If you want to get offspring from the lizards contained in the terrarium, you must provide them with a suitable temperature and humidity level, taking into account their species characteristics. Particular attention should be paid to creating calm conditions for reptiles. Scientists have found that with various stresses the reproductive ability of lizards decreases, and in some cases elements of mating behavior do not appear at all.
The size of the terrarium also matters. Some species require a certain space for breeding, and if it is lacking, you will not be able to obtain offspring.
For reproduction, individuals who have reached puberty are selected. They must be healthy, mobile, brightly colored. The dimensions and proportions of the body should correspond to the average for each particular species.
It is important to properly form a community of lizards. Usually the following ratio of females and males is recommended: 3: 1 for chameleons, geckos, iguanas and agam, 3: 2 for skinks and real lizards, 2: 1 for monitor lizards. Males can be distinguished by their bright color, larger than that of females, in size, as well as by their behavior during the breeding season. Males of almost all types of lizards become very aggressive, their mating games take place in the form of fierce fights, when reptiles hiss, inflate their neck, make threatening movements and inflict sensitive bites on each other.
In some lizards – such as monitor lizards and venoms, it is sometimes difficult to determine sex visually. In this case, special methods are used: in particular, you can conduct a biochemical study for the content of male hormones. In any doubtful cases, it is better to consult a specialist from a veterinary clinic.
If you intend to keep a large number of lizards together, it should be borne in mind that a stronger male can suppress the weak. Therefore, after the formation of groups for breeding other reptiles, they are planted in a separate terrarium.
Lizards reproduce mainly through sexual contact.
It should be noted that when breeding in captivity some species, such as chameleons, you should especially carefully select a pair and carefully monitor the behavior of reptiles, as they may simply not like each other.
To stimulate reproduction, it is necessary to simulate natural conditions. To do this, first spend an artificial wintering for 4-8 weeks, during which feeding is stopped, the ambient temperature is lowered, and the daylight hours are reduced. During this period, you need to constantly monitor the state of reptiles. After the specified time, lizards are placed in the terrarium and gradually increase the temperature and humidity. Lighting should preferably be maintained for 15–16 hours a day for 3 weeks before the start of the breeding season. To achieve the best effect, you can apply ultraviolet radiation, as well as introduce vitamins and special feed additives into the diet of lizards. It should be borne in mind that females of some species may refuse food during pregnancy.
For the successful development of young lizards, it is recommended to regularly irradiate with ultraviolet light. This contributes to the assimilation of trace elements contained in the feed, and reduces the risk of infectious diseases.
For certain species of lizards – such as geckos and chameleons – it is not necessary to arrange an artificial wintering. To stimulate mating behavior, males and females are kept separately for some time at a temperature of 3-4 ° C below normal, and then combined. For geckos in the terrarium, it is recommended to place the remains of the shell from previous clutches.
Most lizards breed only in certain seasons. Depending on the characteristics of a particular species, it can be both winter and spring-summer periods. Others can mate throughout the year, making several clutches. These natural features should be considered when keeping and breeding reptiles in captivity.
It can be noted that in lizards adapted to terrarium conditions, the seasonal nature of reproduction often disappears, and they can lay eggs at any time.
The duration of pregnancy differs markedly in different species of lizards. In ovoviviparous reptiles, this period is longer, since all stages of embryo development take place in the mother’s body. In ovipositing lizards, gestational periods are somewhat shorter.
Lizards, like other reptiles, prepare a nest for future offspring by digging a hole in the ground. Under natural conditions, they can lay eggs in cracks and voids in the soil, in the burrows of rodents.
For home breeding, it is important to ensure that the layer of sand or gravel is of sufficient thickness so that animals can bury their eggs in it. For some species, pieces of bark can be placed in the terrarium, which at the same time serve as a shelter and a place for eggs to attach.
In terrarium conditions, both natural and artificial incubation are possible. Some lizards can guard the clutch until the young. If you intend to transfer the clutch to an incubator, you should be very careful with it, being careful not to damage the egg shell.
Viviparous lizards often take care of offspring not only in nature, but also in the terrarium. They protect the kids from possible danger and take them to warm places.
Incubation usually takes place at a temperature of 28–31 ° C and lasts 50–60 days for geckos and skinks, 60–80 days for iguanas, 130 days for venomous teeth, 170–180 days for Cape monitor lizard, and up to 190 for common chameleon days. The duration of incubation may depend on the ambient temperature, increasing as it decreases.
Humidity of the environment and the substrate in which the eggs are located is also important for the development of embryos. The value of this parameter is individual for each particular species.
To preserve the young, 4-7 days before its appearance in the terrarium, shelters should be equipped for newborns into which adult lizards could not penetrate. This reduces the likelihood of cannibalism.
Young reptiles are also recommended to be planted, which will provide them with the necessary living space for the proper development.
As food for newborn lizards, various small insects are given: crickets, cockroaches and others. Depending on their species preferences, juveniles can be given fruit slices, cabbage and salad leaves, cottage cheese, and newborn mice. For harmonious development, vitamins and mineral supplements should be given. Sometimes young lizards refuse food, so artificial feeding is necessary.
Crocodiles are egg laying reptiles. They produce offspring on average once a year, laying several dozen eggs in a calcareous shell.
Reproduction of crocodiles in captivity is a rather rare event. It becomes possible only if proper conditions of detention and proper feeding are observed.
During the period of sexual activity, it is recommended to create calm conditions for reptiles, to choose the optimal temperature and level of illumination in the terrarium. An important factor is ultraviolet radiation, which in nature crocodiles get in a natural way.
It is necessary for reptiles for the normal assimilation of mineral substances and is especially important during the period of reproduction and growth of young animals. Therefore, when keeping crocodiles in the terrarium, it is necessary to install special ultraviolet lamps.
Since crocodiles are the largest of the captive reptiles, you should provide them with the appropriate area of the terrarium during the breeding season, so that they feel as comfortable as possible.
When reproducing crocodiles at home, great attention should be paid to their diet: along with regular feed during mating and pregnancy, give reptiles vitamin supplements and foods with a high content of calcium and phosphorus. With a lack of these substances, the offspring may have deviations in the development of skeleton bones and teeth.
After laying the eggs, the female should also be given food containing the necessary trace elements to replenish their supply in the body, expended in the process of gestation.
In nature, crocodiles reach puberty by five to seven years. Mating in many species of crocodiles usually occurs in November-December, they lay their eggs in the spring. Crocodile caimans can mate and lay eggs throughout the year.
Crocodiles usually form a pair only for the time of breeding. However, there are cases when these reptiles maintained mating relationships throughout their lives.
For all types of crocodiles mating games are characteristic. Before entering into an intimate relationship, adult males must defend the right to establish a family in a certain territory.
The sizes of individual plots in representatives of different families are somewhat different. So, for every male Mississippian alligator has an area of several square kilometers.
The invasion of a stranger, especially during the mating season, ends with a decisive rebuff. Fierce battles often have sad consequences: broken jaws of opponents, wounds on the body, etc.
The possessions of the Nile crocodile are limited to a 100-meter coastline and territorial waters along it. These animals are less bloodthirsty and during the mating season are limited to a demonstration of their strength. Males take warlike poses and make sharp sounds that resemble a growl. In this case, rivals strive to intimidate each other by striking tails on the surface of the water. The weaker male usually flees, and the winner begins the courtship ritual.
Having overtaken the female, the crocodile begins to describe circles around her, trying to subdue her.
Before laying eggs, the female crocodile builds a nest. Females of the Nile crocodile and gavial usually burrow their eggs in coastal sand. The Mississippi alligator and combed crocodile build mounds of grass about 1.5 m high and 1 m wide, lay eggs in recesses at the top of the nesting chamber, and cover them with grass to maintain a certain degree of humidity.
Under terrarium conditions, the place for masonry can be a bunch of leaves mixed with sand, or a hole with a nesting chamber filled with the same mixture.
Crocodile eggs are similar in shape and size to duck eggs. Their number in the masonry varies depending on the type of crocodile: for a smooth-faced caiman – up to 10 pieces, for a blunt-crocodile and a crocodile cayman – 15-30 pieces, for a Mississippi alligator – 50-60 pieces. By the beginning of laying, the eggs already contain embryos, since their development begins in the mother’s womb.
Little Chinese Alligator
The incubation period averages from 70 to 110 days. The temperature in the terrarium during incubation should be maintained at 31–32 ° C.
When the development process of crocodiles in an egg comes to an end, they begin to make loud peculiar sounds that the female crocodile hears. She helps her offspring to be born by carefully crushing every egg in the mouth and freeing newborn crocodiles from the shell. You can observe how the female holds her cubs in the mouth, without causing them any harm.
Having collected all the newborn babies, the mother transfers them to a previously prepared reservoir. Interestingly, similar operations are sometimes performed by the male, which further continues to take care of the cubs.
At first, about 2-3 months after birth, small crocodiles stay close to their mother and do not leave their nests. Parents protect them from possible enemies, and kids are able to swim and get food for themselves.
In terrarium conditions, small fish, small frogs, mice and insects are given as food for young animals. Young crocodiles are fed every other day, the amount of food is calculated based on their size and should be approximately 10% of body weight.
In the terrarium, shelter for newborn crocodiles should be arranged. It is important to constantly monitor their condition, as young individuals are more sensitive to environmental conditions than adults.
Despite the fact that crocodiles take care of their offspring, it is better to grow up young growth and keep it in a separate terrarium. This will help to control the development of animals, identify abnormalities, symptoms of possible diseases and, accordingly, take timely measures for their treatment. Crocodiles that were born reach a length of about 20 cm. They grow very quickly in the first months of life and can reach 1–1.5 m in size by two or three years.
Watching crocodiles, scientists have established an interesting fact. It turns out that the sex of future crocodiles is determined by the temperature at which incubation occurs. At 31.5 ° C and lower, only females hatch from eggs, at 32–33 ° C females and males appear approximately equally, and at incubation temperatures above 33.5 ° C only males are hatched.