The Purpose of Life and the Mystery of Chameleon Eggs

Introduction

One of the crucial topics in chameleon husbandry is reproduction, particularly the incubation of eggs. This subject is often surrounded by mystery, myths, and a mix of practical advice, misconceptions, and misunderstandings. To clarify the area of chameleon egg incubation, let's break it down step-by-step to build a clear and accurate understanding.

The purpose of life 

The purpose of life has been debated by philosophers and scientists, but in biological terms, it ultimately revolves around survival and reproduction. Organisms exist to grow, adapt, and pass on their genetic material, ensuring continuity across generations. Evolution favors traits that enhance reproductive success, shaping species over time. From simple microbes to complex animals, the transfer of genes defines life's progression. While individuals seek meaning in various ways, nature's driving force remains the transmission of genetic information, preserving diversity and adaptation. Life's essence is coded in DNA, carrying the legacy of all what came before into the future.

The Basis is Genetics, The Curse is Inbreeding and Crossbreeding

The foundation of effective chameleon breeding programs lies in understanding genetics and genome integrity. High-quality genetic material is crucial for producing robust offspring, ensuring compatibility among genetic lines, and maintaining healthy breeding populations.

It is essential to adhere to established breeding lineages based on original natural local populations. This practice prevents crossbreeding, which can result in weaker offspring with reduced fitness and vigor. When genetic material is not sourced from well-documented local populations, the lineage becomes diluted, leading to uncertain heritage and increased susceptibility to genetic weaknesses.

Moreover, preventing inbreeding is vital for maintaining heterozygosity within captive populations. A genetically diverse gene pool is key to the long-term sustainability of breeding programs, as it enhances the health and adaptability of the population. Inbreeding can result in the expression of deleterious traits, lowering the overall vitality and resilience of the species.

The Root of HQ Eggs is the Health and Nutrition of the Mother

The quality of chameleon eggs is fundamentally rooted in the health and nutrition of the mother. To produce high-quality eggs, female chameleons must be kept under naturalistic conditions that closely mimic their native habitats. This approach involves simulating essential environmental parameters such as temperature, humidity, light cycles, and the availability of natural substrates for egg deposition.

In addition to providing appropriate environmental conditions, the nutrition of the mother chameleon is critical. A well-balanced diet should include an adequate quantity of food with the widest possible variety of prey items to ensure all nutritional needs are met. This diet must be further enhanced with proper supplementation of vitamins and trace minerals, which are vital for the development of healthy eggs.

Stress-Free Egg Laying

Chameleons are generally very prone to stress, making the process of egg-laying or deposition critical, as it often creates an inevitable stress for the female anyway. The chameleon's body cavity fills with large round objects that need to be laid within a short time frame, causing the female to potentially lose more than half of its body mass during this process. Therefore, providing an appropriate and comfortable environment for the females is essential.

• Substrate Quality: The quality of the substrate is vital. In the wild, chameleons typically lay their eggs in soil, sand, or under plant debris. Only one species, the Tiger Chameleon of Seychelles, is known to deposit its eggs loosely into palm leaves or pineapple plants without digging. The substrate must be suitable for the female to dig a tunnel deep enough without collapsing, ensuring her safety. Dry sand and heavy soils are not the best options. In captivity, a combination of garden substrate with play sand is often preferred, while moist fine sand can serve as a good alternative. Coconut soil is not recommended due to its acidity and tendency to collapse.

• Substrate Depth: The depth of the substrate is also important. Smaller chameleon species, like the Madagascan Brookesia, lay their eggs on the surface and hide them under a leaf or minimal plant material. Smsll species dig shallow holes, bigger dig deeper. The average depth of a regular hole is usually between the head-and-bony length and total length of the female. So, larger species can dig holes up to half a meter deep. Some species, like the Warty Chameleon, can excavate very deep tunnels relative to their body size, for the eggs to resist to harsh dry conditions. It is however not good to offer too deep substrate, as many chameleon species simply dig so long before they reach a layer which they can not penetrate like roots or rocks. If offered deep substrate easy to dig in, they might exhaust their energy reserves to unnecessary digging and end up in dystocia caused by low level of energy.

• Substrate Temperature: Temperature is another critical factor. Chameleons require a suitable temperature for the eggs deposition, with some species being more tolerant of lower temperatures than others. For instance, the Carpet Chameleon will not deposit eggs if the substrate temperature falls below 20°C, as cooler conditions can impair egg development. Consequently, these chameleons often seek sun-exposed areas to ensure warmth.

• Shade or Sun: The choice of shaded or sun-exposed areas is species-specific. Some species, like the Warty Chameleon, prefer shaded, secluded spots to avoid sun exposure and can remain concealed in their tunnels for several days after laying their eggs. The Panther Chameleon often seeks locations under trees in the shade, but not where it is directly covered by bushes. Other chameleon species have different preferences, making it important to offer various options for laying sites to avoid unnecessary stress.

By allowing females to have choices in their laying environment, the hormonal changes associated with egg-laying can help them overcome stress. Once they find a suitable place, they will dig with focused determination, undistracted by their surroundings.

Understanding the Eggs & Their Environment

Chameleon eggs vary in quality based on species, incubation conditions, and environmental factors. They typically have soft, leathery shells that allow for gas exchange, ensuring proper embryonic development. They are laid in a clutch at the end of the dug tunnel. They are not moving during the entire incubation period, which lasts for many months up to two years in some species. They usually grow during the first months but can shrink in dry months too. 

It is important to understand some crucial principles:

• Egg Position: The eggs lay at the same position the entire course of the incubation period with no to minimum movement caused by their growing or shrinking or by accident. As the eggs are not moved in captivity as a rule during the incubations, there are no data showing whether the moving them is causing harm or not, some experiments suggest that the damage is minor. Anyway, any movement or shaking is unnatural and even solely for this reason, they should be avoided.

• Egg Aggregation: The eggs lay i a clutch together touching one another, communicating and exchanging water and gasses. The embryos even synchronise their heartbeat, speed of development their overall development so that they can hatch at same day, so that the babies can cooperate in digging the tunnel to leave the nest, as they are several centimetres to decimetres underneath the soil surface.

• Temperature Dependent Growth: The embryos grow step by step depending on temperature and might even stop their development in too low temperatures and stay in a dormant phase (called diapause) just supporting the basal metabolism of the embryo. This state can last days, weeks or even many months up to two years or even more. The higher the temperature, the faster the development.

• Sex Determination: Regarding temperature-dependent sex determination (TSD), chameleons exhibit a multifactorial sex determination system rather than strict TSD. Moreover, some species possess a strict genetic system of determining the sex, some not. Studies suggest that egg mass and incubation temperature interact to influence hatchling sex, with larger eggs producing females at lower temperatures and males at higher temperatures. A too high temperatures lead as a rule to development of a fraction of females, which possess male secondary sexual characteristics at last at an intermediate level of development, behave male-like, and, are either infertile or even hermaphroditic.

• Yolk Consumption: During the embryonal development, the yolk is transformed into anatomical structures and their growth on one side an in energy and substances supporting the metabolism of the growing embryo. The bigger the embryo, the more energy goes to cover its metabolism. Therefore, if a diapause is induced to eggs in initial phases of their development, it can last quite long and prolong the incubation e.g. of Panther Chameleon eggs to up to 36 months without significant influence on hatch and survival rates. If the diapause is induced while the embryo is already quite big, its basal metabolism spends the energy reserves of the yolk and if lasting too long, it can lead to weakening of the hatchlings, insufficient energy to hatch or even to death of the embryo prior to hatching (own unpublished data and experiments).

• Hatchling Synchronisation:

  The hatching process is in the wild usually strongly correlated with the onset of the rainy season. Due to diapauses and synchronising of the development of the eggs, the hatchling have the tendency to appear in a certain period of the year, regardless when the eggs were laid. The hatching process is induced by the ripeness of the embryo to do so, when all the structures of the bodies are developed to survive in the outer world, outside of the protective environment of the egg itself. Though not thoroughly studied yet, it seems, that the moistening of the egg membrane by excessive moisture through the heavy rainfall blocks the eggs breathing properties and forces the embryos to hatch due to the limited air exchange and danger of suffocation, similar as it is known e.g. in some terrapins.

• Factors' Fluctuations: All environmental factors to which the eggs are exposed are subject to irregularity and fluctuations. Nothing remains stable; everything changes due to seasonal variations, daily cycles, and unpredictable changes, which may be random fluctuations or trends such as global warming, climatic extremes, or human-induced alterations in the environment. Examples of these changes include habitat destruction, deforestation, irrigation practices, chemical pollution, and the use of pesticides or fertilizers. In captivity, many people operate under the misconception that they must maintain stable parameters for the eggs. Not only is this not necessary, but in some cases, it can also be harmful. Slight fluctuations are normal and, in fact, beneficial, as they mimic natural conditions. Seasonal and daily variations are crucial for the health of embryos and their subsequent development, as well as for the well-being of individuals after hatching. Emulating these fluctuations can enhance the overall vitality and adaptability of the newly hatched chameleons.

To provide the eggs with proper conditions for their successful hatching, the following factors are crucial.

Substrate Moisture

The moisture content of the substrate is crucial for the proper development of chameleon eggs. These eggs are typically deposited during the rainy season when the environment is generally moist, allowing them to absorb significant amounts of water and increase in volume. They also possess the ability to retain moisture over time. However, the egg membrane is permeable, and in very dry conditions, eggs can lose water. 

A fascinating adaptation of chameleon eggs is their ability to transfer moisture between one another. If the lower layer of eggs has access to moisture, the eggs on top, which might be completely dry, can still receive enough moisture from the surrounding eggs. This hydration mechanism helps ensure that all eggs remain viable during the incubation process. 

In captivity, it is essential to monitor and control the humidity of the substrate. This can be achieved using various methods, ranging from simple to more sophisticated techniques. The simplest approach involves regular inspection. If eggs appear dry or begin to shrink or collapse, moisture must be added to the substrate. While advanced hygrometers can provide precise readings of humidity levels, an effective method is to ensure that the substrate is moist before transferring the eggs from the laying site to an incubation box. Weighing the box along with the substrate and eggs during incubation allows for easy monitoring of water loss. Any reduction in weight indicates moisture loss, prompting the need to add water. Maintaining the total weight of the box, substrate, and eggs consistently throughout the incubation period ensures a stable environment conducive to healthy egg development.

Ventilation

From the early stages of embryo development, chameleon eggs need to exchange gases with the environment, similar to postnatal individuals, albeit in tiny amounts. The eggs require this exchange to expel carbon dioxide and absorb oxygen. They are laid in a loose substrate that is not hermetically sealed, allowing air to reach the clutch in both directions.

In captivity, it is imperative to place the eggs in an environment that supports gas exchange. This can be achieved by using a controlled environment such as an incubator, where the air volume is relatively large. Alternatively, eggs can be placed in smaller boxes with ventilation holes to facilitate air exchange. However, these holes also allow for water loss, so it is essential to monitor humidity levels and compensate for any losses throughout the incubation process.

Incubation temperature

The temperature is the most important environmental factor influencing the incubation of eggs, means development of the embryos. Temperature during incubation as a factor consists of the following sub-factors:

The ultimate way to establish the proper temperature regime for incubating chameleon eggs is not to rely solely on well-meaning advice from experienced breeders, which can be biased or even incorrect. Instead, it is essential to study the climatic conditions of the exact place of origin of the relevant species and draw your own conclusions.

The main sources of potential confusion are as follows:

• Not Where Chameleons Live in Fact is Measured: Climatic data are typically measured in dedicated locations, such as cities or airports. These places are heavily modified and do not accurately represent the real climate of the natural habitats inhabited by chameleons, as many of these biotopes have been destroyed by construction and human activities. This data should be viewed as general guidance rather than definitive figures. Real temperatures are often several degrees lower than those reported.

• Habitat Destruction and Fight for Adaaptations: Chameleons are sometimes forced to inhabit different biotopes than those they originally occupied due to habitat destruction. Forests are cut down and converted into agricultural landscapes, gardens, plantations, or even industrial zones. While some chameleon populations may become extinct in these new environments, others manage to survive and try to adapt to the changed conditions. It is important to note that most of the biotopes currently inhabited by chameleons were originally covered by dense rainforests with canopies 40 to 60 meters high. Thus, the original climate may differ from the current one by as much as 5 to 7 degrees higher.

• Global Warming: Whether or not one believes in global warming, it is a fact that average temperatures on Earth have increased by about 1.5 degrees over the last century. Chameleons are uncomfortable and are not fully adjusting to such rapid changes, especially within just a few tens of generations. Some populations show evidence of struggling to cope with this change, so it is prudent to consider this adjustment.

• Soil and Ambient Temperatures are Different: When incubating eggs, it is crucial to understand that soil temperature differs significantly from air temperature. Generally, during the day, soil temperature is several degrees cooler than ambient air temperature, while at night, it may be slightly (1 to 2 degrees) warmer. Soil temperature exhibits fewer fluctuations than air temperature, but it still varies between nighttime minimums and daytime maximums.

If you have thoroughly studied the climate of the relevant region, you can approximate the incubation temperatures as follows: For nighttime, use the nighttime ambient temperature of the area or 1 to 2 degrees lower; for daytime, deduct 5 to 7 degrees from the daily maximum. This adjustment should bring you close to the temperatures you would measure in the soil if you visit the biotopes currently inhabited by chameleons.

Take a look at the comparison of the temperatures I measured in Nosy Be, which highlights the differences in environmental conditions between the Capital City Helville, which is heavily deforested and modified into a town and Lokobe NP, with still original primary forests, which once covered the whole island.

Incubation Temperature Regime

The best practice is to simulate natural conditions.

The worst approach is to maintain a constant temperature in the incubator.

The best option is to set the incubator to the desired temperature regime.

Compromise option 1: Set the incubator to the desired daytime temperature and turn it off at night.

Compromise option 2: Incubate in diverse environments, such as a bathroom, where the temperature can fluctuate naturally.

Risks:

• Extreme high temperatures are fatal.

• High temperatures can negatively impact the vitality of the hatchlings.

• Overly high temperatures can adversely affect secondary sexual characteristics, the development of reproductive organs, hormone levels, and more.

• Excessively low temperatures can halt embryo development, causing the embryos to remain dormant for months. However, if they are inactive for too long, the yolk sac reserves may become depleted, resulting in weak hatchlings or death.

• Extreme low temperatures can be lethal, even in short or one-time exposures.