Caring for Turtle Eggs
This tour was originally prompted by many questions we received asking how to care for or incubate turtle eggs. At the time we had to wait for one of our turtles to lay eggs so we could take pictures to illustrate this tour. That was a long time ago and what we do is routine now. We continue to receive many questions on this subject and we always try to help.
For the sake of our discussion, we will assume that all the turtle eggs in question were laid by captive pet turtles or turtles in someone's yard. Eggs laid in the wild are generally protected by law. We hear from many people who see turtles laying eggs or fine eggs in their yards, gardens, driveways, dirt roads, shoulders of roads, construction sites, dirt piles, and the like. We will consider all such places as simply in someone's yard.
Most people are surprised wild turtles choose to lay eggs in their yards. We think it is not surprising at all. After all we usually see many wild animals do exactly the same thing. Birds and bunnies nest in our yards. Why do bunnies nest in yards with dogs or cats. We call turtles who nest in yards "urban" turtles. Read our opinion Urban Turtles on our In My Hard Shelled Opinion page.
Many people ask what they can do when a turtle lays eggs in their driveway or yard in a location that is unsafe or inconvenient. One reader retrieved eggs laid in her yard when the nest was attached by fire ants. We were holding a northern ringneck snake for photographing when she laid eggs on a piece of wood - see Snake Pictures page. Eggs are laid in indoor and outdoor turtle enclosures which may be accidentally dug up by other turtles. Eggs of pet turtles are found on top of the ground or in water. People uncover turtle eggs when digging. Many people do find turtle eggs.
We retrieve the eggs of our pet turtles because we are impatient and we want to be sure we find the babies when they hatch We want to protect the eggs from harm including another turtle choosing the same nest site. We also want to provide ideal conditions for our turtles' eggs to incubate.
There is another reason we retrieve our turtles' eggs. Occasionally we find a baby turtle in one of our pens. Then we have to be very careful where we step until we find the nest and account for all the eggs. And if we do not find the nest we can not move about the turtle pen freely for fear of stepping on a baby turtle. On one occasion we found a baby western painted turtle in our pond. We searched and found the nest of two eggs and the second baby. This nest was at the intersection of paths in the pen and must have been stepped on dozens of times. Both babies were fine.
When a pet female turtle is unusually active in late afternoon or early evening or a water turtle is out of the water in the morning where we do not expect to see her, we think eggs. If one of our turtles is observed digging a nest, we generally keep our distance. We make note of the location so that we can retrieve the eggs later. If the sight is covered, we know eggs were laid. Some turtles dig test holes over a period of days before laying; these holes are not covered. We also note the date the eggs were laid.
NOTE! Our procedure described herein is for eggs from turtles that live in areas where rain is plentiful and soil is moist. Most are pliable and some are hard shelled. This is typical of most turtles found in the eastern United States. These eggs absorb and loose water through the egg shells and begin to develop immediately. Eggs from turtles and tortoises that would live in arid locations generally have hard shells that do not gain and loose water as readily and may only begin to develop after conditions are right.
Most frequently asked questions: Before we describe what we do with our turtle eggs, we want to answer the questions we hear over and over.
1. How to tell the top of a turtle egg. When a turtle embryo in an egg begins to develop it attaches to the top of the egg shell. If the turtle egg is turned, the embryo will most often die. Therefore, the tops of all turtle eggs should be marked with a felt tipped marker before they are moved. If the eggs are moved and turned without being marked first, there will be no way to tell the top of the eggs. In such cases we recommend leaving them in the positions they are in and hoping for the best.
2. Can turtle eggs be candled (held up to a light). Turtle eggs are not like bird eggs; we have never seen anything by holding them up to a bright light. We strongly recommend not handling turtle eggs once they are placed in incubation containers. As the embryos develop, some of the components of the egg shells are absorbed by the developing baby. Therefore, the egg shells become weaker and are easily broken. Also the egg shells of eggs laid after the first nesting of the season by a given female are often much thinner than her first nest of the season.
3. Can heat lamps be used to keep eggs warm. If turtle eggs become too warm, they will spoil. Radiant heat from a heat source will heat eggs more than the air temperature around them. Therefore, we hesitate to ever agree with using a heat lamp or placing egg containers in the sun. Summer temperatures are warm enough for the eggs to develop without the use of added heat. It is better to allow them to incubate slowly and safely than have no eggs hatch.
Here is what we do:
Before we unearth eggs, we prepare containers in which to place the eggs. Disposable deli containers are good for this purpose. Small holes are punched around the tops of the containers to allow air to circulate. A mixture is prepared in which to place the eggs. We have tried different mixtures recommended by various articles on the subject with mixed results. So we settled on using some of each of the popular ingredients. We use 1 part vermiculite, 1 part peat moss, and 1 part sphagnum moss. The mixture is soaked and the excess water is squeezed out. The containers are filled and depressions are made for the eggs. It's better to have more capacity rather than not enough so we fill what we think will be an extra container. We do this before we disturb the nest.
We expect to have several nests in a season so we prepare enough of the mixture for several additional containers. It is stored in a plastic jar and may be stored wet or dry. It is like moist potting soil; it will not spoil. We have also ceased to make multiple depressions for individual eggs; we now make one big depression of all the eggs like shown above.
Next we move to the nest site. The nest site many be easy to locate, but the eggs may not be exactly where we think they are so we dig carefully like archeologists digging for ancient artifacts. A spoon and paint brush work well. The eggs are carefully uncovered without moving them. A mark is placed on the top of each egg with a black felt marker; the eggs must always be placed right side up after they start developing. After the eggs are marked, they are placed in a container.
A word of caution! Turtle eggs will spoil at temperatures much above 95 degrees F. Therefore, we do not unearth eggs on days the air temperature is above 95 degrees. We also do not work in hot sun. We learned this the hard way.
The eggs are partially buried but we do not cover them completely. This allows us to keep an eye on them and air to reach the eggs. Turtle eggs gain and loose water. It is much better to be wetter rather than drier. We keep our eggs moist with the tops exposed.
The containers are closed and placed in an inexpensive incubator maintained at 84 F. The sex of a turtle is determined by the temperature the egg incubates at. It varies by the species of turtle. 84 degrees F is about the middle of the range for our turtles so either sex may develop. At 84 degrees, we can have box turtles hatch in 50 days. The ringneck snake eggs mentioned above also hatched in 50 days at this temperature.
Tight lids can be hard to open without jarring the delicate eggs inside. If we are using deli containers that seal tightly, we cut the lids so that they are easy to open. We just set the lids on the containers until we think the turtles are ready to hatch. Then we tighten the lids enough to contain the babies. And we always use lids so that the radiant heat from the incubator heat source does not overheat the eggs.
We keep the small thermometer that came with the incubator with the eggs. We do not allow our eggs to get too warm in hot weather. We move the incubator to a cool place if the temperature reaches the 90s. Basically we avoid temperatures in the 90s so the eggs don't spoil.
The eggs are checked about once a week to see that they are moist and not deteriorating or moldy. Mold can be carefully wiped away with a cotton swab if it develops. We never pick up the eggs to clean them because they may break easily after they are developing. At about 45 days, we look at them often to see if they are hatching. A turtle may lie in the egg shell several days after breaking it open. During this time it absorbs the last of the egg yoke sack attached to its belly. A baby turtle has an egg tooth for breaking open the egg which appears as a white bump on its' noise. To see what an egg tooth looks like, study the pictures on the Baby Turtle Pictures page.
As turtles leave their egg shells, the egg shells are removed so as not to contaminate the container unnecessarily. The turtles are placed in another container on a moist paper towel for several days until the yoke sack is completely absorbed and the turtles move about freely. This container is not kept in the incubator. Then they are moved to a vivarium or pan of water.
If one turtle hatches, the others should soon follow. Eggs that don't hatch are given plenty of time. It is natural for some eggs to have dents in them. If they collapse, they are bad. Sometimes eggs leak out the bottoms and look fine. Some eggs will look perfectly fine after six months, but eggs kept consistently warm will not take six months to hatch. At some point after four to six months, we examine the eggs and make a decision regarding discarding them.
The mixture is discarded after the last egg is removed. We only use new mixture for new eggs. The containers may be washed and reused or discarded.
Remember in nature, many eggs are laid for a few to survive. And not all baby turtles will survive. Some live many months without eating. In nature many babies are eaten and the weak ones don't last long. But those that hatch are a joy and those that survive may grow fast. And some give us joy for a year and die for no reason we can identify. Remember, not many turtles survive to become adults. So don't blame yourself if you tried and your eggs don't hatch or a baby dies.
So what can you do if you don't have an incubator. Avoid direct sun! There is too much risk of overheating. Normal summer room temperatures will do. Just watch the high temperatures and keep the eggs moist. Pick a location where you will see the container often and not forget about it.
To check moisture, squeeze a pinch of the mixture. Don't rely on it looking wet. It should at least moisten your fingers. You can add water by pouring it directly over the eggs and around them. The water should be absorbed and held by the mixture rather than fill the container. If you are unsure about over watering, make a hole in the mixture with a pencil. The hole should not have standing water in it. When the eggs begin to hatch, stop watering.
Light is not a problem. Our incubator has a plastic window for viewing the eggs. It also has small holes to allow air to enter from the bottom and exit the top. So if you choose to place your egg containers in the dark such as in a shoe box, provide air holes and watch for mold.
Artificial heat sources like light bulbs and heating elements radiate radiant heat as well as heat the air by convection. Radiant heat is similar to the microwaves in a microwave oven. If you place a hamburger bun in a microwave oven for fifteen seconds, the bun becomes hot while the air in the oven only warms from the bun. Radiant heat can overheat the eggs while the air temperature is acceptable. Overheating caused by radiant heat can be prevented easily by simply covering the eggs with the lid of the deli container. The lid absorbs the radiant heat heating the air above and below it.
Lastly don't hesitate to talk to your eggs like you will talk to your turtles. Some researchers believe the babies communicate with each other before they hatch. Maybe; maybe not. Think of them as your pet turtle eggs before they are your pet turtles. Why not have them know your voice when they hatch. Before we purchased an incubator, I said to my eggs many times "Come on guys, hatch!".
The eggs in the pictures above were laid by an unseen turtle. The site had been used in the past and is kept clear of weeds. The soil was loosened several weeks earlier. It was noticed that the soil had been disturbed. If it had rained after the eggs were laid, the nest would probably have gone undetected. You can learn more about spotting turtle nests on the Breeding Pet Turtles page.
Just 44 days after being laid, five baby box turtles hatched from the seven eggs. All hatched the same day. Another egg cracked open on day 46 revealing a partially developed embryo that had stopped developing. The last egg was attracting tiny insects which is a sign that the egg was bad. Investigation revealed another partially developed embryo that had stopped developing. Five healthy babies out of seven eggs is excellent.
Here are some pictures. Day 44 the eggs break open. Note the position of the turtles. Day 45 the babies roll over on their bellies and hide their faces. Day 46 the babies move out of their egg shells. If these eggs had been buried completely, we would not have known they hatched when they did.
More information about the nest site. The day after the eggs were unearthed we decided to do an experiment. We buried the bulb of an indoor/outdoor thermometer at the depth of the nest at the same location and mounted the thermometer on a stick. Temperatures during this period were hot. There were many hard thunderstorms. The nest site ranged from 72 to 80 degrees F. Pretty good nest site!
Our five babies are featured on the Baby Turtle Pictures page and another tour on feeding turtles. They spent two days on/in a wet paper towel and were then moved to a small plastic critter box with soil and moss. This critter box had been setting around for some time after being a hold box for salamanders. The 20 long vivarium was replanted with moss and readied for the babies. They were moved there after they were more mobile and eating. If they were moved too soon, they would have dug under and been too hard to find.
A Problem Egg: During the incubation of five eastern painted turtle eggs, one egg split open very early. Since we leave the turtles alone until they leave their egg shells themselves, nothing was done. A head was observed in a pool of yoke - not good! Over several days the head was seen several times. About a week after the egg broke open, two other turtles hatched and left their egg shells. A day later the other two eggs split. Still the turtle in the first egg did not emerge. A day later mold was observed in the yoke so the baby had to be removed.
The turtle and the yoke had mold and there was plenty of yoke left. There was no formation of a yoke sack. The baby was small and its shell was not completely developed. It was a runt but it's legs, head, and tail were completely formed and normal. The last two eggs had partially developed embryos.
Our runt appeared fine. It was the first one of the clutch to eat. Take a look.
We never would have expected this runt turtle to survive. It is surprising that the egg yoke did not spoil sooner. But we waited as long as we could and are pleased we did. We would have said that a broken egg was doomed. We were proven wrong. This baby turtle survived a pretty poor start but it made it.
More about turtle eggs:
Now you know how we care for our turtle eggs. But we still get email from people worrying about their eggs. We understand. Let's look closer.
Dirty eggs: As you can see in the pictures above, turtle eggs are not clean when we unearth them. We place them directly into containers. We do not clean them. They only get worse from the wet mixture we put them in. They may stain or discolor. They just are not as pretty as the chicken eggs in our refrigerator. That is the why it is. We do not clean them because we do not wish to break them.
Dents: Generally eggs are full and round when they are laid. However, some may have dents in them when they are laid or they may develop dents. The egg shells are flexible and gain and loose water. Many dents disappear when they absorb water. Dents don't matter.
| pic 43 |
Collapsed eggs: Some eggs collapse or fold over. Obviously these eggs are bad and can be discarded. This usually happens early. A bad egg is a bad egg; there is nothing that can be done about it. But as long as there are other eggs being incubated, there is no hurry to discard a collapsed egg.
| pic 44 |
Bugs: Sometimes an egg look fine but attracts very tiny bugs the size of fruit flies. This is an indication that the egg leaked yoke out the bottom of the egg. If we see bugs, we check the eggs for leaks. Sometimes these eggs are completely empty.
Flies may also lay eggs on the turtle eggs. If these eggs have not leaked, they may be washed clean under running water and placed in a clean container of fresh mixture.
Eggs that don't hatch eventually must be considered for disposal. Having
experience incubating box turtle and painted turtle eggs, we know what
to expect from them. The first rule is to give them more than enough time.
This can be a very long time without an incubator.
We have observed a difference in the eggs as turtles develop inside. At some point before hatching, baby turtles begin to breath. The egg shells become more flexible and there is air inside rather than yoke. It is very noticeable when we draw a finger gently across an egg. We may even feel movement inside. The egg shells are thinner and weaker, too weak to pick up. Other eggs may become rigid and look like they are ready to pop. In these the babies have filled the space completely.
The egg shells of eggs that don't develop may be very strong and flexible. The eggs are generally not completely full. Some we can squeeze in our fingers feeling for anything solid inside. Some take considerable squeezing without breaking. If we feel nothing solid, we open an egg. If it is all yoke, we discard it and continue to examine all the eggs. It is common to have a good clutch of eggs that are not fertile even when males are present.
It can be nerve-racking to incubate eggs without practice. One person kept asking for more information. I finally told him that what he needed to know was that incubating turtle eggs can drive you nuts waiting. So plan on waiting, and waiting, and waiting, and....... It does get easier with practice.
We hope you enjoyed our
eighth behind-the-scenes tour. Come back again.
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