Tour Eight
Caring for Turtle EggsOkay turtle fans, this tour was prompted by the many email questions we get about caring for turtle eggs. We had to wait for one of our turtles to lay eggs so we could take pictures to illustrate this tour. For the sake of our discussion, we will assume that your turtle eggs were laid by captive pet turtles or a turtle in your yard. Eggs in the wild are generally protected by law.
Many questions we get are about what to do when a turtle lays eggs in a yard or garden in a location that is not safe. One reader retrieved eggs laid in her yard when the nest was attached by fire ants. We had eggs laid by a northern ring neck snake on a piece of wood while being held for a few days for photographing - see Snake Pictures page. Eggs laid in an indoor or outdoor turtle enclosure may be accidentally (or intentionally) dug up by other turtles. And you may find an egg on top of the ground or in water which can be a good egg.
We retrieve our turtle eggs because we are impatient and we want to be sure we have the babies when they hatch. We also want to protect the eggs from harm including another turtle choosing the same nest site and we want to provide ideal conditions for the eggs to incubate.
When a pet female turtle is unusually active in the 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 a turtle of ours is seen digging a nest, we generally keep our distance. We do 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 will dig many holes over a period of days before laying; these holes are not covered. We also note the date the eggs were laid. So we have eggs. Here is what we do.
NOTE! Our procedure described herein is for eggs that are pliable from turtles that live in areas where rain in common and soil is moist. These are turtles found in the eastern United States. These eggs absorb and loose water through the 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 and may only begin to develop after a cool period. You will have to research the species for more specific information about incubating their eggs; we have no experience with hard shelled turtle eggs.
Before we unearth the eggs, we prepare trays in which to place the eggs. Disposable deli containers are good for this purpose. Small holes are punched around the top of the containers to allow air to circulate. A mixture is prepared in which to place the eggs. We have tried different mixes 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.
| pic 1 | pic 2 | pic 3 | pic 4 | pic 5 | pic 6 | pic 7 | pic 8 | 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 plastic 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.| pic 9 | pic 10 | pic 11 | pic 12 | pic 13 | pic 14 | pic 15 | pic 16 |
The eggs are partially buried but we do not cover them completely. This allows us to keep an eye on them. 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 of the egg. It varies some by the species of turtle. 84 degrees F is about the middle of the range so either sex may develop. At 84 degrees, we can have box turtles hatch in 50 days. The ring neck snakes also hatched in 50 days at this temperature.
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 do not pick them up to clean them because they break very easily. At about 50 days, we look at them often to see if they are hatching. A turtle may lie in the egg 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 eggs, 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 until the turtles move about freely. 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 start to collapse and they have been kept moist, they are probably 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 months, we examine the eggs and make a decision regarding discarding them.
The mix is discarded after the last egg is removed. We only use new mix for new eggs. The containers may be washed and reused or discarded.
Remember in nature, many eggs are laid for a few to survive. Forty per cent is a good hatch rate for us. 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 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.
The eggs in the pictures in the first part of this tour were laid by an unseen turtle. The site has been used in the past and is kept clear of weeds. The soil had been loosened several weeks earlier. It was noticed that the soil had been disturbed. Had it rained first, the nest would probably have gone undetected. They are probably box turtle eggs. Hopefully we will know more in two months. If we do get babies, they will be featured in the Baby Turtle Pictures page.
So what can you do if you don't have an incubator. Basically the eggs will be at the ambient air temperature but warm and cool slower than the air temperature. You could place them in the sun or under a lamp. The temperature is not as big a problem as moisture. Placing the eggs in a warm location usually means a drier location. And does the warmer location get too warm at times?
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 to wet. Pick a location where you will see them and not forget them.
To check moisture, squeeze a pinch of the mix. 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 mix rather than fill the container. If you are unsure about over watering, make a hole in the mix with a pencil. The hole should not have standing water in it. If 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 leave 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.
Artifical 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.
So whether we are using our incubator or another heat source, we always cover the eggs with a plastic deli container. It does not have to fit tightly but it must be between the heat source and the eggs.
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!".
Two questions now come to mind. How and what to feed baby turtles to start them eating and how do I get my turtles to lay eggs. Both these subjects will be covered in separate tours.
------ 6 weeks later ------
THEY HATCHED! 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 eggs. If these eggs had been buried completely, we would not have known they hatched so soon.
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 eggs 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 will be 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.
Here are some more pictures of the five box turtle babies:
Problem! Here is a story about a clutch of five eastern painted turtle eggs. One egg split open very early. Since we leave the turtles alone until they leave their eggs 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 eggs. 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.
| pic 33 | pic 34 | pic 35 | pic 36 | pic 37 | pic 38 | pic 39 | pic 40 |
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.
NEW>>> 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 mix 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 or they may develop dents. The egg shells are flexible and gain and loose water. Many dents disappear when they absorb water. Some eggs have dents when we unearth them. Dents don't matter.
| pic 43 |
Collapsed eggs: Some eggs collapse or fold over and are empty. Obviously these eggs are bad and should be discarded. This usually happens early on. A bad egg is a bad egg; there is nothing that can be done about it.
| pic 44 |
Bugs: Sometimes eggs look fine but attract 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. Again bad eggs are discarded.
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 media.
Unhatched eggs: 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 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. The babies actually absorb some of the egg shell material.
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 sold inside. Some take considerable squeezing without breaking. If we feel nothing sold, 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.
We know we have helped some viewers; we get email about eggs all summer. We are still learning too. We will pass along new information and revise this tour when we do. It does get easier with practice.
We hope you enjoyed our eighth behind-the-scenes tour. Come back again.
End
Revised 9/8/2006
