Incubating the Eggs

Incubating the Eggs


The incubating of eggs involves containers, media, and of course incubators.

Containers - This year and part of last year I used the Gladware™ Entree containers. You get five of them for less than $2.50 and four fill an incubator. These work well and are microwavable. There are also containers made by Ziploc™. However, these are smaller and don’t completely fill an incubator. I’ve also used Rubbermaid™ containers that are about one inch tall. I think they are meant for sandwiches. These work very well also.

Media - The only media I've used is vermiculite. I've heard that perlite also works well. An important part of the media is the moisture content. In an old Reptiles magazine article, I found a 2 to 1 (vermiculite to water) by volume moisture content recommended. This works fine and usually requires no additional water. Too much water will cause the eggs to have a fungus problem. Too little water causes the eggs to collapse, which seems to slow development even after adding additional water.

Incubators - The only ones I’ve used are Little Giant Still Air Incubator model 9200. I’ve gotten all of them from a local feed store. They run about $42 with tax.

Of course you will need a thermometer to set the temperature, since this is not part of the incubator. The easiest ones to use are digital (indoor/outdoor). Look for one with a small temperature probe since it makes life easier to have the display sit on top of the incubator. Testing the thermometer is important. I use a cup of ice water for this.

If the thermometer is within a couple of degrees of 32º F (0º C), then I use it. This is not exact but it works as a guide. The digital thermometer I’ve liked the best are from Radio Shack™ and cost about $10. The main thing to look for in digital thermometer is the size of the probe. You want it small enough to fit into the holes in the top of the incubator. This minimizes the times you have to open the incubator to monitor the temperature.

Putting It All Together - Gravid female iguanas go into a mode of behavior that could be called hyperactive weeks prior to laying eggs. When I see this, I set up the incubators and adjust the temperatures. I try to get the temperature in the area of 82º to 86º F. T

emperatures higher than 88º F will increase the risk of birth defects in the babies. The 82º F mark seems to produce the best offspring.

The night the female goes into the nest box and digs late, I add the vermiculite and water to the containers. After this, the container goes into the microwave for a minute and 30 seconds.

After heating I leave the lid on loosely and set them on the counter until they cool down. I store them in the incubator until the eggs are laid.

The eggs are put about 3/4 of the way up in the containers. Incubation lasts anywhere from 60 days to 90 days. This year I set a personal record for the longest time at 93 days.