discussion / Sensors  / 2 March 2016

Eggs Eggs and more Eggs

Which came first the chicken or the egg? We know an awful lot about chickens and there eggs but we seem to know a surprisingly little about most other species of birds and how the incubation process happens. We understand the basics of parent sitting on the egg or not and we can count the number of days (even this data can be a little sketchy sometimes).  There are lots of variables in the world for a bird that is incubating an egg such as wind, rain, sun, temp and humidity and yet they manage to get the egg to the point of hatch in most species more often than not. This tell us a couple of things, firstly eggs are designed to hatch and that birds are good at what they do. The problem comes when you add the humans.

Why do we step in?  There are many reasons that we may want to artificially incubate eggs from very low levels of population left to parent birds that may damage or destroy the eggs or chicks, so here comes the crunch. We know how to incubate chickens an get a very high success rate. We know that a percentage of eggs will hatch even if the temperature and the humidity is incorrect (they are designed to hatch) but to get the highest possible percentage we can we need to better understand what is going on under the parent birds as they know what they are doing. There are of course other areas of interest that we are looking at such as the critical first part of the incubation (first 10 days) where if you can get parental incubation the success rate of artificial incubation is much better. So how do we find out more?

There have been many studies that look at temperature and humidity in eggs under parents, there have been studies of rotation of eggs. What we wanted to create is an egg that can go under the bird and measure not just the temperature that the egg is exposed to but also the temperature gradient of the shell. We also want to know more about the movement and the forces that the egg is exposed or subjected to, the environmental conditions also will play a part so the environment needs looking at as well. This would then allow for behavioural studies to be done to help improve the housing for birds in breeding projects.

With all these ideas and a few more we started looking for a solution that would be low cost and be able to be replicated by anyone else interested in doing similar studies with other spices or locations.

The egg shell that we need has to be strong light and it would be an advantage if the finish was egg shell like. Powdered Nylon seemed to fit the bill and the first eggs were printed to allow us to see if the eggs would be strong enough to not break. One of my greatest fears with any tech near animals is harming them. LiPos are a particular potential problem weather it be ingestion, over charging or undercharging leading to fire. The Nylon is very strong and light and passed all the tests that were thrown at it or Condors it was given to. Once we were happy we had to spend a little time getting the shape right. It’s funny how everyone thinks they know what shape an egg is until they have to make one (Jason).

To keep with allowing other to continue the development the Arduino was chosen as the platform to base the project on also it’s low cost and availability.

The sensors we are going to need were for the temp humidity and the movement. We started off with the dream number of sensors and worked our way back to what we could achieve. The proliferation of components available thanks to the mobile phone industry and the project world has been amazing. We opted for a 10 Degrees of Freedom module (10DOF) that would give us:

3-axis gyroscope

3-axis compass

3-axis accelerometer

barometric pressure/temperature

this gives us what is happening to the egg when it is moved by the parents.

The egg then needed an array of temp sensors to cover the surface of the egg allow for the temperature gradient to be monitored. To start with we were using DS18B20s but we have now moved on.         

The data is passed wirelessly via a small base station that also works as a weather station located near the nest site. The option for high-speed data can be used via Micro SD within the egg.

We are trying to achieve a 60 day running time for the egg as this will allow for the monitoring of Griffon Vultures and Condors. Short time should be simpler to achieve but the size of the eggs is a continued limiting factor.

I have to mention that we were very lucky that microduino step up and said they would help with the project. We are currently about to have the fisrt 3 eggs finished and ready for testing and I'll post up links to the code and hardware. If anyone would like to know more or has an interet in this project please let me know.

Latest news about this project was picked up by the BBC world service for a short interview


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