Construction of the bird cages
First cage (2002)
The nesting box is constructed of 6 mm thick wood. However, it is advised to use thicker wood (up to 15 mm) to keep the heat out. When the hole is 33 mm, the most plausible bird to build a nest is the great tit. How to saw the wood is described here. The first camera used was a black/white camera with an analog output. The advantage of black/white cameras is that the are very sensitive and that they normally have no infrared filters built in.
The first summer there was no bird interested, but during winter I discovered that a certain bird came in the house every night. The following summer in May and June I had the first nest. Unfortunately, the six chicks died on a very hot day, hence the advice to use thicker wood. Probably, a lighter colour of paint might help as well.
I could observe the activities in the birdhouse on a monitor. Pictures are taken with a digital camera from the monitor screen. This results into bad quality pictures. Next year I hope to connect a frame grabber to make better pictures and probably even movies.
Improved cage (2014)
The improved cage has thicker wood and internet functionality. How to optimise the camera and illumination is described here. The cage is pretty big from the outside as you can see in the pitcure, but when you look at the inside, the space for the birds is jus normal. I needed this overhead for the long focal point of the camera.
The biggest change is the move from an analog black and white camera to an IP-cam. With an IP-cam connected to the internet, I can easily detect motion and share pictures at real time. I have a software package running which was intended for security camera's that stores 30 seconds of movie every time motion is detected. Now I can monitor the infrequent visits of birds in winter as well.