If the differences (number of nests) are too big between floors then you have to do something to correct it. This is because the Bh was not designed properly and the builder didn’t anticipate how the light density is going to be, it is built based on experience and trial and error. Most of them have no ideas of what light density is and it’s never come across their mind until they discovered that the lowest floor has the least nests. Some Swiftlet farms even find dead birds in the lowest floor.
Young Swiftlets use vision to navigate as they are yet to master the use of their echolocation (radar) in total darkness. So it would be a big problem for them in total darkness. They know, once they fly down to the lower floor chances are they will never find their way out and dead is certain.
I am sure those who have Swiftlet farms had experienced this. Switch on all the lights in your Swiftlet farm you will notice that Birds will keep circling in the Bh it would take a while for them to fly out. Once you switched off the light within minutes all are gone. They have found their way out thru the glare from the entrance hole. (That is why I did mention about the disadvantages of multiple entrance holes which confused the young birds).
If a light is to be installed use one with small watt (5wt), make sure it is not too bright. It has to mimic the natural brightness that glared from the entrance- hole or the roving, recommended “day light” (Not warm light or other colors) use Philip Genie which will last many hours.
Cover the light PVC tube so that the glare will be directed downwards. This is to prevent the glare from hitting the nesting planks. So from far it looks like a ray from the top floor glared all the way down to the lowest floor. By doing this light from the PVC tube would look natural rather than artificial.
Make sure the light is placed at the right area. Put it nearest to the Inter hole, on the wall or below the nesting planks. Never put them on the floor of the ground floor. If you do then you would see birds flying down to the lowest floor circling around the light but still have trouble finding their ways out and you ended up seeing dead birds.
Most important the light must be operated by a timer. I am sure many of you don’t use timer and left the light on for 24/7. The light should be switched on from morning till late evening and should be switched off during night. This is to mimic the daylight. All living things are subjected to the condition of the natural environment and the cycle of the Sun and Earth. By switching off the light during night the birds would feel more comfortable as it affect their biological time thus encourage population growth.
If you have not done it you should do it. I assure that you would see the different.
Good Swiftlet Farming All!