This was a message from a newbie from Sarawak.
He just put his wooden BH into operation but the picture given shows something which makes me feel that the monkey house is just too small.
Firstly we need to understand the basic function of a monkey house and how it can be a useful tool to attract those swiftlet into your BH.
A properly designed monkey house can be a great asset in drawing those birds into the first part of your BH.
First what should be the ideal size and height?
We know that those birds need a 4 meters and 4 meters size area to fly in a smooth circular motion. So why don't we start with this minimum dimension. This should be the minimum size. If you have the space make it bigger say 4.5 meters by 4.5 meters!!
What about their height?
There are many advantages to have the hole as high as you can. However when it is too high the birds will tend not to fly down towards the entrance door leading into your nesting room. They are lost up on the ceiling of your monkey house and don't want to fly downward.
You need to choose the right height, not too high but not too low. I think about 7 to 8 feet above the roof top will be more then enough.
Okay what about the entrance hole(s). Where should I open the window, how many, what is the ideal size plus where should the window face towards?
Once you have the four walls up an its roofing you need to locate the most appropriate opening(s) to draw those birds into the house.
My first choice will be to face the main entrance hole towards the flying path ( the direction they fly home in the evening).
It will be at the right hand corner to ensure that when they enter the monkey house they can fly in an anticlockwise direction.
The size, for a new BH, should be as big as you can. I prefer 3.5 feet wide and 4 feet in height. A wood frame to be put at the perimeter of the hole so that it will easier to mount those external and internal sound tweeters.
You might want to reduce the hole size once the number of birds reaches say 300 nests. You also need to get ready to install those owl protection gate once attack by those owls.
The entrance hole must not be too closed to the ceiling and the side wall of the monkey house. At high speed those birds flying in might grace the side wall or the roof if it is too closed.
The best is to ensure that they are about 1.5 feet away from the roof and from the wall.
Can there be more then one entrance hole?
I think you should open one more on the opposite wall but diagonally. By having the second hole diagonally you allows the birds not to fly straight out from one hole to the other. It also allows the birds entering the second hole to fly in an anticlockwise direction.
The height and distance to the roof and the wall should be similar to the primary entrance hole design.
What about how to install those tweeters?
You might have all sorts of installation but from my point of view try to consider the following way of tweeters installation (see sketch).