This is an interesting question I’ve received from a reader. I guess my reply to this question would be good for those who are facing the same problem.
James I have a Bh operated for 4 years and the lowest floor (ground) has no nest, most of the nests were built on the 3 floor which is the highest floor. Can you please advice?
Why Swiftlets are not building nests in the lowest floor or the floor below the highest floor? This has to do with the design especially the placement of the inter-hole.
When I design a Bh I pay considerable attention to its internal. I make sure the inter-hole is located at the right place so that the birds could easily access all floors without any difficulty.
The most common reasons birds reluctant to fly to the lower floor are:
1) Wrong placement of inter-hole
2) Inter-hole too big or too small
3) Internal partitioning
4) Poor and ineffective internal sound
Swiflets are like Glider plane they fly by gliding in the air. Glider plane can’t take sharp angle or they would hit the walls. This applied to all swiftlets. If the inter-holes are placed somehow away from their gliding path then they would avoid going down to the lower floors. Through my many years of experiences, I have studied and observed this flying behavior and often if they find difficulty in maneuver they would just flap their winds and circling few times and would avoid the inter-hole. If this happened it would be a major setback for the Bh.
Besides getting the inter-hole in the right place, its size also play a significant role. Too big means too much of light density that would penetrate into it if the inter-holes are located near the entrance. This would cause too much of brightness which dislike by birds. To reduce the brightness many have resorted to erect partitions at the same time maintaining the size of the inter-holes but if the partitions are built without taking consideration of the flying path then it would cause more harm than good.
Secondly for those inter-holes that are located away from the entrance that mean birds have to fly deeper into the Bh in order to get down to the Inter-hole. In such circumstances, it would be very dark and the inter-hole is much darker in contrast to the top floor. Bear in mind too dark is no good. Young swiflets that had yet to develop its echolocation may find it hard to fly into the inter-hole and would avoid it by all means. If this happened you may use a small light which is dim, not the normal florescent light otherwise it would defeat the whole purpose of the dim light which is to guide the birds to fly in and out of the inter-hole.
Anything has it setback. If the light is too bright the birds would be attracted to it and wouldn’t find it ways out. It may circle and circle at the light and eventually die of exhaustion. Though Swiftlets could use its echolocation to navigate in darkness but they too relied on find ray of light. If your farm is in total darkness then it is a big problem.
Besides this, in order to lure them to the lower floors the Internal sound of the Bh has to be extremely good quality. When I say good quality it means the internal sound should have a combination of babies, parents, young birds and birds that are in the mating mood, etc….so on in it. All these sounds should be played in clear planned combine sequences. Given any successful Bh if you have the chance to visit, no way that the original chirping sound of birds came from these Bhs are from only one bird or two birds. Often I found most internal sounds in the market are of such..1,2 or 3 birds singing perhaps some even in solo.
A good internal sound should have multiple birds’ tunes from the main sound to the back ground sounds all should be clearly heard. With good sound birds would clinch to the tweeters.
Internal tweeters should be installed at the inter-hole, at least 8 tweeters for a size of 6x6’.As the size of the inter-hole goes bigger, then the number of tweeters should increase too. A 45dg cross each other (tweeters) this is to pull the birds to fly into the inter-hole subsequently to the lower floor.
I use internal sound to pull/attract birds to the lower floor. Obviously there are many who use the external sound, bear in mind the external sound often too loud and it is off during the night. The internal sound has the hypnotic effect which creates an environment of farm that are full of birds and heavily populated with nests Thus birds would feel safe and could be easily lured into the lower floor.
The ground floor “the lower floor” should have its internal sound volume louder by 15% than the 1st floor and this applies to all floor as it goes. This would lure birds to build nests at the lowest floor for those farms that have difficulties in luring birds to the lowest floor.
If your Bh has all the nests built on the lowest floor then the strategies would be different. I shall write about that perhaps in my next post.
Good Swiftlet farming All