This post is a summary of our conclusions following extensive research and trials to ascertain the most effective artificial nest design for BaDL’s Community Nest Project.
In assessing the optimal design, we applied the following criteria:
1. Best environmental outcome
- Highly durable: To be an effective interim solution for the depletion of natural hollows, nests for the major target species need to be habitable for 30-50 years.
- Highly thermally resistant: If made from wood, they need to be at least 30mm thick, according to the scientific research (‘nest project research.pdf’). Research shows that tube nests are also highly effective.
- Water resistant internally
- Stable when installed: The arborists for our trial advised that most species are reluctant to use nests that move separately to the tree.
2. Community engagement and benefit
We need to be able to continue the project, so ongoing voluntary help from our partnering organisations is important. Also, there is a reciprocal benefit. The disadvantaged clients of Fassifern Community Centre and Fassifern Aged Care Service who are young, aged or infirm and the school students will share in making a valued ongoing contribution to the local community.
3. Cost/value for money
We have no available funds for this project. For it to result in any substantial environmental benefit, we need to be able to supply nests in the hundreds. So, we must use our limited resources wisely and not get carried away with uneconomic ideas.
4. Ease of acquisition of materials
We need to be able to build at scale for the project to have any significant environmental impact. This means that we need to get materials gratis, or as cheaply as possible.
5. Ease of manufacture
Unless we have a lot of skilled, dedicated, time-rich members, making the nests needs to involve minimal use of skilled labour.
6. Ease of installation
The arborists, who have installed our nests for landholders, have said that the corrugated tubes were light, and easy to fix in a static position. Cockatubes aren’t dependent on a tree limb to install – which makes more trees available. The arborists were able to install the heavier log and hardwood box nests used for the trial. However, the curved hardwood log ones were unstable without adding flat, backing pieces.
Our investigations revealed that tube nests are the optimal design for us for the following reasons:
- The best possible environmental solution of carved tree hollows in standing trees is prohibitively expensive for us because a suitably qualified arborist is needed to make them.
- The long lifespan of tube nests is similar to that of nests made of hollow logs and other thick hardwood (~50 years, compared with 5 to 10 for exterior ply nests).
- The insulative qualities of tube nests are on a par with hollow log and other thick hardwood nests.
- The cost of materials for tube nests is less than the cost of that of equivalent wooden nests;
- Tube nests are easier to manufacture compared with equivalent wooden nests. Apart from the cutting up of the tubes, tube nests can be built by a ‘production line’ of unskilled people.
- Tube nests are significantly lighter than wooden nests, and easier to install. The tube nests will weigh ~3kg, so they can safely carried up a ladder. Equivalent thick hardwood nests would weigh ~5-25kg, which would require a separate pulley system to elevate.
- A wider range of candidate trees is available for tube nests with two chains as they don’t need to be attached to a bough.
- Tube nests are more stable when installed. Nest movement can deter use by target species. With the two fixing chains inserted along the corrugations and the tree expansion springs, tube nests don’t move.
To find out more or join this project team, please get in touch today!