Nest boxes for wildlife
Over 300 species of our native fauna utilise tree hollows for nesting or roosting, with the size of the hollow depending on the size of the animal. It can take up to 100 years for a tree to develop suitable hollows and up to 400 years to develop hollows that can be used by larger wildlife such as possums and owls.
While nest boxes can never replace an old growth tree with its diversity of hollows, they can, with appropriate management, provide a benefit for some wildlife species in areas where these trees have been lost.
Hints for installing nest boxes
Identify the target species you wish to attract and install the appropriate nest box, remembering that most species will utilize more than one ‘hollow’. Research has shown that our possums and gliders occupy more than one hollow over their home range, with Squirrel Gliders requiring a minimum of five hollows per colony (two to nine individuals) and avian species such as the Owlett Nightjar using up to 23.
Factors such as hollow design, positioning, size of entrance, wood thickness, width and height of box is critical in influencing occupancy.
It's important to consider the following:
- The box should be placed in a shady position with its opening facing away from the prevailing weather. It is important to provide a summer and winter ‘residence’ as hollow dependent mammals will change hollow locations depending on seasonal influences.
- If possible, place the box level with a branch in the tree to provide easy access to the tree.
- Securely fix the nest box to a tree in, or near, your yard. Place it at least 4 metres (12 feet) from the ground to keep it out of reach of domestic cats and dogs.
- It was once considered best practice to secure nest boxes with a bolt directly into the tree; however it has been found that the reaction from the tree to this ‘foreign body’ exacerbates the rusting process, shortening the life of the nest box and creating a safety issue.
- Place the box in a position that is easy to access for monitoring and maintenance.
- It is recommended to attach the box using coated wire or threading the wire through a rubber hose where it contacts the tree. Creating a zigzag pattern in the wire at either end of the join will also allow for expansion as the tree grows.
Maintaining nest boxes
Natural hollows have microorganisms which play an important housekeeping role by helping to break down leaf and waste matter. Nest boxes do not have this and as such, their bases tend to rot out. It has been found that on average, nest boxes will require replacement every 5yrs. Nest boxes can also be prone to invasion by feral species which will have to be removed before the boxes are usable by our native fauna.
Simply placing a nest box in your garden will not bring in wildlife. You will also need to create the appropriate habitat for them, providing preferred food and shelter trees as well as water.
Monitoring your nest box
Monitoring the usage of your nest box is best undertaken by observation. Sitting quietly and observing your boxes on dusk can show you who is coming and going.
Another effective method is to observe the ground beneath your boxes for telltale scats (droppings) this is particularly useful when monitoring avian and bat boxes.
Check the entrance to your nest box – spider webs across the entrance will indicate lack of use. You can tell if a parrot is using the box as there will often be visible chew marks across the entrance.
On smooth barked trees, scratches will indicate movement up your tree and in some cases, a well used pathway will become evident.
In the case of gliders, a smooth, worn patch of bark will indicate where gliders are landing or taking off from - a glider landing pad.
DIY alternatives
Pots for Possums
You can provide a quick and easy nest box for possums by using pot plants. Connect the openings of two large plastic pots (270mm or larger) with cable ties - you will need to drill holes to thread them through. Then simply cut a 110mm hole in one end and line the inside with material, shredded paper or mulch. Secure it safely in a shady tree.
Hanging baskets
Ringtail Possums do not live in hollows, but rather, build their own nest out of leaves and twigs, called a drey.
You can make a drey for your ringtails by attaching two lined wire hanging baskets together with cable ties to form a round ball. Removing a section of wire in the font (80mm) and at the back provides them with an entrance and exit. Secure your drey in dense trees such as a Callistemon.
Providing more than one drey throughout your yard will help increase uptake, as ringtails will use up to six nests throughout their home range.
Budget bats
Insectivorous, or micro-bats, are valuable neighbours to welcome into your yard, with a single bat capable of devouring up to 4000 mosquitoes overnight. These bats occupy tree hollows, tuck themselves under loose bark and squeeze under caps on fence posts. You can provide easy budget accommodation for them in a number of ways:
An old garden umbrella (closed) positioned in your yard can provide accommodation for insectivorous bat species.
Another option is to use recycled plumbing pipe. Place a cap on top of the pipe and hang non-fraying material on the inside to enable them to hide in the folds. This can then be hung up in a tree or under eaves.
Buying boxes
There are a number of companies that make nest boxes and they can also be bought from some pet shops and produce stores. You can also find many designs and ideas in bookshops or on the internet. Below are some resources that you might find useful:
Books:
- The nest box book – by the Gould League
- Nest boxes for wildlife, a practical guide – by Allan and Stacey Franks.
Websites:
Wildlife friendly fencing
Fences are one of the major obstacles to fauna movement. Fences erected across habitat areas and corridors create physical barriers to fauna movement and therefore have the potential to disrupt the feeding, migration, breeding and social patterns of fauna within that area. Due to this, fencing erected in some areas is now required to be “fauna friendly”.
What is fauna friendly fencing?
A fauna friendly fence is a fence that does not inhibit the movement of native fauna between properties.
No single fence design can be classed as fauna friendly. Given the vast variety in animal size, shape and methods of mobility, a fauna friendly fence needs to be defined relative to the areas particular fauna. Also, a fence that is friendly to one species is not necessarily friendly to all. As such, a koala friendly fence that can easily be climbed by koalas is not always a fauna friendly fence.
Structure of a fauna friendly fence
In the Redlands, if a kangaroo, koala or bandicoot can easily negotiate a fence then the fence would not be a barrier to most other native fauna. Such a fence would be considered to be fauna friendly.
Ideally a fauna friendly fence should have either:
- A minimum 50cm gap between ground level and the first rail or strand. Spacing above this level is at the owner’s discretion.
- A series of 50cm gaps between the rails or strands (the first gap should be a minimum of 50cm above ground level)
- Box wire mesh may be used provided that there is a minimum 50cm gap between the ground level and the mesh, and provided the fence is not more than 1.2m in height. A capping rail along the top allows for easy movement.
Rails should not be in excess of 15cm wide. Wire strands should not be too tightly strung.
Koala friendly fencing
Koalas living in urban areas often face several obstacles during their nightly movements. In our suburban areas one of the biggest problems is fencing. Without too much effort or cost, we can assist koalas to move freely and provide them with a quick escape.
Some tips for koala friendly fencing include:
- constructing fences around existing trees and vegetation
- planting of vegetation within close proximity (branches touching) to either side of fence to provide a natural ladder
- place a pole/plank against fence at a 45 degree angle between two supporting upright poles - allows a quick escape
- ensure the thickness of panels or planks provides a walkway along the top of the fence
- leave a small gap between panels/planks to allow koalas to grip and climb
- ensure chain wire fence is topped by a plank or horizontal pole to allow koalas to use it as a bridge
- a suitably planted hedge allows animals passageway while also providing an effective barrier.
These fences are well suited to koalas but not necessarily to the ground dwellers such as bandicoots and wallabies. If these animals are in your area, a fence that allows easy access for all fauna is one that has a 50cm gap from the ground to the bottom rail, chain or post of the fence.
Fencing materials
When choosing your fencing materials, consider the environment in which it will be situated. The character of an area, whether it is of a rural, bush or park nature, attracts residents to live within its boundaries and as such should be taken into account when designing fences.
Wood, brick, metals and wire can be combined in a variety of designs to create an effective and unique fence while maintaining the character of the area. Slight variations in the materials and design of these fences can create an individual look for your property.
Some native plants can be planted to form a dense living hedge line which gives privacy and security and is wildlife friendly.
Barbed wire and high voltage electric fences are not fauna friendly.
A fence for all reasons
Property boundary definition, security, privacy and the containment of livestock can all be achieved while meeting the fauna friendly fencing objectives.
Property definition
A constructed fence may not be necessary to define your property boundary. Consider using garden edges or low wooden posts to subtly define boundaries. Where not possible, the old rural style fence of plain wire strands and wooden posts allows for the uninhibited movement of native fauna while defining boundaries.
Privacy
The privacy of your property can be enhanced through the use of vegetation. A combination of native trees, shrubs and ground covers can effectively screen areas while enhancing the amenity and habitat value of the area. If the alignment of the property were such that privacy is a great concern, a solid fence with a 50cm gap at the bottom would be considered fauna friendly.
Dogs
The presence of a dog does not deter native fauna from entering a property. To assist dogs and native fauna to live in harmony, dogs should be confined to an area in the vicinity of the house. A fence erected around the house provides room for exercise and retains the dog near the house for safety and security, and allows fauna to move freely through the property
Fauna proof fencing should be used to separate dogs from wildlife. The safest fauna proof fence is a solid, vertical, 2 metres high fence, free of vegetation within 3 metres of the fence and with the bracing on the inside. Most fencing other than this would allow some fauna movement. Fencing similar to chain wire can allow small animals to move through and can be climbed by koalas and other mammals. Owners should be aware of this and be watchful of dogs when fauna is on the property.
Dog enclosures
When confining your dog you will need to ensure koalas do not end up in your dog’s enclosure. Dog enclosures should be located away from koala food trees and can be:
- at least 1.5 metres high and made of solid material (e.g. tin, steel/Colorbond, brick, glass) with no gaps, toeholds or joins and the support posts located on the inside. Ensure that the fence is located or maintained so that trees and shrubs do not grow within 3 metres
- made of chain mesh wire with a floppy top that falls to the outside of the enclosure. Ensure that the fence is located or maintained so that trees and shrubs do not grow within 3 metres
- made of chain mesh wire with 60 cm sheet metal attached to the top of the fence on the outside. Ensure that the fence is located or maintained so that trees/ shrubs do not grow within 3 metres
- constructed from an existing fence by adding a 60cm sheet metal to the top of that fence. Ensure that the fence is located or maintained so that trees/ shrubs do not grow or overhang within 3 metres.
Existing fences
The movement of animals through existing fences can be improved by planting a variety of native trees and shrubs along the fence line which allows fauna access to the vegetation on the other side until such time that a fauna friendly fencing can be erected.
The placement of a pole on an angle against the inside of the fence allows for a quick escape route. Placing a pole between two trees on either side of the fence creates a natural bridge for koalas and other wildlife. Sections of the fencing could also be removed and replanted to integrate the fence and vegetation.
Before you construct a fence first decide if you really need one and if so, make it fauna friendly. There are a variety of options available when constructing a fauna friendly fence. By choosing designs and materials carefully, fences can be created that are functional, individual and, fauna friendly.
Redland City Council is dedicated to the protection of our fauna. You can play a part by giving your fence the fauna friendly feel. Your fence will then be one less obstacle in the life of Redland’s fauna.
Further information
For general wildlife fencing enquires please contact the IndigiScapes team on (07) 3824 8611.
For development enquiries please contact the Environment Assessment team on (07) 3829 8999.