This article has been reproduced from the National Heritage Trust “Grassy Box Woodlands Project Update Autumn 2001”. Compiled by Geoff Tonkin (with permission from David Watson, Environmental Studies Unit, Charles Sturt University, Bathurst) and presented at a “Birds and Herds” day run by Greening Australia.
Aussie mistletoe facts and figures
- 90 species of mistletoe are native to Australia of which 71 are endemic to Australia i.e. only found in Australia
- No species have been introduced but several species often parasitise on introduced trees
- Two species are root parasites, all others aerial parasites, attaching to the host plant using a specialized connection called a haustorium
Mistletoe and tree health
- Mistletoe do NOT necessarily kill trees as this can lead to the mistletoe’s own death
- In low density, mistletoe have few deleterious effects on their hosts
- Hosts have many defences which may be less effective when the tree is stressed.
- There is some evidence that unhealthy trees are more prone to mistletoe infection
Mistletoe as a food source
- One of few Australian groups pollinated AND dispersed by animals
- Exhibits extended flowering and fruiting season. Regionally there is always fruit and nectar available
- The fruit is high in protein, carbohydrates and lipids. Often at a time when nothing else is available
- The leaves are very nutritious, high in nitrogen, phosphorous and trace elements
- Feeds many Australian birds and mammals especially during droughts and seasonal scarcity
Mistletoe as a nest site
- A great nesting spot for Australian birds and mammals
- A site which offers dense cover and food close by
- Mistletoe also encourages hollow formation on tree branches after the mistletoe dies
Effects on diversity
- The more mistletoe the more food and nesting resources for native animals
- Previous research has found a positive relationship between mistletoe and diversity
- In a case study at Gundaroo there were fewer birds in a site in which mistletoe has been removed
Mistletoe – weed or wonder?
- Often abundant on road side verges and remnant vegetation
- Considered by many Landholders / Land managers as a noxious weed
- Rather than being the cause of degradation, is actually an indicator of landscape health
- Pollinated and spread by birds, consumed by animals, controlled by fire and browsing
- Abundant mistletoe in a remnant may indicate absence and scarcity of native consumers (e.g. Sugar gliders and possums) and decreasing tree health
Concerned that you have too much mistletoe on your property?
- Try putting up some nest boxes or hollow logs in high gum trees, to encourage possums and gliders to come back. It appears that possums (both brush-tailed and ring-tailed) and greater gliders can effectively control mistletoe abundance in many areas—woodlands with unnaturally high levels of mistletoe are often missing these native herbivores because of hunting, poisoning, or lack of suitable habitat.
- Minimize the use of poisons (especially 1080). Possums will naturally return and bring mistletoe back to normal levels.
- For isolated trees in paddocks, possums will not risk travelling over open ground, and alternative measures may be needed.
Controlled burns in the under-storey are an effective management tool, not just for mistletoes but many other native plants. Unlike many Australian native plants, however, mistletoes are highly sensitive to fires; even low intensity burns restricted to the under-storey.
- For trees containing many mistletoe plants (more than 5–10), try pruning off the mistletoe. In some cases, the tree will not respond, but it may respond with a flush of new growth.
- More than anything, however, take the time to observe mistletoes. Once you start looking, you’ll find nests in them, notice a wide range of animals feeding in them, and generally appreciate them for the beautiful native plants that they are.
More information: please contact Regional Liaison Officer Geoff Tonkin at: firstname.lastname@example.org. ALSO, there is a video available on the NHT website: Associate Professor David Watson from Charles Sturt University describes the importance and roles of Australia’s native mistletoes in conserving native ecosystems.
DISCLAIMER: The information contained in this web site is based on knowledge and understanding at the time of writing. However, because of advances in knowledge, users are reminded of the need to ensure that information upon which they rely is up to date and to check currency of the information with the appropriate officer of National Heritage Trust or Charles Sturt University or the user’s independent adviser. LRTanner 06/03/16 – link to video added 23/2/13