Ringbarking is when male deer use their antlers to scrape and rub against native vegetation resulting in major damage to the trees. They will often return to the same tree and in many instances ringbark it to the point it will snap in half.
They do this because they are trying to remove the velvet from their antlers and it is also a display of dominance to other stags/buck in the area.
They usually target saplings as they fit between their antlers. They will remove the bark including the xylem and phloem which will result in the death of the tree as they can no longer transport water and food via these vessels from the roots to the leaves and vice versa.
This is a major impact as they will do this to multiple trees within their home range resulting in long term forest death as new saplings cannot grow to replace the canopy above.
Deer browsing can be a major impact as they browse extensively throughout the landscape. They have no particular preference but will eat grass, shrubs and leaves throughout the forest floor.
Deer need to eat 6% to 8% of their body weight in green foliage every day to maintain a healthy weight. Considering how large deer can get if we take an average Red deer doe (female) weighing in at 80kg it must eat 6.4kg a day. With deer numerous in many parts of Australia this has a severe impact on available resources for native wildlife.
Major impacts have been shown through research into deer exclusion fences showing impacts of deer on vegetation when they are not present in landscape. The areas as shown in the photos below show the growth of forests. This lower – mid canopy is vital to sustaining long term forest growth.
They are known to eat everything they can access which puts them in direct competition with native wildlife like kangaroos and wallabies.
Deer tend to travel the same paths just like sheep and cattle do. This leads to tracks forming as the vegetation dies off and a defined dirt track is the result. This makes it easier for deer to travel but it comes at an expense to the surrounding environment.
The first major impact of this is erosion, water will continue to erode away at these tracks when the deer aren’t present. This has a few detrimental impacts with water more likely to gather and form small streams along these tracks causing surrounding vegetation to have less available water to use. Further erosion may lead to creeks forming taking vital nutrients via the top soil away from the area.
Secondly a major impact which has formed part of multiple research papers shows that defined tracks like these formed by deer allow invasive predators such as cats and foxes to travel and hunt native prey more easily.
Wallows are formed when deer usually stags/buck (male) dig out a damp area forming a mud bath where they can lie in. They do this as a way to spread their urine and scent to attract the attention of females. It is a breeding behaviour but also seems to be a way for them to clean their coat as the mud dry’s and falls off it takes any ticks with it.
Stag/buck will return to an area causing the wallow to get bigger. The damage to surrounding vegetation is clear in the provided photos and the pooling of the water sucks this resource from the surrounding area however the unseen effects are far greater.
The major impacts of these wallows are the spread of disease as these wallows attract not only deer but all types of animals causing it to be a hotspot for spreading unwanted disease. One of these is Chytrid Fungus which is having devasting effects on amphibians across Australia. This alone is pushing many amphibian species to the brink of extinction.