Impacts of Feral Deer

The Illawarra, Shoalhaven and Southern Highlands have collectively been infested by 5 of the 6 feral deer species in Australia:

1. Red Deer
2. Sambar Deer
3. Rusa Deer
4. Chital Deer
5. Fallow Deer

Environmental impacts
The environmental impacts of deer on our natural rainforests and bushland are widely publicised. We regularly see ringbarking on old growth trees from antler rubbing, excessive muddying of waterways and natural wet areas, near complete lack of understory vegetation and patches of weeds appearing deep in the bush where deer have brought seeds in via their fur and gut.

Practically, the damage to trees and understory reduces the natural habitats for smaller native mammals, both taking away food source and making it easier for predators such as feral cats and foxes to hunt them. It also greatly increases erosion in steep areas where there is no understory to slow down water during heavy rain events.

Agricultural impacts
Another very common impact of deer is fence damage. Nearly all species have strong enough antler to snap barbed wire. If they want to go through a fence, they often jump at it or over it but also simply put their heads in and twist. Obviously this costs money to repair and risks stock escaping in the meantime.

Competition for feed is also an increasing problem as deer populations increase. The average deer eats approximately 7% of its body weight each day. For a 60kg Chital deer, this is about 4.5kg. For a 200kg Red or Sambar, this equals about 14kg. This rate of consumption for body weight is well in excess of the average cow and double that of the average sheep. Debate exists as to exactly how much pasture grass deer eat in Australia although our direct observation of stomach contents over a number of years indicates that a majority of the diet in farming areas is made up of pasture grass.

Deer grazing farmland directly reduces the amount of feed available to stock and commensurately increases the cost of alternative feeding or reduction of livestock herd size. We regularly see mobs of 10+ deer in farmland. For the larger species, the combined consumption of these size mobs would easily exceed 100kg per day - more than 6 cows worth or dozens of sheep worth.

Disease and parasites
Another concern is disease spread. Contrary to some reports, deer in Australia are not known to carry disease and typically have fewer parasites than native species such as kangaroos. Recent reports have investigated the ability to control potential foot and mouth disease outbreaks in farming stock and have concluded that feral deer and pigs would be the main vectors of transmission accross containment lines. Another lesser known disease that affects deer in North America is Chronic Wasting Disease. While not present in Australia, it too could have devastating impacts if it got into the population.

Deer Species

Red Stag in velvet

Red Deer
Red Deer are to Europe. Along with Fallow deer, are the main species seen in the United Kingdom. Reds are widespread across the entire east coast of Australia but are particularly common throughout the Shoalhaven and South Coast.

​Generally considered one of the larger species with mature females regularly exceeding 150kg and stags over 200kg, they are extremely destructive to rainforests and compete directly with stock in local farmland. They form mobs of up to a dozen deer and will stay in a fairly localised area once they are content. Rutting Stags have a deep horn/honk sound which can be heard several km away. The meat is quite gamey in taste and can be a little tough.

Red fawns are very spotty and can easily be mistaken for a spotted species such as fallow or chital.

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Sambar Stag

Sambar Deer
Sambar are native to Indonesia but have become extremely well adapted to Australian conditions. They are very common in eastern Victoria right up to central NSW with populations continuing to expand rapidly. They are now one of the most common species in the Shoalhaven.

As the biggest of the deer species, stags up to 250kg are quite common, they are also the most damaging. Their prefered habitat is bushland, particularly where there are some open areas for them to rut in. They are less keen on really steep environments but do go into them for feed if needed. Their alarm call is a really loud honk/scream while their rutting call is a much deeper honk/croak.

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Rusa stag with some sambar features.

Rusa Deer
Rusa are very closely related to Sambar. They also originate in Indonesia. Visually, Rusa and Sambar are very similar. The main difference is that Rusa are slightly smaller, typically have darker coats, and have slightly more pointed ears. The main difference is that in stags, the Sambar has its tallest tine on the outside whereas Rusa have their tallest tine on the inside. Locally, Sambar and Rusa are hybridising. A hybrid usually exhibits Rusa style antlers and body proportions but Sambar ears, nose, and coat colour.

Rusa are extremely widespread throughout the Illawarra all the way from Royal National Park down to Nowra. They can be commonly seen at nearly any time of day and usually roam in large mobs of 10 or more individuals. Their preferred habitat is semi-open woodland and grasslands. They often graze openly at the edge of the bush and venture a long way into open paddocks in search of good grass. 

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Chital in a small clearing in the rainforest

Chital Deer
Chital deer are the smallest of the local deer species. Mostly confined to the southern Illawarra and the far western parts of the Southern Highlands, their range appears to be steadily increasing despite highly targeted efforts from local landholder organisations. Chital are easily identified by their spotted coats and tall, thin antlers. Typically, Chital will not get much larger than 50kg but the largest stags can approach 100kg in ideal conditions. 

Native to India in the same range as tigers, makes these species one of the most challenging to target. They prefer dense rainforest and rarely emerge into paddocks unless they are confident that no one is out to get them. They have irregular movement patterns and quickly learn if a particular area becomes unsafe for them. With patience, and careful management, it is possible to target them as they browse at the edge of their forest hideaways. Often, they make trails along the edge of a paddock just a few metres into the bush so that they have a quick exit in case of threats.

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Fallow stag with darker colouring (CC licenced photo used to illustrate different coats)

Fallow Deer
Fallow are the most common and recognisable deer across the Australian landscape. They are native to Europe but have become widespread thoughout the east coast from Queensland to Tasmania. Fallow are the most variable in appearance with some being nearly white and others so dark that they are nearly black. The main feature though is spots on the coat. All fallow have some evidence of spots. Most commonly, they have reddish coats with white spots. The fallow stags' antlers are also highly recognisable by the large, flat panels rather than the round antlers of all the other species. Most fallow will not exceed 80kg although larger stags can reach up to 150kg.

Fallow are a grassland species. They do shelter in tree stands and bushland areas but primarily feed in paddocks and open woodland. Mobs of six individuals is generally a small group and mobs of several dozens are quite common. Fallow are less common in the Illawarra but are increasingly appearing, particularly in the Southern Highlands. 

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