People like to interact with wildlife, whether they’re holding it, cuddling it, having their photo taken with it or even shooting it. In order to facilitate this interaction people draw wild animals to their gardens with food. Unfortunately providing artificial food is never a good idea and can never be done properly. It occurs primarily because people only value wildlife for the warm and fuzzy feeling interacting with it gives them.
One of the problems with providing artificial food is that it temporarily increases the stocking rate and density of wildlife in a given area. After the Black Saturday fires of 2009 it was very popular for people to put food out for wildlife because much of the surrounding vegetation was charred and burned. Rather than allow nature to return to a balanced state after such a catastrophe this had the short term potential to artificially increase survival, stocking density and reproduction leading to more animals than the environment could realistically cope with. Unless we enter a farm type scenario, which typically operates with elevated stocking rates, by providing supplementary food ad infinitum populations will eventually crash and animals starve. Unfortunately this occurs some time after the event when the people who mistakenly believed they were helping the wildlife have forgotten about their commitment, lost interest and moved on, leaving the wildlife to fend for itself.
The largest and most obvious ongoing wildlife feeding problem focuses on the provision of bird feeders. All over the world people put seed out to attract birds to their gardens. This is not a balanced diet. Seed mixes contain a high proportion of sunflower seeds, which are palatable to birds because of their high fat content. Most seed is also low in calcium, zinc, Vitamin A, B vitamins and Vitamin E. Birds are as lazy as the rest of us. Why spend all day looking for food when it’s available free of charge? Birds become reliant on this unbalanced diet which results in malnutrition. This is also a problem for carnivorous birds such as magpies and currawongs because people like to feed them mince meat. Every year juvenile birds are presented to veterinary clinics suffering multiple wing fractures and deformed bones because they have grown up on a calcium deficient diet. Affected birds are in considerable pain and usually end up being euthanased (See the attached photo of a young magpie fed a calcium deficient diet. Beaks really should not bend like that).
Bird feeders obviously attract large numbers of birds. All these birds congregating in a small area squabbling, sneezing, and defaecating on each other provides a fantastic opportunity for disease transmission. In fact outbreaks of mycoplasmosis in the US (Ley et al 1997), salmonellosis in New Zealand (Alley et al 2002) and psittacosis in Australia have all been directly linked to bird feeders. Not only are the birds at risk but human cases of salmonellosis in New Zealand and psittacosis in Australia were also traced back to the feeders.
Unfortunately hygiene is not a high priority for many people who put out bird feeders and seed is often left to go mouldy in the rain. A recent study found fungal toxins in the feeders. If consumed in large amounts these toxins can cause kidney damage and death (Oberheu and Dabbert 2001).
The irony is that the people who are so desperate to help and encourage wildlife are also directly responsible for its demise. It’s time people realised that wild animal stocking rates are determined by available resources and any manipulation of these resources will have long term deleterious effects. If there aren’t enough birds around to keep you happy plant some native bushes. If that still doesn’t do it for you and you desperately need to see massive flocks of birds go to a zoo, but if you really care about wildlife please don’t feed it.
Dr. F. Bunny
Alley, M.R., J.H. Connolly, S.G. Fenwick, G.F. Mackereth, M.J. Leyland, L.E. Rogers, M. Haycock, C. Nicol, and C.E. Reed. 2002. An epidemic of salmonellosis caused by Salmonella Typhimurium DT160 in wild birds and humans in New Zealand. New Zealand Veterinary Journal 50:170-176.
Ley, D.H., J.E. Berkhoff, and S. Levisohn. 1997. Molecular epidemiologic investigations of Mycoplasma gallisepticum conjunctivitis in songbirds by random amplified polymorphic DNA analyses. Emerging Infectious Diseases 3:375-380.
Oberheu, D.T., and C.B. Dabbert. 2001. Exposure of game birds to ochratoxin A through supplemental feeds. Journal of Zoo and Wildlife Medicine 32:136-138.