To cull or not to cull ?

In a world where resources and space are limited, overpopulation and spread of disease arise as a major obstacles. One of the current practised resolutions is to cull individuals as a method of population management. The controversy with culling is that the practise is only required due to human influences causing overpopulation, when left undisturbed wild populations naturally regulate themselves. Given that we are causing the difficulties, do we have the right to correct our mistakes by simply killing partial or entire populations?

Countryside sign and urban vehicle warning of cull practices and culled foxes hung on a farmer’s fence.

Whether culling can be considered appropriate can depend on the species in question, is it native or invasive, a threat to humans, or does it damage the ecosystem? Can we justify its removal?

Invasive species

When an invasive species becomes overpopulated in an ecosystem, it is often detrimental to the native species. In 2005, invasive species contributed to 54% of native species extinctions. To stop this native species loss and return the ecosystem to what is once was, eradication of the invasive species is the best option. Surely if it does not belong there in the first place, it is acceptable to remove it?

Successful eradication of an invasive species is neither a simple nor easy task. For example, the culling of the Mute Swan in the U.S in 2008 ran into difficulties in the form of public opposition, so alternative management strategies had to be adopted. It might not be easy to cull an invasive species, but it is possible. The eradication of the Pacific rat from an Island in New Zealand is an example of successful eradication.

Tb or not Tb.jpg

Disease spread

When a disease carrying species becomes overpopulated, the risk of spreading this disease becomes a concern. If one species is putting many others, including ourselves at risk; is it acceptable to eradicate it? This has been a recent controversy in the media concerning the culling of badgers due to the spread of bovine tuberculosis (bTB). While it may seem logical that reducing badger numbers will reduce incidents of bTB, it is not quite so simple. Small scale culls are actually likely to increase spread of bTB, as it encourages badgers to disperse. So although culling may seem a straightforward solution, in this instance perhaps it requires a little more thought and consideration.

Ecosystem damage

When species are overpopulated, the ecosystem in which they live may be unable to cope. This is perhaps one of the most well-known and widely accepted reasons for culling. Annual deer culls are commonplace as overpopulation is damaging their ecosystem. We are essentially acting as replacement to the deer’s natural top predator, the Grey wolf, which humans hunted to extinction. Is it fair to kill portions of a population to correct for a mistake we made? Maybe not, but it is seemingly necessary for ecosystem health.

To cull or not to cull?

I think that under certain circumstances, populations must be managed and culls must occur. There are, however, practises that could take place that might reduce these circumstances of overpopulation, reducing the requirement to carry out mass culls. Such practises include the use of sterilisation, immunity injections or simply predicting problems before they arise.

By Hannah Whitford, based on a presentation by Lisa Kopsieker

Links to Pictures

Badger Tb link

Crow culling – Choo Yut Shing link,

Cull in progress sign – Nigel Corby

Dead foxes hanging on a fence


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