Comment | A possum problem

Where I live, there are possums. 

Cute little things with regular foraging routes. Each night they smell their way around our garden and, in the mating season, take frisky runs across the metal roof of our bungalow. 

Our sneaky rutters are the common brushtail possum, Trichosurus vulpecula,  a nocturnal, semi-arboreal marsupial of the taxonomic Family Phalangeridae, native to Australia, and the second-largest of the possums. They mainly eat leaves (a folivore) but have been known to eat small mammals such as rats. Around human habitation, where the little darlings are at home, they are inventive and determined foragers who like fruit trees, vegetable gardens, and kitchen raids. 

Our brushtails have a particularly delicate taste, and they enjoy anything I try to grow, especially leafy vegetables or herbs or the shoots of root vegetables. These items are manna from heaven. One night we left some sweet potatoes on the deck by accident. Oh my, did they disappear quickly.

Native plants on the eastern seaboard of Australia are designed for hot and dry conditions. They have either spiny, narrow leaves or a waxy coat to keep the moisture in on the hot summer days. The fire-tolerant eucalyptus almost encourages the fire to burn through the turpentines and phenolic oils in their leaves and twigs. 

So if you present a native herbivore and general forager with a delicate, bright green lettuce leaf, they love it. In the same way, the pet rabbit prefers kale over grass and hay. 

Gardening in a possum habitat is a bit like putting an array of tasty treats in front of the kids; they are certainly not going to eat their greens if there are lollies and chocolate cake on the buffet. 

We don’t have the space for the production volume to allow the sacrifice of a few leaves for the benefit of the possums whilst maintaining some sort of crop. So the scale at which you can produce food as an individual in this system struggles against the activities of the native animals. 

People get around it by putting nets over their fruit trees and large cloches over the herb garden. A gent down the road from us has built walk-in ‘greenhouses’ made of mesh rather than glass. I watched him put up a new one recently. And at a rough estimate, I’d say he spent at least a thousand dollars on timber, meshing and various fittings and fixings, not to mention the time it took him with his power tools. 

It seems unlikely that he would get a financial return from the crops that he could grow inside his 100m² ‘greenhouse’. 

Presumably, he enjoys growing the food and having homegrown vegetables with his steak. He was doing it for himself.

This anecdote explains why the modern westerner has no chance of feeding himself on their escape to the countryside and why losing plants to native herbivores is one of the significant challenges of integrating our production systems with nature. 

Humans can have dominion over nature and change it in such a way that it performs to our advantage. Hence the large fields that overwhelm the occasional possum. Pesticides and herbicides deal with the organisms that can increase quickly when a food source is supplied. So we have created systems that ensure that a profitable yield is delivered. 

At the same time, if the idea is to integrate the ecology of these systems into the production cycle. The reality is that everyone must be more accepting of losses and allow the integration time to generate a balance. 

The gentleman with the thousand-dollar-plus greenhouse takes his only option to produce homegrown food for his table. It’s most likely that he’d see a few nibbled around the edges. Then he would see the crop growing and be all excited until one night, the possums decide it is time for chocolate cake, or a wallaby might hop up from the valley floor to avoid the heavy rainfall and take equal delight in the shallots. 

What sustainably FED suggests 

All this is to say that none of the integration of food, ecology and diet that we advocate at sustainably FED is easy. 

Placing our food production into nature will involve significant compromise, especially in the first instance. 

But possums, wallabies, and bush rats can survive quite comfortably in the environment as it stands; they don’t need the lettuces. So if we integrate the systems well enough and ensure that it’s only at the edges that these animals cause impacts, we can learn to live with them. 

It’s the quality of the native vegetation that we have to work on and make sure that we don’t let our vegetation become too weedy. The natural vegetation must be looked after as much as the crop in the fields. 

Allowing balance in the ecology of natural habitats as we try to inject ecology into our production systems will reduce loss and improve our ability to grow foods in a more ecologically sustainable way. 

There is a caveat to all of this. We can hear the farmers chirping at us, saying “tell that to the rabbits and the pigs”. 

There are situations where introduced organisms have adapted to foreign parts very effectively and become pests of even large-scale agriculture. 

Rabbits are a classic example in Australia, where the introduction of a species from northern Europe not previously present on the continent but capable of reproducing rapidly on the grassy systems that exist in the continent became a dramatic pest of livestock production. Billions of rabbits have lived and died in Outback Australia. Controlling them was a challenging problem until the introduction of the calicivirus, and even now, as resistance emerges, rabbits are becoming a problem locally again and again. 

Similarly pigs. They are adaptable and intelligent animals that can utilise resources in the bush just as they’ve done in forests worldwide for millennia. Like the possums, they cannot resist the leafy greens of crops.

These are not trivial issues by any means. 

Most pest control is reactive rather than proactive, with a limited understanding of how these animals impact the ecology. We can say the same about weeds, of course. Where some weeds are native, but most are introduced and become a significant issue for both livestock production and cropping. 

How do we explain to the farmer that getting the system balance will have to suffer some losses? That’s not going to be an easy sell. So we have to do it structurally around the production system itself. Including the amount of money in that system so that compensation and other types of incentives can be put in place to ensure that the ecology can have time to re-establish itself. 

None of this we’re saying is ever going to be easy. 

After all, there are people involved. 

Solutions to sustainably FED are not entirely technical. Most of the time, the solution has to have that pragmatic flavour which recognises that it is much about persuading the people to do things differently as it is to let ecology happen.

Hero image from photo by Eva Blue on Unsplash