Cost-benefit trade-offs of bird activity in apple orchards

This is a guest post from my PhD student Rebecca Peisley, who I am co-supervising with Prof Gary Luck. Rebecca will submit her thesis early next year. She has been working on a really cool project looking at the costs and benefits of bird activity in apple orchards, vineyards and cattle grazing systems across south-eastern Australia; this blog is about her work in apple orchards.


Birds are commonly found in agroecosystems around the world and their foraging activities within crops can result in positive or negative outcomes for producers. For example, birds can help increase saleable yields by preying on insect pests that damage fruit, or removing leftover fruit after harvest, which helps prevent disease and assists in nutrient cycling. However, birds can also contribute to production losses by eating and damaging fruit before harvest, or preying on beneficial insect pollinators.

We cannot then assume that birds are simply ‘good’ or ‘bad’: the same species can in fact be ‘both’. But in our literature review, we showed that most studies of birds in agroecosystems have just considered either costs or benefits separately, which limits our understanding of how birds influence crop yields over spatial and temporal contexts.

In order then to gauge an overall outcome of bird activity, we look at both their beneficial and detrimental activities together in the same crop system and consider the trade-offs that exist between them. For example, the beneficial activity of insectivorous birds preying on pest insects in an apple orchard and reducing insect damage to fruit is traded off against the detrimental activity of the same birds preying on beneficial pollinators resulting in reduced fruit-set. Continue reading

Neonicotinoids linked to wild bee and butterfly declines in UK and US

Two long-term studies were published today showing comprehensive evidence that neonicotinoid use could have long-term effects on populations of non-target insects, especially wild pollinators. The studies look at wild bees in the UK and butterflies in California.

I wrote a piece for The Conversation on why I think these studies are important and how these results relate to Australia.

Read more: Neonicotinoids linked to wild bee and butterfly declines in Europe and US

Also see Jeff Ollerton’s great post on the UK bee study: Bees and pesticides – a major new study just published

© Manu Saunders 2016

Nature, food and people: there’s no magic bean for sustainable agriculture

If you believe your Twitter feed, every Jack and his beanstalk has the quick-fix solution we need to beat the sustainable food challenge. ‘If you want to eat meat, switch to pigs, birds & fish to generate fewer emissions’. That’s convenient, because ‘lettuce is three times worse than bacon for the environment’.

These solutions all sound pretty sexy. But reducing the environmental impact of food production is not as simple as choosing one crop or livestock type over another.

Food production is a social-ecological system. That means it’s a system based on a mutual relationship between nature and humans. The ecosystem (i.e. the farm) influences human lives and actions, via ecosystem services. And humans influence the ecosystem’s structure and function, through direct management and indirect drivers like regulations, subsidies, financial markets and consumer demand. Continue reading

Goodies v baddies? Why labelling wild animals as ‘pests’ or ‘friends’ is holding farming back

It’s hard to keep wild animals out of farms. Birds, mammals and insects all affect crop yields, in positive ways (such as flies pollinating flowers) and negative ones (such as when birds damage fruit).

Agricultural research and management programs often deal with these interactions by focusing on simplistic “good” and “bad” labels: aphids are annoying pests, for example, whereas bees are little angels.

Read the rest of our piece at The Conversation.

And see the papers behind the article here:

Saunders ME, Peisley RK, Rader R, Luck GW (2016) Pollinators, pests, and predators: Recognizing ecological trade-offs in agroecosystems. AMBIO 45:4-14.

Peisley RK, Saunders ME, Luck GW (2015) A systematic review of the benefits and costs of bird and insect activity in agroecosystems. Springer Science Reviews 3:113-125.

Emancipation, Evolution…and Agroecology: Lincoln & Darwin on land-sparing vs. land-sharing

Every year, I get to share my birthday with these guys:

darwinlincoln

I’ve been mildly obsessed with both of them for years, for obvious reasons. But it was only recently that I discovered their early contributions to the land-sharing/land-sparing debate, something directly relevant to my own work. Darwin’s ecological legacy is well-known, but how often do we consider Lincoln’s impact on environmental history? Continue reading

The Good, the Bad and…the Ecology

There are very few (if any) true ‘wilderness’ areas left, those completely untouched by human influence. This isn’t a tragedy – it’s an opportunity to grow, learn and discover more about the amazing planet we live on. Many ‘natural’ ecosystems have become social-ecological systems, where humans and nature can co-exist, not out-compete each other.

Agricultural systems are a perfect example. It’s hard to keep wild animals out of agroecosystems. They affect crop yields directly and indirectly across the growing season through positive (e.g. insects pollinating flowers) or negative (e.g. birds damaging fruit) interactions with crop plants. Because humans tend to label and categorise things (labels are easier to manage, justify or remove) we generally label these animals as either ‘bad’ or ‘good’ – aphids are annoying pests, bees are little angels. That’s all there is to it.

In reality, no organism is completely ‘bad’ or ‘good’ to the extreme; the effect it has on other organisms around it, including us, varies with context. All the individual plant-animal interactions happening in a single crop system are influenced by seasons, landscapes, management practices, and the social, cultural and economic values of the local farming community. Continue reading

Single-crop farming is leaving wildlife with nowhere to turn

Rolling plains of wheat, endless fields of flowering canola, row upon row of fruit trees: these agricultural landscapes are the stuff of stunning photographs.

Filling these paddocks with just one crop, known as monoculture, is a relatively easy, common and efficient way to produce food and fibre.

But international research shows that these monocultures can be bad for the environment and production through effects on soil quality, erosion, plants and animals, and ultimately declining crop yields. Research I have published this week in the International Journal of Agricultural Sustainability shows a possible link between monoculture landscapes and fewer wild pollinators.

Is there a better way to grow our food?

Published today at The Conversation. Read the rest of the story here….