Besides being a major sources of deforestation, production of unsustainable palm oil has an adverse affect on rainforest butterflies.

A paper was released in Biotropica late last year highlighting the research done by scientists at University of York about the fragmentation of natural rainforest habitat caused by oil palm plantations and the impact on rainforest butterfly species. Previous studies have been conducted on how these types of boundaries can impact native animal species but few have looked at potential harm to insects.

Palm oil is used in many commercial products including food and cosmetics for its low production cost. There are many ways in which unsustainably produced palm oil can negatively impact the rainforest’s environment and the people who depend on it. When large areas of rainforests are cut down to make way for oil palm plantations, rainforest species can have a difficult time moving across these rainforest-plantation boundaries. Losing these connective networks can result in biodiversity loss. The study, conducted in Borneo, Southeast Asia, examined the ability of butterflies to cross rainforest boundaries in relation to particular characteristics, such as: wing size, the number of food plants their caterpillars can feed on, where in the world populations can be found, and the presence or absence of food plants within oil palm plantations.

Results showed that larger butterfly species are over two times less likely to cross the rainforest boundary into the oil palm plantations than compared to smaller butterfly species. The major factor was that the larval food sources of the large rainforest butterflies, largely rainforest herbs, shrubs and trees, do not grow in the plantations. Professor Jane Hill of University of York stated “Our results, therefore, suggest that oil palm plantations may act as barriers to the movement of forest-dependent butterflies, which highlights the importance of conserving existing forest areas that form corridors linking forest reserves.” It was also pointed out that butterflies need to be able to cross into neighboring habitats in order to support genetic diversity and stable populations.

Perhaps one of the most important takeaways from this research is that these boundaries will become even more important with climate change. If the current forest habitats become warmer, then butterfly species will need to move across current oil palm plantation barriers to cooler climates.Dr Colin Beale, also from the Department of Biology at York, explains: “Oil palm provides a valuable crop to many farmers in the tropics, but conversion of rainforest to oil palm plantations results in a dramatic change in habitat structure, making plantation habitats unsuitable for many rainforest species.” 

You can read the full study here: