Ecology is not a dirty word

(This is the accepted version of my review published here in Trends in Ecology & Evolution.)

It is an unfortunate paradox that insects, the most abundant and diverse class of animals on Earth, are also the most understudied and misunderstood. With diversity comes complexity, and scientists have only scratched the surface on knowledge of global insect ecology. In The Last Butterflies, ecologist and butterfly expert Nick Haddad explores some of this complexity.

Despite the title, this is not a story of despair. Nor is it just about butterflies. Haddad weaves an absorbing narrative about the multidimensional process of science and insect conservation, the damaging impacts humans can have on the web of life, the ethical quandaries of conservation, and the positive changes and solutions that give us hope. Each main chapter is focused on a single butterfly species: six of the rarest North American butterflies that Haddad has spent his career studying, and two more well-known species from North America and the UK. The eight butterflies are framing devices, each one illustrating pieces of the challenging puzzle that is insect ecology and conservation.

Habitat restoration is critical to support declining populations of any insect species, especially in regions undergoing rapid land use change (Bay Checkerspot). Yet most insects have specialised life cycles completely dependent on other plant or animal species, or particular conditions. Broad assumptions of suitable habitat based on isolated anecdotes or small-scale studies may miss some of the unique ecological interactions that a species needs to survive, like a rare host plant species (Fenders’ Blue), or complex multi-trophic community networks linking specific plants and other animals (British Large Blue). Even abundant, globally-distributed species can suffer unexpected population declines if these processes and interactions are taken for granted (Monarch).

“It took us fifteen years to find just two caterpillars in the wild. Both times, we found them by dumb luck.” (p. 125)

Insect ecology research takes time, prolonged by limited funding and resources. It can take decades of observation and experiment, and a dash of serendipity, to confirm even the most fundamental pieces of information about a species’ taxonomy or natural history. During that time, environmental conditions change, constantly shifting the goalposts (Miami Blue). Progress requires perseverance and resilience, and often some unconventional conservation approaches (St Francis’ Satyr). But single solutions are never enough for conservation. Multiple stressors, including climate change, pesticides, habitat clearing and weather extremes, affect insects everywhere. These stressors may act alone or in combination, and the magnitude and type of effect can change with each event. Searching beyond correlations to understand the underlying causes of these effects is challenging, but essential (Schaus’ Swallowtail).

Why should we care about protecting insects, rare or common? Sometimes, we need to expand our perspective to the human side of the story to reveal potential win-win solutions for effective conservation (Crystal Skipper). This is the crux of the ecosystem services concept, which is a powerful communication and research tool to identify the value of biodiversity and ecosystems, including trade-offs between costs and benefits, to inform effective conservation. In his final chapter, Haddad laments that public engagement can be difficult because rare butterflies “produce no measurable value to human economies or ecological systems” (p. 210). In truth, all insects are important drivers of ecological processes, and all species have measurable values, economic and non-economic, that contribute to ecological function and human well-being. The conservation potential of these social-ecological solutions is highlighted in the story of another rare butterfly from the southern hemisphere (Queen Alexandra’s Birdwing), which was unfortunately cut from the book’s final edit.

Key themes weave together the stories in The Last Butterflies, providing a springboard for important discussions about ecological research priorities and the future of insect conservation. First, natural history observation is fundamental to generating knowledge and doing effective research that translates into insect conservation success. Second, disturbances structure ecological systems, and are often essential to a species’ persistence. Understanding the net effects of human and natural disturbance, as well as gains and losses in response to these events, is a key research goal. Third, collaboration between researchers and local communities, i.e. naturalists, land managers, practitioners, and indigenous communities, is vital to building knowledge, conducting on-ground conservation action, and supporting further research.

Finally, the value of despair narratives in conservation communication must be interrogated. The first chapter frames the book within the popular, but hyperbolic, insect apocalypse narrative, using a figure from Dirzo et al. (2014) showing an apparent global decline trend for “all invertebrates”. Yet this figure is based on data from only 452 species (mostly lepidopterans) out of the approximately 1.5 million named invertebrate species. We urgently need action for wild insect conservation, but exaggerated narratives of despair distract from finding solutions to the real problem, i.e. we need to do better at embedding nature conservation, knowledge generation and long-term monitoring as core goals in land management initiatives. The Last Butterflies shares some inspiring examples of how to achieve this.

© Manu Saunders 2019