Dodging venomous vipers and plant poachers to study how climate change impacts insects

Quirks & Quarks is devoting its first episode of the season to the challenges and adventures of scientists working in the field.

Understanding the impacts of climate change and other environmental challenges to insects is a high priority for biologists. This summer it led one Canadian scientists to travel across hurricane impacted wilderness areas across the southern United States, and another to a paradise of biological diversity in Costa Rica.

Insects, spiders and other arthropods represent a huge fraction of the planet's biological diversity. And many researchers are concerned about what seems to be a worrying decline of insect populations worldwide. These declines have been linked to many factors, including climate change, deforestation, other human habitat disturbances, and the impact of pesticides.

The work of researchers like Jonathan Pruitt, of McMaster University, and Alex Smith, from the University of Guelph, is contributing to our understanding of some of the factors that could be playing into these insect declines, as well as helping to build up a picture of the rich diversity of insects in remote and often unstudied environments.

Field research can be the best part of a scientist's job. "Getting out into the field is something that inspired me to be a biologist," said Smith.  But he and Pruitt both faced a range of challenges in their work this summer, including hard work  under difficult conditions, venomous snakes, and in Pruitt's case, an encounter with a group of menacing poachers.

 "Field seasons are a mix of agony and ecstasy each time," said Pruitt. "Agony because you're about to put yourself in conditions where your quality of life is going to degrade precipitously. Ecstasy because you're going to collect data that humankind hasn't seen before."

Chasing hurricanes and dodging poachers to study insects

Pruitt travelled to 34 different field sites from Virginia to Florida to Texas this summer, looking at how climate change- induced extreme weather events impact insect and spider populations. Essentially, his research program involves chasing hurricanes to look at how the insects are affected before and after major storms. 

Much of Pruitt's work involves constructing various types of traps at each site. These traps capture insects and spiders so he can get an idea of what animals are present and how these weather events have changed things like their abundance, body size and body condition.  

In preliminary results in his work, he's found that tropical cyclones do seem to reduce abundance and diversity of insects. This, he suggests, probably has knock-on effects on animals that prey on them for food or plants that rely on them for pollination.  

Of course, storms are a natural part of the life cycle of the wildlife in the southern U.S. But Pruitt says there is a concern that as climate change potentially increases the frequence or intensity of storms, there could be permanent changes in insect abundance and diversity.

Insects were not the only kind of wildlife that Pruitt encountered in his work. In his work in South Carolina this summer, he had frequent encounters with water moccasins, a species of venomous snake.

These metre-long vipers were not shy in warning Pruitt not to get too close as he hiked along wilderness paths. Fortunately they were easy to see. These snakes open their mouths enormously wide when they threaten to strike, exposing the bright white interior of their mouths. This display made it easy for Pruitt to understand the origin of another name they're known by — the cottonmouth. 

Snakes weren't the only potentially threatening encounters Pruitt had in the distant corners of the state parks and wilderness reserves where he conducts his work. These remote areas are also frequented by poachers. Some were  after reptiles — toads, turtles, snakes — for illegal trade.

Others were seeking out carnivorous plants. Pruitt says that there's an active illicit trade in wild Venus flytraps, with large specimens fetching a few hundred dollars each.  

Pruitt described one encounter with two intimidating strangers who approached him in a well-equipped four-by-four filled with empty plant pots and soil.  "I tried to look as innocuously Canadian as possible," said Pruitt, "and then I tried to hide down some other dirt road and do my job because I actually have something to do." 

Beware of vipers in the forest

Biologist Alex Smith faced his own challenges in his studies of in Costa Rica's stunning Area de Conservación Guanacaste. This remarkable wilderness reserve and UNESCO World Heritage Site is only about the size of the greater Toronto area, but Smith said it harbours about 2.6 per cent of the world's biodiversity.

It encompasses areas representing several tropical ecosystems as it rises from the Pacific into the mountains including dry forest, rainforest and cloud forest.  

Smith, an Associate Professor in the Department of Integrative Biology at the University of Guelph, has been working in the area for several years, studying the arthropods — insects, spiders, millipedes and other small creatures — that make up a huge amount of its biological diversity. He and his students identify new species and try and build an ecosystem level understanding of how they all interact.

One of his areas of focus more recently is how all these creatures are affected by climate change, especially as mountain peaks once covered in almost permanent cloud and mist, are now experiencing warmer and drier conditions. 

"Communities that are tightly packed on these little conical mountains are being transposed and shifted up slope," Smith explained. "That's to the detriment of lots of things that live higher up, because they now have to deal with a much more competitive environment."

While Smith and his group use a range of high-tech tools, including DNA analysis, a significant amount of the work is still on the ground — literally. They spend days crawling around in the leaf-litter on hands and knees.  Smith explained that it's vital to get up close with the biodiversity living there to understand who lives where, who eats whom, and how all this is changing as you work your way up warming volcanic mountainside. 

"You're kind of breaking bark off of trees, fallen logs, and sifting through them and looking for the smallest of the small things, all these jewels that are in the leaf litter." 

It's detailed and engrossing work. And that explains, perhaps, why Smith broke one of his cardinal rules this summer, which almost led to disaster.  

Smith carries his gear in a blue plastic barrel, which he often leaves trailside as he explores on his hands and knees. Smith had trained himself to always walk a complete circle around any equipment or other gear that has been left on the ground for any length of time, before approaching it and picking it up. But on one occasion, he neglected this very simple rule. 

In an instant, a venomous, fanged viper, nearly a metre long, hissed and lunged at him — missing by centimetres. He was saved only because the reptile had become tangled in the straps of the barrel. This saved him from a painful, even potentially lethal, bite.

Smith has learned a valuable lesson he'll be sure to apply when he returns to Costa Rica for future field seasons. He'll carry anti-venom and be a bit more cautious about potential threats.  "I probably won't ever make that mistake again," he said, "I will find new mistakes to make and learn from in the future."