Tempest News | November 2023

"How fast is the world changing? Where is the change seen the most? What are the risks in terms of our health?" These are just a few questions that guide scientist Robert Guralnick's research. As the Curator of Biodiversity Informatics at the Florida Museum of Natural History, Guralnick and his team utilize massive datasets, museum specimens, and crowdsourced observations to assess the impact of our changing climate on the natural world.

Q: Your recent research focused on the impact of weather on insects, primarily weather anomalies vs. longer-term climate patterns. Can you provide a summary of your research and what the findings indicate? 

We have long known that as our climate changes, whether we're talking about natural changes or changes that might have anthropogenic causes, and we know that phenology (the study of cyclic and seasonal natural phenomena, especially in relation to climate and plant and animal life) is super responsive to the changes. Phenology can be described as the canary in the coal mine because that's where we see these changes happening most clearly. That's been shown conclusively across study after study after study. People look at these mean temperature changes, and relate that to the timing of changes, in terms of leaf bud burst or flowering appearing on plants. 

This year saw a remarkably warm summer across most of the world, especially in the US, and we have seen periods of unusually cold winters that are preceded by really warm periods. How do events like that impact the timing of seasonal changes? That was the core idea behind the study. And there have been some really interesting hints about the importance of these anomalous or extreme events, scattered like seeds in the literature. But we hadn't seen anybody look at this question at a broad scale and try to understand contextually how much it matters if you're in, say, Maine, and you have extreme warmth. 

It was fortuitous because we had just finished a study the year before that had an enormous and well-assembled dataset that we could use again. We assumed that these extreme warm and cold fluctuations would have at least a minor impact, but we were shocked to find that they had an incredible impact. These extremes seem to be really strong drivers that moved the system. That was a real surprise.

Q: HISTORICAL WEATHER DATA HAS BEEN COLLECTED FOR QUITE A LONG TIME, SO IT'S FAIRLY EASY TO GET ACCESS TO THOSE DATASETS. BUT INSECT DATA IS A LITTLE BIT TRICKIER TO COME BY, SO YOUR TEAM TURNED TO MUSEUM SPECIMENS. TELL US ABOUT THAT.

Museums are storehouses of our natural heritage. They provide us with probably our best look at the past. Many people particularly love butterflies and birds, so they are monitored pretty well. But generally speaking, the monitoring only goes back to the 70s. Insects don't have the long-term record that many vertebrate organisms have. Museums are a place where you can go and find millions of specimens, each with a label that tells you where it was collected, when it was collected, and who collected it. We can take those, and we can use that data if we're clever. There are some tricks to this. But skipping the technical details, we can use the data to predict the onset of flight or the cessation of flight in a region in a year for species. And that's what we did. And those all came in this study from looking at museum records where we had enough data that was in that region to be able to make those estimates. 

Q: THE RESEARCH SHOWED THAT COLD DAYS KEPT INSECTS AT ALL LATITUDES ACTIVE LONGER. THAT SEEMS COUNTERINTUITIVE. CAN YOU EXPLAIN?

It is counterintuitive in a way. These extreme cold events that we're seeing don’t necessarily kill all the insects in the region. What a lot of insects will do is go dormant for a period of time, but they still have to finish up their activities for the year. They’re still on a deadline. So, while you may see reduced activity during these cold periods when the insects recover, they must still complete a lifecycle. They’re behind schedule, and they must either rush to complete everything they need to or they must extend their lifecycle. Obviously, if they’re hit by wave after wave after wave of these events, they might not recover. But generally, we see them extend their lifecycle. 

Q: WHEN MOST PEOPLE THINK ABOUT INSECTS LIKE BUTTERFLIES OR MOTHS, LONGER ACTIVE PERIODS DO NOT SEEM LIKE A PARTICULARLY NOTABLE THING. HOWEVER, WHEN YOU THINK ABOUT OTHER INSECTS, LIKE MOSQUITOS, THAT HAS A GREATER HUMAN IMPACT. CAN YOU SPEAK TO THAT?

There are two different answers to this question from two different perspectives on insects. Because insects are awesome and valuable, their importance in our ecosystem cannot be overstated. However, they pose a definite threat to human health. 

On the positive side, longer durations mean that more plants get pollinated. And that's really good because there are billions of dollars invested in agriculture for pollination. If we understand phenology and the risks we face under extreme events, we might be able to use that information to make better choices about pollination. We actually do see these relationships in terms of physiological matching between insects and plants in terms of the pollination period. And that's really critical because if these periods become misaligned, that will mean that we're going to lose a lot of the pollination services that nature provides.

The other angle is about the risks posed by many insects. One thing we're actively pursuing is trying to tie together the phenology of vector insects and mosquitoes and how that relates to bird migration because that is critically important for the potential for those insects to infect humans. For example, a mosquito bites a bird, then the bird travels along the migratory path, where another mosquito bites that infected bird and then bites a human, infecting that human. The dynamics of that are even more complicated than anything we talked about, but we are pursuing building tools we need to look at the human impact in terms of disease by really focusing on these physiological questions. 

Q: WHAT COMES NEXT FOR YOU AND YOUR TEAM?

We are actively comparing insect and plant responses to extreme weather. We have a beautiful dataset from community science activity through a project called Naturalist, where we can gather data on plants and insects simultaneously. The hope was that their responses to extreme weather would be similar, but we're finding they are quite different. And because of that differential responsiveness, it'll mean that they'll shift out of sync with each other in ways that will be potentially detrimental to both. And so we're trying to track the consequences of those mismatches over space and time. 

We're trying to mitigate risk. If it’s a certain time of year and a set of conditions we’ve noted previously, we can better forecast the risk of West Nile or a shorter window for pollinators that would impact agriculture in a specific location. There are certainly challenges, but we're very excited about the potential of giving stakeholders and people in the public better ways to know and use information for making good decisions.

A lot of the work we do is curiosity-driven. Science is really fun, and I love that I get to do it. But really, we're doing this work to support human health and well-being and keep our planet healthy and vibrant. 

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