Wildfires Can Still Impact Wildlife Hundreds Of Miles Away
Many places in the West have been enveloped in wildfire smoke this summer. Common advice for people living in these communities is to go inside, close the windows, and turn on the AC, if possible, to escape the smoke. But wildlife don't have an "inside" they can go to.
As climate change continues to fuel more and larger wildfires, smoke in the skies will only become more common. Currently, there isn't a lot of research into how that smoke will affect animals. There's some research into how smoke affects dairy cows. And then there's a Cornell University research paper that gives vital information on smoke and wildlife. It only looks at one impacted species, but it gives vital insight into the understudied topic.
"So we do know that smoke has a lot of bad ingredients, has poisonous gases, like carbon monoxide, dangerous particulate matter, like the Pm 2.5, which is these really tiny, fine protocols that do a good job of penetrating the lungs," said Wendy Erb, a postdoctoral associate at the K Lisa Yang Center for Conservation Bioacoustics in the Cornell Lab of Ornithology.
She studies primate behavioral ecology and she looked at the effects of wildfire smoke, and these bad ingredients, on orangutans in Indonesia. She was there in 2015 studying the health dynamics of flange male orangutans during one of their worst wildfire seasons. The smoke was thick, and it traveled pretty far. She said there were around three months of extremely poor air quality.
"These fires had created these plumes of smoke, or it's often referred to as haze there, that reached as far as Malaysia and Singapore and caused an estimated 100,000 excess human deaths," she said.
Her team was stressed and she started to wonder about how the animals in nearby unburned areas were doing, and specifically, her study animal, orangutans. They were already collecting data and taking samples for another project.
After analyzing it all in terms of the wildfires though, what Erb and her team found was a bit counterintuitive. The animals were eating the same amount of food as before the smoke events and moving around less, but the chemicals in their bodies told her they were burning fats and using more energy than before - almost like they were fasting or traveling long distances.
"So we hypothesize that if the biology of these orangutans is like humans, because we have a pretty decent understanding of some of the physiological changes that humans experience in response to this air pollution, that it could signal that they were launching an energetically expensive immune response," she said.
These immune responses are known as cytokine storms. They happen when the bloodstream is flooded with inflammatory proteins called cytokines. They're usually triggered by an infection and can kill tissue and damage organs.
And, according to Erb, they can last for at least four months after the smoke has cleared. That's when they stopped collecting samples.
"There was a clear signal. In fact, for a lot of the things that we looked at, the post smoke period is actually where we saw even more dramatic changes than during the smoke period," she said.
Erb does add the caveat that during the time when the fires were the closest and the smoke was the worst, they weren't collecting data because they were helping fight the fires. But, she said regardless, it's clear that there are impacts of smoke, and that they linger. And because they last longer than four months in humans, they probably last longer in animals too.
She also adds that animals that are already stressed might also then have to deal with food shortages.
"It appears that the forests themselves are responding to the smoke. And it makes a lot of sense from a plant physiology perspective that the plants are less able to photosynthesize when there's a thick blanket of smoke covering everything. And so that sort of changes the whole cycle of fruiting," she said. "And so if you get those double whammies... we don't know yet."
But more research needs to be done into these long-term effects before a definite conclusion can be drawn.
Erb didn't just look at physical changes to the orangutans though. She could hear changes too. The animals called to each other less, and their voices were different. Erb said they had to turn to the literature on human smoking to understand it because the changes were so similar. And because females find and choose their mates partly through the sounds they make, this could possibly make it harder to find a "suitable" mate and maybe eventually impact the population, but Erb said that's also an area that needs further study.
According to Erb, researchers in Singapore reported a change in overall forest soundscapes during the same smoke event as her research - indicating that not just orangutans change their calls because of smoke.
Wildfires and their smoke will continue to be a problem for both people and wildlife to deal with. As climate change exacerbates wildfires, research into smoke's effects will only become more urgent.