Vanishing Insects and the Silence of the Forests

Special thanks to Jay Thompson for his contribution to this blog!

Vanishing insects are the silent alarm of climate change—one we can’t afford to ignore.

Some of my most cherished memories come from forests, such as the rainforests of Borneo, or in Tasmania where I was greeted by a curious pademelon at the entrance of my log cabin. In the Amazon rainforest I watched wild macaw parrots gather at clay licks — a vibrantly colorful and magical sight I wish everyone could experience.

In nearly any forest on Earth, the productions of nature saturate our senses: the smell of moist ground and humid air, the sounds of birdsong, of tree branches creaking against one another, and of leaves rustling in the breeze. And day or night, in the background is a vast symphony of insects — a multitude of small exoskeletal creatures seen and unseen.

I once believed that forests — especially those in nature reserves — were natural strongholds for wildlife. Even if conditions outside of forests were inhospitable, the flora and fauna within forests must be less vulnerable to the machinations of humans, as if a forest were a fortress. Ecologists, the scientists who study how animals and plants live together, once believed the same. But they’re now finding that insects are vanishing, even in protected woodlands.

A Forest is Not a Fortress

One of the wild and peaceful forests I’ve visited is the Guanacaste Conservation Area, a World Heritage site in northwestern Costa Rica. The forest feels hushed, almost as if it’s holding its breath. No wind stirs the trees, no footsteps rustle the underbrush. Only the steady hum of insects and the occasional call of a bird break the stillness. A distant trill echoes from the canopy, followed by the soft whirr of wings or the rhythmic chirp of a hidden cricket. It’s a soundscape made entirely of tiny lives — fragile, fleeting, and essential. Without them, the silence would be absolute.

Biologists Daniel Janzen and Winnie Hallwachs studied insects in Guanacaste. They noticed a sharp decline in moth, beetle, and butterfly populations—even though the area remains untouched by farming or urban development. And as is often the case, the root cause of declining wildlife populations is indirect.

Back in the 1980s, thick clouds used to hang over these thriving forests almost every day, covering the tops of mountains like Volcán Orosí and Volcán Cacao. But in the 1990s, Janzen and Hallwachs noticed that clouds were becoming less common. Now there are many days with no cloud cover at all.

Forest insects don’t necessarily dislike sunshine itself, but fewer clouds mean more hours of direct sunlight on forest soil, which then becomes drier. That’s bad news for insects and other animals that rely on moist soil and damp leaves to survive. Even the rivers and streams are shrinking, which affects farms and people living in nearby areas.

Vanishing Insects — When The Dominoes Fall

This isn’t just happening in Costa Rica. Researchers are observing similar insect declines all over the world. If you search “vanishing insects” online, you’ll find countless articles and research studies on the matter.

In Germany the number of flying insects dropped by 75% over just 27 years. In the U.S., beetle numbers fell by 83% over 45 years. And in Puerto Rico, the total mass of insects could be 60 times lower than it was in the 1970s. Keep in mind, these studies are six or seven years old, so the numbers could now be even worse.

Not everyone would shed a tear about living with fewer insects. But both the living things we enjoy and those we don’t enjoy play essential roles in keeping ecosystems in balance.

Forests are like the land-based counterpart to coral reefs. Instead of corals, trees provide the large-scale structures that make the habitat so inviting for other living things. And like coral reefs, forests host impressive biodiversity as well as a delicate harmony and interdependence between species. That’s partly why humans find both forests and reefs so appealing; they’re calming not only because they seem serene but because those environments demonstrate how undisturbed wildlife can settle into a balance and a seeming permanence.

But when the population of one or more species is added to or subtracted from an ecosystem, the longstanding balance can collapse and have unpredictable and permanent consequences. In other words, if small fish disappear from a coral reef, so do their predators. Likewise, if insects disappear from a forest, so do the birds, lizards, amphibians, and carnivorous plants that depend on them as food. Insects also pollinate about 80% of wild plants, helping those plants grow and make seeds. So, when insect numbers drop, the effect cascades through the entire ecosystem.

Even in protected rainforests in the U.S., Brazil, Ecuador, and Panama, scientists have seen huge drops in bird populations. The birds disappearing the most are the ones that eat insects, which are getting harder to find as the climate changes. And it’s not just tropical birds. A 2019 study from Cornell found that nearly 3 billion birds have vanished from the U.S. and Canada since 1970. That’s not a small change—it’s a massive loss.

Why Are Insects Disappearing?

Vanishing insects in protected areas suggests that deforestation or farming aren’t solely to blame. Scientists say changing climate is the main problem now. Long-term changes in weather patterns can create unprecedented droughts, can increase or reduce rainfall and temperature, or change the timing of those events.

Plants and animals adapt over centuries or millennia. When weather patterns change in decades or even a few years, living things can’t adapt quickly enough to survive. When one species — even mere insects — disappear, they often take other species with them, leading the finely-tuned and interconnected ecosystem to fall apart.

---

We can’t protect what we don’t understand — and right now, even our most cherished forests are sounding the alarm.

Insects are vanishing, birds are falling silent, and the rich symphony of life is fading — not just in faraway places, but in protected forests once thought safe. This is the hidden face of climate change.

🌍 We need your voice. Your action. Your care.

🌱 Speak up for the forests.
🦋 Protect the insects and the birds that depend on them.
🔥 Demand bold climate solutions that preserve moisture, life, and balance.

Don’t let the silence grow. Share this story. Keep up to date on climate change and human impacts on the planet. Support climate action. And help keep our forests alive.