Mountain gorillas were just taken off the 'critically endangered' species list.

On Thursday, the Conservation of Nature announced a major win in fight to save mountain gorillas.

The gorilla population has been designed from "critically endangered" to "endangered" as their population has nearly doubled over the past decade. The latest numbers say there are over 1,000 mountain gorillas in the wild, up from just over 600.

After teetering on the brink of extinction, mountain gorilla numbers are on the rise. That's awesome news.

Living in East Africa's Virunga Mountains and highlighted in the movie "Gorillas in the Mist" (in which Sigourney Weaver played primatologist and conservationist Dian Fossey), critically endangered mountain gorillas have been battling extinction for decades.

Image via Brent Stirton/Getty Images.

In 1981, when their numbers had plunged to 242, Fossey doubted that the species would survive into the 21st century. Thanks in large part to concerted effort from conservationists, however, their population has slowly but steadily grown. In 2010, there were 480 animals, and as of a June 2016 census there were 604. With an estimate of several hundred uncounted gorillas roaming the forests, that number could be close to 1000.

But they are not totally out of the woods yet.  

Habitat loss and poaching are the biggest threats to gorillas.

Human encroachment and deforestation due to agriculture, livestock grazing, and firewood collection threaten the mountain gorillas' habitat. In addition, people are burning trees inside the forest to create charcoal — a commodity that makes up a massive illegal trade industry in an area with limited economic options.

Poachers going after other animals, such as antelope or bush pigs, also catch gorillas in their wire snares. When a gorilla can't remove a snare, it can end up losing a limb or dying from gangren.

Such threats are a byproduct of an overarching reality: human economic strife.

Battling economic inequality is a key to saving endangered species.

In order to mitigate threats to endangered species, we need to understand why those threats exist in the first place. Most people aren't on a mission to kill animals or destroy the environment; they're on a mission to live. When economic options are limited, people do what they have to, which often means sacrificing long-term sustainability for short-term survival.  

In other words, we can save endangered species by eliminating the economic need that drives the industry that threatens conservation.

Patrick Karabaranga, a warden at Virunga National Park, plays with an orphaned mountain gorilla in the gorilla sanctuary east of the Democratic Republic of Congo. Image via AFP/Stringer/Getty Images.

Researchers at Canada's McGill University highlighted the correlation between poverty and species protection in a 2007 study of 45 countries and 45 U.S. states. They found that income inequality actually predicts the number of threatened species in an area. The greater the unequal distribution of income, the greater the loss of biodiversity.

This correlation has clearly played out in the story of mountain gorillas. Rwanda and the Democratic Republic of the Congo — the two countries bordering the Virunga Mountains — have some of the highest economic inequality in the world. However, Rwanda in particular has made significant strides to reduce inequality — and as it has made those strides, gorilla populations in the region have increased.

For this very reason, Dian Fossey's organization uses the tagline: "Helping People. Saving Gorillas."

Folks at the Dian Fossey International Gorilla Fund understand that economy and ecology are intertwined. That's why a significant part of their work is helping develop the communities in the regions near gorilla habitats.

"When people have to focus on basic survival, this puts additional pressure on the environment, such as using the forests for hunting, firewood, water, or crop land," the organization's website says. "The Fossey Fund has programs targeted at meeting basic needs in these communities, which not only helps people, but also supports effective conservation efforts."

Economic inequality is a complex issue, and certainly not the only driving factor threatening endangered species — but it's a big one. "With biodiversity loss, if we don’t link the science to the social causes, we will never solve the problem" said Dr. Andrew Gonzalez, associate professor and Canada Research Chair in biodiversity.

Mountain gorilla research has offered a real-world example of this truth. As the Fossey Fund states, "Only when people are thriving can gorillas, other wildlife, and their habitats thrive, too."