What is an extinction vortex?

Sounds like a bad 80s hair band, but it’s something far worse

There are some things that are plainly true even though we don’t think about them often or ever. Coke tastes better out of glass bottles. S’mores aren’t ever as good as you remember them being when you were a kid. If you’re wearing a white shirt and have a meeting after lunch, you will spill your lunch on your shirt. And the less you have of something that you need, the more precious those few things are. This is true for lots of things: money in your bank account, friends, toilet paper in a pandemic, and it’s especially true for animals that are endangered or worse, critically endangered. When this happens, we call it an extinction vortex. Enter the golden lion tamarin.

Golden lion tamarins are small, fascinating primates found only in the Atlantic Coastal Forest of Brazil. They get their name from their yellow to orange fur and the fact that it is thick and long around their heads and resembles a lion’s mane. In the late 1960s, a census was taken of wild GLTs, and the estimated wild population was fewer than 200 individuals. Thanks to the efforts of conservation organizations and the international zoo community, including Zoo Atlanta, the wild population is now around 2,500, with another 400 to 500 in zoological settings.

Golden lion tamarins are a model conservation story.  Their success is one of my favorite things to talk about when guests ask me, “Why do zoos matter?” If it weren’t for zoos, golden lion tamarins and many other species would be extinct in the wild or completely extinct.

Golden lion tamarins are primates, just like humans. Like humans, they are prone to diseases such as yellow fever. In 2019, a yellow fever outbreak reduced their wild population by at least a third. Such a reduction can be cataclysmic for an already small population. Zoo Atlanta’s conservation partner, the Golden Lion Tamarin Association, worked to vaccinate wild golden lion tamarins.

Within the Association of Zoos and Aquariums (AZA), we work with what is called the Species Survival Plan® (SSP) for individual species of animals. Not every animal you see in the Zoo has an SSP, but most species that are vulnerable, endangered, or critically endangered do. To simplify what an SSP does, it is kind of like a zoo matchmaking service where experts track genetics of members of a species that are in zoological settings, and try to match those genetics and animal temperaments with other members of that species at other zoos. This helps us to have sustainable, viable populations within zoos. Working with the SSP to keep zoological populations healthy now and for future generations is important to sustaining a small population of animals, no matter the species.   

As we look to bolster future populations of other animals including golden lion tamarins, we can use a One Health approach to see how all life is connected. Ecosystems live harmoniously in a sometimes complex but fragile balance, and the decimation of certain populations can have major implications for the ecosystem. Tamarins are seed dispersers, helping to spread the growth of plants around the forest, bringing life, oxygen, and habitats to many other species. Without them, the forest would suffer.  We can see the same thing in our own state where gopher tortoise populations are shrinking, and their burrows provide shelter for hundreds of animals during wildfires. Without gopher tortoise burrows, we could lose many other animals because they won’t be able to use those burrows during a fire.

Through small actions like supporting native plants and wildlife in your backyard and continuing to support AZA institutions like Zoo Atlanta, you can help to be a part of supporting the growth of these small vulnerable populations of animals, both where you live and around the world, to avoid the extinction vortex.

Zach Stich
Public Programs Coordinator

 

Source:

Datry, T., Corti, R., Heino, J., Hugueny, B., Rolls, R. J., & Ruhí, A. (2017). Habitat fragmentation and metapopulation, metacommunity, and metaecosystem dynamics in intermittent rivers and ephemeral streams. Intermittent Rivers and Ephemeral Streams, 377–403. https://doi.org/10.1016/b978-0-12-803835-2.00014-0