Prosperous and hardy, the Eastern red-backed salamander is an unassuming creature that plays a pivotal role in maintaining the health and stability of woodland habitats in northeastern North America. Learn about these tiny ecological powerhouses before you visit them at the Smithsonian’s National Zoo.

1. There are billions of them.

Eastern red-backed salamanders are the most common salamanders in the Eastern and Appalachian regions of the United States – and in a healthy forest ecosystem, they’re often more plentiful than any other vertebrate species. 

Shockingly, these tiny animals are so abundant that in a healthy landscape, their total biomass is overall greater than the combined weight of all other animals living in the same area (excluding insects and other invertebrates.) One recent study estimated a healthy patch of forest the size of a football field can contain somewhere around 5,300 red-backed salamanders, each with their own tiny territory.

2. However, they spend most of their lives out of sight.

Eastern red-backs spend much of their lives underground, tucked away in small holes and decaying root systems. While buried in the soil, these tiny predators tunnel through the earth, pushing around dirt and preying on soil invertebrates. This tunneling activity has a dual role in engineering the micro-habitats that keep nutrients cycling through the soil.

While aboveground, these secretive salamanders prefer to stay hidden among the leaf litter covering the forest floor. Despite their tiny stature, their hungry appetites makes them the top predator in the leaf litter on insects, worms and other invertebrates.

3. They don’t have lungs.

Like two-thirds of salamander species, Eastern red-backed salamanders evolved without the use of lungs—instead, they breathe through pores on their skin in a process called cutaneous respiration. Their pores must remain damp for the animals to absorb oxygen.

Because of these traits, red-backed salamanders are typically spotted aboveground on cool, rainy nights when there’s plenty of moisture in the air.

4. They are hidden heroes for the environment.

Naturalists have long been aware of the connection between Eastern red-back salamander populations and thriving forest ecosystems. Salamanders are often referred to as "indicator species," meaning their presence—or absence—signals the health of their environment.

Salamanders like the Eastern red-back are critical nodes in the forest food web – they keep insect populations in check, and in turn, are preyed upon by larger animals. This role helps them stabilize populations both upward and downward, ensuring that no single species comes to dominate the woodland ecosystem.

5. Not all Eastern red-backed salamanders have red stripes on their backs.

These critters come in several different color varieties and forms, making them a polymorphic species. One of the most common color morphs turns the salamanders completely dark gray (or “leadback”) instead of red and brown (“redback”).

6. They appear to be hardier than many of their salamander cousins.

Eastern red-backs can be found in suburban backyards, urban parks and other habitats that have been changed by human activity. However, their porous skin can easily absorb toxins and other environmental pollutants, so you won’t find them in places where pesticides and herbicides are heavily used.

7. They are the official state amphibian of the District of Columbia.

In 2024, a group of elementary school students testified in front of the city council that Eastern red-backed salamanders should be recognized as the official amphibian of Washington, D.C. The students argued that declaring the animal “official” is important for raising awareness about these tiny predators and the threats they face in the wild. The proposal became a bill and was signed by Mayor Muriel Bowser on October 28.

8. Populations of many amphibian species are on the decline—but Smithsonian scientists are working to save them.

Due mainly to human activity, even common amphibian species like Eastern red-backed salamanders may undergo massive die-offs in the next few decades. Logging, urban expansion, and soil contamination disrupt salamander habitats, while rising temperatures and changing rainfall patterns challenge the animals’ moisture-dependent lifestyles.

No two species face the exact same threats to their survival. That’s why Smithsonian scientists research species-specific conservation strategies for safeguarding wild animals and their habitats. Learn about their efforts to save salamanders—and what you can do to help—during your next trip to the Zoo’s Reptile Discovery Center or Amazonia exhibits.

Mike Bock | READ MORE

Mike Bock is a web content writer for the Smithsonian’s National Zoo and Conservation Biology Institute, where he focuses on animal care, conservation science and research.