Scientists studied what cave salamanders eat by examining 1,108 salamanders from 36 different populations across Europe. They looked at both salamanders living underground in caves and those living above ground in forests and woodlands. By carefully checking what was in each salamander’s stomach, researchers found 8,899 different prey items and discovered how the diet changes depending on whether salamanders live underground or above ground. This research helps us understand how animals adapt when they move to new environments, especially the dark world of caves.
The Quick Take
- What they studied: What different populations of European cave salamanders eat, comparing those living underground in caves to those living above ground in forests and on stone walls
- Who participated: 1,108 cave salamanders from 36 different populations across Europe, representing seven of the eight known cave salamander species, studied between 2021 and 2024
- Key finding: Researchers identified 8,899 individual prey items from 50 different categories in the stomachs of 930 salamanders, revealing detailed information about what these salamanders eat in different environments
- What it means for you: This research helps scientists understand how animals change their eating habits when they live in different places, which is important for protecting these rare salamanders and understanding how life adapts to extreme environments like caves
The Research Details
Scientists traveled to 36 different locations across Europe where cave salamanders live. They captured salamanders from both underground caves and above-ground forests, measuring and photographing each one to track their health. The researchers used a special technique called stomach flushing—a safe, non-harmful method to gently collect food from the salamanders’ stomachs without hurting them. They then examined everything they found under a microscope to identify exactly what each salamander had eaten. Some locations were visited once, while others were checked multiple times in different seasons to see if eating habits changed throughout the year.
The study covered a huge area: 4,667 square meters underground and 34,640 square meters above ground. This large-scale approach allowed researchers to compare many different populations and see patterns in how salamanders eat depending on where they live. The data collection happened over four years (2021-2024), giving scientists a good picture of eating habits across different times and seasons.
This type of research is called a ‘dataset paper’ because its main purpose is to share detailed information that other scientists can use for future studies. The researchers are making all their information publicly available so that other scientists around the world can learn from their work.
Understanding what animals eat is crucial for protecting them. When we know the diet of rare species like cave salamanders, we can better understand what they need to survive and how to keep their environments healthy. This research is especially important because cave salamanders are strictly protected by law in Europe, and some species are found nowhere else on Earth. By comparing underground and above-ground populations, scientists can see how these salamanders have adapted to one of Earth’s harshest environments—complete darkness with very few food sources.
This study is strong because it involved a very large number of animals (1,108 salamanders) across many locations (36 populations) over several years. The researchers used careful, scientific methods to identify what the salamanders ate, examining stomach contents under a microscope rather than guessing. The study covered both underground and above-ground environments, allowing for meaningful comparisons. However, this is primarily a data collection study rather than an experiment testing a specific hypothesis, so it provides information rather than proving cause-and-effect relationships. The data is being shared publicly under an open license, which means other scientists can verify and build upon this work.
What the Results Show
The researchers examined the stomachs of 930 salamanders and found 8,899 individual prey items, which they organized into 50 different categories. This means each salamander ate an average of about 9-10 different prey items. The prey items ranged from tiny insects to other small creatures that live in caves and forests.
The study revealed important differences between salamanders living in caves versus those living above ground. Cave salamanders had access to different types of food than surface salamanders because caves have fewer types of animals living in them. The researchers also found that different populations of the same salamander species sometimes ate different things, suggesting that salamanders adapt their diet based on what’s available in their specific location.
The research included detailed information about body size and condition of the salamanders. By weighing and photographing each salamander, scientists could see whether salamanders in different locations were healthy and well-fed. This information helps show whether the available food in each location is enough to keep the salamanders healthy.
The dataset includes information from multiple visits to nine locations, allowing researchers to see how diet changes between seasons and years. This revealed that salamander eating habits aren’t fixed—they change based on what food is available at different times of year.
The study found that the hybrid zone where two salamander species overlap (S. italicus × S. ambrosii) had interesting dietary patterns that differed from pure populations of either species. The large number of samples from one species (S. italicus) allowed researchers to see how much variation exists within a single species across different locations. Salamanders living on dry-stone walls (old stone structures without mortar) had different diets than those in forests or caves, showing that even small habitat differences affect what salamanders eat. The research also documented the body condition of salamanders across seasons, revealing patterns in how well-fed salamanders are at different times of year.
This research adds significantly to an ongoing European project studying what cave salamanders eat. By including seven of the eight known species and comparing underground versus above-ground populations, it provides a much more complete picture than previous smaller studies. The large sample size (1,108 salamanders) and detailed prey identification (50 categories) represent one of the most comprehensive dietary studies of these rare salamanders. The research confirms what scientists suspected—that cave-dwelling populations have adapted different eating strategies than their above-ground relatives—while providing specific data to support this idea.
This study is primarily a data collection effort rather than an experiment, so it describes what salamanders eat but doesn’t explain why they eat what they do. The researchers used stomach flushing, which is safe but only captures what the salamander had recently eaten—it doesn’t show everything the salamander eats over longer periods. Some locations were only visited once, so seasonal patterns couldn’t be studied there. The study focuses only on European cave salamanders, so the findings may not apply to other salamander species or animals in different parts of the world. Finally, while the researchers identified prey into 50 categories, some prey items were too digested to identify exactly, so the true diversity of food might be slightly higher.
The Bottom Line
This research doesn’t provide direct health recommendations for people, but it does suggest that cave salamanders are successfully eating and surviving in both underground and above-ground environments. For conservation efforts, the findings suggest that protecting the natural habitats of these salamanders—both caves and forests—is important because different populations depend on different food sources. Scientists and conservation organizations should use this data to better understand what each salamander population needs to thrive. Confidence level: High for describing what these salamanders eat; moderate for making predictions about future populations.
This research matters most to scientists studying salamanders, conservation organizations working to protect rare species, and environmental managers responsible for cave and forest habitats in Europe. Cave salamander enthusiasts and people interested in how animals adapt to extreme environments will also find this valuable. This research does NOT apply to people looking for health or nutrition advice—it’s about wild animals, not human health. People who live near caves or forests where these salamanders live should care because it helps explain the importance of protecting these habitats.
This is a data collection study, not a treatment or intervention, so there’s no ’timeline for benefits.’ However, the data will be useful for scientists for many years as they conduct future research. Conservation efforts based on this research might take years or decades to show results in terms of protecting salamander populations. The ongoing nature of this project means scientists will continue collecting data and refining their understanding over time.
Want to Apply This Research?
- If you’re a citizen scientist or nature enthusiast, you could track salamander sightings in your area using a nature observation app, noting the location (cave, forest, or wall), date, and any visible characteristics. This type of crowdsourced data helps scientists like those in this study gather information about where salamanders live.
- If you live near caves or forests with salamanders, you can help by protecting these habitats—avoiding disturbing caves, maintaining natural forests, and reporting salamander sightings to local conservation organizations. This supports the kind of research described in this study.
- Long-term monitoring of salamander populations in your area could involve regular visits to known salamander locations and documenting what you observe. Sharing photos and observations with local universities or conservation groups contributes to the kind of large-scale dataset this research represents.
This research describes what cave salamanders eat in their natural environments. It is not medical or nutritional advice for humans. If you encounter cave salamanders in the wild, do not attempt to capture or handle them—they are strictly protected by European law. This study is based on scientific observation of wild animals and should not be used to make decisions about keeping salamanders as pets or attempting to replicate their diets. Always consult local wildlife regulations and experts before interacting with protected species. The findings apply specifically to European cave salamanders and may not generalize to other salamander species or animals in different regions.