Humans and ecosystems: how do vultures provide ecosystem services?

- [Instructor] Can you imagine eating bones for breakfast? It sounds crunchy and pretty gross, but that's exactly what the lammergeier eats. The lammergeier is a scavenger, which means it eats the decaying flush and bones of dead animals. Rotting animal carcasses can be full of harmful substances, including toxins produced by bacteria. These toxins can cause serious health issues in humans. However, the vultures have evolved an incredibly acidic digestive system, allowing them to eat deceased carcasses without becoming sick. The lammergeier's stomach acid is so acidic that it can digest most bones in about 24 hours. Vultures are essential to keeping our ecosystems and us healthy by getting rid of harmful substances that could contaminate soil, water or food. Carcass cleanup by vultures is something we call an ecosystem service, which is a way that we humans benefit from ecosystems. There are many different kinds of ecosystem services, which can be sorted into four categories. First, we have provisional ecosystem services, which are the resources that are provided by nature that we can use or eat, like fruits, vegetables\ and fish. Provisional ecosystem services also include clean drinking water, timber, oils, some medicines and natural energy sources. We also have regulating ecosystem services, which are all the processes that help keep ecosystems healthy and functional. These include bacteria and invertebrates decomposing or breaking down waste, bees and hummingbirds pollinating all kinds of plants and trees and other plants holding soil together with their root systems to help with flood control and to stop soil erosion, and, of course, regulating ecosystem services also include our friends, the vultures, who help with carcass removal and disease control. Ecosystems wouldn't work without supporting ecosystem services. These are the underlying natural processes that are the foundation of ecosystems and without them, we wouldn't be able to breathe air, drink clean water or grow food. Take photosynthesis for example. When plants use sunlight, water and carbon dioxide to make sugars and oxygen. Without photosynthesis, we wouldn't have enough oxygen in our atmosphere to breathe, and we wouldn't have all the foods that we get from plants, like fruits, seeds, and nuts. Other supporting ecosystem services include the water cycle, the nutrient cycle and even soil formation and finally, we also have cultural ecosystem services. Have you ever visited or seen photos of the Grand Canyon, the Redwoods in California or Yellowstone National Park? These are incredible landscapes that provide a lot of meaning and inspiration to us. Think about the art and music that gets made about different ecosystems. Maybe you've heard Dolly Parton's "My Tennessee Mountain Home." She couldn't have written that song about any other part of the country. You might have hobbies that you enjoy doing outside too. For me, I love bird-watching and learning about all of the different bird species that I can see where I live, and that's a cultural ecosystem service. Plus, ecosystems have religious, spiritual and historical value for diverse groups of people. For example, American-Indian tribes have deep ancestral and spiritual connections to many North-American ecosystems. So ecosystems also play an important role in maintaining the richness and diversity of people's cultures and societies of our world, but a loss of biodiversity can make ecosystems less healthy, which makes it harder for us to get the resources and ecosystem services we rely on. Vultures might be able to eat all kinds of nasty toxins, but they can get sick and die from human-made chemicals. For example, diclofenac, a common veterinary drug used to treat cattle, will unfortunately kill vultures if they eat it from a cow carcass. Vulture populations have declined by 95% in parts of the world, and that's caused some pretty big problems in ecosystems. With fewer vultures around to clean up carcasses, diseases can quickly spread, and bacteria from the carcasses can contaminate surrounding soil and water. In turn, people can get very sick when vultures and others scavengers aren't around to keep the ecosystem healthy. So the next time you see a vulture gliding through the sky, take a moment to think about how that species is helping to keep the ecosystem clean and healthy for all. Through cleaning up carcasses and eating bones, vultures play an important role conserving the health of our ecosystems by transforming death and decay into life.