I just listened to the most exciting interview on The Jefferson Exchange. In it, Geoffrey Riley talked to Dr. Mark Elbroch and graduate student Josh Barry about a truly fascinating study that they just published about cougars’ (Puma concolor; mountain lions; pumas) roles as ecosystem engineers.
An ecosystem engineer is a species that significantly alters its habitat, such as beavers and human beings. As Dr. Elbroch explains in the interview, he and his co-researchers have been studying pumas in the Greater Yellowstone Ecosystem (GYE) since the year 2000. Because their research permits required Dr. Elbroch and his team to visit every puma kill site that they could, they decided to examine how the presence of these deer and elk carcasses might be affecting the landscape.
What they learned is that the large chunks of meat left behind by pumas had a significantly positive impact on beetle abundance and diversity. Up to 215 species of beetles can use a single puma kill for a variety of purposes: eating the leftover meat, eating fur and skin, laying eggs, hiding from predators, preying on the snails that thrive in the moist soil underneath carcasses, and more. These beetles, in turn, are vital parts of the GYE, since they clean up waste and recycle nutrients back into the earth.
It’s not just beetles that benefit from puma kills, either. Elbroch, Barry, and their colleagues learned that the diversity of birds and mammals that feed on puma kills is higher than any other source of carrion on the planet.
What makes puma kills so special? It comes down to how they eat. When a puma consumes a deer or elk that it brought down, the cat leaves most of the carcass intact. This means that pumas tend to deposit large chunks of meat on the landscape, whereas wolves (Canis lupus) tear a carcass apart and leave small pieces of meat scattered over a larger area. It turns out that the large chunks of meat left behind by pumas are more ecologically important than smaller, more dispersed remains.
This really is a fascinating interview, and at only seventeen minutes long, it doesn’t consume much time. I thus strongly recommend that you follow the link below to learn more.