by Christopher Arnett
Native Foods Cafe
A story posted July 15 on AFP discussed how an international team of scientists has determined that global decline in predator populations is having a very real and detrimental impact, and humans are being affected! Hopefully this isn’t a surprise for most people. Time and again we have seen how the life forms on this planet are interdependent and mutually influential. And if people aren’t aware of this, then we have serious problem in our education system. A took a parasitology course in college which was a real eye-opener. I wasn’t quite sure what place a fluke worm had in the balance of things, but it turns out that the existence of parasites has essentially driven the evolution behind sexual reproduction, and they are indicators of the health of an ecosystem! It seems all lifeforms have their place, and predators are no exception!
William Ripple, a professor of forestry at Oregon State University and co-author of the report in the journal of science said “These predators and processes ultimately protect humans. This isn’t just about them, it’s about us.” The example given regarding lions and leopards in Africa was most striking. The loss of these animals to poachers has led to a surge in olive baboon populations which in turn are transferring intestinal parasites to local humans.
Other examples include:
• Fewer cougars in western Utah led to an explosion in deer population. The deer thus consumed more vegetation which, which lowered the path of local streams and lowered overall biodiversity.
• In the 20th century, industrial whaling led to a change in the diet of killer whales. This led the whales to eat more seal lions, seals, and otters, thus dramatically reducing population counts.
• Some of the other far reaching and surprising consequences caused by decline in predators include changes in: wildfire frequency, infectious diseases, invasive species, water quality, and nutrient cycles. Yikes! Sounds like we really need those predators!
• Wolves are my favorite animal (dogs are second, and llamas a close third!) So I was curious exactly how their loss would impact local ecosystems. It turns out their presence provides a number of ecological benefits in Yellowstone National Park including: recovery of streambank habitats, maintaining healthy wildlife herds, and providing habitat for other species by allowing aspen groves to heal from the over-grazing done by elk. So save the wolves!
Native Foods Cafe
Overall, our planet is in the midst of the sixth mass extinction. However, unlike past extinctions, the current one is driven entirely by human activity and is focused on large, or apex, predators. Changes in land use, climate, pollution, hunting, fishing, and poaching have all contributed to the problem. Lead author in the article James Estes, professor of ecology and evolution at the University of California Santa Cruz says “By looking at ecosystems primarily from the bottom up, scientists and resource managers have only been focusing on half of a very complex equation…These findings demonstrate that top consumers in the food web are enormous influencers of the structure, function, and biodiversity of most natural ecosystems.”
Once its over, its over... for real. Just ask Sue at the The Field Museum in Chicago.
Thankfully, the research done by Estes and his colleagues has big implications for conservation efforts. Because of the sheer size of most apex predators, restoring them in order to restore their associated ecosystems would necessitate conservation on a much larger scale than was previously conceived. In Estes’ words “You can’t restore large apex consumers on an acre of land. These animals roam over large areas, so it’s going to require large-scale approaches.”
So what can we do as concerned individuals and citizens of this beautiful but ailing planet? Check out some of these organizations to see how you can help!
*Read the article Trophic Ripple Effects in the July 15 issue of Science (you can register for FREE to view the article).