You wanted to know
A sixth-grader in Maureen Petricca's class at Nerge Elementary School in Roselle submitted this: "Determine the world's greatest predator in current existence."
Check it outThe Schaumburg Township District Library suggests these titles on predators:
• "Nature's Predators -- Lions" by Kris Hirschmann
• "Tigers: Prowling Predators" by Lucy Sackett Smith
• "Tigers" by Marc Tyler Nobleman
• "DK Pocket Eyewitness: Shark Facts At Your Fingertips" by DK Dorling Kindersley
• "Everything Sharks" by Ruth Musgrave
• "Land Predators of North America" by Erin Pembrey Swan
Animals at the top of the food chain are called apex predators.
"The obvious advantage to being an apex predator is that you don't have to fear other animals. The other advantage is that you can feed on many other species in the food chain/food web," said Jim Covel, senior manager at Monterey Bay Aquarium in California.
Covel calls the great white shark, a 4,000-pound eating machine with stomping grounds that include the coasts of California, Alaska, South Africa, Australia and New Zealand, the world's greatest predator alive today.
"Since 70 percent of the world is ocean -- that would support the idea that the great white shark is the world's greatest predator," Covel said.
Great whites aren't picky eaters -- they dine on a variety of marine mammals, including seals, sea lions, dolphins, fish and other sharks. Each of these streamlined predators has about 300 teeth and consumes about 11 tons of food annually.
Apex predators are important to maintaining a healthy food chain.
Covel said, "Because they often feed on lower levels of the food chain, they can help maintain stability in populations of both predators and prey. For example, adult great white sharks feed primarily on seals and sea lions, keeping their numbers at healthy levels.
"In turn, that helps maintain healthy numbers of fishes and squids since their predators don't get out of control."
Sadly, overfishing and fatalities from being trapped in fishing nets have reduced the great white population. Just this month, great whites were designated an endangered species in California.
In the world today, the circle of life has become very fragile with loss of habitat, environmental hazards and overhunting as key reasons why there are so many endangered species. Humans hold the key to keeping animal populations and their homes healthy.
On land, lions and tigers are considered apex predators. But like the great white, their numbers are dwindling, and many species are now on endangered lists. Lions have seen a 30 percent to 50 percent decline in numbers the past 20 years. In only 100 years, the tiger population has plummeted by 90 percent from habitat destruction and poaching.
"Humans are the most effective predators and have caused the most animal extinctions," said Jay Petersen, curator of carnivores and primates at the Chicago Zoological Society's Brookfield Zoo. "Animals end up with no place to live or are hunted out of their habitats."
Zoos and aquariums around the world are helping to change outcomes for many apex predators.
"Zoos work with people to increase an appreciation for wildlife and nature and to develop awareness for conservation," Petersen said.
Brookfield Zoo has a Center for Conservation Leadership that collaborates with zoos and animal experts worldwide to support animals and their habitats. The Monterey Bay Aquarium has linked with academic institutions to research and protect tuna, sea otters and great white sharks. Supporting zoos and aquariums means your dollars support these efforts.
Petersen also recommends joining in other conservation organizations like the World Wildlife Fund and the National Wildlife Federation, publisher of the children's magazine Ranger Rick.
"We support all kinds of conservation causes for the protection of species," he said.