There have been five “great mass extinctions” during the last half a billion years, Creighton biologist Ted Burk, DPhil, told faculty, staff and students at an Earth Month lecture in the Skutt Student Center on Friday. “And some people are concerned that we’re actually in the midst of a sixth great mass extinction … a human-caused one,” he said.
Burk joined with biology colleague Carol Fassbinder-Orth, PhD, to present a lunchtime sustainability forum titled “Protect Our Species,” which is the theme for this year’s April 22 Earth Day. Burk has been a member of the Biology Department at Creighton since 1982 and his research has focused on insect conservation biology, especially butterflies and other pollinators. Fassbinder-Orth’s research includes studying the plight of the honeybees; she grew up on a honeybee farm in Iowa.
Burk began the forum by ticking off a list of troubling statistics.
- 28% of all species on earth are threatened with extinction in the next few centuries, according to the International Union for Conservation of Nature.
- 25% of all mammals are threatened with extinction.
- 200 vertebrate species have gone extinct just in the last century, which is 100 times the natural extinction rate.
“And this one kind of staggered me,” Burk said. “The weight of all humans on earth is nine times that of the weight of all wild mammals on earth. The weight of livestock on earth is 14 times the weight of all wild mammals on earth.”
He added that 60% of all animals on earth are livestock, and 70% of all birds on the planet are poultry. “It really shows you the impact of the human footprint,” he said.
Some scientists project that within the next 200 years, the largest mammal on the planet will be the cow.
While large animals are in peril, nature’s smaller creatures are also facing difficult times.
Burk referenced one study by Francisco Sánchez-Bayo and Kris Wyckhuys that showed that 40% of all insects were in decline, about a third of insect species are threatened with extinction, and insect bio-mass is decreasing by 2 ½ % per year. A 2018 New York Times Magazine headline labeled these disturbing trends the “Insect Apocalypse.”
Burk reminded the audience that insects are important pollinators. “About one-third of our food comes from insect-pollinated crops,” he said. Insects are also important in the control of other insect pests. And, in general, they are critical to our earth’s ecosystem.
“They provide food for other animals; they regulate plant populations; they clean up the environment of dead carcasses,” Burk said.
Fassbinder-Orth said honeybee numbers have also been declining in the U.S. over the last 30 years. “Globally, the worst areas for colony loss have been Europe and the United States,” Fassbinder-Orth said. “And, actually, the U.S. Midwest has been the area with some of the highest rates of colony loss.”
Urbanization, intensive agriculture practices, various pesticides and parasites have all contributed to colony loss, she said.
So what can we do?
Get involved, Burk said, whether it’s lobbying for environmental legislation, joining a citizen science project or planting an insect-friendly garden. (He recommended two books: Never Home Alone and Bringing Nature Home.)
“Insects have beautiful, wonderful stories. They are a special part of creation,” Burk said. Quoting a line from prominent American biologist E.O. Wilson, Burk said, “Losing a species … is like losing a great work of art.”
