Study shows extinction's ripple effect through the animal kingdom

Washington, Mar 8 (ANI): A new study from the University of Florida has demonstrated the cascading effect of extinction through the animal kingdom.

It also shows how the death of large mammals 20,000 years ago led to the disappearance of one species of cowbird.

"There's nothing worse for a terrestrial ecosystem than the loss of large mammals - and the loss of apex predators like sharks, tuna and other large fish will have the same negative impact on the oceans," said David Steadman.

"We're seeing it with the loss of lions and elephants in parts of Africa, as well as in Florida with the decline of panthers. There's no question these losses will have a negative domino effect on our ecosystems."

The team found an extinct cowbird, Pandanaris convexa, the most common bird found at the fossil site called Terapa, in Sonora, Mexico, about 150 miles south of Arizona.

Jim Mead, chair of the department of geosciences at East Tennessee State University, described the findings at Terapa as "bizarre and exciting."

"The tropical environment is unusual because the site is so far from the coast. The fossil record also provides evidence animals migrated from north to south and, unexpectedly, from south to north," he said.

The study expands the bird's known range and creates new questions about whether it may have lived across the southern U.S.

"The extinct cowbird needed grasslands and these big mammals to survive," said Jessica Oswald.

"Those two things play into each other because mega mammals maintain grasslands. They keep big trees from coming in and colonizing the areas because they graze, stomp and trample little saplings."

Like modern cowbirds, this species probably fed on seeds and insects large mammals exposed, Oswald said. The mammals included extinct species of ground sloth, mammoth, horse, tapir, camel and bison.

"Big species can't exist in a vacuum, nor can smaller species. When one piece of the puzzle goes extinct, there is no good way of predicting what sort of trickle-down effect, what kind of cascade effect that will have," said Steadman.

The study will appear in Tuesday's print edition of the journal Palaeogeography, Palaeoclimatology, Palaeocology. (ANI)