February 09, 2009
Analyzing discoveries of mammal species since 1993, Paul Ehrlich of Stanford University and Gerardo Ceballos of the Mexico's National University found that "a substantial number persist only in areas undergoing rapid habitat destruction" implying "even greater threats to ecosystem services and human well-being than previously assumed" since mammals are generally the best-studied and most "charismatic" of animals.
The recently discovered Grey-faced sengi. Photos by Francesco Rovero.
"I think what most people miss is that the human economy is a wholly owned subsidiary of the economy of nature, which supplies us from our natural capital a steady flow of income that we can't do without. And that income is in the form of what are called 'ecosystem services'-keeping carbon dioxide out of the atmosphere, supplying fresh water, preventing floods, protecting our crops from pests and pollinating many of them, recycling the nutrients that are essential to agriculture and forestry, and on and on," he said.
"Our analysis indicates how much more varied biodiversity is than we thought and how much bigger our conservation problems are if we're going to maintain the life-support services that we need from biodiversity."
He cited disease control as an example.
Click image to enlarge
Ehrlich and Ceballos found that of the 408 "new" species, 221 have restricted distribution, while 23 are already likely at risk of extinction. 40 percent of the species are large and distinctive, the balance are "cryptic". Many of the discoveries have occurred in areas that are not considered "biodiversity hotspots".
Worldwide half of mammal species are in decline, according to last year's IUCN new assessment of the planet's 5,487 mammals. 21 percent are at risk of extinction.
Gerardo Ceballos and Paul R. Ehrlich. Discoveries of new mammal species and their implications for conservation and ecosystem services. PNAS for the week of Feb 9, 2009