Rainfall Helps Baby Lemurs Survive, Tooth Study Shows

November 14, 2005

Baby lemurs born to older females with worn-out teeth are likely to survive, as long as their first few months of life are wet, a new study suggests.

Patricia Wright, an anthropologist at the State University of New York at Stony Brook, helped discover the surprising link between rainfall and infant lemur survival.

The finding is based on data collected by a team of researchers for a long-term study on how tooth wear affects the ability of lemurs to successfully reproduce.

Wright notes, however, that the rain forests where lemurs make their homes are tending to be drier.

"As we have more deforestation and more fragmentation, it just really means more drying of the rain forest and less rainfall," Wright said. "We've seen that trend over time—we're seeing more erratic rainfall."

Wright is a member of the National Geographic Society's Committee for Research and Exploration, which partially funded the research. She is one of the world's foremost experts on lemurs and a leading advocate for conservation in Madagascar.

Wright and her colleagues report their latest findings in the November 15 issue of the Proceedings of the National Academy of Sciences.

Tooth Map

Lemurs are tree-dwelling, mainly nocturnal primates found only on Madagascar, an island nation located off the east coast of Africa in the Indian Ocean. Most lemur species are endangered.

Primates in general are relatively long-lived and, except for humans, females of most species can reproduce well into old age.

Scientists have theorized, however, that tooth deterioration over time may eventually affect offspring survival.

To test this theory in lemurs, Wright and her colleagues used dental casts and a novel application of Geographic Information System (GIS) technology to document tooth wear in a population of sifaka lemurs (Propithecus edwardsi) over the past 20 years.

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