Madagascar's Lemurs

THE EXPEDITION
1. PROJECT OVERVIEW
“I learned about the country and people of Madagascar – of the resiliency and strength of an incredibly
hardscrabble lifestyle, of the value of a drop of pure water, or a simpler, less complicated life that made a
bowl of rice a wonderful meal and the smile of others, especially the children, a grand experience.”
~ Sharon Pittman, 2005 Earthwatch Volunteer
The lemur species found within Ranomafana National Park (RNP) in Madagascar’s southeastern
rainforest represent an ancient primate lineage – an isolated group that persisted in Madagascar
while the rest of the world changed around them. They exhibit behavioral patterns and respond
to their environment in ways that are different from monkeys and apes, their more modern
primate relatives, and are extremely scientifically interesting. Because they are restricted
geographically to this area, they are also a high conservation priority. Of the 13 lemur species
found within RNP, six are listed as “Endangered” or “Critically Endangered” by the IUCN. Each
year more and more of this unique forest habitat is cleared for agriculture. To better understand
these amazing creatures and develop management plans to ensure their future survival, the
Institute for the Conservation of Tropical Environments (ICTE) facilitates the research of
scientists and students from Madagascar and around the world.
As an Earthwatch volunteer, you will assist Principal Investigator (PI) Dr. Patricia C. Wright with
her long-term study of the behavior, ecology, and demography of the Milne-Edwards’ sifaka, one
of the lemur species found within RNP. This research began in 1986, before RNP was even legally
recognized. It is the first long-term study of a Malagasy rainforest primate species and is the
longest running continuous project of its kind. Behavioral observations have been conducted on
more than 76 individual lemurs from four groups over a 20-year time span. Forty-six individuals
have been captured, marked with identification collars, and released. Individual groups range
from three to nine individuals, and these individuals are followed during all 12 months of the
year. A great deal of data has been collected on the behavior and ecology of this species.
The sifaka study also helps to increase the overall understanding of the park for two important
reasons. First, as the largest primate within the park, the sifaka is at particularly high risk for local
extinction in light of habitat disturbance and therefore serves as a good indicator species for the
overall primate community at RNP. Second, as these sifaka are generalists – eating leaves, fruits,
and seeds – variations in the quality of the forest in different areas of the park will be indicated
by differences in their diet.
Since 1996, Earthwatch volunteers have participated in research that has suggested that the
overall population size of this endangered species may be declining. This is disturbing
information because all groups that are studied live entirely within RNP and should be protected
from human disturbance (aside from tourists and scientists). Predation by the fossa, the largest
carnivore in the park, appears to play an important role in population size, and it is possible that
the disturbance of the park’s borders has increased fossa density within RNP. The selective
logging which occurred in the late 1980s may also be having an effect. Studies of habitat
disturbance have shown that there is often a lag-time between the actual disturbance and the
response of the animal and plant communities to this disturbance. Finally, in 2004 genetic
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