Fourth CAS Madagascar Expedition
CAS Expedition crew from top row (standing) from left to right: Dr.
Kipling Will, Roberta Brett, Dr. David Kavanaugh (team leader); second
row: Emile Randrianirina, Jean Samuelson Randrianarisoa, Kathryn Kavanaugh,
Flor Vargas, Ravu Ranaivosolo, Charlie Raveloson, Nicolas Ranivoson;
bottom row: Emily Elsom, Nicole Rasoamanana, Tsil Ravelomanana
January 2001, the California Academy of Sciences launched its third
expedition to Ranomafana
National Park, located in southeastern Madagascar. The field
team, all entomologists, was led by Curator and Director of Research
David Kavanaugh. Accompanying Dave were two of his graduate
students from San Francisco State University (SFSU)--Roberta
Brett, who is also a Senior Curatorial Assistant at the Academy,
and Emily Elsom, a Graduate Assistant at
the Academy. Flor Vargas, an undergraduate student at SFSU and intern
in the Education Department at the Academy, field assistant Kathryn
Kavanaugh, and Dr. Kipling Will, from the University of Arizona,
completed the U.S. part of the team.
in Madagascar, the Academy researchers were joined by six Malagasy
graduate students from the University of Antananarivo, including
Ravu Ranaivosolo, Emile Randrianirina, Nicole Rasoamanana, Tsil
Ravelomanana, Charlie Raveloson and Nicolas Ranivoson.
primary goal of the expedition was to continue the survey of the
terestrial arthropod fauna of the Park that began with the
first expedition in the Spring of 1998. The team's main focus
for this field period was to sample the carabid beetles of the Park.
Dave, Kip, Roberta, and Emily are all engaged in research programs
devoted to the study of this family of beetles. However, significant
collecting effort was directed also at sampling other selected insect
groups (such as Neuroptera, Homoptera, Hymenoptera, and non-carabid
Coleoptera), arachnids (such as spiders, scorpions, daddylonglegs)
and myriapods (centipedes and millipedes).
entomologists search for carabids along the secondary flood plain
of the Namorono River.
second major goal of the expedition was to provide a collaborative
research and training field experience for the Academy graduate
students, Academy undergraduate intern, and our Malagasy student
colleagues. For all the Academy students and for several of the
Malagasy students, this was their first major, intensive field experience.
Training sessions were provided for all the students in a full array
of collecting, field preservation, and data recording techniques.
Lectures and more informal discussions provided background, context,
and rationale for the fieldwork itself. The desired end of all of
these activities was to increase personal competence and fuel long-term
interest in continuing educational and research pursuits in entomology.
Kavanaugh and the students sort through their catch.
Will lectures the class on the biology and ecology of carabid
unceasing rains, typical of the monsoon season, punctuated the month-long
trip and made collecting difficult at times, but the team was productive
nonetheless. Each day, they ventured out to localities throughout
Ranomafana NP as well as sites beyond the protection of the national
park, literally beating the bushes, turning over rocks, scratching
tree bark, splashing riverbanks and searching rotten logs for insects.
Many insects and arachnids are only active at night and were found
by visually scanning the forest's vegetation lit by the researcher's
headlamps. When torrential rains did not prohibit it, ultraviolet
and mercury vapor light traps were set up to collect insects attracted
bit worse for the wear, the CAS entomologists emerged from the forest
wet, dirty, smelly, and leach ridden, but happy.
group tears apart a large rotten log in the dark recesses
of the rainforest.
Vargas beats insects from bushes onto a beating sheet in
the lower Vohiparara area.
The daily morning
insect sort in one of RNP's two facilities for researchers.
morning following breakfast, the team would gather to compare notes
and sort through the material collected the day and night before.
Through their efforts, over 1700 carabids representing about 75
species were collected, as well as several thousand other insects
and arachnids. Included among these were several species of Carabidae
not previously recorded from the park.
insects were then carefully packed to ensure their safe arrival
back at CAS where they would be pinned, labeled and more thoroughly
examined and identified. It is too early to tell, but it is quite
likely there were species collected that are new to science! A list
of species being compiled for the Park is expanding with each expedition.
In particular, a species list and identification guide of the Platynini,
a tribe of carabids that is highly diverse (with more than 60 species
represented) in the Park, is being developed by Emily as part of
her master's thesis.
specimens provide important information about the Park's biodiversity.
Knowledge gained about many of these species may allow them to be
as indicators of environmental health in the future. Previous inventories
of the carabids in the Park focused on mass collecting methods,
such as the use Malaise flight traps and light traps, so little
was known about the microhabitat preferences of the species collected.
A key to maintaining viable populations of these beetles and other
organisms in the Park is to know where they live. Because most of
the carabids were hand-collected on this trip, the scientists were
able to record the exact conditions under which they were found.
Most carabid beetles are predaceous on other invertebrates and are
usually found on the ground in temperate regions of the world. However,
in tropical rain forests such as at Ranomafana, many species are
arboreal. Suggestions for why this is true include avoidance of
intense competition with ants on the ground or the danger of being
swept away off the forest floor by runoff from heavy rains.
searches a gravelly stream for Omophron using the trademark
"claw" and "pooter" tools.
activity of these beetles in January 2001 was relatively low compared
to March-April sampling in 1998, and there were few observations
of beetles on the ground, on tree trunks and on foliage surfaces
at night when they are typically active. This suggests a seasonality
to the activity of most adult carabid species, probably centered
around the early peak of the rainy season, which is usually late
November to early January. Hot and dry conditions prevailed when
the team first arrived, but it changed to cooler and wetter weather
later. There was a marked increase in both beetle activity and sampling
success as wet conditions became sustained. Carabids typically found
in trees (arboreal) were found only in masses of leaf and twig debris
on or near the ground, not on the tree foliage and trunks as seen
in 1998. The scientists believe these masses may serve as refuges
for the arboreal carabids during the dry season and may be extremely
important to the survival of these species in the Park. Once the
wet season is in full swing, these same species move out into the
trees from these refuges and search for other insects on which they
this information, the CAS scientists were able to inform Park administrators
about the health of its habitats. Park officials and resource managers
were eager to learn if there were any negative effects on the Park
due to increased tourism in the area. While the team could see no
evidence of that, they suggested that the current trail system continue
to be maintained and the massive accumulations of dead leaves and
twigs that develop periodically at various places throughout the
Park be allowed to remain intact. These may serve as important refuges
for carabid beetles and other moisture-loving invertebrates during
the dry season.
marked seasonality of the organisms found on this trip suggests
the need for a year-round sampling program to properly inventory
the terrestrial arthopod fauna of the Park. Future trips to Madagascar
are being planned as CAS will continue its commitment to collaborate
with the Malagasy government in its efforts to document the biodiversity
of its country-diversity that continues under threat of expanded
clear-cutting of the little remaining native forest for fuel and
agriculture. But the long-term success of our efforts is best assured
by the development of expertise within Madagascar that will support
continued study and year-round sampling and monitoring of biodiversity.
Our commitment to assist with the development of a strong and capable
cadre of Malagasy scientists to carry on and expand this effort
remains firm as well.
A typical scene
in the Malagasy countryside is this terraced rice field seen by
the group on their journey from Tana to Ranomafana. The lush green
can be deceiving as these fields occupy what used to be forested
traveler's palm, Ravenea madagascarensis, is a familiar native
tree in Madagascar
Updated May 14, 2001