Fruit-frugivore interactions in a Malagasy littoral forest - Universiteit ...

Chapter 5
at a very low density in apparent pristine area (Donati pers.obs.). Discussions with local
people and observations of many cut trunks lead us to the conclusion that some plant
species, like Cinnamosma madagascariensis, are already rare due to selective logging.
At the end of our study period (December 2000) logging intensified and trucks
transporting the logs could be observed at night on the national road heading to Fort-
Dauphin. This short-sighted commercial logging is even more harmful and a serious
threat to all forests in the surrounding area of Fort-Dauphin as needs for construction
wood get larger in the city. The only wood people are allowed to take out of the forest by
law is ‘dead wood’. As such, people have been very inventive in interpreting this law.
They cut several trees in the forest, leave the logs there for a month to afterwards collect
this ‘dead’ wood (Donati and Bollen pers. obs.). Nowadays they even circumcise the bark
deep enough so eventually trees will die (Hapke pers. comm.).
The villagers take several other products out of the forest. Large palms (Dypsis
prestoniana) are cut at the base only to collect the nervature of their leaves of which traps
for crabs and langoustines are made. The enormous logs are often left behind unused.
Canoes are dug out of the largest trees, such as ‘ramy’ Canarium boivinii and ‘vitano’
Calophyllum sp. (Table 1) and different vine species serve for fishing gear. People also
eat the fruits of several endemic tree species, but no real large-scale harvesting occurs.
During famine, people collect and eat the roots of tavolo (Tacca leontopetaloides) and via
(Typhonodorum lendleyanum)(Table 1).
Besides the indirect threat of habitat loss, hunting also has its impact on littoral forest
dynamics. However in contrast to sites more inland, such as Andohahela NP, Mandena
and Petriky, the impact of hunting in Sainte Luce is rather limited. Fish rather than bush
meat make up the largest proportion of animal protein in the daily menu. The majority of
villagers are fishermen and catching fish (year-round) and shellfish (langoustines only
April-December) represents their most important income. Bush meat is only eaten on rare
occasions or during traditional events. Nocturnal lemurs, such as Cheirogaleus major,
Cheirogaleus medius and the tiny Microcebus rufus, that hibernate during austral winter
in hollow tree trunks are an easy catch. The larger Eulemur fulvus collaris is hunted by a
traditional technique called tandroho (Randriamanalina et al. 2000). More specifically a
strip of forest (50 m²) is cleared, so that canopies are too far apart for the lemurs to cross.
Long logs are then placed between both ends as the only crossover with two snares in
the middle. This hunting technique could be at the base of the unbalanced sex-ratio in
favour of males reported in S9 (Donati unpubl. data), as in this species females often
have progression priority and as such they are more likely to become victims of these
traps. E. f. collaris was also captured by the use of row slings, a practice particularly
frequent in young mans and probably responsible for the cryptic behaviour of these
lemurs at the beginning of our study. Hunting pressure on E. f. collaris declined drastically
in the study area (S9) during the presence of researchers based on several discussions
with the local people. Nevertheless traps were still encountered in September 2000 in
S17 (Fig. 1). Pteropus rufus is very vulnerable to hunting as it roosts communally and can
thus be located and killed easily in great numbers. Catapults, long branches and stones
were often found under their roost site. The animals were harassed during daylight and
even changed their roost site twice in 2000 (Bollen and Van Elsacker 2002a, Chapter 3a).
Terrestrial birds are trapped using snares or other ingenuous systems on the ground.
Fruit pigeons (Treron australis, Alectroenas madagascariensis), parrots (Coracopsis vasa
and C. nigra) and bulbuls (Hypsipetes madagascariensis) are hunted with arrows or
catapults. Alternatively, fruit pigeons get stuck onto small branches covered with sticky
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