Once, every group of islands in the Malagasy region had its own species of
Foudia (Passeriformes, Ploceidae), but in recent years things have changed
profoundly. Except for the widespread Madagascar Fody F. madagascariences,
most of the species are more or less endangered. This paper reports on two
surveys of the island of Mayotte (Comores) on the presence of the Forest Fo
dy in October 1993 and March 1995. All other available observations are dis
cussed in view of these results. Currently the population is subdivided in
6 sub-groups. Total population size must be several thousands of birds. The
species occupies a wide variety of habitats, but it is remarkable that are
as with very similar habitat where not occupied in other parts of the islan
d, even when adjacent to another sub-group. On Mayotte, ill sharp contrast
with most of the other islands, Forest Fodies live in rather open areas and
surely not in evergreen forest. Also in 1993, blood samples were collected
to analyse the population genetic structure of the supposedly isolated sub
-populations, using band-sharing coefficients from multilocus DNA-fingerpri
nting. Band-sharing analyses showed that all four sub-groups studied showed
an increased level of band-sharing compared to open populations of various
other songbirds. The between-sub-group band-sharing is lower than the with
in-sub-group band-sharing suggesting a rather high degree of isolation betw
een the subgroups tested. The apparently low dispersal activity together wi
th the patchy habitat occupation in the different subgroups, are important
factors to watch when considering conservation measures for the species.