ABSTRACT
A bio-ecological and abundance study of Sakalava Rail
Amaurornis olivieri, an endangered and endemic waterbird of
Madagascar, was conducted from July to October 2015 in the Mandrozo Protected
Area, in the western part of Madagascar. Listening point and play-back methods
were used to census individuals of Sakalava Rail in Mandrozo Lake and its
surroundings. Nests were discovered from tracking the individuals of the pair,
and using a questionnaire with the fisherman. Located active nests were
directly and continuously observed, every day from 6:00 a.m to 6:00 p.m, in
order to track all activities during the breeding period (from nest building to
the full independence of Juveniles). The diet has been studied using direct
observation and taking pictures of the consumed foods. At the site of survey,
16 individuals of this species were counted on a surface of 23,55 ha, which was
used to estimate the population density to 0,68 individual/ha. Three pairs
belonging to three different nests were directly and continuously observed.
Nest construction was assured by both adults and it took three days' on average
to complete a nest (n = 2 nests). Male did more work than female during nest
construction. Nests were constructed in a dense mat of reeds Phragmites
mauritianus and located 56,67 cm (n = 3 nests) on average above water
level. Thirteen matings were observed and lasted 4,08 #177; 0,07 seconds on
average (n = 2 pairs). Clutch size was three eggs in each active nest (nest 1
and nest 3). Incubation started on laying of the first egg and both sexes
incubated. Eggs hatched after 17 days (n = 1 nest). During the 204 hours of the
nest observation, female incubated 51,5 % (105 hours), male 43,1 % (88 hours)
and the nest was unattended for 5,4 % (11 hours). Both male and female brooded
and fed the young. Young remained three days in the nest and they were
completely independent of their parents at 45 days of age. Based on 194
identified food items, Sakalava Rail ate invertebrates : Spiders (53,1 %),
Insects (32 %), Crustaceans (10,8 %) and Mollusks (4,1 %). The habitat of this
species is characterized by the dominance of Reeds in which it nests and feeds.
The home ranges of two radio-tracked individuals were respectively 0,95 and
1,98 hectares. Sakalava rail was aggressive during reproduction season.
Keywords: Bio-ecology, Sakalava rail Amaurornis
olivieri, Waterbird, Endemic, Protected
VIII
Area of Madrozo, Madagascar, Reproduction.
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