Flores monarch (Symposiachrus sacerdotum) is a species of bird in the family Monarchidae. This species is endemic to the western half of Flores, Nusa Tenggara, Indonesia, where it appears to be extremely local and largely uncommon, with very tentative density estimates of 2.3 (± 0.8) birds per hectare in suitable habitat, made during fieldwork in 1993 (BirdLife International 2001). However, recent surveys estimated the total population at three forest blocks (Mbeliling, Sano-Nggoang and Nggorang-Bowosie) to be 1,855-6,659 birds, at a density of 8.52-23.98 birds/km2 (Ora 2002). There are also recent records from Sesok (3 adults and one possible juvenile [Reeve and Rabenak 2016]), Puarlolo Telkom (‘frequent’), Paku (‘uncommon’), Cereng (‘frequent’), Golo Bilas (‘rare’) and Bari (C. Trainor in litt. 2007). This last site is a northward range extension and increases the area of suitable forest habitat within its range by c.200 km2. Remaining areas of forest within its range appear to be under considerable pressure and the species is thought to be in decline as a result.
The population is estimated to number 2,500-9,999 mature individuals based on an assessment of known records, descriptions of abundance and range size. This is consistent with recorded population density estimates for congeners or close relatives with a similar body size, and the fact that only a proportion of the estimated Extent of Occurrence is likely to be occupied. This estimate is equivalent to 3,750-14,999 individuals, rounded here to 3,500-15,000 individuals.
This species is suspected to be in rapid decline owing to the rapid past and continuing clearance of forest habitats, particularly in the lowlands. It inhabits primary semi-evergreen rainforest from 350 m to 1,000 m, and also occurs in moist deciduous monsoon forest. It has been recorded in old secondary and partially degraded forest, indicating some tolerance of degradation, although the vast majority of records derive from primary forest, which likely holds the highest densities of this species (see Reeve and Rabenak 2016), implying that it may not adapt well to modified habitats. There appears to be some mutual exclusion between this species and the closely related S. trivirgatus, presumably as a result of ecological overlap.
Forest loss and fragmentation (chiefly as a result of shifting cultivation, dry season burn-off and road-building) is already extensive on Flores, and has presumably resulted in a substantial decline in numbers and contraction of range. No semi-evergreen forest below 1,000 m is included within gazetted protected areas and the large tract of lowland moist deciduous forest at Golo Bilas through to Bari-Rego (also important for the threatened Wallace’s Hanging Parrot Loriculus flosculus and Flores Crow Corvus florensis) is currently being cleared for firewood and construction materials. As a species of foothill and montane elevations, it is potentially threatened by the effect of projected climate change on the extent and distribution of suitable habitats.