Species

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Justification
This rather diminutive crow has a very small population, which is subject to a continuing decline in the face of rampant deforestation on its island home. It thus qualifies as Endangered.

Taxonomic source(s)
Sibley, C. G.; Monroe, B. L. 1990. Distribution and taxonomy of birds of the world. Yale University Press, New Haven, USA.

Identification
40 cm. Medium-sized, forest-dwelling crow. Plumage all black, dark iris. Feathering extends halfway along ridge of bill. Similar spp. Large-billed Crow C. macrorhynchos is much larger with more massive bill. Voice High-pitched, downwardly inflected cwaaa or cawaraa. Also waak repeated 1-3 times, resonant popping or gurgling and wheezing contact call.

Distribution and population
Corvus florensis is endemic to the islands of Flores and Rinca (C. Trainor in litt. 2007), Nusa Tenggara, Indonesia, where it is known chiefly from the lowlands in the western half of Flores (BirdLife International 2001). It seems likely that it has always been relatively uncommon, although locally frequent in undisturbed habitat. Overall, it is acknowledged to occur only at low densities, with most encounters involving single birds, and appears to have declined.


Population justification
The population is estimated to number 1,000-2,499 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 667-1,666 mature individuals, rounded here to 600-1,700 mature individuals.

Trend justification
This species is suspected to be declining at a moderate rate, through forest loss and from the added pressure of brood parasitism by cuckoo-shrikes, Coracina spp.

Ecology
It inhabits semi-evergreen forest and degraded, moist, deciduous monsoon-forest (especially along watercourses) from sea-level to 950 m, where it generally frequents the canopy or subcanopy. In coastal areas it occurs in open bamboo and "open monsoon woodland or scrub" which constitutes "very dry, lightly wooded terrain". It evidently tolerates some forest degradation and will feed at the forest edge and in adjacent vegetable cultivation, but its general absence from small, relict forest patches suggests it may not adapt well to habitat fragmentation.

Threats
The primary threat is further habitat loss and fragmentation, driven principally by small-scale agricultural encroachment, which is already extensive on Flores, and has presumably resulted in a substantial decline in numbers and contraction of the species's range. Although it appears fairly tolerant of forest degradation, and of drier formations, it is basically forest-dependent. The large tract of lowland moist deciduous forest at Golo Bilas (one of two sites where the species is described as frequent) is also being cleared for firewood and construction materials. An additional minor threat may be posed by cuckoo parasitism, as the species is a host for Asian Koels Eudynamys scolopacea, and probably much less frequently for Channel-billed Cuckoos Scythrops novaehollandiae.

Conservation actions underway
Two recent surveys have been conducted on Flores, with C. florensis being a species targeted for study. It has been recorded in the Wolo Tadho Strict Nature Reserve and Wae Wuul Nature Reserve.

Conservation actions proposed
Conduct further surveys in central and eastern Flores (particularly in northern Ende, where moist, deciduous monsoon-forest is reported to be extensive) to establish its current distribution and population size. Conduct ecological research to assess its success in different forest-types and the impact of cuckoo parasitism. Extend Wolo Tadho Strict Nature Reserve and support the establishment of further protected areas in western Flores (including Tanjung Kerita Mese, Golo Bilas and Nanga Rawa).

References
BirdLife International. 2001. Threatened birds of Asia: the BirdLife International Red Data Book. BirdLife International, Cambridge, U.K.

Further web sources of information
Detailed species accounts from the Threatened birds of Asia: the BirdLife International Red Data Book (BirdLife International 2001).

Hear sounds for this species from xeno-canto, the community database of shared bird sounds from around the world.

View photos and videos, and hear sounds of this species from the Internet Bird Collection

Text account compilers
Benstead, P., Bird, J., Davidson, P., Taylor, J., Tobias, J.

Contributors
Butchart, S., Pilgrim, J., Trainor, C.

IUCN Red List evaluators
Butchart, S., Symes, A.

Recommended citation
BirdLife International (2013) Species factsheet: Corvus florensis. Downloaded from http://www.birdlife.org on 22/05/2013. Recommended citation for factsheets for more than one species: BirdLife International (2013) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 22/05/2013.

This information is based upon, and updates, the information published in BirdLife International (2000) Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International, BirdLife International (2004) Threatened birds of the world 2004 CD-ROM and BirdLife International (2008) Threatened birds of the world 2008 CD-ROM. These sources provide the information for species accounts for the birds on the IUCN Red List.

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