Data Zone
Justification of Red List category
This species has declined drastically during the 20th century, so that the population and range became restricted and fragmented. These declines however seem to be historic, and observational records suggest that the species is expanding and recolonising large areas of its former range. Given that the rapid population declines continued until recently, the species is assessed as Vulnerable, though it may qualify for a lower threat category should the population recovery go on.
Population justification
As a consequence of the substantial declines in the past, the population was suspected to number less than 10,000 mature individuals. Given the recent recovery and the frequency of records within the range (per eBird 2023), the population is now likely considerably larger than this, though the historic population was certainly far larger. An accurate quantification of the current population size is required.
Trend justification
The species has suffered catastrophic declines and local extinctions in the past (Keith et al. 2003, Latta et al. 2006). Observational records (per eBird 2023) however suggest that these declines have ceased, and that the species is now expanding and recolonising areas of its former range on Hispaniola. Even though the population trend has not been quantified the suspected rapid declines that the species underwent in the past are considered sufficiently recent with reports of declines ongoing until 2009 at least (see Marzluff 2020) and previously severe to still apply within the past long three-generation period of 17.5 years. Over the past three generations (17.5 years) therefore, declines of 30-49% are suspected to have taken place. It is not clear when exactly declines slowed, but based on the number of observational records (per eBird 2023) this may have occurred only recently, during the past 5-10 years. Based on the observed range expansions the species is inferred to be currently increasing, though the rate is not known. The reasons for the apparent population increase are unclear, but it is suspected that rates of persecution and hunting must have reduced. However, rates of forest cover loss are moderately high within the range of the species (c. 10% over the past three generations) and have accelerated in recent years such that if projected forwards the future rate of loss is equivalent to 15% (Global Forest Watch 2023; using data from Hansen et al. [2013] and methods disclosed therein). Given that the species is forest dependent, the extent to which the apparent recovery can reverse previous losses is uncertain.
Corvus leucognaphalus is now confined to Haiti and the Dominican Republic, including the islands of Gonâve, Vache, Saona and further offshore islets (Raffaele et al. 1998, T. Brooks in litt. 2000). It was once abundant on Puerto Rico (to USA), but was last recorded there in 1977 (R. Rodriguez in litt. 2007). On Hispaniola, it was considered locally common even in the early 1980s, but there has been a subsequent range contraction, when the species became largely restricted to Los Haitises and Jaragua national parks and Sierra de Baoruco in the Dominican Republic, as well as around Port-au-Prince and on Île-à-Vache, Haiti (T. Brooks in litt. 2000, Keith et al. 2003). By now the population appears to be expanding again; the species is observed at many additional sites across large parts of Hispaniola (eBird 2023).
It inhabits lowland and montane wooded regions, where it favours old, mature forest in hilly, inaccessible areas, but also swamps, mangrove and cactus forest (Madge and Burn 1993, Kirwan et al. 2019). It is intolerant of degraded habitats or areas opened up by forest clearance (Madge and Burn 1993). It occurs from the lowlands to 1,500 m, occasionally to 2,650 m (Kirwan et al. 2019). The diet is mainly fruit and seeds, but also vertebrates and large insects (Raffaele et al. 1998). It nests high in large trees or palms between the end of February and May (Madge and Burn 1993, Wiley 2006).
The extinction of this species on Puerto Rico and the historic decline on Hispaniola are attributed to hunting for food and as a crop pest as well as to habitat loss for timber and agricultural conversion. There is no assessment of current rates of hunting or persecution or of changes in hunting pressure over the past few decades, but given the apparent recent turn around in the population trajectory it appears logical to suspect these have declined or even ceased. This suggestion is further supported by the acceleration in recorded rates of forest cover loss within the range of this forest dependent species in the past decade despite the increasing population (Global Forest Watch 2023), indicating the past reduction must have been driven chiefly by hunting rather than habitat loss. However, this ongoing reduction in the area, extent and quality of habitat is likely to restrict the ability of the species' population to fully recover.
Conservation Actions Underway
It occurs in Los Haitises, Jaragua and Sierra de Baoruco National Parks in the Dominican Republic. There are currently no plans to reintroduce the species to Puerto Rico owing to concerns about negative impacts on the Puerto Rican Amazon Amazona vittata (R. Rodriguez in litt. 2007).
Conservation Actions Proposed
Survey to delimit the population range and to quantify the population size. Investigate the likely causes of the range expansion. Carefully monitor the population trend. Monitor hunting pressure.
Increase the area of suitable habitat that has protected status. Establish environmental education programmes to raise awareness for the species.
42-46 cm. Large, black crow with purplish or bluish gloss. Heavy, black bill with markedly decurved culmen. Reddish iris, but yellow also reported. Bases of neck feathers are white but this cannot be seen in field. Similar spp Smaller Hispaniolan Palm Crow C. palmarum differs in voice and stronger, more direct and less flappy flight action. Also flies higher and even soars occasionally. Nasal tufts are swept upwards and do not conceal nostrils as in C. palmarum. Voice Unusual and variable bubbling and squawking, reminiscent of chattering parrot. Also raven-like notes. Hints Usually found in pairs or small parties at fruiting trees.
Text account compilers
Martin, R., Hermes, C.
Contributors
Brooks, T., Isherwood, I., Mahood, S., Pople, R., Rodríguez-Estrella, R., Sharpe, C.J. & Wege, D.
Recommended citation
BirdLife International (2024) Species factsheet: White-necked Crow Corvus leucognaphalus. Downloaded from
https://datazone.birdlife.org/species/factsheet/white-necked-crow-corvus-leucognaphalus on 23/12/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from
https://datazone.birdlife.org/species/search on 23/12/2024.