This species is considered Critically Endangered because it has an extremely small and fragmented population, which continues to decline. Only effective protection of Los Haitises National Park and captive breeding and release are likely to save this species from extinction.
del Hoyo, J.; Collar, N. J.; Christie, D. A.; Elliott, A.; Fishpool, L. D. C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Barcelona, Spain and Cambridge UK: Lynx Edicions and BirdLife International.
Distribution and population
36-41 cm. Medium-sized, compact hawk. Adult has brown-grey upperparts, greyish barred underparts with reddish-brown wash, rufous thighs and black-and-white barred tail. White crescent-shaped wing panels or "windows" visible during flight are diagnostic. Male slightly smaller (330-350g) than female (360-420g). Male is greyer than female and has rufous carpal area (paler rufous in female). Female also paler below and more barred. Immature has buffy white underparts with grey and brown streaks, and less well marked tail. Similar spp. Red-tailed Hawk B. jamaicensis is larger and adults have reddish tail. Voice Shrill calls and squeals.
This species occurs in the Dominican Republic
and formerly occurred in Haiti, with historical reports from the adjacent Haitian islands of Gonâve; the Cayemite Islands, where it was reportedly common in 1934; Île-à-Vache, where it was reportedly common in 1962 (Wiley and Wiley 1981
) but is now apparently extinct (T. Brooks in litt.
), and the Dominican islands of Isla Beata and Alto Velo. There is a single record from the island of Culebra off Puerto Rico (to U.S.A.) (Raffaele et al.
. It was formerly widespread, but has been extirpated from over 96% of its original Extent of Occurrence during the last century (Woolaver 2011). Its population has declined steeply and it is now rare (A. Keith in litt.
, with c.80-120 pairs estimated in 2006 (Woolaver 2005, 2006) and 200-300 individuals in 2010 (J. L. Brocca in litt.
2010). The latest estimates from 2014 put the population at 120 pairs confined to Los Haitises National Park, north-east Dominican Republic and two established pairs at a release site in Punta Cana (The Peregrine Fund 2014). In 2003, 93 individuals were recorded in Los Haitises, including 37 pairs, 30 of which attempted nesting with eight successful pairs fledging 10 chicks (Thorstrom et al.
. In 2005, 19 fledglings were produced from 11 successful (out of 28 total) attempts (Woolaver 2005, 2006), while in 2007, 40 fledglings were produced from 22 successful nests (Woolaver 2007). Of the 120 pairs recorded in Los Haitises in 2014, 70 pairs were followed over the breeding season, 60 attempted nesting, with 36 nests producing a total of 89 nestlings of which 65 survived to fledging (The Peregrine Fund 2014).
There have been very few recent records outside Los Haitises National Park (S. Latta in litt.
. It was also recorded in human-modified habitat on the Samaná Peninsula in 2003 (Thorstrom et al.
. The species has been reported from Isla Beata and Valle Nuevo in 1981 (Wiley and Wiley 1981)
; both sites have not been surveyed significantly since then and confirmation of its status at these two sites is a priority. A new population is being established through releases of young birds at Punta Cana, a private land holding in south-east Dominican Republic (The Peregrine Fund 2014). The first birds were released at Punta Cana in 2009. The Peregrine Fund is also attempting to establish a new population in the private reserve of Loma la Herradura by translocating individuals from the Los Haitises National Park (Thorstrom 2008), however releases were suspended in 2013 due to the large human population near the release site and a large number of missing hawks (The Peregrine Fund 2014). The species is declining rapidly with an annual loss of c.5-10% of pairs recorded at a key study site, Los Limones, within Los Haitises National Park. Furthermore, forest loss at the same site is estimated at 10-15% (L. Woolaver in litt
. 2007, 2008)
annually with no park infrastructure in place to prevent slash-and-burn agriculture. Population justification
In 2014, 120 territorial pairs were recorded in Los Haitises National Park and two pairs in Punta Cana (The Peregrine Fund 2014). This equates to an estimate of 244 mature individuals. The population was previously estimated at 160-240 individuals (roughly equivalent to 110-160 mature individuals) based upon densities at Los Limones extrapolated for remaining habitat in the rest of Los Haitises National Park.Trend justification
Ongoing monitoring at Los Limones in the east of Los Haitises National Park shows a 5-10% annual decline in the number of individuals at this site, equating to a decline over ten years of 40-65%. Declines in the west of the park are expected to be continuing at a similar, although perhaps slower rate, hence overall rates of decline are perhaps best estimated to fall within the band 30-50% over ten years. However, forest clearance within the park boundary remains rapid with an annual loss of c.10-15%, thus careful monitoring is a priority and it may reveal that a higher rate of decline is occurring (Woolaver 2007).Ecology
It occurs up to 2,000 m in a variety of undisturbed forest-types including rainforest, subtropical dry and moist forests, pine forest, limestone karst forest and marshland and is occasionally seen in secondary and agricultural habitats (Wiley and Wiley 1981)
. Prey consists primarily of reptiles (lizards, in particular Celestus
skinks [Woolaver et al
. 2013c], and snakes comprising 80% of the diet) and frogs. Hawks will occasionally prey on small mammals (bats and rodents), centipedes and small mammals (Woolaver 2011). Nests have been found in the crowns of tall endemic trees, with Hispaniolan Royal Palms Roystonea hispaniolana
particularly favoured (Woolaver 2005, 2006, 2011). Nest-building occurs in January-March and eggs are laid in February-April (Wiley and Wiley 1981)
. It lays 2-3 eggs and pairs have successfully fledged three chicks, but more typically one or two. Males are known to participate in incubation. Disturbance by humans is the major cause of nest failure (Woolaver 2011). The home range of three adjacent breeding pairs was just c.60 ha (Wiley and Wiley 1981)
Large-scale habitat loss through clearance for livestock farming, coffee and other crop plantations, and direct persecution have been major factors in this species's decline (Thorstrom 2004)
. Even within Los Haitises National Park wood burning is widespread and areas are cleared for the cultivation of root crops. Virtually all primary forest within the park has now been destroyed, and the remaining secondary fragments are being cleared at a rapid rate (J.L. Brocca in litt.
. In 2010, the situation appeared to be getting worse, largely attributed to a lack of awareness regarding the location of the park boundaries (J.L. Brocca in litt.
2010). In 2005, of 28 monitored nests, four nests were destroyed by human activity during the nestling stage. A fifth nest was abandoned during incubation when two local men flushed the female off the nest during a rainstorm, and then attempted to kill the female with a slingshot. Human disturbance was also likely, but not confirmed, for another five failed nests (Woolaver 2006). Significant causes of natural mortality are poor weather (rain lasting over several days when nestlings are less than one week old), collapse of nests and infestations of the parasitic fly Philornis pici
(The Peregrine Fund 2014), but overall natural mortality is not nearly as much of a threat as habitat loss and human persecution. Local people still regard the species as a serious threat to poultry, although such predation, whilst likely, is not proven and requires further study (J.L. Brocca in litt.
2010). Electrocution by collision with power lines has been identified as a significant cause of mortality (The Peregrine Fund 2014). Woolaver et al
. (2013a) detected a weak but consistent sex ratio bias towards female nestlings, which could give cause for concern in the future. Inbreeding within the small population also poses a threat (Woolaver et al
. 2013b).Conservation Actions Underway
CITES Appendix II. Los Haitises National Park is an important but very poorly protected site, supporting the majority of pairs in the Dominican Republic (Thorstrom 2004)
. However, recent evidence suggests that the park has been mainly deforested (J.L. Brocca in litt.
. Intensive research of the species's breeding ecology and conservation genetics are part of an ongoing study initiated in 2005, and annual surveys are conducted to monitor the population within the park, with 53 active nests monitored in 2007 (Woolaver 2006, 2007) and 70 pairs monitored in 2014 (The Peregrine Fund 2014). The Peregrine Fund have developed a number of intensive management actions to increase productivity in the species: reducing human disturbance to nests, which has been achieved through engaging with local communities and providing concerned farmers with chicken coops to protect their chickens; repairing nests to prevent them falling; removing young (~5-10 days old) nestlings and raising them in captivity, so that the adults lay a second clutch. An ongoing publicity campaign was initiated by the Peregrine Fund in 2005 to raise awareness within local communities in the Dominican Republic (Woolaver 2006). In 2010, the species's conservation was the subject of articles in the popular press, as well as an information commercial (J. Brocca in litt.
2010). Conservation staff working on this species have received training and financial support from the Peregrine Fund (Thorstrom 2004)
, Sociedad Ornitológica de la Hispaniola, Wildlife Preservation Canada, York University and the Smithsonian Institution. Ongoing DNA work is comparing the extent of genetic variation remaining in the current population with the historical population to determine if poor genetic diversity should be a concern for species recovery (L. Woolaver in litt.
. This work has identified that the species experienced a recent genetic bottleneck and inbreeding occurs within the population (Woolaver et al
The Ridgway's Hawk project, a collaboration of The PUNTACANA Ecological Foundation and The Peregrine Fund, began releases in 2008 of nestlings taken from Los Haitises National Park at two sites in the Dominican Republic (www.puntacana.org; www.peregrinefund.org; www.globalgiving.org), with juveniles having been translocated to the Loma la Herradura private reserve and Punta Cana (in 2009) (Thorstrom 2008,
J. L. Brocca in litt.
2010, The Peregrine Fund 2014). Between 2008 and 2014 a total of 68 birds were released at both sites (48 in Punta Cana), of which 62 became fully independent, no longer relying on provisioned food (The Peregrine Fund 2014). In 2013, released birds in Punta Cana became the first known breeding pair of the species outside Los Haitises National Park, producing one nestling. This was followed by a second breeding pair in 2014 (The Peregrine Fund 2014). A stakeholder workshop was planned for 2010, which was to result in a conservation plan being finalised by January 2011 (J.L. Brocca in litt.
2010). Environmental education activities have been ongoing, with community lectures and school visits taking place and education materials being distributed (J.L. Brocca in litt.
2010). The environmental education programme has engaged with over 1,168 individuals in communities around Punta Cana (The Peregrine Fund 2014). The Peregrine Fund and Punta Cana Ecological Foundation have begun installing wooden perches on electricity pylons to provide birds with a safe place to perch (The Peregrine Fund 2014).Conservation Actions Proposed
Ensure the de facto
protection of remaining habitat in Los Haitises National Park. Continue and expand education and awareness campaigns to reduce direct persecution, including campaigning for 'Ridgway's Hawk Day' to become a national holiday in the Dominican Republic (The Peregrine Fund 2014). Survey remaining forest fragments adjacent to Los Haitises National Park, as well as historical sites that have not experienced significant habitat loss including Isla Beata and Valle Nuevo. Continue monitoring and banding work (The Peregrine Fund 2014), including monitoring of nestling sex ratios (Woolaver et al
. 2013a). Establish a captive population as a safeguard in the event that wild populations become extirpated. Assess potential sites for future relocation to establish additional populations within secure habitat and ensure that translocated nestlings are genetically diverse (Woolaver et al
. 2013b). Evaluate the threat posed by power lines and retrofit them where necessary (The Peregrine Fund 2014). Research methods to reduce Philornis pici
Related state of the world's birds case studies
Collar, N. J.; Gonzaga, L. P.; Krabbe, N.; Madroño Nieto, A.; Naranjo, L. G.; Parker, T. A.; Wege, D. C. 1992. Threatened birds of the Americas: the ICBP/IUCN Red Data Book. International Council for Bird Preservation, Cambridge, U.K.
IUCN. 2015. The IUCN Red List of Threatened Species. Version 2015-4. Available at: www.iucnredlist.org. (Accessed: 19 November 2015).
Puntacana Resort and Club. Protecting the Ridgeway's Hawk. web page. Available at: http://www.puntacana.org/ridgway/index.html. (Accessed: 01/08/2013).
Raffaele, H.; Wiley, J.; Garrido, O.; Keith, A.; Raffaele, J. 1998. Birds of the West Indies. Christopher Helm, London.
The Peregrine Fund. 2001. West Indies Program. web page. Available at: http://www.peregrinefund.org/projects/west-indies. (Accessed: 01/08/2013).
The Peregrine Fund. 2014. Report Ridgway's Hawk Project 2014 - Restoration of the Distribution and Abundance of the Ridgway's Hawk in Historic Areas within and outside of Los Haitises National Park, Dominican Republic. The Peregrine Fund, Boise, USA.
Thorstrom, R. 2004. Ridgway's Hawk. Peregrine Fund Newsletter no 35.
Thorstrom, R.; Almonte, J.; Balbuena de la Rosa, S.; Rodriguez, P.; Fernandez, E. 2005. Surveys and breeding biology of Buteo ridgwayi (Ridgway's Hawk) in Los Haitises, Dominican Republic. Caribbean Journal of Science 41: 864-869.
Wiley, J. W.; Wiley, B. N. 1981. Breeding season ecology and behaviour of Ridgway's Hawk Buteo ridgwayi. Condor 83: 132-151.
Woolaver, L. 2005. Conserving Ridgway's Hawk in the Dominican Republic. BirdLife Caribbean: 13-14.
Woolaver, L. 2006. Partnering for conservation: the Peregrine Fund. The Palmchatter.
Woolaver, L. G. 2011. Ecology and conservation genetics of Ridgway's Hawk Buteo ridgwayi. Graduate Program in Biology, York University .
Woolaver, L.G., Nichols, R.K., Morton, E. and Stutchbury, B.J.M. 2013a. Nestling sex ratio in a Critically Engangered Dimorphic Raptor, Ridgway's Hawk (Buteo ridgwayi). Journal of Raptor Research 47(2): 117-126.
Woolaver, L.G., Nichols, R.K., Morton, E.S. and Stutchbury, B.J.M. 2013c. Feeding ecology and specialist diet of critically endangered Ridgway's Hawks. Journal of Field Ornithology 84(2): 138-146.
Woolaver, L.G., Nicols, R.K., Morton, E.S. and Stutchbury, B.J.M. 2013b. Population genetics and relatedness in a critically endangered island raptor, Ridgway's Hawk Buteo ridgwayi. Conservation Genetics 14(3): 559-571.
www.globalgiving.org. Conserving the Ridgway's Hawk in Punta Cana, DR. web page. Available at: http://www.globalgiving.org/projects/conserving-the-ridgways-hawk-in-punta-cana-dr/. (Accessed: 01/08/2013).
Further web sources of information
Alliance for Zero Extinction (AZE) species/site profile. This species has been identified as an AZE trigger due to its IUCN Red List status and limited range.
Click here for more information about the Alliance for Zero Extinction (AZE)
Detailed species account from the Threatened birds of the Americas: the BirdLife International Red Data Book (BirdLife International 1992). Please note taxonomic treatment and IUCN Red List category may have changed since publication.
Detailed species account from the Threatened birds of the Americas: the BirdLife International Red Data Book (BirdLife International 1992). Please note, taxonomic treatment and IUCN Red List category may have changed since publication.
Explore HBW Alive for further information on this species
Recuento detallado de la especie tomado del libro Aves Amenazadas de las Americas, Libro Rojo de BirdLife International (BirdLife International 1992). Nota: la taxonomoía y la categoría de la Lista Roja de la UICN pudo haber cambiado desde esta publicación.
Search for photos and videos, and hear sounds of this species from the Internet Bird Collection
Text account compilers
Benstead, P., Bird, J., Butchart, S., Calvert, R., Isherwood, I., Sharpe, C J, Symes, A., Taylor, J., Wege, D. & Ashpole, J
Brocca, J., Brooks, T., Keith, A., Latta, S., Williams, R. & Woolaver, L.
IUCN Red List evaluators
BirdLife International (2016) Species factsheet: Buteo ridgwayi. Downloaded from
http://www.birdlife.org on 27/10/2016.
Recommended citation for factsheets for more than one species: BirdLife International (2016) IUCN Red List for birds. Downloaded from
http://www.birdlife.org on 27/10/2016.
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.
To provide new information to update this factsheet or to correct any errors, please email BirdLife
To contribute to discussions on the evaluation of the IUCN Red List status of Globally Threatened Birds, please visit BirdLife's Globally Threatened Bird Forums.
Additional resources for this species