During the 2019 hunting season, one of the indigenous hunters trapped two black-billed parrots (A. agilis) using indigenous trapping methods. Both parrots appeared to be hybrids. A. agilis is mostly with some colour on the primary covets. However these birds, whose bills were black, had red lores. National NGO Jamaica Environment Trust, in personal communication, had relayed reports of hybridisation by other local conservation professionals. We expected this to be with endemic congener, yellow-billed parrot (A. collaria). However, with a blue crown and white lore, it was clear that the catch (pictured above had not hybridised with the yellow-billed parrot).
After consulting the identification guide Birds of the West Indies, it became clear that the only possible hybridisation that could have occurred was between the black-billed parrot and the Puerto Rican parrot (A. vittata) - a critically endangered parrot endemic to Puerto Rico. However with both non-migrant species being endemic to different countries, which species travelled where?
There has been much debate about whether or not the Jamaican subspecies of Plain Pigeon (P. inornata exigua/ C. inornata exigua) still exists. In the 90s Miyamoto et al (1994) suggested that it had gone extinct. In 2001, sightings were reported in the secondary dry forests of Portland (Strong and Johnson, 2001). Data from Davis (2017) indicate its widespread presence across Cockpit Country - though it uses data from the 1990's.
Rivera-Milán and colleagues (2003) describe the Puerto Rican subspecies of Plain pigeon (P. inornata wetmorei/ C. inornata wetmorei) as habitat-generalists who nest and roost 'mainly in mesic second growth forests' but 'can disperse long distances in search of food'. Now, with the devastating hurricanes that have hit Puerto Rico and the severe droughts across the Caribbean in the summer of 2019, what if the Puerto Rican subspecies travelled as far as Cockpit Country in search of food? What if it has being doing so for quite some time? If the plain pigeon has had to undertake such migration, it is possible that the Puerto Rican parrot - whose size is comparable to the larger yellow-billed parrot and therefore more equipped to migrate longer distances than the smaller congener black-billed parrot - has done the same. If this is the case, this finding could not only have serious consequences for the future distribution and population of the black-billed parrot, but also the critically endangered Puerto Rican parrot, of which less than 50 remain in the wild.
Arlott, N. (2010). Birds of the West Indies. HarperCollins UK.
Davis, H. (2017). Forest disturbance has negative consequences for the persistence of Jamaica’s threatened and endangered bird species in Cockpit Country. Journal of Caribbean Ornithology, 30(1), 57-68.
Miyamoto, M. M., Allard, M. W., & Moreno, J. A. (1994). Conservation genetics of the plain pigeon (Columba inornata) in Puerto Rico. The Auk, 111(4), 910-916.
Rivera-Milán, F. F., Ruiz, C. R., Cruz, J. A., Vazquez, M., & Martinez, A. J. (2003). Population monitoring of plain pigeons in Puerto Rico. The Wilson Journal of Ornithology, 115(1), 45-51.
Strong, A. M., & Johnson, M. D. (2001). Exploitation of a seasonal resource by nonbreeding Plain and White-crowned pigeons: Implications for conservation of tropical dry forests. The Wilson Journal of Ornithology, 113(1), 73-77.
IUCN Red List criterio: A4e
Data availability: suspicion