Conservation taxonomy of the Cuban Parrot (Amazona leucocephala): variation in morphology and plumage
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Abstract: Conservation taxonomy, the study of organismal classification to clarify conservation priorities, seeks to define species and subspecies limits. Allopatric populations, such as those present on islands, pose special challenges to identifying taxonomic boundaries which can be practically addressed using diagnostic criteria. Because some of the island populations of Cuban Parrot (Amazona leucocephala) are highly endangered, the five recognized subspecies need careful re-evaluation. We measured 18 morphological and plumage characters from 188 museum specimens representing the six extant and one extirpated island populations. We relied largely on discriminant function analyses (DFA) to assess diagnosability and to examine patterns of similarity among the populations. Most morphological characters indicated sexual dimorphism, with males 1-4% larger than females. The plumage characters, in contrast, demonstrated complete absence of sexual dichromatism. Stepwise discriminant analyses including all specimens and 14 characters revealed substantial differentiation among island groups, with 81.4% of individuals classified correctly to island. Pairwise comparisons among islands showed reciprocal discrimination > 80%, with the exception of Cuba / Cayman Brac (67%). None of the populations possessed a single diagnostic character. Although currently lumped into a single subspecies (A. l. bahamensis), each of the three Bahamas populations, including an extirpated population on Acklins Island, was equally distinct as the four other currently-recognized subspecies. Collectively, the evidence supports the view that all seven island populations, including the extirpated population, warrant subspecies status. We apply the name A. l. bahamensis to the extirpated Acklins population and propose the new names A. l. abacoensis for the Abaco Parrot and A. l. inaguaensis for the Inagua Parrot. The small and vulnerable populations on Abaco, Inagua, Isla de la Juventud, Cayman Brac, and Grand Cayman deserve special conservation status and should be treated as independent conservation units. Exemplary programs using these threatened populations as “flagship” taxa illustrate why recognizing the subspecies rank can greatly benefit conservation efforts by island nations.
Keywords: conservation taxonomy, systematics, Cuban Parrot, Amazona leucocephala, morphology, plumage, new subspecies
Resumen: Taxonomía conservacionista de la Cotorra Cubana (Amazona leucocephala): variación en la morfología y el plumaje- La taxonomía para la conservación, que es el estudio de la clasificación de los organismos para esclarecer las prioridades de conservación, busca definir los límites de las especies y subespecies. Las poblaciones alopátricas, como las presentes en las islas, plantean desafíos especiales para la identificación de los límites taxonómicos que pueden abordarse de forma práctica utilizando criterios de diagnóstico. Debido a que algunas de las poblaciones de Cotorra Cubana (Amazona leucocephala) están en grave peligro de extinción, las cinco subespecies reconocidas necesitan de una cuidadosa reevaluación. Se midieron 18 caracteres morfológicos y del plumaje de 188 especímenes de museo, que representan a las seis poblaciones existentes y a una población extirpada. Se basó en gran medida en análisis de función discriminante (DFA) para evaluar la capacidad de diagnóstico y examinar los patrones de similitud entre las poblaciones. La mayoría de los caracteres morfológicos indican dimorfismo sexual, siendo los machos 1-4% mayores que las hembras. Los caracteres del plumaje, en cambio, demostraron la ausencia completa de dicromatismo sexual. El análisis discriminante paso a paso, incluyendo todas las muestras y 14 caracteres, reveló diferencias sustanciales entre los grupos de las islas, con 81,4% de los individuos clasificados correctamente en relación con la isla. Las comparaciones por pares entre las islas mostraron la discriminación recíproca > 80%, con la excepción de Cuba / Cayman Brac (67%). Ninguna de las poblaciones tuvo un carácter de diagnóstico único. Aunque las tres poblaciones de Bahamas y la población extirpada de Acklins están incluidas en una sola subespecie (A. l. bahamensis), todas fueron igualmente diferentes, como ocurre con las restantes cuatro subespecies actualmente reconocidas. Colectivamente, las evidencias apoyan el punto de vista de que las siete poblaciones de diferentes islas, incluyendo la población extirpada, merecen el estado de subespecie. Le asignamos el nombre de A. l. bahamensis a la población extirpada de Acklins y proponemos los nuevos nombres de A. l. abacoensis para la cotorra de Abaco y A. l. inaguaensis para la cotorra de Inagua. Las poblaciones pequeñas y vulnerables de Abaco, Inagua, Isla de la Juventud, Caimán Brac y Gran Caimán, merecen un estatus especial de conservación y deben ser tratadas como unidades de conservación independientes. El uso de estos programas puede ser un ejemplo en el estudio de poblaciones amenazadas de especies banderas, ya que ilustra por qué el reconocimiento del rango de subespecies, puede beneficiar enormemente los esfuerzos conservacionistas en las naciones insulares.
Palabras clave: Amazona leucocephala, Cotorra Cubana, morfología, nuevas subespecies, plumaje, sistemática, taxonomía para la conservación
Résumé: Taxonomie et conservation de l’Amazone de Cuba (Amazona leucocephala): variation de la morphologie et du plumage- Taxonomie et conservation s’associent pour que l’étude de la classification des organismes permette de clarifier les priorités de conservation, en redéfinissant les limites séparant les espèces et les sous-espèces. Les populations allopatriques, telles que les populations insulaires, offrent des défis particuliers quant à l’identification de limites taxonomiques grâce à des critères de diagnostic. Certaines populations insulaires d’Amazone de Cuba (Amazona leucocephala) étant fortement menacées d’extinction, le statut des cinq sous-espèces actuellement reconnues doit être soigneusement ré-évalué. Nous avons mesuré 18 caractères morphologiques et de plumage, sur 188 spécimens de muséums, issus de 7 populations insulaires dont une éteinte localement. Nous nous sommes appuyés essentiellement sur des analyses discriminantes pour évaluer les possibilités de diagnostic et examiner des patrons de similitude entre populations. La plupart des caractères morphologiques présentaient un dimorphisme sexuel, les mâles étant de 1 à 4% plus grands que les femelles. Le plumage, en revanche, n’a montré aucun dichromatisme sexuel. Les analyses discriminantes pas à pas, concernant tous les spécimens et 14 caractères ont révélé des différences importantes entre les groupes d’îles, avec 81,4% des individus classés correctement par île. Les comparaisons par paires entre les îles ont montré une discrimination réciproque supérieure à 80%, à l’exception de Cuba / Cayman Brac (67%). Aucune des populations ne présentait un caractère de diagnostic unique. Bien qu’elles soient actuellement considérées comme appartenant à une seule sous-espèce (A. l. bahamensis), chacune des trois populations des Bahamas, y compris une population éteinte sur l’île Acklins, étaient toutes aussi distinctes que les quatre sous-espèces actuellement reconnues. Ainsi, ces résultats viennent soutenir l’hypothèse que les sept populations insulaires, y compris la population localement éteinte, justifient le statut de sous-espèce. Nous appliquons le nom de A. l. bahamensis à la population localement éteinte et nous proposons les nouveaux noms A. l. abacoensis pour l’Amazone Abaco et A. l. inaguaensis pour l’Amazone Inagua. Les populations d’Abaco, d’Inagua, de Isla de la Juventud, de Cayman Brac et de Grand Cayman sont petites et vulnérables. Elles méritent de ce fait un statut de conservation particulier et devraient être traitées comme des unités de conservation indépendantes. Des programmes exemplaires traitant ces populations menacées comme taxons «phares» démontrent en quoi la reconnaissance du rang de sous-espèce peut grandement bénéficier aux efforts de conservation des pays insulaires.
Mots clés: Amazona leucocephala, Amazone de Cuba, morphologie, nouvelle sous-espèce, plumage, systématique, taxonomie de la conservation
Citas
diversity. Pp. 57-75 in Phylogeny and Conservation
(A. Purvis, J. L. Gittleman, and T. Brooks,
eds.). Cambridge University Press, Cambridge,
UK.
AGAPOW, P-M., O. R. P. BININDA-EMONDS, K. A.
CRANDALL, J. L. GITTLEMAN, G. M. MACE, J. C.
MARSHALL, AND A. PURVIS. 2004. The impact of
species concepts on biodiversity studies. Quarterly
Review of Biology 79:161-179.
AVISE, J. C. 2000. Phylogeography: The history and
formation of species. Harvard University Press,
Cambridge, MA.
BEAUCHAMP, G., AND P. HEEB. 2001. Social foraging
and the evolution of white plumage. Evolutionary
Ecology Research 3:703-720.
BIRDLIFE INTERNATIONAL. 2009. Species factsheet:
Amazona leucocephala. www.birdlife.org.
BRYANT, H. 1867. Additions to a list of birds seen
at the Bahamas. Proceedings of the Boston Society
of Natural History 11:63-70.
BOWEN, B. W., AND S. A. KARL. 1999. In war, truth
is the first casualty. Conservation Biology 13:
1013-1016.
CARO, T., A. ENGILIS, E. FITZHERBERT, AND T.
GARDNER. 2004. Preliminary assessment of the
flagship species concept at a small scale. Animal
Conservation 7:63-70.
CICERO, C., AND N. K. JOHNSON. 2006. Diagnosability
of subspecies: lessons from Sage Sparrows
(Amphispiza belli) for analysis of geographic
variation in birds. Auk 123:266-274.
CLARK, A. H. 1905. The West Indian parrots. Auk
22:337-344.
CONOVER, W. 1999. Practical nonparametric statistics.
3rd edn. John Wiley and Sons, New York.
CORY, C. B. 1886. Descriptions of thirteen new
species of birds from the island of Grand Cayman,
West Indies. Auk 3:497-501.
CORY, C. B. 1891. List of birds collected on the
island of Inagua, Bahama Islands, from May 1 to
July 10, 1891. Auk 8:391.
DE MATTOS, K. K., S. N. DEL LAMA, A. R. C.
SALLES, M. R. FRANCISCO, A. MEDAGLIA, A. M.
TOMASULO, F. M. S. CARMO, J. M. C. PEREIRA,
AND M. A. DE OLIVEIRA. 1998. Sex determination
of parrots Amazona a. aestiva and Amazona
amazonica using the polymerase chain reaction.
Journal of Experimental Zoology 281:217-219.
DOUCET, S. M., M. D. SHAWKEY, M. K.
RATHBURN, H. L. MAYS, JR., AND R. MONTGOMERIE.
2004. Concordant evolution of plumage
colour, feather microstructure and a melanocortin
receptor gene between mainland and island populations
of a fairy-wren. Proceedings of the Royal
Society of London B 271:1663-1670.
DUBOIS, A. 2003. The relationships between taxonomy
and conservation biology in the century of
extinctions. Comtus Rendus Biologies 326:S9-
S21.
EDWARDS, S. V., S. B. KINGAN, J. D. CALKINS, C.
N. BALAKRISHNAN, W. B. JENNINGS, W. J.
SWANSON, AND M. D. SORENSON. 2005. Speciation
in birds: genes geography, and sexual selection.
Proceedings of the National Academy of
Sciences 102:6550-6557.
ENKERLIN-HOEFLICH, E. C., N. F. R. SNYDER, AND
J. W. WILEY. 2006. Behavior of wild Amazona
and Rhynchopsitta parrots, with comparative insights
from other psittacines. Pp. 13-25 in Manual
of parrot behavior (A. U. Luescher, ed.). Blackwell
Publishing, Oxford, UK.
FERNÁNDEZ DE OVIEDO Y VALDÉS, G. 1959. Natural
history of the West Indies. University of North
Carolina Press, Chapel Hill, NC.
FORSHAW, J. M. 1989. Parrots of the world. 3rd ed.
Lansdowne Editions, Melbourne.
FRASER, D. J., AND L. BERNATCHEZ. 2001. Adaptive
evolutionary conservation: towards a unified
concept for defining conservation units. Molecular
Ecology 10:2741-2752.
GNAM, R., AND R. F. ROCKWELL. 1991. Reproductive
potential and output of the Bahama Parrot,
Amazona leucocephala bahamensis. Ibis 133:
400-405.
GONZÁLEZ ALONSO, H. 2001. Conductas de gregarismo
y vocalización de la Cotorra Cubana (Amazona
leucocephala). Ornitología Neotropical 12:
141-152.
GREEN, D. M. 2005. Designatable units for status
assessment of endangered species. Conservation
Biology 19:1813-1820.
HAIG, S. M., E. A. BEEVER, S. M. CHAMBERS, H.
M. DRAHEIM, B. D. DUGGER, S. DUNHAM, E.
ELLIOTT-SMITH, J. B. FONTAINE, D. C. KESLER,
B. J. KNAUS, I. F. LOPES, P. LOSCHL, T. D. MULLINS,
AND L. M. SHEFFIELD. 2006. Taxonomic
considerations in listing subspecies under the
U. S. Endangered Species Act. Conservation Biology
20:1584-1594.
HALE, E. E. 1891. The life of Christopher Columbus:
from his own letters and journals and other
documents of his time. G. L. Howe and Co., Chicago.
HAYES, W. K. 2006. The urgent need for conservation
taxonomy in the Bahamas: new bird species
as an example. Bahamas Naturalist and Journal of
Science 1:12-24.
HELBIG, A. J., A. G. KNOX, D. T. PARKIN, G.
SANGSTER, AND M. COLLINSON. 2002. Guidelines
for assigning species rank. Ibis 144:518-525.
JOHNSON, N. K., J. V. REMSEN, AND C. CICERO.
1999. Resolution of the debate over species concepts
in ornithology: a new comprehensive biologic
species concept. Pp. 1470-1482 in Proceedings
of the 22nd International Ornithological
Congress, Durban (N. J. Adams and R. H.
Slotow, eds.). Birdlife of South Africa, Johannesburg,
South Africa.
KEEGAN, W. F. 1992. Beachhead in the Bahamas—
Columbus encounters a new-world. Archaeology
45:44-50.
LANCE, R. F., M. L. KENNEDY, AND P. L. LEBERG.
2000. Classification bias in discriminant function
analyses used to evaluate putatively different
taxa. Journal of Mammalogy 81:245-249.
MACE, G. M. 2004. The role of taxonomy in species
conservation. Philosophical Transactions of the
Royal Society of London B 359:711-319.
MASELLO, J. F., M. L. PAGNOSSIN, C. SOMMER,
AND P. QUILLFELDT. 2006. Population size, provisioning
frequency, flock size and foraging
range at the largest known colony of Psittaciformes:
the burrowing parrots of the north-eastern
Patagonian coastal cliffs. Emu 106:69-79.
MCNEELY, J. A. 2002. The role of taxonomy in
conserving biodiversity. Journal of The Nature
Conservancy 10:145-153.
MERTLER, C. A., AND R. A. VANNATTA. 2002. Advanced
and multivariate statistical methods. 2nd
edn. Pyrczak Publishing, Los Angeles.
O’BRIEN, J. J., C. STAHALA, G. P. MORI, M. A.
CALLAHAM, JR., AND C. M. BERGH. 2006. Effects
of prescribed fire on conditions inside a Cuban
Parrot (Amazona leucocephala) surrogate nesting
cavity on Great Abaco, Bahamas. Wilson Journal
of Ornithology 118:508-512.
OTTENS-WAINRIGHT, P., K. M. HALANYCH, J. R.
EBERHARD, R. I. BURKE, J. W. WILEY, R. S.
GNAM, AND X. G. AQUILERA. 2004. Independent
geographic origin of the genus Amazona in the
West Indies. Journal of Caribbean Ornithology
17:23-49.
PATTEN, M. A., AND P. UNITT. 2002. Diagnosability
versus mean differences of Sage Sparrow subspecies.
Auk 119:26-35.
PETERS, J. 1928. The races of Amazona leucocephala
(LINN). Auk 45:342-344.
PHILLIMORE, A. B., AND I. P. F. OWENS. 2006. Are
subspecies useful in evolutionary and conservation
biology? Proceedings of the Royal Society of
London B 273:1049–1053.
RAFFAELE, H. A., T. PEDERSEN, AND K. WILLIAMS.
1998. A guide to the birds of the West Indies.
Princeton University Press, Princeton, NJ.
REMSEN, J. V., JR. 2005. Pattern, process, and rigor
meet classification. Auk 122:403-413.
REYNOLDS, M. B. J. 2006. Conservation taxonomy
of the Cuban Parrot: morphological, plumage and
flight call variation. Unpubl. M.S. Thesis, Loma
Linda University, Loma Linda, CA.
RIDGWAY, R. 1916. The birds of North and Middle
America. Pt. 7. Bulletin of the U. S. National Museum
50:1-543.
RIVERA-MILÁN, F. F., J. A. COLLAZO, C. STAHALA,
W. J. MOORE, A. DAVIS, G. HERRING, M.
STEINKAMP, R. PAGLIARO, J. L. THOMPSON, AND
W. BRACEY. 2005. Estimation of density and
population size and recommendations for monitoring
trends of Bahama Parrots on Great Abaco
and Great Inagua. Wildlife Society Bulletin 33:
823-834.
ROJAS, M. 1992. The species problem and conservation:
what are we protecting? Conservation
Biology 6:170-178.
SNYDER, N. F. R., W. B. KING, AND C. B. KEPLER.
1982. Biology and conservation of the Bahama
Parrot. Living Bird 9:91-114.
SNYDER, N. F. R., P. MCGOWAN, J. GILARDI, AND
A. GRAJAL (eds). 2000. Parrots: status, survey,
and Conservation Action Plan 2000-2004. International
Union for Conservation of Nature.
Gland, Switzerland.
SNYDER, N. F. R., J. W. WILEY, AND C. B. KEPLER.
1987. The parrots of Luquillo: natural history and
conservation of the Puerto Rican Parrot. Western
Foundation of Vertebrate Zoology, Los Angeles.
SPSS INC. 2003. SPSS for Windows. Version 12.0.
SPSS Inc., Chicago.
STAHALA, C. 2005. Demography and conservation
of the Bahama Parrot on Great Abaco Island. Unpubl.
M. S. thesis, North Carolina State University,
Raleigh.
STAHALA, C. 2007. Habitat use and population genetic
analysis of the Bahama Parrot on Great
Abaco and Great Inagua Islands, Bahamas. Unpubl.
report to The Nature Conservancy, Bahamas
Country Program.
TODD, W. E. C., AND W. W. WORTHINGTON. 1911.
A contribution to the ornithology of the Bahama
Islands. Annals of the Carnegie Museum 7:388-
464.
TURNER, G. F., AND M. T. BURROWS. 1995. A
model of sympatric speciation by sexual selection.
Proceedings of the Royal Society of London
B 260:287-292.
WIENS, J. J. 2004. The role of morphological data in
phylogeny reconstruction. Systematic Biology
53:653-661.
WILEY, J. W. 1991. Status and conservation of parrots
and parakeets in the Greater Antilles, Bahama
Islands, and Cayman Islands. Bird Conservation
International 1:187-214.
WILEY, J. W., R. S. GNAM, S. E. KOENIG, A. DORNELLY,
X. GALVEZ, P. E. BRADLEY, T. WHITE,
M. ZAMORE, P. R. REILLO, AND D. ANTHONY.
2004. Status and conservation of the family Psittacidae
in the West Indies. Journal of Caribbean
Ornithology 17:94-154.
WILEY, J. W., N. F. R. SNYDER, AND R. S. GNAM.
1992. Reintroduction as a conservation strategy
for parrots. Pp. 165-200 in New World parrots in
crisis: solutions from conservation biology. (S. R.
Beissinger and N. F. R. Snyder, eds.). Smithsonian
Institution Press, Washington, DC.
WILLIAMS, M. I., AND D. W. STEADMAN. 2001. The
historic and prehistoric distribution of parrots
(Psittaciformes, Psittacidae) in the West Indies.
Pp. 175-187 in Biogeography of the West Indies:
patterns and perspectives (C. A. Woods and F. E.
Sergile, eds.). 2nd ed. CRC Press, Boca Raton,
FL.
WILSON, S. M. 1990. Hispaniola: Caribbean chiefdoms
in the age of Columbus. University of Alabama
Press, Tuscaloosa, AL.
ZINK, R. M., G. F. BARROWCLOUGH, J. L. ATWOOD,
AND R. C. BLACKWELL-RAGO. 2000. Genetics,
taxonomy, and conservation of the threatened
California Gnatcatcher. Conservation Biology
14:1394-1405.
ZINK, R. M. 2004. The role of subspecies in obscuring
avian biological diversity and misleading conservation
policy. Proceedings of the Royal Society
of London B 271:561-564.
ZINK, R. M. 2006. Rigor and species concepts. Auk
123:887-891.
