Introduction
An integral component of contemporary wildlife conservation is the relocation of threatened or endangered species. There are several important considerations for a successful reintroduction program. One component is that relocated populations be free of pathogens. A relocated population may introduce pathogenic infectious agents that could threaten the health of the wild population of the same or a different species.1,5,6,8,9,17 As the result of introduction of novel or emerging diseases, epizootics can cause complete or severe decimation of a population.1,5 Diseases can also have sub-catastrophic effects such as reduced survival and reproduction as well as increased susceptibility to predators or environmental stress.1 The threat of epizootics caused by relocations is ever present but economic resources often limit preventative measures. A concerted effort must be made to evaluate the health status of the relocated populations prior to release.
Methods
Approximately 300 Amazon parrots (Amazona autumnalis autumnalis, Amazona farinosa guatemalae, Amazona albifrons albifrons, and Amazona xantholora) were confiscated by government officials from poachers, and assigned for rehabilitation by a non-governmental organization, Asociacion de Rescate y Conservacion de Animales Silvestre (ARCAS). The birds were to be relocated to Peten province in northeastern Guatemala. Prior to release they were evaluated for the presence of intestinal and blood parasites.
A total of 95 blood and 75 fecal samples from birds were examined. Blood smears were air-dried, fixed with 100% methanol, and stained with Diff-Quick (Mercedes Medical, Sarasota, FL, USA). Fecal samples were collected and placed in 2% formalin. Standard sedimentation and floatation techniques were used.
Results
No hemoparasites were observed in any of the smears. The prevalence of intestinal parasites was 3/75 (4%) with all of the parasites being Isospora spp.
Discussion
The low prevalence of intestinal parasites could be attributed in part to the small sample volume of feces samples and the fact that only one sample was taken from each bird. The lack of intestinal parasites in psittacines could be due to the lack of a complete parasitic life cycle in these arboreal species that eat predominantly fruits and nuts. The low prevalence of hemoparasites in this study agrees with results of other evaluation of neotropical birds.2-4,7,10-12,14,16,18,19 This is in contrast to the remainder of the world where hemoparasite prevalence is much higher.4 The low prevalence of intestinal parasite found in this study coincides quite well with other reports involving wild psittacines.12,14,15
Despite the apparent freedom of these birds from intestinal and blood parasites, medical evaluation of wildlife, such as these parrots, destined for reintroduction or translocation is essential.
Literature Cited
1. Ballou, J. 1993. Assessing the risks of infectious disease in captive breeding and reintroduction programs. J Zoo Wildl Med. 24:327–335.
2. Bennett, G.F., A.A. Aguirre, and R.S. Cook. 1991. Blood parasites of some birds from northeastern Mexico. J Parasitol. 77:38–41.
3. Bennett, G.F., and J.I. Borrero. 1976. Blood parasites of some birds from Columbia. J Wildl Dis. 12:454–458.
4. Bennett, G.F, M.C. Garvin, and J.M. Bates. 1991. Avian hematozoa from west central Bolivia. J Parasitol. 77:207–211.
5. Bennett, G.F, H. Witt, and E.M. White. 1980. Blood parasites of some Jamaican birds. J Wildl Dis. 16:29–38.
6. Chivers, D.J. 1991. Guidelines for reintroductions: procedures and problems. Symp Zool Soc Lond. 62:89–99.
7. Clubb, S.L., D. Cramm, and M.E. Fowler. 1981. Blood parasites of psittacine birds—a survey of the presence of Haemoproteus, microfilaria, and trypanosomes. In: Proc Am Assoc Zoo Vet. Seattle, WA. 32–37.
8. Cooper, J.E. 1989. The role of pathogens in threatened populations: a historical view. International Council of Bird Preservation Technical Bulletin. 10:51–59.
9. Cunningham, A.A. 1996. Disease risks of wildlife translocations. Conserv Biol. 10:349–353.
10. Galindo, P., and O. Sousa. 1966. Blood parasites of birds from Almirante, Panama with ecological notes on hosts. Revista de Biologica Tropical (Universidad de Costa Rica). 14:27–46.
11. Garvin, M.C., and P.P. Marra. 1991. Blood parasites of some birds form Puerto Rico. Caribbean J Sci. 27:1–2;93–94.
12. Gilardi, K.V., L.J. Lowenstine, J.D. Gilardi, and C.A. Munn. 1995. A survey for selected viral, chlamydial, and parasitic diseases in wild dusky-headed parakeets (Aratinga weddellii) and tui parakeets (Brotogeris sanctithomae) in Peru. J Wildl Dis. 31:523–528.
13. Griffith, B., J.M. Scott, J.W. Carpenter, and C. Reed. 1989. Translocation as a species conservation tool. Science. 245:477–480.
14. Joyner, K.L., N. de Berger, E. Lopez, A. Brice, and P. Nolan. Health parameters of wild psittacines in Guatemala: a preliminary report. In: Proc Assoc Avian Vet. 1992;287–303.
15. Webster, W.A. 1982. Internal parasites found in exotic birds imported into Canada. Can Vet J. 23:230.
16. White, E.M., E.C. Greiner, G.F. Bennett, and C.M. Herman. 1979. Distribution of the hematozoa of Neotropical birds. Revistabe Biologica Tropical. 26:43–102.
17. Woodford, M.H. 1993. International disease implications for wildlife translocation. J Zoo Wildl Med. 24:265–270.
18. Woodworth-Lynas, C.B., J.R. Caines, and G.F. Bennett. 1989. Memorias do Instituto Oswaldo Cruz Rio de Janeiro. 84:515–526.
19. Young, B.E., M.C. Garvin, and D.B. Macdonald. 1993. Blood parasites in birds form Monteverde, Costa Rica. J Wildl Dis. 29:555–560.