Against a multi-green background of lush vegetation, a splash of yet another shade of intense green commands attention as a flock of Great Green Macaws (Ara ambiguus) flies across the clearing. However, the sighting is not in the forest home of these majestic macaws, but in the controlled environment of the NATUWA Macaw Sanctuary (“Santuario de Lapas NATUWA”) in Puntarenas in western Costa Rica. The 65 Great Green Macaws in the sanctuary (all of the nominate subspecies ambiguus) are integral to the “Ara ambiguus Conservation Project”, a key step of which is to apply molecular biological techniques to survey the genetic variability of these captive individuals.
This genetic survey is regarded as an essential component of the several stages leading to the eventual reintroduction of the macaws to their wet lowland and foothill forests on the eastern (Caribbean) slope of Costa Rica. Genetic variability of wild Great Green Macaws in Costa Rica has previously been studied*, and the value for variability (HE = 0.587) is lower than values for species of macaws with lower (IUCN) categories of threat, but not as low as those reported for other threatened species of macaws (e.g. Hyacinth Macaw Anodorhynchus hyacinthinus, HE = 0.438). The study found a low percentage of related individuals and no evidence of inbreeding.
With its support to the Great Green Macaw project in the NATUWA sanctuary, one of the most important Costa Rican breeding centres, the Loro Parque Fundación (LPF) continues its involvement in efforts to conserve this species and its forest habitat. This involvement commenced in 1997 and has included projects in Ecuador, Panama, Nicaragua and Costa Rica. On the eastern side of the latter country, between 2009 and 2014 the LPF aided activities by Dr. Olivier Chassot and Dr. Guiselle Monge, of the Tropical Science Center, for research and conservation of the species in 340,067 hectares of forest in the Castillo-San Juan-La Selva Biological Corridor, and adjoining areas. These activities have had a positive effect. A census conducted in 1994 revealed an estimated population of 200 individual Great Green Macaws in Costa Rica, but by 2013 a new census estimated the abundance of the species in Nicaragua and Costa Rica to be 1,530 individuals, a significantly higher figure than the 871 extrapolated from 1994 population data.
Nevertheless, the threats to the Great Green Macaw still exist and the species is listed as ‘Endangered’. Annual deforestation rates remain high throughout its geographical distribution, and there is illegal capture for trade, food and feathers. Even the key tree species for the feeding and nesting of the macaw, the mountain almond tree (Dipteryx panamensis) is selectively logged in Costa Rica. Within this apparently unpromising scenario there are windows of opportunity, in particular some protected areas currently depopulated of Great Green Macaws which offer the chance of re-establishment through reintroduction.
Hence the purpose of the NATUWA Macaw Sanctuary is to increase the number of A. ambiguus in captivity with a science-based ex-situ breeding programme, leading to a release and in-situ programme for conservation of this speciesin its natural habitat. Given that the macaws help to keep the forest healthy by dispersing seeds of a large variety of trees, NATUWA sustains its management programme for macaws to preserve the functions vital in the wild. The programme involves rescue, rehabilitation and environmental enrichment in spacious aviaries, and experimental reintroduction to the environment. Naturally, the information generated in the sanctuary is being well-used to create awareness within Costa Rica about the protection of the macaws. For all these purposes, the sanctuary receives macaws that are confiscated by the Ministry of Environment and Energy (MINAE), as well as those surrendered voluntarily by the general population or through the police and fire departments.
The genetic survey part of the “Ara ambiguus Conservation Project” rests on an important collaboration between the sanctuary and experts elsewhere, notably Dr. Federica Ardizzone and Professor Oliviero Olivieri at the University of Perugia and Professor Mauro Delogu at the University of Bologna, Italy. Also in Italy, another partner is Parco Natura Viva, Bussolengo, and in the United States the Schubot Exotic Bird Health Center of Texas A&M University. Using blood samples collected from the 65 macaws, a cutting edge technique (double digest restriction-site associated DNA – ddRADseq) makes possible a genetic characterization and the selection of individuals of higher genetic diversity to form breeding pairs. If each member of the pair likes the other, the first purpose, to avoid any increase in inbreedingrate the sanctuary population, can be fulfilled.
This charismatic macaw species will only be saved by the integration of actions which complement each other, but without doubt the use of molecular biology for the genetic profiling of individual macaws will contribute in no small way to help maximise genetic variability within the Great Green Macaw population. The NATUWA Macaw Sanctuary and the LPF are committed to make that happen.
* Ramírez Molina, H. A. (2018) Análisis de variabilidad y diferenciación genética poblacional de la lapa verde (Ara ambiguus) en Costa Rica [Analysis of genetic variability and population differentiation of the Great Green Macaw (Ara ambiguus) in Costa Rica]. Master’s thesis, Nacional University, Heredia.
Author: Dr. David Waugh, Correspondent, Loro Parque Fundación
Title photo: Three Great Green Macaws at the NATUWA Macaw Sanctuary (c) NATUWA