In many places of the world where centres take in and provide professional care to sick, injured and confiscated wild animals, most will include rehabilitation as part of their mission, which implies the return of the animals to their natural habitat. Prior to their release, best practice includes to administer appropriate health care, minimise stress, provide as natural of a setting and enclosure as possible, and ensure each animal has all the skills needed to make a successful rehabilitation and survive in the wild.
If individuals are not released, it might be because of debilitation from injury or, in the case of species threatened with extinction, their participation in captive breeding for the eventual release of offspring to bolster wild populations. In either case, wildlife rehabilitation centres usually utilise these animals to educate the public about wildlife’s importance to humans and the environment, and some participate in research related to conservation efforts.
Supported by the Loro Parque Fundación, one such captive breeding and research programme for the endangered Great Green Macaw (Ara ambiguus) is taking place at a rehabilitation centre in Costa Rica, the NATUWA Macaw Sanctuary. The programme intends to increase the number of Great Green Macawsin captivity, leading to a release of the macaws to their natural habitat of wet lowland and foothill forests on the eastern slope of Costa Rica. A key step of the project is the application of molecular biological techniques to survey the genetic variability of the 65 captive individuals. The results make possible a genetic profiling and the selection of individuals of higher genetic diversity to form breeding pairs.
An essential aspect of appropriate health care of the macaws, and any other species in programmes for release to the wild, is the screening of animals to detect any potential pathogens, be they bacteria, fungi, viruses or parasites. The prevention of disease and known pathogen transfer is important, both to maximise the health of released individuals and to minimise the risk of introducing a new pathogen to the wild population. A recent scientific article* reports on the screening for intestinal and blood parasites of 93 Great Green Macaws and 107 Scarlet Macaws (Ara macao) accommodated in four wildlife rehabilitation centres in Costa Rica.
Table 1. Individual macaws sampled, according to housing arrangements
Centre | Scarlet Macaws | Great Green Macaws | ||||||
Indivi-duals | Pairs | Groups | Total | Indivi-duals | Pairs | Groups | Total | |
1 | 0 | 8 | 22 | 30 | 0 | 20 | 0 | 20 |
2 | 0 | 0 | 28 | 28 | 0 | 0 | 35 | 35 |
3 | 0 | 22 | 16 | 38 | 0 | 32 | 6 | 38 |
4 | 4 | 0 | 7 | 11 | 0 | 0 | 0 | 0 |
All | 4 | 30 | 73 | 107 | 0 | 52 | 41 | 93 |
Intestinal parasites % | 0.0 | 6.7 | 40.0 | – | 26.9 | 100 |
As regards gastrointestinal parasites in faecal samples, at Centre 1 none were detected, while at Centre 2 the pooled samples from the Great Green Macaw aviary and the Scarlet Macaw aviary tested positive for Ascaridia roundworms. At Centre 3, one group of 6 Great Green Macaws, 7 Great Green pairs and 1 Scarlet pair also tested positive for Ascaridia. At Centre 4, pooled faecal samples from the group aviary were positive for Capillaria roundworms. Overall, 47% of collected samples were positive for intestinal parasites, but there were no obvious clinical signs of systemic or gastrointestinal disease in the positive individuals. Blood samples were taken from 8 Great Green and 15 Scarlet Macaws in Centres 1 and 2, all in good health, and no haemoparasites were detected.
This pilot study found that intestinal parasites were present in captive macaws from diverse geographical areas in Costa Rica. The results support the need for future, controlled studies of sufficient sample size to allow evidence-based recommendations about the costs and benefits of parasite screening at the time of entry and release of individual animals from rehabilitation centres. Screening at both the time of capture and repeated before release could help elucidate whether parasites are being acquired during captivity or prior to capture. Repeated screening can also form the basis of treatment protocols to avoid the risk of spreading endoparasites to wild members of the species upon release.
Expanding the screening protocols to detect other pathogenic organisms has great importance for centres involved in release to the wild of macaws and other psittacids. Of special concern are viruses such as Circovirus which causes Psittacine Beak and Feather Disease, and Avian (Parrot) Bornavirus which causes Proventricular Dilatation Disease (macaw wasting disease). However, if rigorous precautions are taken and appropriate prophylaxis applied, with stress minimised in the process, there is rarely any cause to consider rehabilitation and release unfeasible.
* Dieckmann, H., Jiménez-Soto, M., Jiménez-Rocha, A., Rojas, E. and Conrad, P.A. (2020) Intestinal and blood parasites in Scarlet (Ara macao) and Great Green (Ara ambigua) macaws in wildlife rehabilitation centers in Costa Rica, Journal of Zoo and Wildlife Medicine, 51(2), 385-390.
Author: David Waugh, Correspondent, Loro Parque Fundación
Photos: title – C. Sparkes, 1 – M. Romack, 2 – Natuwa, 3 – Dieckmann et al, 2020