Health screening of macaws in wildlife rehabilitation centres in Costa Rica

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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.

Scarlet Macaw pair

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
0.0 6.7 40.0   26.9 100  
Scarlet Macaw aviary at Natuwa Macaw Sanctuary

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.

Intestinal nematode parasites under the microscope: a) Ascaridia sp. (52.5×75μm); b) Capillaria sp. (42.5×77.5 μm)

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

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