Echo Parakeet (Psittacula eques): revise global status?

BirdLife species factsheet for Echo Parakeet

Echo Parakeet (Psittacula eques) is endemic to Mauritius, where it inhabits forests and scrubland (Jones 1987, Marshall 1997, Jones et al. 2013). Once widespread across the island, numbers started to decline in the 19th century to an estimated 20 individuals in the 1980s (Jones et al. 2013, V. Tatayah and S. Henshaw in litt. 2019). The species’s decline and contracting distribution was likely caused by the severe and large-scale destruction and degradation of its forest habitat for conversion into plantations (Jones 1987, Greenwood 1996, Jones et al. 1998). Apart from habitat loss, predation by, and competition with, introduced mammals and birds, as well as outbreaks of Psittacene Beak and Feather Disease (PBFD), threatened the species (Greenwood 1996, Thorsen and Jones 1998, C. Jones in litt. 2000, V. Tatayah in litt. 2006, Richards 2010, V. Tatayah in litt. 2012, Mauritian Wildlife Foundation 2019).

Since then, intense conservation efforts have aided the continuous recovery of the species, especially after 1994. These efforts have included a captive breeding programme set up in the 1970s with reintroductions into the wild since 1997, translocations, habitat protection and restoration at key sites, invasive species control, as well as supplementary feeding and nest box provision (Jones and Hartley 1995, Greenwood 1996, Jones et al. 1998, Jones 2010, Mauritian Wildlife Foundation 2019, V. Tatayah in litt. 2019).

By now, the largest part of the population is confined to restricted areas of the Black River Gorges National Park (6,800 ha) in southwestern Mauritius. Reintroductions of captive-bred birds there ceased in 2005/2006 (C. Jones in litt. 2019), following the outbreak of PBFD. Currently, two additional populations are being established in other parts of Mauritius: Between 2015 and 2017, wild-born individuals were translocated to the Bambous Mountains on the East Coast of the island, where breeding could be confirmed in 2018, and this population is deemed self-sustaining (V. Tatayah, S. Henshaw and C. Jones in litt. 2019). Another translocation programme started in early 2018 to establish a population in Chamarel in the south-west; however this population has not been breeding yet (V. Tatayah and S. Henshaw in litt. 2019). Translocations to both Bambous and Chamarel are planned to continue in the next few years to reinforce the population (V. Tatayah in litt. 2019).

According to IUCN Guidelines (IUCN Standards and Petitions Subcommittee 2017), the population in Chamarel cannot be included in a Red List assessment yet, as no breeding could be confirmed and the population is hence not yet self-sustaining. Therefore by now, only the populations in the Black River Gorges National Park and in the Bambous Mountains count for the assessment.

Thanks to conservation efforts, the number of Echo Parakeets in the wild increased to over 750 known individuals in 2017 post-breeding (V. Tatayah and S. Henshaw in litt. 2019). It is assumed that the total population on Mauritius contains around 450 mature individuals (S. Henshaw in litt. 2019). It is therefore placed in the band 250-999 mature individuals.

Echo Parakeet is currently listed as Endangered under Criterion B1ab(iii) on the IUCN Red List. However, given the increase in population size and habitat availability following intensive conservation effort, the species appears to warrant a change in Red List status. Therefore, we present here our reassessment against all criteria for the species.

Criterion A – Over the past three generations (22.5 years) the population has been increasing rapidly, from around 50 individuals to over 750 individuals. Therefore, Echo Parakeet may be considered Least Concern under Criterion A.

Criterion B – The species has an Extent of Occurrence (EOO) of 272 km2, which meets the threshold value for Endangered under Criterion B1. The Area of Occupancy (AOO) has not been directly calculated. The maximum AOO however, as derived by placing a 4 km2-grid over the area of mapped range, is 152 km2, which falls below the threshold for listing as Endangered under Criterion B2 (500 km2). However, in order to be listed under Criterion B, at least two other conditions have to be met.

So far, the species was assumed to occur at 2-5 locations* in the Black River Gorges National Park. With the establishment of the population in the Bambous Mountains, this number increased by at least 1 additional location*. Therefore, the current number of locations* of occurrence may be at least 3-6, but most likely less than 10. Therefore, under the precautionary assumption that the true number of locations is closer to the lower band of the estimate, the species would meet the threshold for Endangered under condition (a).

The species is not undergoing a continuing decline in EOO, AOO, number of locations or population size. While in some places the habitat quality might still be declining due to invasive alien species, habitat restoration efforts in key areas used by the Echo Parakeet suggest that overall, there is no longer a continuing decline in area/quality of habitat where the species is currently found. Therefore, Echo Parakeet would not meet condition (b).

The population size has been increasing steadily over the last decades and the species does not show severe fluctuations sensu IUCN (fluctuation in the scale of one order of magnitude; IUCN Standards and Petitions Subcommittee 2017). Therefore, Echo Parakeet does not meet condition (c).

Overall, the species would not warrant listing as threatened under Criterion B. However, the threshold values for EOO and AOO are met and one of two further conditions is fulfilled. Moreover, the species may have qualified as threatened under criterion B were it not for continued conservation efforts. Therefore, Echo Parakeet may warrant listing as Near Threatened under Criteria B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v).

Criterion C – The population size may be placed in the band 250-999 mature individuals, which meets the threshold value for Endangered under Criterion C. However, in order to be listed under this criterion, the population must undergo a continuing decline. As the population of Echo Parakeet has been increasing over the last decades, this condition is not fulfilled. However, as for criterion B, this may be due to ongoing conservation efforts. With acceptance of the Bambous Mountains population, the population may be considered to be in multiple subpopulations, and so it could warrant a precautionary listing as Near Threatened under criterion C2a(i).

Criterion D – The population size is estimated at 250-999 mature individuals. This meets the threshold value for listing under Criterion D1. While the AOO of the species is too large to meet the threshold (AOO < 20 km2), it is precautionarily assumed that Echo Parakeet may occur at least at 3-6 locations* (with a threat that may drive the species to CR or EX in a short period of time), meeting the threshold for Criterion D2 as well. Therefore, Echo Parakeet may be listed as Vulnerable under Criteria D1+2.

Criterion E – To the best of our knowledge there has been no quantitative analysis of extinction risk conducted for this species. Therefore, it cannot be assessed against this criterion.

Therefore, it is proposed that Echo Parakeet (Psittacula eques) be listed as Vulnerable under Criteria D1+2. We welcome any comments on this proposed listing.

Please note that this topic is not designed to be a general discussion about the ecology of the species, rather a discussion of its Red List status. Therefore, please make sure your comments are relevant to the discussion outlined in the topic.

*The term ‘location’ refers to a distinct area in which a single threatening event can rapidly affect all individuals of the taxon present, with the size of the location depending on the area covered by the threatening event. Where a taxon is affected by more than one threatening event, location should be defined by considering the most serious plausible threat (IUCN 2001, 2012).

An information booklet on the Red List Categories and Criteria can be downloaded here and the Red List Criteria Summary Sheet can be downloaded here. Detailed guidance on IUCN Red List terms and definitions and the application of the Red List Categories and Criteria can be downloaded here.

References

Greenwood, A. G. 1996. The Echo responds – a partnership between conservation biology, aviculture and veterinary science. PsittaScene 8(1): 6-7.

IUCN. 2001. IUCN Red List Categories and Criteria: Version 3.1. IUCN Species Survival Commission. IUCN, Gland, Switzerland and Cambridge, U.K.

IUCN. 2012. IUCN Red List Categories and Criteria: Version 3.1. Second edition. IUCN Species Survival Commission. IUCN, Gland, Switzerland and Cambridge, U.K. www.iucnredlist.org/technical-documents/categories-and-criteria.

IUCN Standards and Petitions Subcommittee. 2017. Guidelines for Using the IUCN Red List Categories and Criteria. Version 13. Prepared by the Standards and Petitions Subcommittee. http://www.iucnredlist.org/documents/RedListGuidelines.pdf.

Jones, C. G. 1987. The larger land-birds of Mauritius. In: Diamond, A.W. (ed.), Studies of Mascarene Island birds, pp. 208-300. Cambridge University Press, Cambridge, U.K.

Jones, C. G. 2010. Back from the brink: the Echo Parakeet story. PsittaScene 22(3): 3-5.

Jones, C. G.; Hartley, J. 1995. A conservation project on Mauritius and Rodrigues: an overview and bibliography. Dodo: Journal of the Jersey Wildlife Preservation Trust 31: 40-65.

Jones, C. G.; Malham, J.; Reuleaux, A.; Richards, H.; Raisin, C.; Tollington, S.; Zuel, N.; Chowrimootoo, A.; Tatayah, V. 2013. Echo Parakeet Psittacula eques. In: Safford, R. J.; Hawkins, A. F. A. (ed.), The Birds of Africa. Vol. VIII: The Malagasy Region, pp. 517-522. Christopher Helm, London.

Jones, C. G.; Swinnerton, K.; Thorsen, M.; Greenwood, A. 1998. The biology and conservation of the Echo Parakeet Psittacula eques of Mauritius. Proceedings of the IVth International Parrot Convention: 110-123.

Marshall, T. 1997. The Echo bouncing back. AFA Watchbird 24: 42-43.

Mauritian Wildlife Foundation. 2019. Echo Parakeet Psittacula eques. http://www.mauritian-wildlife.org/application/index.php?tpid=30&tcid=32 (Accessed 25 March 2019).

Richards, H. 2010. The 500 mark: a landmark season. PsittaScene 22(3): 6-10.

Thorsen, M.; Jones, C. 1998. The conservation status of Echo Parakeet Psittacula eques of Mauritius. Bulletin of the African Bird Club 5(2): 122-126.

This entry was posted in Africa, Parrots and tagged , . Bookmark the permalink.

3 Responses to Echo Parakeet (Psittacula eques): revise global status?

  1. Red List Team (BirdLife International) says:

    Preliminary proposal
    Based on available information, our preliminary proposal for the 2019 Red List would be to adopt the proposed classifications outlined in the initial forum discussion.
    There is now a period for further comments until the final deadline in mid-July, after which the recommended categorisations will be put forward to IUCN.
    Please note that we will then only post final recommended categorisations on forum discussions where these differ from those in the initial proposal.
    The final 2019 Red List categories will be published on the BirdLife and IUCN websites in December, following further checking of information relevant to the assessments by both BirdLife and IUCN.

  2. Carl G. Jones says:

    The decline in the distribution of this species is likely to have mirror the destruction of native forest which has been occurring since the 17th century, and this would have cause a concomitant reduction in numbers.
    Psittacine beak and feather disease, the circo virus that affects the parakeet has likely been in the population for at least a century and is not affecting the species at a population level. Considerable research is going into trying to understand this disease looking at its pathogenicity and epidemiology (Kundu, et al., 2012; Tollington, 2015, 2019) and have tried to control the spread (Fogell, et al., 2019). It is however widespread in the population, at variable viral loads, and is poorly detectable at low levels. Many birds test positive for the causative agent, beak and feather disease virus, when blood samples are analysed via PCR (including here qPCR), however it is important to distinguish between a viral infection and clinical disease.
    It is common for Echo Parakeets to tolerate an infection without showing clinical signs and thus may be infected but not affected (Tollington, et al., 2015). Further, some birds that have developed acute clinical signs have recovered. It is also important to note here that viral prevalence (proportion of birds PCR positive) is not a good predictor of the impact of that virus on a population. In the Echo Parakeets, despite the outbreak of a novel and virulent genotype of the virus in 2004/5 (Kundu, et al., 2012), the number of breeding pairs continued to increase with the only detectable negative impact (to date) illustrated by a marked, but short-lived reduction in hatch success (Tollington et al., 2015).
    Despite our extensive research on this virus over more than a decade we still know very little about the predictors of individual infection and clinical disease. In fact, when looking at infection among individual nestlings there appear to be no brood-related predictors which contrasts our original assumptions and highlights difficulties with interpreting infection status derived from a single time-point (Tollington, et al., 2018).
    A key publication on the early conservation work that is not quoted in your review is Jones and Duffy (1993). The early recovery of the species was aided to a large extent by clutch and brood manipulations and the enhancement of natural cavities by weather and predator proofing them. The captive population was established using many rescued young from failing nests and hence did no impact upon the wild population.
    The free-living population is going to require long-term conservation management in the form of the provision of nest-boxes and supplemental feeding. These management procedures will be necessary while the remaining tracts of native forest, that are badly degraded with exotic plants, are being rehabilitated. The impacts of these management procedures are being carefully monitored and are discussed in several publications (already quoted here and in your summary).
    The population is healthy with high rates of egg fertility (84%), high hatchability of fertile eggs (82%) and fledging success of hatched young (76%) (Jones et al., 2013). There have been recent (2017-2019) reductions in hatching and fledging rates and these may be due to density dependant factors, and are being carefully monitored.
    The conservation management of this species is being driven by the Mauritian Wildlife Foundation and the National Parks and Conservation Service. This project is based upon long-term long-term population studies. This work has the support of Chester Zoo, the Durrell Institute of Conservation and Ecology (University of Kent) and the Institute of Zoology. We also acknowledge the past and present contributions of the Durrell Wildlife Conservation Trust, the World Parrot Trust and Wildlife Vets International.

    Fogell, D.J., Groombridge, J.J., Tollington, S., Canessa, S., Henshaw, S., Zuel, N., Jones, C.G., Greenwood, A. and Ewen, J.G., 2019. Hygiene and biosecurity protocols reduce infection prevalence but do not improve fledging success in an endangered parrot. Scientific reports, 9(1), p.4779.
    Jones, C.G. and K. Duffy, 1993. Conservation Management of the Echo Parakeet Psittacula eques echo. Dodo 29:126-148.
    Tollington, S., Greenwood, A., Jones, C.G., Hoeck, P., Chowrimootoo, A., Smith, D., Richards, H., Tatayah, V. and Groombridge, J.J., 2015. Detailed monitoring of a small but recovering population reveals sub-lethal effects of disease and unexpected interactions with supplemental feeding. Journal of Animal Ecology, 84(4), pp.969-977.
    Kundu, S., Faulkes, C.G., Greenwood, A.G., Jones, C.G., Kaiser, P., Lyne, O.D., Black, S.A., Chowrimootoo, A. and Groombridge, J.J., 2012. Tracking viral evolution during a disease outbreak: the rapid and complete selective sweep of a circovirus in the endangered Echo Parakeet. Journal of Virology, 86(9): 5221-5229.
    Tollington, S., Ewen, J.G., Newton, J., McGill, R.A., Smith, D., Henshaw, A., Fogell, D.J., Tatayah, V., Greenwood, A., Jones, C.G. and Groombridge, J.J., 2019. Individual consumption of supplemental food as a predictor of reproductive performance and viral infection intensity. Journal of Applied Ecology, 56(3), pp.594-603.

  3. Red List Team (BirdLife International) says:

    Recommended categorisation to be put forward to IUCN
    Following further review, the recommended categorisation for this species has been changed.
    Echo Parakeet is now recommended to be listed as Vulnerable under Criterion D1.
    The final 2019 Red List categories will be published on the BirdLife and IUCN websites in December, following further checking of information relevant to the assessments by both BirdLife and IUCN.

Comments are closed.