Archived 2019 topic: Imperial Amazon (Amazona imperialis): revise global status?

BirdLife species factsheet for Imperial Amazon

Imperial Amazon (Amazona imperialis) is endemic to Dominica, where it occurs in the central highlands. While the species had declined significantly to less than 50 mature individuals in 1979, it increased again to 100 mature individuals in 2003 and to 160-240 mature individuals in 2012 (P. R. Reillo in litt. 2003, Wege and Anadón-Irizarry 2008, P. R. Reillo in litt. 2012).

The species mainly inhabits montane and elfin forest at 600-1,300 m, but forages down to 150 m in response to food shortages (Dominica Ministry of Agriculture and the Environment in litt. 2000, Snyder et al. 2000). It is highly sensitive to habitat modification and readily abandons traditional foraging and nesting territories in case of disturbance (Dominica Ministry of Agriculture and the Environment in litt. 2000). Nests are situated in cavities in tall forest trees. However, despite the intensive work carried out towards this species’s conservation, its ecology remains poorly known.

Much suitable habitat has long been destroyed or severely degraded due to anthropogenic impact, mainly for conversion into banana plantations (Snyder et al. 2000). Hunting for food and trapping for the cage-bird trade also played a significant role in the species’s decline up until 1990 (P. R. Reillo in litt. 2012). Local trade has been considerably reduced, if not eliminated, as a result of a successful education programme, but foreign bird-collectors may still pose a threat (Snyder et al. 2000). Competition for nest-sites from the more numerous Red-necked Amazon (Amazona arausiaca) will presumably become more significant as lowland forest is lost and the two species come increasingly into contact (Dominica Ministry of Agriculture and the Environment in litt. 2000).

Imperial Amazon is substantially threatened by hurricanes. Following Hurricane David in 1979, the population decreased to only 25-40 mature individuals (Evans 1991). After that, the population slowly re-built as a consequence of conservation action focussing on the protection of habitat and on environmental education. By 2012, the population was estimated at 160-240 mature individuals. However, since the devastating Hurricane Maria struck Dominica in September 2017, the population crashed again, likely to an all-time low. The exact impacts of Maria on the habitat availability and the population size of Imperial Amazon are not yet known. However, it is estimated that Maria was the most severe storm that ever hit Dominica, felling 30% of the trees on the island and stripping the remaining 70% of their leaves and fruits (Forestry and Agriculture Department per Palmer et al. 2018). This estimate is supported by Global Forest Watch, which indicates a loss of 24,000 ha of forest, equating to 34%, between 2000 and 2017 (Global Forest Watch 2014).

By January 2018, preliminary surveys detected 11 Imperial Amazons at nine localities throughout the island, all outside of the original range in the montane forest (Palmer et al. 2018). It is conceivable that the species evaded into lower-quality lowland habitat as a consequence of the hurricane (Palmer et al. 2018). One male, which was rescued after the hurricane and brought to a rehabilitation centre, has by now been exported to a breeding facility in Germany (Palmer et al. 2018).  

Overall, while Imperial Amazon seems to have the potential to recover after a sharp population decline, as it proved in the aftermath of Hurricane David in 1979, climate change and the subsequent higher frequency of severe storms are of immediate concern. If Dominica was to be struck by other hurricanes in the near future, before the species could recover sufficiently, the risk of extinction would increase drastically (Collar et al. 2019).

Currently, Imperial Amazon is listed as Endangered under Criterion D, indicating a small, but stable or increasing, population size. However, since Hurricane Maria hit Dominica in September 2017, there is growing evidence that the population size has declined dramatically, and Imperial Amazon appears to warrant a change in Red List status. Therefore, we present here our reassessment against all criteria for the species.

Criterion A – Until recently, the population has been increasing slowly due to conservation efforts, from an estimated 25-40 mature individuals in 1979 to 50-70 mature individuals in 1993, 100 mature individuals in 2000 and 160-240 mature individuals in 2012 (BirdLife International 2019). As a consequence of Hurricane Maria, the population has likely declined drastically (Palmer et al. 2018, P. Romanoski in litt. 2018). Apart from habitat loss, the species also faces various other threats, including illegal hunting and trapping (P. R. Reillo in litt. 2012). However, as the overall rate of population change over the last three generations (36.9 years) is not known, Imperial Amazon cannot be assessed against this criterion.

Criterion B – In the aftermath of Hurricane Maria, the remaining individuals have only been observed in sites outside of the original range, possibly because the hurricane pushed the species out of the preferred habitat (Palmer et al. 2018). Until now, it is unclear whether Imperial Amazon still persists in its native range, or whether it might re-colonize it in case of a habitat recovery. However, as the species is still found in close proximity to the native range and has not been deliberately introduced to new areas, it cannot be treated as Extinct in the Wild. Pending new information on potential changes in the distribution range, we can tentatively use the original value for the Extent of Occurrence (EOO), which has been calculated as 240 km2. This value meets the thresholds for Endangered (EOO < 5,000 km2). However, in order to warrant listing as threatened under this criterion, at least two further conditions must be met.

Imperial Amazon is not considered to be severely fragmented sensu IUCN (i.e., all individuals belong to the same subpopulation; IUCN 2012). With hurricanes being the most severe threat and their impact covering the whole island, it can be concluded that the species occurs at only 1 location*. Consequently, Imperial Amazon meets the threshold for Critically Endangered and Endangered under condition (a). In order to qualify for condition (b), the species has to be undergoing a continuing decline. The population was severely reduced by Hurricane David in 1979, after which is recovered, and was reduced again by Hurricane Maria in 2017. A continuing decline sensu IUCN does however not need to be continuous, but can be sporadic and unpredictable, but must likely continue into the future (IUCN Standards and Petitions Subcommittee 2017). Also single events like hurricanes can cause a continuing decline, as long as they are likely to occur at least once within three generations, while the population cannot recover between the events. The frequency of hurricanes is expected to increase with climate change, so it is possible that the next severe storm may hit the population within the next three generations (36.9 years). Using a precautionary approach, we can therefore conclude that the hurricanes indeed contribute to a continuing decline of the species. Consequently, we can infer a decline in Area of Occupancy (AOO), habitat quality and number of mature individuals, and the species thus meets the requirements for condition b(ii,iii,v). The species is not known to undergo extreme fluctuations and therefore does not meet the threshold for condition (c).

As the AOO of the species has not been quantified, it cannot be assessed against Criterion B2. In summary, Imperial Amazon still meets the conditions for listing as Endangered under Criterion B1ab(ii,iii,v).

Criterion C – Prior to Hurricane Maria, the population of Imperial Amazon was estimated at 160-240 mature individuals and increasing. Recent population data are not available yet; however, based on the severe habitat loss due to the hurricane, it is highly likely that the previously positive population trend has been reversed. We can precautionarily infer a continuing population decline (see Criterion B), even though the rate is not known, and assume that the current population size is likely much lower than the previous estimate. All individuals are part of the same subpopulation (BirdLife International 2019). Therefore, Imperial Amazon now qualifies for listing as Critically Endangered under Criterion C2a(i,ii).

Criterion D – Since Hurricane Maria struck Dominica, the population size of Imperial Amazon has not been quantified. However, we can draw inferences based on the effects of previous hurricanes and on recent sightings of the species. Prior to Maria, the population numbered 160-240 mature individuals. Maria is considered to be the strongest and possibly most destructive hurricane that hit the island so far. Previously, the most severe storm was Hurricane David in 1979, after which the population of Imperial Amazon plummeted to only 40-60 individuals (Evans 1991, Palmer et al. 2018). If we tentatively assume that the impact of Maria on the population was at least as severe as David, the population size may have decreased to less than 40-60 individuals, equating to less than about 25-40 mature individuals. Consequently, the species would meet the threshold for Critically Endangered. This preliminary estimate is supported by field data, reporting only 11 individuals about half a year after Hurricane Maria (Palmer et al. 2018). Pending new information on the population size of Imperial Amazon, the species may precautionarily be listed as Critically Endangered under Criterion D.

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

Therefore, assuming that the population decline is continuing, it is proposed that Imperial Amazon (Amazona imperialis) be listed as Critically Endangered under Criteria C2a(i,ii); D. We welcome any comments on this proposed listing and specifically request recent information on the population size of Imperial Amazon.

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

BirdLife International. 2018. Species factsheet: Amazona imperialis. http://www.birdlife.org (Accessed 12 February 2019).

Evans, P. G. H. 1991. Status and conservation of Imperial and Red-necked Parrots Amazona imperialis and A. arausiaca on Dominica. Bird Conservation International 1: 11-32.

Global Forest Watch. 2014. World Resources Institute. www.globalforestwatch.org (Accessed 12 February 2019).

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

Palmer, C. A.; Martin, T. E.; Durand, S.; Lamont, M. 2018. First observations of the impacts of Hurricane Maria on the endemic imperial amazon. Oryx 52: 410-411.

Collar, N.; Boesman, P.; Kirwan, G. M. 2019. Imperial Amazon (Amazona imperialis). In: del Hoyo, J.; Elliott, A.; Sargatal, J.; Christie, D.A.; de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona, Spain. https://www.hbw.com/node/54759 (Accessed 12 February 2019).

Snyder, N.; McGowan, P.; Gilardi, J.; Grajal, A. 2000. Parrots: Status survey and conservation action plan 2000-2004. International Union for Conservation of Nature and Natural Resources, Gland, Switzerland and Cambridge, U.K. Wege, D. C.; Anadón-Irizarry, V. 2008. Important Bird Areas in the Caribbean: Key sites for conservation. BirdLife International, Cambridge, U.K.

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3 Responses to Archived 2019 topic: Imperial Amazon (Amazona imperialis): revise global status?

  1. Post-Maria assessments of A. imperialis by experienced Forestry Division personnel are being hampered by difficult access to interior forest areas strewn with fallen trees and debris and which are currently being colonized by opportunistic vegetation. Recent sightings have occurred within and adjacent to the Morne Diablotin and Morne Trois Pitons National Parks, Central Forest Reserve, Northern Forest Reserve and private lands. Most birds are sighted along forest edges and ridges that offer a vantage point, but estimating bird densities from such watch-point accounts is inherently problematic.

    A. imperialis matures slowly and exhibits a low reproductive rate, with mature pairs typically fledging a single offspring every year or other year. Since the population reduction by Maria is likely to be unquantified for some time, listing the species as Critically Endangered under Criteria C and D appears prudent. Comprehensive surveys may require years to complete, which, like post-David surveys, should be sustained to document recovery and range expansion over decades.

    All conservation, intervention and recovery measures for A. imperialis should be undertaken on Dominica. In-country infrastructure for parrot rehabilitation and release by the Forestry, Wildlife and Parks Division should be enhanced (note that all aviary birds survived Maria at the Parrot Conservation and Research Centre [PCRC]), and increasing Forestry Division professional capacity must be a priority. Existing protective legislation must be aggressively enforced and no parrots must be permitted to leave Dominica for ex situ purposes, as per ACTP’s removal of two A. imperialis (and 10 A. arausiaca) from the PCRC in March 2018.

  2. The case for revising the global status of Amazona imperialis to Critically Endangered is a compelling one, with regards to the following considerations:

    • The species possessed a small population (c. 250-350 individuals), restricted to a very limited spatial range, before Hurricane Maria struck Dominica on 18th September 2017. While quantitative data on population estimates post-Maria do not currently exist (owing to much of the species range being inaccessible because of fallen trees and very dense undergrowth), it is highly likely the species has experienced a significant population decline as a result of this Hurricane, given that Hurricane David (a less destructive storm) reduced the population of the species to an estimate 40-60 individuals (Evans 1991). While A. imperialis is an elusive species which is difficult to survey, mortalities in the aftermath of Maria were recorded, as was evidence of the species being displaced beyond its natural range in Dominica’s high-altitude forest (Palmer et al. 2018).

    • Given that the species nests within tree cavities (Collar et al. 2019), and 30% of trees in Dominica are estimated to have been felled by Hurricane Maria (Palmer et al. 2018), many nesting sites for the species may have been lost. Regeneration of the forest, and trees that will be suitable for nesting could take decades to grow, so there could be a need for nesting boxes to try to aid recovery.

    • Reproduction rates in the species are slow, meaning the species will require a long period to recover from the effects of Hurricane Maria.

    • Importantly, while hurricane disturbance is a natural feature of Dominica’s environment, and A. imperialis populations may fluctuate cyclically due to this periodic disturbance, global climate change patterns may increase the frequency of particularly intense (category 4 and category 5) hurricanes in the Caribbean (Bender et al. 2010; Knutson et al. 2010). This means there could be a high likelihood of a further hurricane of a similar intensity to Maria hitting Dominica before A. imperialis populations have a chance to recover; an event which could have severe consequences for the species.

    • While issues relating to the ex-situ conservation of this species are complex and often controversial, it is worth highlighting that the number of individuals held in captivity is extremely low and there is no co-ordinated breeding program in place. Therefore, no effective captive breeding ‘safety net’ exists, meaning that the extirpation of the few remaining wild individuals will likely mean the functional extinction of the species.

    • Recent reports from Dominica indicate the species is not extinct in the wild. Numerous sightings have been reported from several locales to the Forestry and Agriculture department, especially around the vicinity of Syndicate, and one of our team observed an individual in this location on 20th June 2019 and two individuals on 26th June 2019 (A. Fairbairn, pers. obs.). However, individuals are still being recorded in lower lying areas outside of their usual range (S. Durand, pers. comms), which may indicate that Dominica’s highland forests still retain a low carrying capacity for the species. Although foliage has returned to the living trees on Dominica, large areas of dead trees, representing low quality habitat, remain.

    • While accessibility to the interior of the Island is steadily improving, particularly with regards to the National Trail paths, much of the core range of A. imperialis remains inaccessible and it is likely to be some time before a quantitative assessment of the species’ population becomes viable. However, given that Hurricane Maria is likely to have driven a significant population decline in the species, that population recovery in the species is likely to be slow, and that it is feasible that another high intensity storm event could occur in Dominica before A. imperialis populations have a chance to recover, we believe changing the species’ status to Critically Endangered under categories C and D would be a prudent measure.

    References cited:

    Bender, M. A.; Knutson, T. R.; Tuleya, R. E.; Sirutis, J. J.; Vecchi, G. A.; Garner, S. T.; Held, I. A. 2010. Modeled Impact of Anthropogenic Warming on the Frequency of Intense Atlantic Hurricanes. Science 22: 454-458.

    Collar, N.; Boesman, P.; Kirwan, G. M. 2019. Imperial Amazon (Amazona imperialis). In: del Hoyo, J.; Elliott, A.; Sargatal, J.; Christie, D.A.; de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona, Spain. https://www.hbw.com/node/54759 (Accessed 22 June 2019).

    Evans, P. G. H. 1991. Status and conservation of Imperial and Red-necked Parrots Amazona imperialis and A. arausiaca on Dominica. Bird Conservation International 1: 11-32.
    Knutson, T. R.; McBride, J. L.; Chan, J.; Emanuel, K.; Holland, G.; Landsea, C.; Held, I.; Kossin, J. P.; Srivastava, A. K.; Sugi, M. 2010. Tropical cyclones and climate change. Nature Geoscience 3: 157-163.

    Palmer, C. A.; Martin, T. E.; Durand, S.; Lamont, M. 2018. First observations of the impacts of Hurricane Maria on the endemic imperial amazon. Oryx 52: 410-411.

  3. 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.

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