Northern Bald Ibis (Geronticus eremita): downlist from Critically Endangered to Endangered?

Northern Bald Ibis, Geronticus eremita, is currently listed as Critically Endangered under criterion C2a(ii) on the basis that the species has undergone a long-term decline and now has an extremely small population, with >95% of wild birds in one subpopulation (BirdLife International 2017). This subpopulation is located in Souss-Massa National Park and Tamri, Morocco, where the population numbered 59 pairs in 1998 after 40 individuals died mysteriously in 1996 (Bowden 1998, Touti et al. 1999), but this has increased and is now relatively stable, with 116 breeding pairs present in 2015 (Latifa et al. 2016, Oubrou and El Bekkay 2015). A semi-wild population exists in Turkey, but because this population is managed and not truly wild, they are not included in an assessment of this species’s status. A tiny colony of 7 individuals was discovered at Palmyra, Syria in 2002 (Serra et al. 2004), but this subpopulation has dwindled with only one individual returning to the colony in 2013 and 2014; and no individuals in 2015 (Serra 2015), although since then one individual has been reported in Ethiopia which likely represents an individual that has migrated from Syria (C. Bowden pers. comm. 2017). The current situation in Syria makes monitoring very difficult, but it is likely that it is now extinct as a breeding species there (BirdLife International 2017). Re-introductions of this species have occurred in the Alps and Spain, with the latter holding a small number of independent, breeding individuals. Therefore, despite the decline in Syria, thanks to the growth and recent stability of the Moroccan subpopulation and the potential presence of a second wild population in Spain, the species likely no longer qualifies as Critically Endangered.

Focussing on Morocco, the main threats to the species there are illegal building and disturbance close to breeding cliffs and changes in farming on the feeding grounds. A proposed tourist development at the Souss-Massa National Park could also prove detrimental to the birds if it is not constructed in a sensitive way (Anon. 2009), though the most recent causes of breeding failure at this site have been loss of eggs to predators and, more importantly, poor chick survival as a result of starvation and predation (Bowden et al. 2003). Despite the presence of these potential threats around the Moroccan subpopulation, the number of breeding pairs has remained stable over recent years and the total number of individuals continues to grow (443 individuals at the end of 2013 breeding season [Oubrou and El Bekkay 2013]; 524 individuals in 2014 [Oubrou and El Bekkay 2014]; and 580 individuals at the end of the 2015 breeding season [Oubrou and El Bekkay 2015]). The most recent population size estimate (referring to the number of mature, breeding individuals) is 116 breeding pairs, which equates to 232 mature individuals.

There are two introduced populations in the Alps, totalling 30 individuals, in Burghausen (Germany) and Salzburg (Austria) (Wald 2014). These birds have undertaken human-led migration to Orbetello Lagoon in Tuscany, Italy and in 2011 the first bird independently migrated from Italy to Burghausen (Waldrappteam 2014a). A further colony is to be established at Uberlingen (Germany) (Waldrappteam 2014b). However, because of the continued management of these populations, they are not included as part of this assessment. With continued success and removal of management they may be included in future assessments.

The reintroduced population in southern Spain is more independent, and potentially could be included in an assessment of this species’s status. This population was set up to be more sedentary than the Alpine re-introductions, although interestingly individuals from this population have been observed crossing into Morocco (Muñoz and Ramírez 2017). A total of 190 birds were released in southern Spain between 2004 and 2009 (Boehm and Bowden 2010), and population supplementation continues (C. Bowden in litt. 2016). Although juvenile mortality has been high, the first breeding pair was formed on nearby cliffs in 2008, and a small independent non-migratory colony is now becoming well established in the area (Matheu et al. 2014). Up to a total of 24 breeding adults were present in 2013 on three separate cliffs (Jordano and Márquez 2013) and 25 breeding pairs were present in 2014 (UvA Bird Tracking System undated).

This equates to 50 mature individuals, which (combined with the Moroccan population) would give a global population size estimate of 282 mature individuals. However, given that the establishment of the wild, breeding population in Spain is only very recent, it is suggested that the global population size be conservatively retained in the range of 200-249 mature individuals. Therefore, it is proposed that the species be listed as Endangered under criterion D.

 We welcome any comments or further information regarding this proposed downlisting.



Anon. 2009. Bald Ibises – update. RSPB Legal Eagle: 16

BirdLife International. 2017. Species factsheet: Geronticus eremita. Downloaded from on 13/03/2017.

Boehm C. and Bowden C.G.R. 2010. Northern Bald Ibis Conservation and Reintroduction workshop. Proceedings of 3rd Meeting of International Advisory Group for Northern Bald Ibis (IAGNBI), November 2009. Palmyra, Syria.

Bowden, C. 1998. Birecik: the current situation of the semi-wild Bald Ibis Geronticus eremita population.

Bowden, C. G. R.; Aghnaj, A.; Smith, K. W.; Ribi, M. 2003. The status and recent breeding performance of the critically endangered Northern Bald Ibis Geronticus eremita population on the Atlantic coast of Morocco. Ibis 145: 419-431.

Jordano, P.; Márquez, M. 2013. Status of the Northern Bald Ibis in southern Spain. HBW Alive Ornithological Note 6. In: Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from on 13 March 2017).

Latifa, S.; Ouidade, O.; Mohammed, El B. 2016. Morocco wild population update. Pp 29-30 in Boehm C. & Bowden C. G. R. (eds): Northern Bald Ibis Conservation and Reintroduction Workshop. Proceedings of 4th Internatinal Advisory Group for the Northern Bald Ibis (IAGNBI) meeting. Seekirchen, Austria; August 2016.

Matheu, E., del Hoyo, J., Kirwan, G.M. and Garcia, E.F.J. 2014. Northern Bald Ibis (Geronticus eremita). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. and de Juana, E. (eds), Handbook of the Birds of the World Alive, Lynx Edicions, Barcelona.

Muñoz, A.-R.; Ramírez, J. 2017. Reintroduced Northern Bald Ibises from Spain reach Morocco. Oryx 51(2): 204-205.

Oubrou, W. and El Bekkay, M. 2013. Rapport sur la reproduction 2013 de la population des Ibis chauves dans la région de Souss-Massa. Report of the 2013 Northern Bald Ibis breeding season at Sous-Massa NP, Morocco. Available at: (Accessed: 07/10/2013).

Oubrou, W. and El Bekkay, M. 2014. Rapport sur la reproduction de l’Ibis chauve dans la région de Souss-Massa. Haut Commissariat aux Eaux et Forêts et à la Lutte Contre la Désertification, Aires Protégées du Maroc, Parc National de Souss Massa.

Oubrou, W. and El Bekkay, M. 2015. Rapport sur la saison de reproduction de l’Ibis chauve Geronticus eremita dans la région Massa. Haut Commissariat aux Eaux et Forêts et à la Lutte Contre la Désertification, Aires Protégées du Maroc, Parc National de Souss Massa.

Serra, G. 2015. The Northern Bald Ibis is extinct in the Middle East – but we can’t blame it on IS. The Ecologist. Available at: (Accessed: 29/07/2015).

Serra, G.; Abdallah, M.; Assaed, A.; Abdallah, A.; Al Qiam, G.; Fayad, T.; Williamson, D. 2004. Discovery of a relict breeding colony of Northern Bald Ibis Geronticus eremita in Syria. Oryx 38: 106-108.

Touti, J.; Oumellouk, F.; Bowden, C. G. R.; Kirkwood, J. K.; Smith, K. W. 1999. Mortality incident in Northern Bald Ibis Geronticus eremita in Morocco in May 1996. Oryx 33: 160-167.

UvA Bird Tracking System. Undated. Northern Bald Ibis (Geronticus eremita) Reintroduction programme in Andalusia. (Accessed 13/03/2017).

Wald, C. 2014. Flying lessons. BBC Wildlife August: 82-88.

Waldrappteam. 2014a. Breeding area Burghausen. Waldrappteam. Available at: (Accessed: 29/07/2015).

Waldrappteam. 2014b. Reason for Hope. Waldrappteam Available at: (Accessed: 30/07/2015).

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8 Responses to Northern Bald Ibis (Geronticus eremita): downlist from Critically Endangered to Endangered?

  1. Jorge F. Orueta says:

    I’ve been involved in NBI conservation in Morocco since 2000, and have monitored the evolution of the population since then. I’m currently member of the AEWA working group for the species.
    It’s still soon to download NBI because:
    – The Spanish colony is not still self-sustainable. In fact, this year breeding has totally failed due to predation.
    – In fact, every year some 25 young birds are still released in Andalusia.
    – The cross of several individuals from Spain to Morocco shouldn’t be regarded as an expansion but more a leak of recently released young birds.
    – The Moroccan population, although steadily growing since the 1990s, still needs to expand to other territories to be considered safe. 1996’s mortality (and the lack of evidence of the cause) is a proof of the potential threats that could still impact the species.

  2. I am the manager of the European LIFE+ reintroduction project ( I basically agree with Jorge F. Orueta in the opinion that it is too soon to downlist the NBI.
    I think, there are promising attempts to reintroduce NBI populations in southern Spain (Projecto Eremita) and in central Europe (our LIFE+ project) and I agree that these European projects are essential to reach the goals of the AEWA Single Species Action Plan.
    But to date, none of both populations reached the minimum viable population size, due to that they are not regarded as self-sustaining. In our project, we aim to reach the MVPs about mid of the 2020’s; I assume our colleague in Spain will reach this threshold some years earlier.
    Thus, I think the global situation for the NBI did change in a positive way, but the Red List status should be modified if we can be fairly sure that this change is sustainable in the sense of the MVBs concept.
    In addition, as written on the IAGNBI website there is a crisis in wardening of the Moroccan NBIs (, this also does not speak – for strategic reasons – for immediate downlisting of the species.
    I also want to point out, that in may view continued management of a release populations may not be a suitable parameter to exclude this population from the assessment of downlisting. As stated in the IUCN reintroduction guidelines, some translocation populations may require long term or even permanent management. Sustainability seems me a more reasonable parameter.
    Finally, I may add that more recent literature for our project is available, either the IAGNBI report 2016 ( or a recently published article in the International Zoo Yearbook (

  3. Andy Symes (BirdLife) says:

    Miguel Quevedo (Proyecto Eremita) has provided the following comment:

    It is stunning to hear that BirdLife Redlist team proposes to downlist NBI from CE to Endangered. In the last years significant progress in the Moroccan population has occurred with slightly increase in breeding pairs, but still is the only real population in the world. From our point of view, the arguments presented in the proposal are not good enough to downlist the status. At present the eastern population is extinct in the wild, the Moroccan subpopulation with 116 breeding pairs might still suffer from any catastrophic incident (similar to 1996 event) which could decrease the number of birds.
    Regarding the two introduced populations in Europe, our Austrian colleagues can give us more accurate data on the status and progress of the project, but we feel that could be still soon to consider this migratory population stable and could need some management over time. The Spanish population is considered stable and sedentary but still not sel-sustainable. The number of free-flying birds is considered around 90, with 20 breeding pairs. This population still depends on annual release of zoo-born juveniles (EEP programe). Although positive breeding progress has occurred in the last years, 2017 breeding season has suffered from a severe predation incident in nests (Barca de Vejer) that killed at least 14 chicks and several adults. The culprit of this predation incident is thought to be a pair of eagle owl nesting nearby. This mean that this breeding season has failed with only 2 fledglings hatched in the second breeding site (Torre de Castilnovo, Conil).
    Hence, taking into account all this data we think the NBI population is still in critical endangered status and further assessment, monitoring and conservation measures has to be taken to guarantee their survival.
    Best regrads

    Proyecto Eremita (José Manuel López, Iñigo Sánchez, Miguel A. Quevedo) Spain

  4. I join this debate in my capacity as a member of IAGNBI. I agree with the consensus of comments so far: it would be premature to downlist this species. The designation of a species on the list, however, should be a relatively objective process and not subject to personal opinion. If objective criteria are used, the global population size of wild birds is hardly different to when the species was initially listed as CE, when compared to its historical population size. While there has been an increase in the Moroccan population in recent years, this is still very small and geographically limited. The Spanish birds do not yet form a self-sustaining population, being reliant on annual restocking. The European and Turkish birds are not included in the assessment for the reasons given and Middle-East population probably has been pretty much extirpated over recent years. I don’t see any evidence for downlisting, but if there is, please can it be made clear?

  5. Personally, I think it would be hasty to down list the NBI from (CR) to (EN) because of the lack of information on different ecological and trend aspects using reliable predictors and modelling.

    In fact and despite the regular monitoring of the NBI is Souss Massa national Park and Tamri and the breeding reports published each year. So far there are no current and well-founded scientific studies using accurate statistical models to highlight the trend of Moroccan population over the last 20 years and its interaction with habitats, climate and human parameters.

    My question on which basis we would make such suggestion as increase of the population show a very slow pace over two decades and threats are increasing especially in foraging areas?

    In conclusion there isn’t enough evidence to downlist the species. Yet, the icrease of foraging habitat loss require caution on our part.

  6. Chris Bowden says:

    Its been very instructive to read the comments so far, and personally, I’m also left feeling that downlisting is premature. But we will need to examine the RDB criteria very closely to justify this and these don’t seem as clear cut in this case as for most species. The points that seem to me to be most pertinent are as follows:

    1) I agree and accept the comments that the release projects (including Spain which appears closer to being self-sustaining) can not be considered in any way sustainable as things stand, so this consideration should be disregarded with respect to downlisting the RDB status. (at least until that changes).
    2) We have meanwhile recently witnessed the effective extinction of the relict Eastern breeding population (Syria), with hunting pressure (and other threats) in this context probably still not addressed as key threats for any prospect of return at least in the immediate future.
    3) This means we focus on Morocco and the population size, threats and trend there, which: 3.1) has increased (from 59 to 118 breeding pairs over 19 years) ie marginally increasing almost every year, and
    3.2) World population persists at just two colonies 100km apart, with no expansion in range at all (and growing development threats in the area in fact) – so with the small spatial area covered by those colonies, we could still regard their range as miniscule? This seems to be the strongest (maybe only?) argument for keeping it as CR? So it depends on how you define the area they occur in (obviously the feeding areas over the course of the year are huge by comparison), but at one level, this could be regarded as the physical space of these colonies (ie one cliff-face with 50% of the population and three cliff-faces within 4km of each other holding the other 50%) and so can be regarded as just a few hundred square meters in total?
    3.3) The small area and geographical range of the two colonies mentioned above is especially significant when considering the potential threats to the species, and how susceptible they can be to a single event, threat or problem. Even more worrying is that after the breeding season each year, up to 80% of the world population roosts for several weeks at a single cliff site. Plus the fact that the Tamri area (holding 50% of breeding population) still carries only very rudimentary (basic) protection status.

    With the above points in mind, I agree with the suggestion to await the colonization or recolonisation of an additional site away from Souss-Mass as a quite feasible target to trigger downlisting – which is highlighted as a priority in the updated action plan…

    This seems most logical to me (to use colonization of a third site as a trigger for downlisting) – but lets see what the RDB experts say on applying the criteria consistently across species. Chris

  7. I had posted my comment weeks ago but somehow it was not recorded. Reposting now.

    The proposed down listing of NBI is definitely premature, according to me.
    I agree with the observations of Andrew Cunningham (increase of Morocco colonies is still very small and geographically limited) and of Chris B. (limited geographic range of Morocco colonies).

    The justification by birdlife for downscaling the conservation status of NBI does not include any consideration in relation to the existence of two subpopulations physically separated for centuries and genetically distinct (Pegoraro et al. 2001, Broderick et al. 2001). The use of criteria based only on number of mature individuals does not account for the complexity of having two genetically different subpopulations.

    In these regards, criteria C for CR may be met by NBI: “Population size estimated to number fewer than 250 mature individuals” in combination with point #1:“An estimated continuing decline of at least 25% within three years or one generation, whichever is longer, (up to a maximum of 100 years in the future).

    Provided that the genetic pool (and the cultural/behavioural heritage) of the species is considered (instead of the mature individuals), point #1 may be considered as met because 50% (i.e. the whole eastern subpopulation) will go extinct for good most likely “within three years”.

    Also point #2 of same criteria may be met: “A continuing decline, observed, projected, or inferred, in numbers of mature individuals” (as the species is still declining and actually becoming extinct in its eastern component/ 50% of its genetic pool) in combination with “(ii) at least 90% of mature individuals in one subpopulation.”

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