Aquila adalberti 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Aves Accipitriformes Accipitridae

Scientific Name: Aquila adalberti
Species Authority: Brehm, 1861
Regional Assessments:
Common Name(s):
English Spanish Imperial Eagle, Adalbert's Eagle, Spanish Eagle
Spanish Aguila Imperial Ibérica
Taxonomic Source(s): del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A. and Fishpool, L.D.C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Lynx Edicions BirdLife International, Barcelona, Spain and Cambridge, UK.
Identification information: 75-84 cm. Large, dark eagle. Generally dark brownish-black with prominent white "shoulders" on forewing and scapulars. Pale golden-cream nape and pale grey basal area on uppertail. Juvenile red-brown fading to pale buff with dark flight feathers and white fringes to coverts. In soaring and gliding flight wings held flat. Similar spp. Adult Golden Eagle A. chrysaetos lacks white "shoulders" and is less dark overall. Immature has large white wing flashes and white base to tail. Wings held in a flattened "V" shape. Voice Repeated barking owk.

Assessment Information [top]

Red List Category & Criteria: Vulnerable D1 ver 3.1
Year Published: 2016
Date Assessed: 2016-10-01
Assessor(s): BirdLife International
Reviewer(s): Butchart, S. & Symes, A.
Contributor(s): Atienza, J., Balmori, A., Cabezas-Díaz, S., Caldera, J., Criado, J., Franco, A., Garrido, J., González, L.M., Izquierdo, E., Iñigo, A., Madroño, A., Montoro, J., Moreno-Opo, R., Nunes, M., Pacheco, C., Pain, D., Pandolfi, M., Sánchez, B. & Sánchez-Aguado, F.
Facilitator/Compiler(s): Benstead, P., Derhé, M., Ekstrom, J., Harding, M., Pople, R., Taylor, J., Ashpole, J
This species qualifies as Vulnerable because it has a very small population, which is dependent on on-going intensive management measures to mitigate the impact of threats such as poisoning, electrocution and insufficient food availability, as well as the increasing cooperation of land-owners.

Previously published Red List assessments:

Geographic Range [top]

Range Description:This species breeds in Spain in the Sierras of Guadarrama and Gredos, the plains of the Tajo and Tiétar rivers, the central hills of Extremadura, Montes de Toledo, the Alcudia valley, Sierra Morena and the Guadalquivir marshes, with occasional nesting in Salamanca (González 1996b). The species has not been recorded as breeding in Málaga province since at least the early 1970s (J. R. Garrido in litt. 2013). In the 1960s, only 30 pairs remained, but recovery began in the early 1980s at a rate of five new breeding pairs per year up to 1994. After 1994, the population again started to decline from 148 pairs to 131 pairs in 1998 (J. Criado in litt. 1999), and breeding success in important areas such as the Guadalquivir marshes declined dramatically in the late 1990s (J. Criado in litt. 1999). However, this is thought to represent a brief levelling out of a positive trend, and in 2000 the population began increasing (Grupo de Trabajo Nacional del Águila Imperial Ibérica unpubl. data; A. Madroño in litt. 2005), associated with a decline in the number of poisoning events (González et al. 2007). In 2007, there were 232 breeding pairs in Spain and three in Portugal (Sánchez et al. 2008). In 2011, the species's global population had increased to 324 pairs, with 318 pairs in Spain, of which 71 pairs were in Andalucía, increasing to 80 in 2012 (S. Cabezas-Díaz, J. C. Atienza et al. in litt. 2013, J. R. Garrido in litt. 2013). The species recolonised Portugal in 2003, after an absence of breeding activity for over 20 years, and has been slowly increasing since, with six breeding pairs located in 2011 and nine located in 2012 (S. Cabezas-Díaz, J. C. Atienza et al. in litt. 2013). The population in Spain showed an average annual increase of c.7% between 1990 and 2011, with the population in Andalucía increasing by c.8% per year on average over the same period (J. R. Garrido in litt. 2013). These positive trends are largely attributed to mitigation measures to reduce mortality associated with powerlines, supplementary feeding, reparation of nests, reintroductions and decreases in the disturbance of breeding birds (S. Cabezas-Díaz, J. C. Atienza et al. in litt. 2013, J. R. Garrido in litt. 2013), although some of the observed increases may be due to more thorough searches within its range. This may be particularly true in Andalucía, which harbours three subpopulations (Sierra Morena mountains, Doñana National Park and a reintroduced population in Cádiz; González and Oria 2004, J. R. Garrido in litt. 2013), with interchange of individuals amongst these and with the population in Portugal (J. R. Garrido in litt. 2013).

Countries occurrence:
Portugal; Spain
Regionally extinct:
France; Gibraltar
Additional data:
Continuing decline in area of occupancy (AOO):Unknown
Extreme fluctuations in area of occupancy (AOO):NoEstimated extent of occurrence (EOO) - km2:204000
Continuing decline in extent of occurrence (EOO):UnknownExtreme fluctuations in extent of occurrence (EOO):No
Number of Locations:11-100Continuing decline in number of locations:Unknown
Extreme fluctuations in the number of locations:No
Upper elevation limit (metres):1600
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:The species's global population was estimated at 324 breeding pairs in 2011, equating to 648 mature individuals (S. Cabezas-Díaz, J. C. Atienza et al. in litt. 2013), and assumed to be indicative of a total population of c.1,000 individuals. The Portugese population was estimated at 11-18 pairs in 2013 and the Spanish population estimated at 358 pairs in 2012 giving an overall estimate of c.370-380 pairs, equivalent to c.1,100 individuals (BirdLife International 2015).

Trend Justification:  Over the period 1990-2011, the population in Spain showed an average annual increase of c.7%, with the population in Andalucía increasing by an average of c.8% annually over the same period (J. R. Garrido in litt. 2013). The Spanish population is estimated to have increased by 135% between 2001-2012 (BirdLife International 2015). The species recolonised Portugal in 2003, and has been slowly increasing since, with six breeding pairs recorded in 2011, nine in 2012 (S. Cabezas-Díaz, J. C. Atienza et al. in litt. 2013) and 11-18 pairs in 2013 (BirdLife International 2015). The Portugese population is estimated to have increased by 1,000-1,700% between 2003 and 2013 (BirdLife International 2015).
Current Population Trend:Increasing
Additional data:
Number of mature individuals:740-760Continuing decline of mature individuals:Unknown
Extreme fluctuations:NoPopulation severely fragmented:No
No. of subpopulations:1Continuing decline in subpopulations:Unknown
Extreme fluctuations in subpopulations:NoAll individuals in one subpopulation:Yes
No. of individuals in largest subpopulation:100

Habitat and Ecology [top]

Habitat and Ecology:It occurs in alluvial plains and dunes in the Guadalquivir marshes, plains and hills in central Spain, and high mountain slopes in the Sistema Central and other areas of Portugal, where there is an absence of irrigated farmland. The abundance and distribution of rabbits, its favoured prey, influence population density, range (Fernández et al. 2009) and reproductive performance. Indeed, its evolutionary dependence on rabbits has been suggested as permanently limiting its abundance and distribution (Ferrer and Negro 2004), although a recent study has suggested the species exhibits a certain dietary plasticity, at least during the non-breeding season, adapting its diet when rabbits are scarce (Sánchez et al. 2010). Data from Doñana National Park in Spain show that the most important variables explaining nest site selection are height of tree and distance from human activity (Bisson et al. 2002). Many recently-colonised territories are in marginal areas, and several of the occupying pairs include at least one sub-adult bird (González and Oria 2004, González et al. 2006b, Margalida et al. 2007).

Systems:Terrestrial; Freshwater
Continuing decline in area, extent and/or quality of habitat:Unknown
Generation Length (years):16
Movement patterns:Not a Migrant

Threats [top]

Major Threat(s): The analysis of 267 records of non-natural mortality in this species over a 16-year period (1989-2004) shows an average annual rate of 15.1 individuals found dead annually, and that electrocution (47.7%) and poisoning (30.7%) were the most frequent causes of mortality (González et al. 2007). Juveniles are frequently killed through electrocution by powerlines, and this has increased in recent years (L. M. González in litt. 2005). This remains the primary threat in Andalucía, with six birds found to have died this way in 2011 and three found dead in 2012 where mitigation measures had been attempted (J. R. Garrido in litt. 2013). Renewable energy development poses another potentially significant threat. Habitat fragmentation has occurred as a result of deforestation for agriculture and timber, having negative impacts on nest site preferences in particular. Suitable habitat in breeding and dispersal areas has also declined as a consequence of urban development and land-use changes (e.g. new irrigation schemes in Huelva [B. Sánchez in litt. 2007]). Mortality from intentional poisoning has risen sharply, particularly in hunting reserves where game is commercially exploited. Between 1990-1999, 57 birds died from poisoning and this is thought to be the primary cause of declines in the late 1990s (J. Criado in litt. 1999). In Doñana National Park in particular, the population has been seriously affected by the illegal use of poisoned bait, especially during the 1990s (Ortega et al. 2009). Rabbit populations have declined in both Spain and Portugal, as a result of viral haemorrhagic disease, and this is believed to have reduced breeding success (Margalida et al. 2007; S. Cabezas-Díaz, J. C. Atienza et al. in litt. 2013). In addition, changes in the management of hunting estates in both Spain and Portugal to favour larger quarry species, such as deer and boar, rather than rabbits and partridges, has further reduced prey availability (B. Sánchez in litt. 2007; S. Cabezas-Díaz, J. C. Atienza et al. in litt. 2013). In spring 2009, a male Spanish Imperial Eagle was shot and killed in Portugal, highlighting the current threat of hunting to this species. Human activities in the vicinity of active nests can disturb incubating adults and reduce hatching success (González et al. 2006a, Margalida et al. 2007). The ingestion of lead shot embedded in the flesh of prey items may be a problem in certain areas (Pain et al. 2005, González and Oria 2004). Recent modelling suggests no subpopulations are currently at risk of extinction, provided that active management is maintained (L. M. González in litt. 2005).

Conservation Actions [top]

Conservation Actions: Conservation Actions Underway
CITES Appendix I and II. CMS Appendix I and II. EU Birds Directive Annex I. There are 24 Important Bird Areas identified for the species, 22 in Spain and 2 in Portugal. Altogether, there are 107 areas protected by Law (national and EU Special Protected Areas,) containing c.70% of the total breeding population (Barov and Derhé 2011). Since 1987, national and regional governments have been implementing a coordinated conservation plan for the species. A European action plan was published in 1996 and updated in 2008 (Sánchez et al. 2008), and a national plan is being implemented. From 1991-1999, 14,370 dangerous electric towers were modified, considerably reducing deaths from electrocution (L. M. González in litt. 2005) and more recently, work has been carried out to isolate dangerous powerlines on private farms (Cabezas 2011). It is thought that nearly €2.6 million were spent on the mitigation of bird electrocution in Andalucía during 1992–2009, although not all mitigation measures have proved to be totally effective for this species (J. R. Garrido in litt. 2013). A supplementary feeding programme has been established to mitigate the effects of rabbit decreases, and has significantly increased breeding success (L. M. González in litt. 2005). Nest monitoring has reduced disturbance and improved reproductive success. The Flying High Programme created by SEO/BirdLife in 2006, begun its second phase in 2009 until 2012, based on a large land stewardship network (of municipalities, land-owners and schools). This network focuses on habitat management, species conservation, awareness and information activities covering the species’s entire distribution. So far, 54 municipalities have joined the network. Work is on-going to raise awareness and support on private land where the species breeds, including improving habitat management (García 2007), and nearly 50% of breeding pairs are covered by such projects (L. M. González in litt. 2005). From 2002 to 2011, 73 young birds were released in Cádiz as part of a reintroduction project, and by 2012 five breeding pairs had become established in the province; however, mortality associated with powerlines appears to be high amongst these birds (M. Pandolfi in litt. 2003, B. Sánchez in litt. 2007, J. R. Garrido in litt. 2013). Nevertheless, the establishment of a breeding population in Cádiz further reduces the overall probability of extinction (Muriel et al. 2011). Two birds originating from a reintroduction project in Andalucía are known to have bred in Portugal (J. R. Garrido in litt. 2013).

Conservation Actions Proposed
Continue with actions to reduce mortality, particularly from poisoning and electrocution (González and Oria 2004). Survey the breeding population annually.  Approve regional recovery plans (González and Oria 2004).  Maintain an adequate area of legally protected habitat (e.g. within the Natura 2000 network [González and Oria 2004]).  Protect and manage breeding sites and key dispersal areas.  Continue the successful nest monitoring and supplementary feeding programmes (González and Oria 2004) and develop a captive breeding programme to support future reintroduction and supplementation efforts.  Promote the recovery of the rabbit population (González and Oria 2004). Modify dangerous powerlines.  Avoid the construction of wind farms in key areas for the species (B. Sánchez in litt. 2007). Increase coordination between private landowners, NGOs and government (González and Oria 2004, B. Sánchez in litt. 2007).

Citation: BirdLife International. 2016. Aquila adalberti. The IUCN Red List of Threatened Species 2016: e.T22696042A90406056. . Downloaded on 24 April 2017.
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