scholarly journals Age and Territory-Quality Effects on Fecundity in the Spanish Imperial Eagle (Aquila Adalberti)

The Auk ◽  
2003 ◽  
Vol 120 (1) ◽  
pp. 180-186 ◽  
Author(s):  
Miguel Ferrer ◽  
Isabelle Bisson
Keyword(s):  
National Park ◽  
Breeding Performance ◽  
Age Classes ◽  
Territory Quality ◽  
Doñana National Park ◽  
High Quality ◽  
Age Related ◽  
Spanish Imperial Eagle ◽  
Imperial Eagle ◽  
Aquila Adalberti

Abstract Over a period of 19 years, we studied 237 breeding attempts of Spanish Imperial Eagles (Aquila adalberti) in Doñana National Park (southwestern Spain), including 29 pairs with at least one immature member, to investigate age-related effects on population fecundity. Without considering effect of territory quality, adult pairs were significantly more productive than immature pairs. Highly significant differences in breeding performance among territories were independent of age-classes of birds occupying them. Low-quality territories were more frequently occupied by immature pairs, whereas high-quality territories were occupied mostly or exclusively by adult birds. Therefore, age and territory quality appear to be interrelated. We found no effect on average population fecundity due to breeding by immature pairs.

scholarly journals A demographic description of the recovery of the Vulnerable Spanish imperial eagle Aquila adalberti

Oryx ◽  
2009 ◽  
Vol 43 (01) ◽  
pp. 113 ◽  
Author(s):  
Enric Ortega ◽  
Santi Mañosa ◽  
Antoni Margalida ◽  
Roberto Sánchez ◽  
Javier Oria ◽  
...  
Keyword(s):  
Spanish Imperial Eagle ◽  
Imperial Eagle ◽  
Demographic Description ◽  
Aquila Adalberti

A long-term large-scale study of the breeding biology of the Spanish imperial eagle (Aquila adalberti)

2007 ◽  
Vol 148 (3) ◽  
pp. 309-322 ◽  
Author(s):  
Antoni Margalida ◽  
Luis Mariano González ◽  
Roberto Sánchez ◽  
Javier Oria ◽  
Luis Prada ◽  
...  
Keyword(s):  
Large Scale ◽  
Breeding Biology ◽  
Large Scale Study ◽  
Spanish Imperial Eagle ◽  
Imperial Eagle ◽  
Aquila Adalberti

scholarly journals Nesting habitat selection by the Spanish imperial eagle Aquila adalberti

1992 ◽  
Vol 59 (1) ◽  
pp. 45-50 ◽  
Author(s):  
Luis M. González ◽  
Javier Bustamante ◽  
Fernando Hiraldo
Keyword(s):  
Habitat Selection ◽  
Nesting Habitat ◽  
Spanish Imperial Eagle ◽  
Imperial Eagle ◽  
Aquila Adalberti

Taphonomic study of leporid remains accumulated by the Spanish Imperial Eagle (Aquila adalberti)

Geobios ◽  
2008 ◽  
Vol 41 (1) ◽  
pp. 91-100 ◽  
Author(s):  
Lluís Lloveras ◽  
Marta Moreno-Garcia ◽  
Jordi Nadal
Keyword(s):  
Spanish Imperial Eagle ◽  
Imperial Eagle ◽  
Aquila Adalberti

scholarly journals Causes and spatio-temporal variations of non-natural mortality in the Vulnerable Spanish imperial eagle Aquila adalberti during a recovery period

Oryx ◽  
2007 ◽  
Vol 41 (4) ◽  
pp. 495-502 ◽  
Author(s):  
Luis Mariano González ◽  
Antoni Margalida ◽  
Santi Mañosa ◽  
Roberto Sánchez ◽  
Javier Oria ◽  
...  
Keyword(s):  
Central Region ◽  
Recovery Period ◽  
Power Lines ◽  
Natural Mortality ◽  
The West ◽  
Small Game ◽  
West Central ◽  
Spanish Imperial Eagle ◽  
Imperial Eagle ◽  
Aquila Adalberti

AbstractThe analysis of 267 records of non-natural mortality of the Spanish imperial eagle Aquila adalberti over a 16-year period (1989-2004) shows an annual rate of 15.1 individuals found dead per year and that electrocution (47.7%) and poisoning (30.7%) were the most frequent causes of mortality. Most cases (91.7%) were of human origin, and of those 92.3% were accidental. Just over half (50.2%) were related to the transmission of electricity and human activity (collisions and electrocution), and 40.7% related to game practices and livestock protection (control of predators). No differences between sexes were found but subadults were electrocuted more frequently than expected whilst adults were poisoned more frequently. In breeding areas poison was the most frequent cause of mortality, whereas electrocution was the most common cause of death in dispersal areas. Poisoning occurred more frequently than expected in the Northern and Southern regions compared to the West-Central region. Electrocution was significantly more frequent in the West-Central region, and less common in the Southern region. The increase in electrocutions over the last few years is associated with previous non-permanent corrections on electricity power lines, whilst the increase in the cases of poisoning appears to be associated with the use of illegal poison in predator control by small game practices and for livestock protection. Permanent corrections in power lines and more research and awareness effort in the small game sector are recommended to reduce human-induced mortality in this Vulnerable species.

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