Browsing by Subject "Booted eagle"

Now showing 1 - 4 of 4
  • Thumbnail Image
    Publication
    Open Access
    Changes in blood pesticide levels in booted eagle (Hieraaetus pennatus) associated with agricultural land practices
    (Elsevier, 2009) Martínez, José E.; Calvo, José F.; García Fernández, Antonio Juan; María Mójica, Pedro; Martínez López, Emma; Romero García, Diego; Ciencias Sociosanitarias
    We estimated the degree of exposure to lindane and endosulfan in the blood of booted eagle nestlings (Hieraaetus pennatus) (1999–2003), in order to assess the usefulness of these samples as a unit for monitoring changes in exposure as a result of shifts in agricultural practices and the implementation of legal measures. The highest blood lindane concentrations were obtained 1 year prior to its prohibition by the European Union. Subsequent to that year, the drop in blood concentrations was dramatic. Furthermore, endosulfan blood concentrations follow a progression coinciding with an increase in olive, grape and plum-tree crops. We conclude that concentrations of organochlorine pesticides in the blood of booted eagle nestlings may be used to monitor the use of those pesticides over a particular agricultural region and alert the authorities of possible environmental or health risks.
  • Thumbnail Image
    Publication
    Restricted
    Organochlorine residues in booted eagle (Hieraaetus pennatus) and goshawk (Accipiter gentilis) eggs from southeastern Spain
    (Blackwell Publishing Ltd, 2007-06-20) Martínez, José E.; Calvo, José F.; Wright, Julian; Shore, Richard F.; García Fernández, Antonio Juan; María Mójica, Pedro; Martínez López, Emma; Romero García, Diego; Ciencias Sociosanitarias
    Most organochlorine (OC) use has been banned in Spain, but these compounds are persistent and may still adversely affect predatory birds. Data generally are lacking, however. Residues of hexachlorobenzene, -hexachlorocyclohexane, lindane, hexachloro-octahydro-epoxy-dimethanonaphthalene, DDT, dichlorodiphenyldichloroethane, dichlorodiphenyldichloroethylene (DDE), and polychlorinated biphenyls (PCBs) were measured in 22 failed eggs of booted eagles (Hieraaetus pennatus) and goshawks (Accipiter gentilis) from southeastern Spain; both species are declining in this region. Hexachloro-octahydro-epoxy-dimethanonaphthalene, DDE, and sum PCB congener concentrations were significantly higher in booted eagle than in goshawk eggs, and an inverse relationship was found between shell thickness and DDE concentrations in booted eagles. Organochlorides may have been associated with the failure of some booted eagle eggs, but concentrations in booted eagle and goshawk eggs decreased over the period during which populations have dwindled. Thus, although OCs may be a contributory factor, they are unlikely to be the primary cause of the recent population declines in southeastern Spain.
  • Thumbnail Image
    Publication
    Open Access
    Shared pattern in morph inheritance system and recessive gene conservation mechanisms in two polymorphic Hieraaetus species
    (Universidad de Concepción , Chile, 2026-07-08) Bosch, Josep; Larkin, Candice; Calvo Sendín, José F.; Martínez, José Enrique; Debus, Stephen J. S.; Baiges. Claudi; Mestre, Joan; Jiménez Franco, María Victoria; Ecología e Hidrología; Facultades de la UMU::Facultad de Biología
    La selección disruptiva, la transmisión no aleatoria de alelos y la selección sexual se consideran uno de los principales mecanismos para el mantenimiento del polimorfismo genético en algunas especies de aves. Analizamos la influencia de estos mecanismos y de la herencia mendeliana en el mantenimiento y evolución del polimorfismo en dos especies de rapaces polimórficas: el águila calzada Hieraaetus pennatus y el águila australiana Hieraaetus morphnoides. Utilizando datos observacionales de eventos reproductivos exitosos, nosotros examinamos tres poblaciones en España (águila calzada) y Nueva Gales del Sur, Australia (águila australiana). Nuestros resultados mostraron que la descendencia oscura producida en los eventos de cría que implican parejas mixtas formadas por un macho claro y una hembra oscura excede con mucho el valor esperado bajo el equilibrio Hardy-Weinberg. Además, el bajo número de aguiluchos oscuros nacidos de parejas formadas por individuos claros indica que el número de eventos de cría de parejas heterocigóticas de morfos claros fue mucho menor de lo esperado. Dado que la plausible existencia de un fenómeno de distorsión de la relación de transmisión en los machos heterocigotos de morfo claro no explica por sí sola el desproporcionado número de aguiluchos oscuros observado, nuestros resultados sugieren que en este sistema polimórfico pueden estar produciéndose uno o dos fenómenos de apareamiento selectivo. Finalmente, discutimos nuestros resultados sugiriendo que las dos especies comparten los mismos mecanismos para el mantenimiento del polimorfismo de color procedentes de un ancestro común durante el Pleistoceno.
  • Thumbnail Image
    Publication
    Open Access
    Survival differences of embryos and eaglets in a polymorphic raptor probably linked to colour morph
    (Springer, 2026-04-24) Bosch, Josep; Martínez, José Enrique; Calvo Sendín, José F.; Mestre, Joan; Baiges, Claudi; Jiménez Franco, María Victoria; Ecología e Hidrología; Facultades de la UMU::Facultad de Biología
    We analysed the mechanisms that, together with Mendelian inheritance, may be acting in the maintenance and evolution of colour polymorphism in the Booted Eagle (Hieraaetus pennatus), using observational data from successful breeding events of mixed pairs formed by light morph males and dark morph females, from a long-term study conducted in south-eastern Spain. Our results show that dark offspring produced in breeding events involving mixed-morph pairs far exceed the value expected in the Hardy–Weinberg equilibrium. Two-eaglet broods mostly resulted in one fledgling of each colour morph and in broods in which only one survived, it was predominantly the dark morph, with a ratio of 0.143:1 light/dark. In the two-egg clutches where only one hatched, the resulting eaglet was mostly dark morph with a ratio of 0.167:1 light/dark. Furthermore, three single-egg clutches produced a dark morph eaglet fledgling. However, these biases in embryo viability, chick survival and single clutches accounted for only seven (19.44%) of the 36 dark eaglets obtained. Of the remaining twenty-nine, six (16.67%) were expected according to Hardy–Weinberg equilibrium and twenty-three (63.89%) were produced by disassortative mating, a phenomenon described in previous studies, whereby heterozygous light males preferentially mate with dark females, likely based on the imprint of the colour morph of their mother. This long-term monitoring of breeding events has allowed us to understand the importance of each of the combined phenomena that contributes to the positive bias towards the dark morph in relation to the expected proportion according to the Hardy–Weinberg equilibrium.