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Kinds of Eagles Terms modified by Eagles Selected AbstractsEAGLE: galaxy evolution with the E-ELTASTRONOMY & GEOPHYSICS, Issue 2 2010Dr Chris Evans Chris Evans, Simon Morris, Jean-Gabriel Cuby, Matt Lehnert, Mark Swinbank and Mathieu Puech describe an instrument that could bring distant galaxies and stellar populations within reach of the European Extremely Large Telescope. [source] OF EAGLES AND CROWS, LIONS AND OXEN: Blake and the Disruption of EthicsJOURNAL OF RELIGIOUS ETHICS, Issue 1 2009D. M. Yeager ABSTRACT Why focus on the work of William Blake in a journal dedicated to religious ethics? The question is neither trivial nor rhetorical. Blake's work is certainly not in anyone's canon of significant texts for the study of Christian or, more broadly, religious ethics. Yet Blake, however subversive his views, sought to lay out a Christian vision of the good, alternated between prophetic denunciations of the world's folly and harrowing laments over the wreck of the world's promise, and wrote poetry as if poetry might mend the world. Setting imagination against the calculations of reason and the comfort of custom, Blake's poems inspire questions about the relationship of ethics to prophecy, and open the possibility that ethics itself would be markedly enriched could it find a place for what Thomas J. J. Altizer has called Christian epic poetry. [source] Influence of contamination by organochlorine pesticides and polychlorinated biphenyls on the breeding of the Spanish Imperial Eagle (Aquila adalberti)ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 2 2008Mauro Hernández Abstract We evaluated temporal and regional trends of organochlorine (OC) pesticide (including polychlorinated biphenyl [PCB]) levels in eggs of the Spanish Imperial Eagle (Aquila adalberti) collected in Spain between 1972 and 2003. Levels of p,p,-dichlorodiphenyldichloroethylene (DDE) and PCBs varied significantly (p = 0.022) among regions (central, western, and Doñana), being higher in Doñana than in the central and western populations (DDE: 1.64 ± 5.56, 0.816 ± 1.70, and 1.1 ± 2.66 ,g/g, respectively; PCBs: 1.189 ± 5.0, 0.517 ± 1.55, and 0.578 ± 1.75 ,g/g, respectively). Levels of DDE decreased with time, but a significant interaction was observed between region and time. In Doñana, egg volume and breadth as well as Ratcliffe Index were significantly lower after DDT use (p = 0.0018) than during the pre-DDT period (p = 0.0018); eggs were significantly smaller overall than in the other two regions (p = 0.04) and were smaller when DDE levels increased, even when controlling for regional differences (p = 0.04). Productivity in Doñana was significantly lower than in the other regions (p < 0.001). Clutch size in Doñana varied according to DDE concentrations (p = 0.01), with the highest DDE concentrations found in clutches consisting of one egg. When considering eggs with DDE levels greater than 3.5 ,g/g, a significant effect of DDE on fertility was found (p = 0.03). Clutches with DDE levels greater than 4.0 ,g/g had a higher probability of hatching failure (p = 0.07) and produced fewer fledglings (p = 0.03). If we consider 3.5 ,g/g as the lowest-observable-adverse-effect level, the proportion of sampled clutches that exceeded that level in Doñana (29%) was significantly higher than in other regions (p < 0.001). These eggs showed a mean percentage of thinning of 16.72%. Contamination by OCs, mainly DDE, could explain, at least in part, the low productivity of the Spanish Imperial Eagles in Doñana. [source] Effect of berberine on proliferation, cell cycle and apoptosis in HeLa and L1210 cellsJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 8 2003a Jantová Previous studies on the anticancer activity of protoberberine alkaloids against a variety of cancer cell lines were extended to human tumour HeLa and murine leukemia L1210 cell lines. An attempt was also made to investigate the relationship between the cytotoxic activity of berberine and its molecular mechanism of action. Cytotoxicity was measured in-vitro using a primary biochemical screening according to Oyama and Eagle, and the growth inhibition assay. The in-vitro cytotoxic techniques were complemented by cell cycle analysis and determination of apoptotic DNA fragmentation in L1210 cells. Berberine acted cytotoxically on both tumour cell lines. The sensitivity of leukemia L1210 cells to the berberine was higher than that of HeLa cells. The IC100 was below 100 ,g mL,1 for HeLa cells and approached a 10 , mL,1 limit for the leukemia L1210 cells. For both cell lines the IC50 was found to be less than 4 ,g mL,1, a limit put forward by the National Cancer Institute (NCI) for classification of the compound as a potential anticancer drug. In L1210 cells treated with 10,50 , mL,1 berberine, G0/G1 cell cycle arrest was observed. Futhermore, a concentration-dependent decrease of cells in S phase and increase in G2/M phase was detected. In addition, apoptosis detected as sub-G0 cell population in cell cycle measurement was proved in 25,100 ,g mL,1 berberine-treated cells by monitoring the apoptotic DNA fragmentation (DNA ladder) using agarose gel electrophoresis. [source] Crouching Tiger, Weakened EagleNEW PERSPECTIVES QUARTERLY, Issue 2 2010MARTIN JACQUES Buoyed by its creditor's hold on the United States and its ability to withstand the harsh winds of recession blowing from across the Pacific, China has graduated in its own mind from an emerging economy to a world power. From their confrontation with Google to their renewed repression of dissidents to their dissing of President Obama, China's leaders clearly feel that the time has come for the world to accomodate China, not vice-versa. Is the West ready for this new reality? Is China's new arrogance well-founded, or is it going to be the next bubble to burst? As it moves beyond "the primary stage of socialism" is it ready to open up politically? In this section, some top China scholars, one of China's most well-known dissidents and a former US spy chief discuss these issues. [source] Influence of contamination by organochlorine pesticides and polychlorinated biphenyls on the breeding of the Spanish Imperial Eagle (Aquila adalberti)ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 2 2008Mauro Hernández Abstract We evaluated temporal and regional trends of organochlorine (OC) pesticide (including polychlorinated biphenyl [PCB]) levels in eggs of the Spanish Imperial Eagle (Aquila adalberti) collected in Spain between 1972 and 2003. Levels of p,p,-dichlorodiphenyldichloroethylene (DDE) and PCBs varied significantly (p = 0.022) among regions (central, western, and Doñana), being higher in Doñana than in the central and western populations (DDE: 1.64 ± 5.56, 0.816 ± 1.70, and 1.1 ± 2.66 ,g/g, respectively; PCBs: 1.189 ± 5.0, 0.517 ± 1.55, and 0.578 ± 1.75 ,g/g, respectively). Levels of DDE decreased with time, but a significant interaction was observed between region and time. In Doñana, egg volume and breadth as well as Ratcliffe Index were significantly lower after DDT use (p = 0.0018) than during the pre-DDT period (p = 0.0018); eggs were significantly smaller overall than in the other two regions (p = 0.04) and were smaller when DDE levels increased, even when controlling for regional differences (p = 0.04). Productivity in Doñana was significantly lower than in the other regions (p < 0.001). Clutch size in Doñana varied according to DDE concentrations (p = 0.01), with the highest DDE concentrations found in clutches consisting of one egg. When considering eggs with DDE levels greater than 3.5 ,g/g, a significant effect of DDE on fertility was found (p = 0.03). Clutches with DDE levels greater than 4.0 ,g/g had a higher probability of hatching failure (p = 0.07) and produced fewer fledglings (p = 0.03). If we consider 3.5 ,g/g as the lowest-observable-adverse-effect level, the proportion of sampled clutches that exceeded that level in Doñana (29%) was significantly higher than in other regions (p < 0.001). These eggs showed a mean percentage of thinning of 16.72%. Contamination by OCs, mainly DDE, could explain, at least in part, the low productivity of the Spanish Imperial Eagles in Doñana. [source] The regulation of brood reduction in Booted Eagles Hieraaetus pennatus through habitat heterogeneityIBIS, Issue 4 2008EVA CASADO Brood reduction, the death of one or more chicks through siblicide or starvation, can occur through density-dependence in fecundity. Brood reduction may arise in territorial breeding systems either as a response to a high level of territorial interference in a situation of high density or as a result of habitat heterogeneity. To test the predictions of the two main hypotheses that attempt to explain how density-dependent fecundity is generated, the Habitat Heterogeneity Hypothesis (HHH) and the Individual Adjustment Hypothesis (IAH), we analysed the relationship between density and fecundity in an expanding population of Booted Eagles in Doñana National Park, Spain, using an 18-year data series. We also studied the occurrence and frequency of brood reduction in the same Booted Eagle population to appreciate further its effects and the factors that influence its occurrence and frequency. Our results support the HHH in the present situation of high density, as fecundity in the better territories (older and more frequently occupied) was higher than in low quality territories and was not affected by population density in high density periods. Nevertheless, the fecundity of high quality territories was affected (although not significantly) by population density in periods of low density, suggesting that the IAH was supported when only high quality territories were occupied. Older territories were used more frequently and chicks in these areas hatched earlier and suffered lower mortality than in new territories. We found a significant negative relationship between mean fecundity and its skewness, a finding that also supports HHH. During years of food shortage, less frequently occupied territories suffered higher rates of brood reduction. Brood reduction in this Booted Eagle population was a consequence of the heterogeneous structure of the habitat, with some territories having a higher probability of brood reduction than others. Parental nutritional condition did not affect brood reduction. The effect of brood reduction on nestling quality and population dynamics is also discussed. [source] Movements and foraging effort of Steller's Eiders and Harlequin Ducks wintering near Dutch Harbor, AlaskaJOURNAL OF FIELD ORNITHOLOGY, Issue 2 2007John A. Reed ABSTRACT We studied the movements and foraging effort of radio-marked Steller's Eiders (Polysticta stelleri) and Harlequin Ducks (Histrionicus histrionicus) to evaluate habitat quality in an area impacted by industrial activity near Dutch Harbor, Alaska. Foraging effort was relatively low, with Steller's Eiders foraging only 2.7 ± 0.6 (SE) hours per day and Harlequin Ducks 4.1 ± 0.5 hours per day. Low-foraging effort during periods of high-energetic demand generally suggests high food availability, and high food availability frequently corresponds with reductions in home range size. However, the winter ranges of Harlequin Ducks did not appear to be smaller than usual, with the mean range size in our study (5.5 ± 1.1 km2) similar to that reported by previous investigators. The mean size of the winter ranges of Steller's Eiders was similar (5.1 ± 1.3 km2), but no comparable estimates are available. Eutrophication of the waters near Dutch Harbor caused by seafood processing and municipal sewage effluent may have increased populations of the invertebrate prey of these sea ducks and contributed to their low-foraging effort. The threat of predation by Bald Eagles (Haliaeetus leucocephalus) that winter near Dutch Harbor may cause Steller's Eiders and Harlequin Ducks to move further offshore when not foraging, contributing to an increase in range sizes. Thus, the movement patterns and foraging behavior of these ducks likely represent a balance between the cost and benefits of wintering in a human-influenced environment. SINOPSIS Estudiamos los movimientos y esfuerzo de forrajeo de individuos de eidero (Polusticta stelleri) y el pato arlequín (Histrionicus histrionicus)(ambos con radiotransmisores) para evaluar la calidad del habitat en un área impactada por actividad industrial localizada en Dutch Harbor, Alaska. El esfuerzo de forrajeo (en horas/dia) fue bajo en el eidero con 2.7 ± 0.6 y en el arlequín 4.1 ± 0.5. Un bajo esfuerzo de forrajeo durante periodos de alta demanda energética por lo general sugieren una buena cantidad y calidad de alimentos. Alimentos en abundancia por lo general dan origen a una reducción en el ambiente ocupado (home range). Sin embargo, el ambiente ocupado del arlequín fue de 5.5 ± 1.1 km cuadrados, similar al informado en otros estudios, por lo que no parece haberse reducido. En el eidero el tamaño del área ocupada fue de 5.1 ± 1.3 km cuadrados y no hay otros estudios que nos permitieran hacer comparaciones. La eutroficación de las aguas en los alrededores de Dutch Harbor, causado por el procesamiento de pescado y las aguas usadas municipales, pueden haber incrementado los invertebrados de los cuales se alimentan ambas especies de aves estudiadas, y haber contrubuido al bajo esfuerzo de forrajeo observado en estas. El peligro de ser depredados por individuos de Haliaeetus leucocephalus, que pasan el invierno en el área de la bahía, puede haber sido el responsable del movimiento de las aves tierra adentro, cuando no se estaban alimentando, contribuyendo al tamaño del área ocupada por ambas especies. Por ende los movimientos y patrones de forrajeo de ambas especies probablemente no representa un balance entre el costo y los beneficios de pasar el invierno en un ambiente influenciado por la presencia de humanos. [source] Of eagles and flies: orientations toward the siteAREA, Issue 3 2010Keith Woodward The macro-micro distinction is one of the most powerful in the human and physical sciences. In this article we challenge the macro by positing an alternative that recognises the intricacies and complexities of material geographies. We employ the Latin proverb , Aquila non captat muscas (Eagles don't catch flies) , to epitomise our position. Instead of looking to general theory , the bird's eye view , we argue for interrogating the ontological and methodological implications of a reciprocal, but antithetical, perspective , that of the flies. We call this alternative the site, an ontology that attempts to account for the different and varying political possibilities , virtually infinite and ,un-catalogue-able', constantly at work in the world. The site is a formulation that recognises social life as a realm of infinite singularity and variability, where matter is immanently self-organising and pure difference unfolds. We explore the spatiality of the site through the concepts of topology and difference and then develop four methodological orientations for exploring the terrain of situated practices enmeshed in and unfolding through sites. [source] Large-scale spatio-temporal shifts in the diet of a predator mediated by an emerging infectious disease of its main preyJOURNAL OF BIOGEOGRAPHY, Issue 8 2009Marcos Moleón Abstract Aim, To explore the influence of an emerging infectious disease (EID) affecting a prey species on the spatial patterns and temporal shifts in the diet of a predator over a large geographical scale. We reviewed studies on the diet of Bonelli's eagles (Hieraaetus fasciatus) in order to determine the repercussions of the reduction in the density of its main prey, the rabbit (Oryctolagus cuniculus), caused by outbreaks of rabbit haemorrhagic disease (RHD) since 1988. Location, Western continental Europe. Methods, We compiled published and unpublished information on the diet of breeding Bonelli's eagles from Portugal, Spain and France for a 39-year study period (1968,2006). Nonparametric tests were used in order to analyse temporal shifts in diet composition and trophic diversity (H,) between the periods of ,high' (before outbreak of RHD) and ,low' rabbit density (after outbreak of RHD). A combination of hierarchical agglomerative clustering and non-metric multidimensional scaling (NMDS) analyses were used to test for the existence of geographical patterns in the diet of Bonelli's eagles in each period. Results, The diet of the Bonelli's eagle consisted of rabbit (28.5%), pigeons (24.0%), partridges (15.3%), ,other birds' (11.6%), ,other mammals' (7.1%), corvids (7.0%), and herptiles (6.4%). However, RHD had large consequences for its feeding ecology: the consumption of rabbits decreased by one-third after the outbreak of RHD. Conversely, trophic diversity (H,) increased after outbreak of RHD. At the same time, the analyses showed clear geographical patterns in the diet of the Bonelli's eagle before, but not after, RHD outbreak. Main conclusions, Geographical patterns in the diet of the Bonelli's eagle in western Europe seem to be driven mainly by spatio-temporal variation in the abundance of rabbits and, to a lesser extent, by the local (territorial) environmental features conditioning the presence and density of alternative prey species. We show that an EID can disrupt predator,prey relationships at large spatial and temporal scales through a severe decline in the population of the main prey species. Hence we argue that strict guidelines should be drawn up to prevent human-aided dissemination of ,pathogen pollution', which can threaten wildlife not only at the population and species level but also at the community and ecosystem scale. [source] Predicting the distribution of four species of raptors (Aves: Accipitridae) in southern Spain: statistical models work better than existing mapsJOURNAL OF BIOGEOGRAPHY, Issue 2 2004Javier Bustamante Abstract Aim, To test the effectiveness of statistical models based on explanatory environmental variables vs. existing distribution information (maps and breeding atlas), for predicting the distribution of four species of raptors (family Accipitridae): common buzzard Buteo buteo (Linnaeus, 1758), short-toed eagle Circaetus gallicus (Gmelin, 1788), booted eagle Hieraaetus pennatus (Gmelin, 1788) and black kite Milvus migrans (Boddaert, 1783). Location, Andalusia, southern Spain. Methods, Generalized linear models of 10 × 10 km squares surveyed for the presence/absence of the species by road census. Statistical models use as predictors variables derived from topography, vegetation and land-use, and the geographical coordinates (to take account of possible spatial trends). Predictions from the models are compared with current distribution maps from the national breeding atlas and leading reference works. Results, The maps derived from statistical models for all four species were more predictive than the previously published range maps and the recent national breeding atlas. The best models incorporated both topographic and vegetation and land-use variables. Further, in three of the four species the inclusion of spatial coordinates to account for neighbourhood effects improved these models. Models for the common buzzard and black kite were highly predictive and easy to interpret from an ecological point of view, while models for short-toed eagle and, particularly, booted eagle were not so easy to interpret, but still predicted better than previous distribution information. Main conclusions, It is possible to build accurate predictive models for raptor distribution with a limited field survey using as predictors environmental variables derived from digital maps. These models integrated in a geographical information system produced distribution maps that were more accurate than previously published ones for the study species in the study area. Our study is an example of a methodology that could be used for many taxa and areas to improve unreliable distribution information. [source] Hunting strategies and foraging performance of the short-toed eagle in the Dadia-Lefkimi-Soufli National Park, north-east GreeceJOURNAL OF ZOOLOGY, Issue 3 2010D. E. Bakaloudis Abstract The foraging performance and the hunting strategies of foraging short-toed eagles Circaetus gallicus were studied in Dadia-Lefkimi-Soufli National Park during 1996,1998. A general linear model analysis showed that the eagle's hunting mode was related to wind velocity. At low wind speeds, the eagles more frequently soared and/or hovered, whereas on windy days, they hung more frequently than soared or hovered. Individuals appear to compensate for the high-cost foraging method (hovering) with a high capture rate or a low capture rate with low-cost foraging methods (soaring and hanging). In addition, their foraging activities exhibited two patterns. In the early (April) and late (September) breeding season, eagles foraged mainly during midday, while from May to August eagles foraged largely during the morning and a little during the afternoon, reflecting to some extent the diurnal activity of prey (reptiles) throughout the breeding season. Short-toed eagles tended to forage for longer as the breeding season progressed, peaking during August due to additional food requirements before autumn migration. Following a mixed foraging strategy throughout the breeding season, short-toed eagles increased their hunting efficiency, which may benefit increased breeding success and energy reserves for migration. [source] Using bald eagles to indicate the health of the Great Lakes' environmentLAKES & RESERVOIRS: RESEARCH AND MANAGEMENT, Issue 3 2002William W. Bowerman Abstract The bald eagle (Haliaeetus leucocephalus) is one of the most studied birds of North America, and a great amount of natural life-history information, including the response of various stressors on the eagles' ability to reproduce, are well known. In Michigan, the eagle has been chosen to track the trends of bioaccumulative compounds of concern across watersheds in the state. The state has been divided into major watersheds, and 20% of these are surveyed each year. A control area in northern Minnesota, Voyageurs National Park, is also sampled annually. We report here on the methods used, the preliminary results of the 1999 field season, and how differences in mercury concentrations varied over a 10-year period. Mercury in feathers of nestling eagles declined over time only in Lakes Michigan and Huron, but have not decreased among other subpopulations in Michigan. Concentrations of polychlorinated biphenyls (PCBs) and 4,4,-DDE in blood plasma from nestling eagles have declined over time for most subpopulations; however, they remain greater for breeding areas associated with the Great Lakes' food web. Sea eagles of the genus Haliaeetus are a good sentinel species to track trends in bioaccumulative compounds in aquatic systems. [source] Population fragmentation leads to spatial and temporal genetic structure in the endangered Spanish imperial eagleMOLECULAR ECOLOGY, Issue 3 2007B. MARTÍNEZ-CRUZ Abstract The fragmentation of a population may have important consequences for population genetic diversity and structure due to the effects of genetic drift and reduced gene flow. We studied the genetic consequences of the fragmentation of the Spanish imperial eagle (Aquila adalberti) population into small patches through a temporal analysis. Thirty-four museum individuals representing the population predating the fragmentation were analysed for a 345-bp segment of the mitochondrial control region and a set of 10 nuclear microsatellite loci. Data from a previous study on the current population (N = 79) were re-analysed for this subset of 10 microsatellite markers and results compared to those obtained from the historical sample. Three shared mitochondrial haplotypes were found in both populations, although fluctuations in haplotype frequencies and the occurrence of a fourth haplotype in the historical population resulted in lower current levels of haplotype and nucleotide diversity. However, microsatellite markers revealed undiminished levels of nuclear diversity. No evidence for genetic structure was observed for the historical Spanish imperial eagle population, suggesting that the current pattern of structure is the direct consequence of population fragmentation. Temporal fluctuations in mitochondrial and microsatellite allelic frequencies were found between the historical and the current population as well as for each pairwise comparison between historical and current Centro and historical and current Parque Nacional de Doñana nuclei. Our results indicate an ancestral panmictic situation for the species that management policies should aim to restore. A historical analysis like the one taken here provides the baseline upon which the relative role of recent drift in shaping current genetic patterns in endangered species can be evaluated and this knowledge is used to guide conservation actions. [source] Tetranucleotide microsatellites for aquila and haliaeetus eaglesMOLECULAR ECOLOGY RESOURCES, Issue 1 2005JOSEPH D. BUSCH Abstract A unique community of four syntopic eagle species exists in north-central Kazakhstan. Questions about behaviour and genetics in these four species would benefit from the development of microsatellite markers. We isolated eight polymorphic microsatellite repeats (AAAG)n from the eastern imperial eagle (Aquila heliaca) genome using a hybridization enrichment technique. These loci revealed moderate diversity in a local population of eastern imperial eagles (observed heterozygosity 0.26,0.78), and were also polymorphic in steppe eagles (A. nipalensis) and white-tailed sea eagles (Haliaeetus albicilla). These primers may be polymorphic in other species of Aquila and Haliaeetus eagles. [source] Preface: phys. stat. sol. (c) 1/9PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 9 2004Andrew Leitch The Conference on Photo-responsive Materials took place at the Kariega Game Reserve in the Eastern Cape, South Africa from 25,29 February 2004. More than 60 delegates from 12 different countries participated in the four-day event. The purpose of the conference was to bring together scientists working on various aspects of photo-responsive materials, so as to stimulate this important field of solid state physics in Southern Africa. As may be seen from the list of papers appearing in these proceedings, there was much interest in copper indium diselenide as a thin film material for photovoltaic applications. Also worth mentioning were the valuable contributions on ZnO, GaN and other materials that are currently attracting attention worldwide. The conference program allowed sufficient time for interaction and exchanging of views. Being in a game reserve in the heart of the beautiful Eastern Cape, delegates were also taken on game drives and had the opportunity of taking a river cruise up the Kariega River to view the majestic fish eagle. The members of the academic program committee were: Vivian Alberts (Rand Afrikaans University), Danie Auret (University of Pretoria), Darrell Comins (University of the Witwatersrand), and Reinhardt Botha and Andrew Leitch (University of Port Elizabeth). All papers appearing in these proceedings underwent a strict reviewing process separate from the conference. We express our appreciation to the referees for their diligence in this important task. The conference was organized by the Department of Physics at the University of Port Elizabeth, under the auspices of the Condensed Matter Physics and Materials Science (CMPMS) subgroup of the South African Institute of Physics. It was sponsored by EMF Limited (UK), Sensors Unlimited Inc. (USA), and Carl Zeiss (Pty) Ltd. Special thanks must go to Dr Eunete van Wyk for her professional assistance in the preparation of these proceedings. [source] Brief communication: Plio-Pleistocene eagle predation on fossil cercopithecids from the Humpata Plateau, southern AngolaAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 3 2009Christopher C. Gilbert Abstract Recent studies suggest a large raptor such as the crowned eagle (Stephanaoetus coronatus) was responsible for collecting at least a portion of the primate fauna from the South African fossil site of Taung, including its lone hominin specimen. This taphonomic signature at Taung is currently regarded as a unique and, most likely, isolated case in primate and human evolution. However, the activities of large, carnivorous birds should also be detectable at other primate fossil localities in Africa if raptors have been a strong selective force throughout primate evolution. Over the last 60 years, a collection of extinct cercopithecids has been assembled from several cave breccias on the Humpata Plateau in southern Angola. The material, dated near the Plio-Pleistocene boundary, includes an assortment of craniodental and postcranial remains variably assigned to Papio (Dinopithecus) cf. quadratirostris, Parapapio, Cercopithecoides, and Theropithecus. We compare the Angolan and Taung material to remains of extant primates killed by crowned eagles in the Ivory Coast's Tai National Park. Our analysis indicates that the size distribution and composition of fauna from the localities is quite similar and that there are striking consistencies in damage to the crania from each site. The absence of large bodied (>20 kg) primates and other mammalian taxa at the Taung hominin locality and Tai, and their rarity in Angola, combined with the strong likelihood that raptor nests were positioned near fissure openings at both fossil localities, provides additional support for eagle involvement. On the basis of this evidence, we conclude that at least some of the Angolan cercopithecids were most likely raptor prey and hypothesize that raptor predation has been a strong and perhaps underappreciated selective force during the course of primate evolution. Am J Phys Anthropol 2009. © 2009 Wiley-Liss, Inc. [source] Primate remains from African crowned eagle (Stephanoaetus coronatus) nests in Ivory Coast's Tai Forest: Implications for primate predation and early hominid taphonomy in South AfricaAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 2 2006W. Scott McGraw Abstract Understanding the initial processes of deposition can help with interpretations of fossil assemblages. Here we discuss the taphonomy of primate remains collected under 16 nests of African crowned eagles (Stephanoaetus coronatus) in the Tai Forest, Ivory Coast. From 1,200 bones collected, including 669 primate bones, we calculated minimum number of individuals (MNI), survivability profiles, and damage profiles using methods identical to those employed by Sanders et al. (2003 J. Hum. Evol. 44:87,105) in their analysis of bones from eagle nests in Uganda. Crowned eagles leave a consistent taphonomic signature on their prey remains; hence, results from our analysis of the Tai assemblage are similar to those from the Ugandan sample. Hindlimb and cranial bones are relatively abundant in the sample, while ribs, vertebrae, carpals, and tarsals do not survive well. Primate crania typically display puncture marks around the eye, long bones remain largely intact, and scapulae exhibit raked breakage. These data have implications for understanding the dynamic between extant primates and one of their principle predators, as well as the taphonomy of hominid-bearing caves in South Africa. We concur with Berger and Clarke (1995 J. Hum. Evol. 29:275,299) that a large raptor could have been responsible for the death of the Taung child, Australopithecus africanus. Am J Phys Anthropol 131:151,165, 2006. © 2006 Wiley-Liss, Inc. [source] Changes in productivity and contaminants in bald eagles nesting along the lower Columbia River, USAENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 7 2005Jeremy A. Buck Abstract Previous studies documented poor productivity of bald eagles (Haliaeetus leucocephalus) in the lower Columbia River (LCR), USA, and elevated p,p,-dichlorodiphenyldichloroethylene (DDE), polychlorinated biphenyls (PCBs), dioxins, and furans in eagle eggs. From 1994 to 1995, we collected partially incubated eggs at 19 of 43 occupied territories along the LCR and compared productivity and egg contaminants to values obtained in the mid-1980s. We found higher productivity at new nesting sites along the river, yet productivity at 23 older breeding territories remained low and was not different (p = 0.713) between studies. Eggshell thickness at older territories had not improved (p = 0.404), and eggshells averaged 11% thinner than shells measured before dichlorodiphenyltrichloroethane use. Decreases in DDE (p = 0.022) and total PCBs (p = 0.0004) in eggs from older breeding areas occurred between study periods. Productivity was not correlated to contaminants, but DDE, PCBs, and dioxin-like chemicals exceeded estimated no-effect values. Some dioxin-like contaminants in eggs were correlated to nest location, with highest concentrations occurring toward the river's mouth where productivity was lowest. Although total productivity increased due to the success of new nesting pairs in the region, egg contaminants remain high enough to impair reproduction at older territories and, over time, may alter productivity of new pairs nesting near the river's mouth. [source] Is there a connection between weather at departure sites, onset of migration and timing of soaring-bird autumn migration in Israel?GLOBAL ECOLOGY, Issue 6 2006Judy Shamoun-Baranes ABSTRACT Aims, Different aspects of soaring-bird migration are influenced by weather. However, the relationship between weather and the onset of soaring-bird migration, particularly in autumn, is not clear. Although long-term migration counts are often unavailable near the breeding areas of many soaring birds in the western Palaearctic, soaring-bird migration has been systematically monitored in Israel, a region where populations from large geographical areas converge. This study tests several fundamental hypotheses regarding the onset of migration and explores the connection between weather, migration onset and arrival at a distant site. Location, Globally gridded meteorological data from the breeding areas in north-eastern Europe were used as predictive variables in relation to the arrival of soaring migrants in Israel. Methods, Inverse modelling was used to study the temporal and spatial influence of weather on initiation of migration based on autumn soaring-bird migration counts in Israel. Numerous combinations of migration duration and temporal influence of meteorological variables (temperature, sea-level pressure and precipitable water) were tested with different models for meteorological sensitivity. Results, The day of arrival in Israel of white storks, honey buzzards, Levant sparrowhawks and lesser spotted eagles was significantly and strongly related to meteorological conditions in the breeding area days or even weeks before arrival in Israel. The cumulative number of days or cumulative value above or below a meteorological threshold performed significantly better than other models tested. Models provided reliable estimates of migration duration for each species. Main conclusions, The meteorological triggers of migration at the breeding grounds differed between species and were related to deteriorating living conditions and deteriorating migratory flight conditions. Soaring birds are sensitive to meteorological triggers at the same period every year and their temporal response to weather appears to be constrained by their annual routine. [source] Predator functional response and prey survival: direct and indirect interactions affecting a marked prey populationJOURNAL OF ANIMAL ECOLOGY, Issue 1 2006DAVID A. MILLER Summary 1Predation plays an integral role in many community interactions, with the number of predators and the rate at which they consume prey (i.e. their functional response) determining interaction strengths. Owing to the difficulty of directly observing predation events, attempts to determine the functional response of predators in natural systems are limited. Determining the forms that predator functional responses take in complex systems is important in advancing understanding of community interactions. 2Prey survival has a direct relationship to the functional response of their predators. We employed this relationship to estimate the functional response for bald eagle Haliaeetus leucocepalus predation of Canada goose Branta canadensis nests. We compared models that incorporated eagle abundance, nest abundance and alternative prey presence to determine the form of the functional response that best predicted intra-annual variation in survival of goose nests. 3Eagle abundance, nest abundance and the availability of alternative prey were all related to predation rates of goose nests by eagles. There was a sigmoidal relationship between predation rate and prey abundance and prey switching occurred when alternative prey was present. In addition, predation by individual eagles increased as eagle abundance increased. 4A complex set of interactions among the three species examined in this study determined survival rates of goose nests. Results show that eagle predation had both prey- and predator-dependent components with no support for ratio dependence. In addition, indirect interactions resulting from the availability of alternative prey had an important role in mediating the rate at which eagles depredated nests. As a result, much of the within-season variation in nest survival was due to changing availability of alternative prey consumed by eagles. 5Empirical relationships drawn from ecological theory can be directly integrated into the estimation process to determine the mechanisms responsible for variation in observed survival rates. The relationship between predator functional response and prey survival offers a flexible and robust method to advance our understanding of predator,prey interactions in many complex natural systems where prey populations are marked and regularly visited. [source] Non-independence of demographic parameters: positive density-dependent fecundity in eaglesJOURNAL OF APPLIED ECOLOGY, Issue 5 2008Miguel Ferrer Summary 1Using information on the Doñana population of Spanish imperial eagles Aquila adalberti from 1959 to 2004, we present strong empirical support to theoretical models on the regulation of population trajectories by the relationships between breeder mortality and floater availability. 2During the study period, the eagle population showed three distinct phases: (i) a population increase with negative density-dependent fecundity; (ii) a period of stability without any relationship between density and fecundity; and (iii) a population decrease with a positive relationship between density and fecundity. 3A dramatic increase in annual adult mortality due to an increase in poisoning in hunting areas surrounding the Doñana National Park was recorded. The use of poison against generalist predators accounted for more than 54% of the total number of breeding eagles found dead since 1990, increasing annual adult mortality from 6·07 to 12·01%. 4This high mortality reduced the population annually by 6% during the 1992,2004 period. Also, the population changed from a negative to a positive relationship between density and fecundity (Allee effect). These trends made the population approach extinction due to the double effect of increasing breeder mortality and low availability of floaters. 5A supplementary feeding programme established in 1990 did not increase fecundity because it was a consequence of high adult mortality rather than low food availability. The high mortality of adults increased the risk of breeding failure and also decreased the availability of floaters, decreasing the likelihood of mate substitution. 6Synthesis and applications. The main target in species conservation management plans is often a single demographic parameter (typically, fecundity in raptor populations). Our research demonstrates, however, that demographic parameters must not be considered as independent variables when formulating management programmes. The essential relationship between adult mortality and the availability of floaters must be better understood to avoid the risk of implementing inefficient management strategies. Although fecundity was low in this eagle population, it was a result of high adult mortality rates. Consequently, management must aim to correct the unusual mortality and recover the floater population. [source] Large-scale spatio-temporal shifts in the diet of a predator mediated by an emerging infectious disease of its main preyJOURNAL OF BIOGEOGRAPHY, Issue 8 2009Marcos Moleón Abstract Aim, To explore the influence of an emerging infectious disease (EID) affecting a prey species on the spatial patterns and temporal shifts in the diet of a predator over a large geographical scale. We reviewed studies on the diet of Bonelli's eagles (Hieraaetus fasciatus) in order to determine the repercussions of the reduction in the density of its main prey, the rabbit (Oryctolagus cuniculus), caused by outbreaks of rabbit haemorrhagic disease (RHD) since 1988. Location, Western continental Europe. Methods, We compiled published and unpublished information on the diet of breeding Bonelli's eagles from Portugal, Spain and France for a 39-year study period (1968,2006). Nonparametric tests were used in order to analyse temporal shifts in diet composition and trophic diversity (H,) between the periods of ,high' (before outbreak of RHD) and ,low' rabbit density (after outbreak of RHD). A combination of hierarchical agglomerative clustering and non-metric multidimensional scaling (NMDS) analyses were used to test for the existence of geographical patterns in the diet of Bonelli's eagles in each period. Results, The diet of the Bonelli's eagle consisted of rabbit (28.5%), pigeons (24.0%), partridges (15.3%), ,other birds' (11.6%), ,other mammals' (7.1%), corvids (7.0%), and herptiles (6.4%). However, RHD had large consequences for its feeding ecology: the consumption of rabbits decreased by one-third after the outbreak of RHD. Conversely, trophic diversity (H,) increased after outbreak of RHD. At the same time, the analyses showed clear geographical patterns in the diet of the Bonelli's eagle before, but not after, RHD outbreak. Main conclusions, Geographical patterns in the diet of the Bonelli's eagle in western Europe seem to be driven mainly by spatio-temporal variation in the abundance of rabbits and, to a lesser extent, by the local (territorial) environmental features conditioning the presence and density of alternative prey species. We show that an EID can disrupt predator,prey relationships at large spatial and temporal scales through a severe decline in the population of the main prey species. Hence we argue that strict guidelines should be drawn up to prevent human-aided dissemination of ,pathogen pollution', which can threaten wildlife not only at the population and species level but also at the community and ecosystem scale. [source] Hunting strategies and foraging performance of the short-toed eagle in the Dadia-Lefkimi-Soufli National Park, north-east GreeceJOURNAL OF ZOOLOGY, Issue 3 2010D. E. Bakaloudis Abstract The foraging performance and the hunting strategies of foraging short-toed eagles Circaetus gallicus were studied in Dadia-Lefkimi-Soufli National Park during 1996,1998. A general linear model analysis showed that the eagle's hunting mode was related to wind velocity. At low wind speeds, the eagles more frequently soared and/or hovered, whereas on windy days, they hung more frequently than soared or hovered. Individuals appear to compensate for the high-cost foraging method (hovering) with a high capture rate or a low capture rate with low-cost foraging methods (soaring and hanging). In addition, their foraging activities exhibited two patterns. In the early (April) and late (September) breeding season, eagles foraged mainly during midday, while from May to August eagles foraged largely during the morning and a little during the afternoon, reflecting to some extent the diurnal activity of prey (reptiles) throughout the breeding season. Short-toed eagles tended to forage for longer as the breeding season progressed, peaking during August due to additional food requirements before autumn migration. Following a mixed foraging strategy throughout the breeding season, short-toed eagles increased their hunting efficiency, which may benefit increased breeding success and energy reserves for migration. [source] Using bald eagles to indicate the health of the Great Lakes' environmentLAKES & RESERVOIRS: RESEARCH AND MANAGEMENT, Issue 3 2002William W. Bowerman Abstract The bald eagle (Haliaeetus leucocephalus) is one of the most studied birds of North America, and a great amount of natural life-history information, including the response of various stressors on the eagles' ability to reproduce, are well known. In Michigan, the eagle has been chosen to track the trends of bioaccumulative compounds of concern across watersheds in the state. The state has been divided into major watersheds, and 20% of these are surveyed each year. A control area in northern Minnesota, Voyageurs National Park, is also sampled annually. We report here on the methods used, the preliminary results of the 1999 field season, and how differences in mercury concentrations varied over a 10-year period. Mercury in feathers of nestling eagles declined over time only in Lakes Michigan and Huron, but have not decreased among other subpopulations in Michigan. Concentrations of polychlorinated biphenyls (PCBs) and 4,4,-DDE in blood plasma from nestling eagles have declined over time for most subpopulations; however, they remain greater for breeding areas associated with the Great Lakes' food web. Sea eagles of the genus Haliaeetus are a good sentinel species to track trends in bioaccumulative compounds in aquatic systems. [source] Tetranucleotide microsatellites for aquila and haliaeetus eaglesMOLECULAR ECOLOGY RESOURCES, Issue 1 2005JOSEPH D. BUSCH Abstract A unique community of four syntopic eagle species exists in north-central Kazakhstan. Questions about behaviour and genetics in these four species would benefit from the development of microsatellite markers. We isolated eight polymorphic microsatellite repeats (AAAG)n from the eastern imperial eagle (Aquila heliaca) genome using a hybridization enrichment technique. These loci revealed moderate diversity in a local population of eastern imperial eagles (observed heterozygosity 0.26,0.78), and were also polymorphic in steppe eagles (A. nipalensis) and white-tailed sea eagles (Haliaeetus albicilla). These primers may be polymorphic in other species of Aquila and Haliaeetus eagles. [source] Brief communication: Plio-Pleistocene eagle predation on fossil cercopithecids from the Humpata Plateau, southern AngolaAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 3 2009Christopher C. Gilbert Abstract Recent studies suggest a large raptor such as the crowned eagle (Stephanaoetus coronatus) was responsible for collecting at least a portion of the primate fauna from the South African fossil site of Taung, including its lone hominin specimen. This taphonomic signature at Taung is currently regarded as a unique and, most likely, isolated case in primate and human evolution. However, the activities of large, carnivorous birds should also be detectable at other primate fossil localities in Africa if raptors have been a strong selective force throughout primate evolution. Over the last 60 years, a collection of extinct cercopithecids has been assembled from several cave breccias on the Humpata Plateau in southern Angola. The material, dated near the Plio-Pleistocene boundary, includes an assortment of craniodental and postcranial remains variably assigned to Papio (Dinopithecus) cf. quadratirostris, Parapapio, Cercopithecoides, and Theropithecus. We compare the Angolan and Taung material to remains of extant primates killed by crowned eagles in the Ivory Coast's Tai National Park. Our analysis indicates that the size distribution and composition of fauna from the localities is quite similar and that there are striking consistencies in damage to the crania from each site. The absence of large bodied (>20 kg) primates and other mammalian taxa at the Taung hominin locality and Tai, and their rarity in Angola, combined with the strong likelihood that raptor nests were positioned near fissure openings at both fossil localities, provides additional support for eagle involvement. On the basis of this evidence, we conclude that at least some of the Angolan cercopithecids were most likely raptor prey and hypothesize that raptor predation has been a strong and perhaps underappreciated selective force during the course of primate evolution. Am J Phys Anthropol 2009. © 2009 Wiley-Liss, Inc. [source] Primate remains from African crowned eagle (Stephanoaetus coronatus) nests in Ivory Coast's Tai Forest: Implications for primate predation and early hominid taphonomy in South AfricaAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 2 2006W. Scott McGraw Abstract Understanding the initial processes of deposition can help with interpretations of fossil assemblages. Here we discuss the taphonomy of primate remains collected under 16 nests of African crowned eagles (Stephanoaetus coronatus) in the Tai Forest, Ivory Coast. From 1,200 bones collected, including 669 primate bones, we calculated minimum number of individuals (MNI), survivability profiles, and damage profiles using methods identical to those employed by Sanders et al. (2003 J. Hum. Evol. 44:87,105) in their analysis of bones from eagle nests in Uganda. Crowned eagles leave a consistent taphonomic signature on their prey remains; hence, results from our analysis of the Tai assemblage are similar to those from the Ugandan sample. Hindlimb and cranial bones are relatively abundant in the sample, while ribs, vertebrae, carpals, and tarsals do not survive well. Primate crania typically display puncture marks around the eye, long bones remain largely intact, and scapulae exhibit raked breakage. These data have implications for understanding the dynamic between extant primates and one of their principle predators, as well as the taphonomy of hominid-bearing caves in South Africa. We concur with Berger and Clarke (1995 J. Hum. Evol. 29:275,299) that a large raptor could have been responsible for the death of the Taung child, Australopithecus africanus. Am J Phys Anthropol 131:151,165, 2006. © 2006 Wiley-Liss, Inc. [source] Brief communication: Predatory bird damage to the Taung type-skull of Australopithecus africanus Dart 1925AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 2 2006Lee R. Berger Abstract In this issue of the Journal, McGraw et al. ([2006] Am. J. Phys. Anthropol. 000:00,00) present new data on the taphonomic signature of bone assemblages accumulated by crowned hawk eagles (Stephanoaetus coronatus), including characteristic talon damage to the inferior orbits of primates preyed upon by these birds. Reexamination of the Taung juvenile hominin specimen (the type specimen of Australopithecus africanus Dart 1925) reveals previously undescribed damage to the orbital floors that is nearly identical to that seen in the crania of monkeys preyed upon by crowned hawk eagles (as reported by McGraw et al., this issue). This new evidence, along with previously described aspects of the nonhominin bone assemblage from Taung and damage to the neurocranium of the hominin specimen itself, strongly supports the hypothesis that a bird of prey was an accumulating agent at Taung, and that the Taung child itself was the victim of a bird of prey. Am J Phys Anthropol 131:166,168, 2006. © 2006 Wiley-Liss, Inc. [source] Albatrosses, eagles and newts, Oh My!: exceptions to the prevailing paradigm concerning genetic diversity and population viability?ANIMAL CONSERVATION, Issue 5 2010D. H. Reed Abstract Numerous recent papers have demonstrated a central role for genetic factors in the extinction process or have documented the importance of gene flow in reversing population declines. This prompted one recent publication to declare that a revolution in conservation genetics has occurred. Contemporaneously with this revolution are a series of papers demonstrating long-term population persistence for several species despite having little or no detectable genetic variation. In a couple of notable cases, populations have been shown to have survived for centuries at small population size and with depleted levels of genetic variation. These contradictory results demand an explanation. In this review, I will show that these results do not necessarily fly in the face of theory as sometimes stated. The reconciliation of these two sets of observations relies on the incorporation of two major concepts. (1) Genetic factors do not act in a vacuum and it is their interaction with the environment, the strength and type of selection imposed, and the life history of the organism that determine the relative importance of genetic factors to extinction risk. (2) The relationship between molecular estimates of genetic variation and evolutionary potential, the relevance of genetic bottlenecks to adaptive genetic variation, and the nature of the stochastic process of extinction must be better integrated into expectations of population viability. Reports of populations persisting for hundreds of generations with very little detectable genetic variation provide us not only with valuable information but also with hope. However, recent studies suggest that we should not be sanguine about the importance of genetic diversity in the conservation of biodiversity. [source] | ||||||||||||||||