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| DC Field | Value | Language |
|---|---|---|
| dc.contributor.author | Σιδηρόπουλος, Λαυρέντιος | el |
| dc.date.accessioned | 2026-01-22T08:25:44Z | - |
| dc.identifier.uri | https://olympias.lib.uoi.gr/jspui/handle/123456789/39732 | - |
| dc.rights | Attribution-NonCommercial-NoDerivs 3.0 United States | * |
| dc.rights.uri | http://creativecommons.org/licenses/by-nc-nd/3.0/us/ | * |
| dc.subject | Golden Eagle | en |
| dc.subject | Τροφική οικολογία | el |
| dc.subject | Θνησιμότητα | el |
| dc.title | Conservation ecology of the Golden Eagle (Aquila chrysaetos, L) in Northern Greece | en |
| dc.title | Οικολογία διατήρησης του Χρυσαετού (aquila chrysaetos, l) στη Βόρεια Ελλάδα | el |
| dc.type | doctoralThesis | en |
| heal.type | doctoralThesis | el |
| heal.type.en | Doctoral thesis | en |
| heal.type.el | Διδακτορική διατριβή | el |
| heal.classification | Οικολογία διατήρησης | el |
| heal.classification | Χρυσαετός | el |
| heal.classification | Aquila chrysaetos | en |
| heal.dateAvailable | 2029-01-21T22:00:00Z | - |
| heal.language | en | el |
| heal.access | embargo | el |
| heal.recordProvider | Πανεπιστήμιο Ιωαννίνων. Σχολή Επιστημών Υγείας. Τμήμα Βιολογικών Εφαρμογών και Τεχνολογιών | el |
| heal.publicationDate | 2025-11 | - |
| heal.abstract | The life cycle of the Golden Eagle entails a few months of a post-fledging dependence period (PFDP), a transient dispersal phase that may last several years and with recruitment, a territorial settlement and breeding that usually lasts for life. All the while individuals need to adjust their movement in order both to survive and exploit breeding opportunities. This thesis seeks to fulfil crucial gaps in the baseline ecology of the species for the study population of Northern Greece. The population is resident throughout the year, is known to use tortoises as the main prey and is the stronghold of the national, endangered population. We investigated the population’s diet (Chapter 2) with the basic aims of formally quantifying the tortoise dependence and assessing the importance of alternative prey, especially in the non-breeding season when tortoises are scarce or altogether absent. To this end, dietary analysis of pellet and prey remain collections from 15 territories identified 827 prey items. The analysis was complemented by 102 records of eagle – prey interactions. Tortoises comprised 70.3% of the breeding season diet and 55.1% of hunting/feeding observations. Diet – habitat associations emerged regarding canopy cover with seasonal differences: Tortoises were predated more in the summer in areas with high canopy cover and more in winter in areas with low. The opposite pattern was observed with hares. A marked diet diversity expansion occurred when quantified for six territories where adequate samples were available in both seasons: eagles shifted from a narrow, reptile- based breeding season diet dominated by tortoises to a broader non-breeding season diet, that included more carrion, mammals and birds. The study population’s dependence on ectothermic prey is usually displayed by migratory raptors in the Western Palearctic and the resulting dietary plasticity in winter, highlights the adaptability of the golden eagle, a generalist predator. The declining tortoise populations are threatened by land use changes, expected to intensify through interactions with climate change and the subsequent high potential for wildfires. Natal dispersal (chapter 3) was investigated using GPS data of 18 young eagles. Onset was determined 176 days post fledging, and their first 10 months were spent relatively close (40–60 kms) to the natal ranges. The eagles displayed a variable temporary settlement behavior with an average of 8.4 temporary settlement events. Overall dispersal ranges did not differ seasonally, but space use within Temporary Settlement Areas covered larger areas in winter. The three eagles that were successfully recruited, settled at 20-60 kms from their natal ranges. The Scottish GET topographic model was an adequate fit to the dispersal GPS dataset and was slightly improved when adding canopy cover in topographically suitable areas. Eagles used areas that had higher topographical relief and lower canopy cover during their natal dispersal. These preferences were evident also in TSAs where broader range levels were contrasted with core areas and there is also a possible influence of habitat heterogeneity. The observed patterns are likely linked to habitat structure and food availability, and the heterogeneous open areas of complex topography should be conserved for the species. Specific measures can be applied in temporary settlement areas once these are defined. Poisoning through the illegal use of baits against carnivores was known to be the main mortality factor, that also devastated vulture populations. Chapter 4 addressed the population’s mortality, with the aim of quantifying the poisoning impacts and assessing the relative importance of other factors. It contains mortality data for the last 35 years, including the fates of 29 satellite-tagged individuals from the last decade. Poisoning accounted for 65% of the overall mortality, the highest percentage recorded globally for any eagle population. Known fate survival models from telemetry data revealed 0.78 and 0.85 annual survival rates for immature and adults, respectively (the lowest reported in telemetry studies), improving markedly when censored for poisoning mortality. Poisoning happened disproportionately close to protected areas, more often in areas with high carnivore livestock depredation and almost exclusively in winter when eagles are more likely to scavenge. Direct feeding on carcasses and offal baits was the primary ingestion path with secondary poisoning also evident. Most substances detected were illegal at the time of use, prominently carbofuran. The second most concurrent threat seems to be powerline related mortality and wind turbine collision was also registered. A restructuring of policies against the illegal use of poisoned baits is urgently necessary with changes at the prevention, legislative and enforcement levels such as assisted improvements in livestock husbandry, detailed wildlife crime investigation and introduction of environmental liability for cases of mortality in energy infrastructure. Chapter 5 investigated territorial eagle range use and the potential for surrogacy of Post Fledging Dependence Period (PFDP) juvenile data. Home range analyses utilized a minimum of one tracking year from eight territorial eagles. High resolution analyses revealed overall range sizes of 94.2 (± 43.9) km2. Winter ranges were considerably larger than summer (104.4 vs 69.7 km2 ). More traditional Utilization Distribution (UD) analyses provided estimates of overall size 137.6 (±71.7) km2 and even with this estimate, there was limited territorial overlap. Juvenile Utilization Distributions (UDs) derived from PFDP GPS data showed a relatively high similarity between UDs, improving on previous estimates of a similar application, after adjusting for the exclusion of juvenile exploratory forays. Testing for exclusion of pre-flight capability acquisition (determined at the first two months), did not improve the similarity indices, highlighting the importance of the nest area for the ranging behavior within the territories. | en |
| heal.sponsor | Natural Research Scotland | en |
| heal.sponsor | Ίδρυμα Α. Γ. Λεβέντη | el |
| heal.advisorName | Κατή, Βασιλική | el |
| heal.committeeMemberName | Ποϊραζίδης, Κωνσταντίνος | el |
| heal.committeeMemberName | Αστάρας, Χρήστος | el |
| heal.committeeMemberName | Margalida, Antoni Vaca | en |
| heal.committeeMemberName | Halley, John | en |
| heal.committeeMemberName | Σωτηρόπουλος, Κωνσταντίνος | el |
| heal.committeeMemberName | Μπατσίδης, Απόστολος | el |
| heal.academicPublisher | Σχολή Επιστημών Υγείας. Τμήμα Βιολογικών Εφαρμογών και Τεχνολογιών | el |
| heal.academicPublisherID | uoi | el |
| heal.numberOfPages | 221 σ. | el |
| heal.fullTextAvailability | true | - |
| Appears in Collections: | Διδακτορικές Διατριβές - ΒΕΤ | |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| Thesis_Golden_Eagle_SIDIROPOULOS_final.pdf | Διδακτορική Διατριβή 221 σελίδων για την Οικολογία του Χρυσαετού στη Βόρεια Ελλάδα, εκπονήθηκε στο Εργαστήριο Διατήρησης Βιοποικιλότητας, τμ. Βιολογικών Εφαρμογών και Τεχνολογιών από τον Λαυρέντιο Σιδηρόπουλο | 5.67 MB | Adobe PDF | View/Open Request a copy |
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