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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Agriculture and the life histories of Mauritius kestrels

Cartwright, Samantha J. January 2012 (has links)
Habitat modification for agriculture is one of the greatest current threats to global biodiversity. Studies show large-scale population declines and short-term demographic impacts, but knowledge of the long-term effects of agriculture on individuals remains poor. This thesis examines the short- and long-term impact of agriculture on a reintroduced population of the Mauritius kestrel Falco punctatus, a tropical forest-dwelling raptor endemic to the island of Mauritius, that also utilises agricultural habitats. This population is a particularly appropriate model system, because complete life history data exists for individuals over a 22-year period, alongside detailed habitat and climate data. Agriculture has a short-term detrimental effect on Mauritius kestrel breeding success by exacerbating the seasonal decline in fledgling production. This is partly driven by the habitat-specific composition of the prey community that kestrels exploit to feed their chicks. The fledglings from agricultural territories tend to recruit in agricultural territories. This is largely due to poor natal dispersal and fine-scale spatial autocorrelation in the habitat matrix. Breeders do not respond to agriculture in the breeding territory by dispersing, unless the pair bond is broken. Therefore, individuals originating in agricultural territories tend to recruit, and remain in, agricultural territories throughout their lives. In addition to this, females from agricultural natal territories have shorter lifespans, schedule their peak reproductive output earlier in life, and exhibit more rapid senescence than non-agricultural females. The combination of this long-term effect and the adult experience of agriculture imposed by life history and environmental constraints, leads to a lower mean lifetime reproductive rate compared to females originating in non-agricultural habitats. These results demonstrate that agriculture experienced in early life has a lifelong effect on individuals. The effects can persist in time and space, with potentially delayed effects on population dynamics. These findings are important for understanding species’ responses to agricultural expansion.
2

The ecology and management of a re-introduced population of the Mauritius kestrel (Falco punctatus)

Nicoll, Malcolm A. C. January 2004 (has links)
No description available.
3

The occurrence and consequences of inbreeding in a reintroduced population of the Mauritius kestrel (Falco punctatus)

Ewing, Steven January 2005 (has links)
No description available.
4

Habitat selection and breeding ecology of lesser kestrels Falco naumanni : implications for conservation

Franco, Aldina M. A. January 2003 (has links)
Through an understanding of the lesser kestrel Falco naumanni habitat preferences and breeding ecology it is possible to determine the causes responsible for the species decline and suggest conservation measures. This study was conducted in the Iberian Peninsula during the lesser kestrel breeding period. Unlike Spain, nest site availability was found to be a constraint for the lesser kestrels in Portugal. The model for selection of buildings indicated that this species prefer buildings with many roof and wall cavities and surrounded by extensive agriculture. In Portugal and Spain, the villages selected by lesser kestrels had many old buildings and monuments, were located in areas with few rivers, and low percentage cover of cereals, olive groves and forest. Habitat preferences were determined using telemetry and transect count data and the two methods provided similar results. The effectiveness of radio tracking and visual sighting transect data was compared and the costs and benefits of each technique were assessed. Telemetry resulted in a larger number of significant differences between the habitats, but the costs were higher. Telemetry also required more effort to set up and collect the data. Transects were a cheaper technique but telemetry allowed areas with no roads to be covered. Findings indicate that lesser kestrel conservation is strongly dependent on the maintenance of extensive agriculture characterised by a rotation of cereal and grazed fallow. Abandonment of traditional agriculture and the recent changes in the agrienvironmental programme support, which favour afforestation and intensification, are jeopardising the future of cereal steppes and the lesser kestrel. Telemetry data indicated that lesser kestrels prefer to forage close to the colony. In steppe habitats, the protection of such foraging habitats within 3-km from the colonies could be an effective conservation measure. Vlll
5

Cytogenetic and genomic characterisation of the Gyrfalcon and related species: individual genomic signature and genome evolution

Al Mutery, Abdullah Fahad January 2011 (has links)
Falcons are among the most spectacular animals in the world as they can be found in most continents and many environments; they are vary vastly in size, behaviour, habitat and hunting techniques. For reasons of conservation, veterinary practice and economical issues, further insight into the genome of at least one falcon species is apriority. To date however only three avian genome sequences have been completed (chicken, turkey and zebra finch) with the latter two published on1y last year. Therefore the aims of this thesis were to focus on the Gyrfalcon (Falco rusticolus the national emblem of the UAE) and: I. Establish the basic genomic structure (karyotype and standard ideogram) and perform a comparative study between Falco nlsticoius and the most genomically characterised bird, the chicken. Results suggested that Falco rusticolus has a similar karyotype to the previously described Falco tinnunculus (common kestrel) and thus both can be considered as ancestral. Studies of telomeric sequences did not reveal the presence of interstitial telomeres at evolutionary fusion points. 2. Establish the presence of inter-species copy number variants (CNVs) by comparison of falcons and other birds with chicken on a chicken genomic microarray. Results provided an overview of CNVs and CNV regions (CNVRs) in several ?ird species. They indicated that bird genomes contain smaller CNVRs than mammalian genomes and that bird genomes, like mammalian genomes, contain CNV hotspots. 3. Fully sequence the mitochondrial DNA of Falco rusticolus and Falco cherrug (Saker falcon) and compare to the published Falco peregrinlls to establish evolutionary relationships between them. Results suggested that Gyrfalcon and saker fa lcon are closer to one other while peregrine is more distantly related. In fact Gyrfalcon and Saker falcons consistently differ by only a single nucleotide in the control region. 4. Initiate a complete draft nuclear genome sequence of Falco rusticoills and attempt to establish the nature of the chromosomal fusions that have occurred during evolution. Also, as proof of principle, to use the resultant BLAST tool to identify selected genes (interleukin family), their Gyrfalcon orthologues and their evolutionary relationship between other published sequences. Chromosome fusion points were not detected however the gene orhologies were indicating the potential for the genome sequence. The thesis was largely successful in its stated aims and has provided resources and tools that will ultimately aid in the understanding of the biology of all member of Falconidea family.
6

Χωρική προσέγγιση της βιολογίας του είδους Falco eleonorae (Aves, Falconiformes) στην Ελλάδα: η περίοδος της αναπαραγωγής, μετανάστευσης και διαχείμασης

Κασσάρα, Χριστίνα 27 June 2012 (has links)
Ο Μαυροπετρίτης (Falco eleonorae Géné, 1839) είναι ένα μεσαίου μεγέθους μεταναστευτικό γεράκι το οποίο επισκέπτεται τη χώρα μας τους καλοκαιρινούς μήνες για να αναπαραχθεί. Οι αναπαραγωγικές αποικίες εντοπίζονται σε νησιά και ακτές της Μεσογείου, της Μακαρονησίας και της βορειοδυτικής Αφρικής, ενώ τους υπόλοιπους μήνες το είδος απαντά στη Μαδαγασκάρη και γειτονικές περιοχές. Στο παρελθόν έχει πραγματοποιηθεί ένας μεγάλος αριθμός μελετών σχετικά με την περίοδο αναπαραγωγής, ενώ για τον υπόλοιπο κύκλο ζωής του είδους οι γνώσεις μας μέχρι τις αρχές του 21ου αιώνα ήταν περιορισμένες. Στην παρούσα διατριβή μελετώνται τα βασικότερα στάδια του κύκλου ζωής του Μαυροπετρίτη, επικεντρώνοντας στην περίοδο αναπαραγωγής, μετανάστευσης και διαχείμασης ατόμων που αναπαράγονται στην Ελλάδα. Συγκεκριμένα, διερευνάται (α) η αναπαραγωγική επιτυχία του είδους και η επίδραση περιβαλλοντικών παραγόντων στην έκβαση της αναπαραγωγικής επιτυχίας, (β) το πρότυπο κατανομής των αναπαραγωγικών αποικιών στο Αιγαίο και Ιόνιο πέλαγος, (γ) τα κριτήρια που χρησιμοποιούν τα αναπαραγωγικά ζευγάρια κατά την επιλογή θέσης φωλιάσματος σε ακατοίκητες νησίδες του Αιγαίου πελάγους, (δ) η περίοδος μετανάστευσης τεσσάρων γερακιών από μια αποικία του Κεντρικού Αιγαίου και οι παράγοντες που επηρεάζουν το πρότυπο μετανάστευσής τους και, (ε) η περίοδος διαχείμασης και το πρότυπο κατανομής των τεσσάρων γερακιών στην περιοχή διαχείμασης. Η εκπόνηση της παρούσας διατριβής βασίσθηκε σε μεγάλο βαθμό στα πρωτογενή δεδομένα που συλλέχθηκαν στο πλαίσιο του προγράμματος «LIFE - ΦΥΣΗ 2003 Δράσεις για την προστασία του Μαυροπετρίτη (Falco eleonorae) στην Ελλάδα (LIFE 03NAT/GR/000091)», με κύριο ανάδοχο την Ελληνική Ορνιθολογική Εταιρεία (Ε.Ο.Ε.) σε συνεργασία με το Μουσείο Φυσικής Ιστορίας Κρήτης (ΜΦΙΚ), το Υπουργείο Αγροτικής Ανάπτυξης και Τροφίμων και τη Βρετανική Ορνιθολογική Εταιρεία (RSPB) και με χρηματοδότηση της Ευρωπαϊκής Επιτροπής και συγχρηματοδότηση του ιδρύματος «Α. Γ.Λεβέντης». Το πρόγραμμα παρακολούθησης της μετανάστευσης των τεσσάρων Μαυροπετριτών πραγματοποιήθηκε στο πλαίσιο του προγράμματος «Μελέτη των πτηνών του ελληνικού θαλάσσιου χώρου» με ανάδοχο την Ελληνική Ορνιθολογική Εταιρεία και με χρηματοδότηση του ιδρύματος «Α. Γ. Λεβέντης». / Eleonora's falcon (Falco eleonorae Géné, 1839) is a medium-sized migratory raptor that visits the Greek islands during the breeding season. Its breeding colonies are distributed on islands and coasts of the Mediterranean Sea, Macaronesia and northwest Africa, while during the rest of the year the species is found in Madagascar and surrounding islets. In previous years most studies focused on the breeding period, while up to the 21st century our knowledge with regards to the rest of its life cycle remained relatively poor. In this thesis i study the main stages of Eleonora's falcon life cycle, focusing on the breeding, migratory and wintering period of individuals that breed in Greece. In particular, i investigate (a) the breeding success of the species and the effect of environmental factors on the outcome of the breeding effort, (b) the distribution pattern of the breeding colonies in the Aegean and Ionean Sea, (c) the criteria the breeding pairs use at the time of nesting site selection in uninhabited islets of the Aegean Sea, (d) the migratory period of four falcons originating from a breeding colony of the Central Aegean Sea and the factors that shape the irmigratory pattern and, (e) the wintering period and the distribution pattern of the four falcons in their wintering grounds. This thesis was based to a great extent on the data collected in the frame of the project "LIFE-Nature 2003 Conservation Measures for Falco eleonorae in Greece (LIFE 03NAT/GR/000091)" undertaken by the Hellenic Ornithological Society (H.O.S.) in collaboration with the Natural History Museum of Crete (NHMC), the Ministry of Rural Development and Food and the Royal Society for the Protection of Birds (RSPB), which was funded by the European Commission and cofunded by the A.G. Leventis Foundation. The migration tracking project was funded by the A.G. Leventis Foundation through project "Survey and Conservation of Seabirds in Greece".

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