E-Locus - Institutional Repository of the University of Crete

Home Search

Results - Details

Search command : Author="Μυλωνάς" And Author="Μωυσής"

Current Record: 21 of 53

[Add to Basket]

Identifier

000403543

Title

Eνδιαιτήματα αναπαραγωγής και τροφοληψίας των υδροβίων πουλιών της λίμνης Αγυιάς Χανίων

Alternative Title

Breeding and foraging habitats of waterbirds at lake Agyia, Chania

Author

Δαριώτη, Πελαγία

Thesis advisor

Μυλωνάς, Μωυσής

Reviewer

Πουλακάκης, Νίκος
Καρακάσης, Ιωάννης

Abstract

Aims and objectives: The so far research efforts and studies in relation to the avifauna of Crete have highlighted the importance of the island for migratory- and not only- birds. However until now there is no comprehensive research demonstrating the value of Cretan wetlands- artificial and no- offered as breeding and foraging habitats for waterbirds. This paper tries to show the importance of an artificial wetland, lake Agyia, for waterbirds. For this purpose the study aims to the following: 1) The identification of suitable habitats of the lake for the birds, through the measurement of depths and mapping of vegetation of the lake, in order to create maps. 2) The collection of data from the midwinter counts of waterbirds (at species, order and family level) during wintering period for Lake Agyia and all wetlands of Crete that have counts from 1996 to 2015. The concentration of midwinter counts data is complementary in this study and intends to highlight the role of Lake Agyia relative to the potential of Crete. 3) The study and recording of the diurnal-time activity budget for specific species belonging to Anatidae family during wintering period and the connection with the offered habitats of Agyia lake. 4) The study of the reproduction of waterbirds of Podicipidae and Rallidae families relative to the offered habitats of the lake Agyia. Also there were chosen wetlands (Potamoi and Aposelemis dams, Kournas Lake) in order to compare the density of couples(per shoreline and surface area). Methods: The measurements of depths were carried out with sounder, boat and GPS device, while vegetation recordings with visual observations, photographs and GPS. For t and breeding studies we used appropriate equipment (binoculars, telescope, GPS device). ArcGIS Desktop 10.2. was used for the creation of the maps. For the statistical analysis of the results IBM Statistics 22 and G-test were used. Also Microsoft Excel 2010 for processing the data and carrying out diagrams. Results: The average depth of Agia lake is 1,9m. The study area is mostly covered by aquatic vegetation and reeds (Phragmites australis, Arundo donax). The dominant behaviors, by studying the daily activity, was resting and feeding throughout the period of the recordings. Generally, dabbling ducks allocated most of their daily activities to rest, while the pochards to forage. The dabbling ducks covered very specific and small areas of the lake, while pochards used the most of it. The midwinter recordings showed that Agyia lake hosts significant numbers for the species Anas strepera, A. clypeata and Aythya fuligula and a good number of Anatidae species in relation to wetlands of Crete. From breeding species the most multitudinous was Coot. The major vegetation types and three species were Aquatic vegetation (free water), Phragmites australis and Typha domingensis. The dominant nesting habitats were positions dominated by Typha domingensis and reed Phragmites australis. The comparison among the wetlands showed that Agyia lake has the largest density of pairs for all three species. Conclusions: All individual surveys of this study show that Agyia biotope, with the shallow depths and variety of vegetation, is suitable for foraging and resting for both wintering and breeding waterbirds. It also shows a stability in the nesting density compared with the other wetlands of the study.

Language

Greek

Subject

Breeding

Bυθομέτρηση

Cretan Wetlands

Diurnal time activity budget

Sounding

Vegetation

Αναπαραγωγή

Βλάστηση

Ημερήσια δραστηριότητα