Fauna and Flora
Fauna and Flora on Gavdos
European populations of migratory birds
Some of those crucial stopover sites for European populations of migratory birds are Aegean and Ionian Islands, utilized by millions of birds in spring and autumn passage, witnessed and greeted by their inhabitants every year. As a natural two-side funnel, Greek islands congregate large numbers of migrants coming from and dispersing to distant areas in Europe and Africa, and are receiving increased attention of ornithologists in recent years. The origin of birds trapped along the migratory routes is revealed by the simple method of ringing and subsequent recovering of the same bird elsewhere. Bird ringing campaigns have been organized in several of the islands to provide basic information on migration of birds over this migratory route, which is comparatively poorly researched and understood in the European scale. One of the most important islands for studying the spring migration over this route is Gavdos, the first green and forested island which northward bound birds reach flying over the open sea from Africa.
A three-year study of spring migration organized by the Natural History Museum of Crete of the University of Crete has proven that Gavdos plays a crucial role in the network of staging areas for a large number of migrants. Three successive ringing campaigns revealed that more than 50 species of migrants utilize the various habitats on Gavdos for resting and fattening up. This refuelling of the depleted energy reserves allows them to continue their journey northwards, towards their breeding areas. The most important sites on Gavdos for migrants, in terms of the availability of food and suitable cover, are located in the open and cultivated habitats, such as the plateaus of Kastri, Ambelos and Metochi.
These sites congregate large numbers of migrants throughout the spring, and are a perfect location for bird watching. Large flocks of Tree Pipits (Anthus trivialis) and smaller flocks of Red-throated Pipits (Anthus cervinus) roam the cereal cultivations, mixed with flocks of different subspecies and races of the Yellow Wagtail (Motacilla flava). During the peak of migration, from mid-April until the beginning of May, every fence post and bush is occupied by hundreds of birds. The succession of migration peaks of different species is very obvious, the most obvious being the peaks of Pied, Collared and Semi-collared Flycatchers (Ficedula hypoleuca, F.albicollis, F. semitorquata) in the third week of April, followed by a peak of Stonechats (Saxicola rubetra), and the Spotted Flycatcher (Muscicapa striata) in the beginning of May. Still, although almost completely inconspicuous, the Garden Warbler (Sylvia borin) is the most commonly trapped bird throughout the spring in Gavdos, making up almost 40% of the total number of ringed birds in three years. Some of the other common and abundant species are: Common Whitethroat (Sylvia communis), Sedge Warbler (Acrocephalus schoenobaenus), Wood Warbler (Phylloscopus sibilatrix), Woodchat Shrike (Lanius senator), Swallow (Hirundo rustica), House Martin (Delichon urbica), Sand Martin (Riparia riparia), Bee-eater (Merops apiaster), Wheatear and Black-eared Wheatear (Oenanthe oenanthe, O.hispanica). Several raptors are regularly recorded on passage, the most numerous being the Kestrel and the Lesser Kestrel (Falco tinnunculus ,F.naumanni) and the Marsh Harrier (Circus aeruginosus), while the Hen, Pallid and Montagu's Harriers (C.cyaneus, C.macrourus, C.pygargus) are regularly observed as well. The Scops Owl (Otus scops) is a numerous spring migrant as well, common throughout the spring on Gavdos, while the Nightjar (Caprimulgus europaeus) is mostly observed in May.
A peculiar feature of Gavdos is that outside the migration seasons, particularly the spring, the island has very few species breeding and appears almost abandoned by birds! Apart from sea birds such as the Shag (Phalacrocorax aristotelis), and the Yellow-legged Gull (Larus cachinnans), other breeders have very modest numbers and are scarce throughout the island. The regular breeders are the Gold Finch (Carduelis carduelis), Pied Wagtail (Motacilla alba), Blue Rock Thrush (Monticola solitarius), Black-eared Wheatear (O.hispanica), Scope Owl and Little Owl (Athene noctua).
Source: Natural History Museum of Crete of the University of Crete
Some more picture from our Gavdos Fauna and Flora. No comments.