Stefano Sponza

• University of Trieste

Mixed clutches are relatively uncommon among colonial shorebirds and challenging to document. Here, we report the co-occurrence of three species’ eggs, belonging to Pied Avocet Recurvirostra avosetta, Little Tern Sternula albifrons and Common Tern Sterna hirundo, in the same nest within a large colony in the Marano and Grado Lagoon, Friuli Venezia...

The Collared Pratincole Glareola pratincola has a large and fragmented breeding distribution in the Palearctic. In Italy it is an uncommon migrant breeder and he breeding sites are very patchily distributed and irregularly used, with most frequent occurrences in the N Adriatic, N Apulia, Campania, Sardinia and Sicily. We report a new breeding site...

The advantages derived from the use of Uncrewed Aerial Vehicles (UAVs) are well-established: they are cost-effective and easy to use. There are numerous environmental applications, particularly when monitoring contexts characterized by rapid morphological changes and high rates of sediment transport, such as coastal areas. In this paper, three diff...

Le forme tipiche della laguna di Marano e di Grado hanno subito importanti mutamenti dalla metà del secolo scorso, ben documentati. L’ambiente fisico continua a trasformarsi per la “marinizzazione” causata dall’innalzamento del livello del mare, accentuato da altri fattori locali. Assistiamo così a una progressiva semplificazione delle morfologie l...

Bycatch, the incidental capture of vulnerable species in fisheries, has been recognized as one of the main conservation issues affecting seabird species globally. According to recent estimates, 200.000 seabirds drown each year in European waters as a result of bycatch. Bycatch rates vary widely geographically due to fishing activity, environmental...

The shoreline, the line where the sea and the shore meet, is an important feature of the coastal environment. While the shoreline concept is simple, it's extremely difficult to track in real-world contexts. What are we already measuring considering the ongoing Sea-Level Rise? How far will the shoreline be from the datum's zero in the future? These...

The Greater Flamingo Phoenicopterus roseus is known as an ecosystem engineer, rearranging sediment in peculiar bedforms as a consequence of its filter-feeding behaviour. In recent decades, the populations of the Greater Flamingo have notably increased, and now the species is one of the most abundant waterbirds in Mediterranean wetlands. Owing to it...

The necessity of balancing conservation issues with the protection of aquaculture activities drives research to quantify the impact of the Great Cormorant Phalacrocorax carbo and to identify the best mitigation strategies. This study aims to characterise the diet in relation to the possible impact of the Great Cormorant on the extensive aquaculture...

While beach erosion and sand loss are typically of great concern to the tourism industry, managing rapid morphological changes linked to large amounts of moving sediments is the challenge facing Grado, an important seaside resort in the northern Adriatic, Italy. The cause of the unusual management conflict is the presence of the Mula di Muggia Bank...

The main goal of this work is to understand the interactions between primary producers (plants) and consumers (herbivore birds) for the conservation of ecosystems such as lagoons, in the view of plant-herbivore interactions. We studied the relationships between the abundance of the herbivore bird Eurasian Wigeon (Anas penelope) and the distribution...

A comprehensive understanding of the interactions between primary producers and consumers plays an important role for the conservation of sensitive ecosystems such as lagoons. In this light, we studied the relationships between the flocks' size of Mareca penelope and the distribution of three seagrass species (Cymodocea nodosa, Zoostera marina and...

Fisheries have an enormous economic importance but reconciling their socio-economic features with the conservation and sustainability of marine ecosystems presents major challenges. Bycatch mortality from fisheries is clearly among the most serious global threats for marine ecosystems, affecting a wide range of top predators. Recent estimates repor...

Geographically separated populations tend to be less connected by gene flow, as a result of physical or non-physical barriers preventing dispersal, and this can lead to genetic structure. In this context, highly mobile organisms such as seabirds are interesting because the small effect of physical barriers means non-physical ones may be relatively...

The third national census of the breeding colonies of the Great cormorant Phalacrocorax carbo sinensis was carried out in Italy in 2011 as a part of the project "Cormorant Counts in the western Palearctic " coordinated by the IUCN-WI Cormorant Research Group. Counts were carried out in 11 regions and 36 colonies and 2,870 nests (range 2,830-2,980)...

Movements of Mediterranean Shags (Phalacrocorax aristotelis desmarestii, Payraudeau 1826) between Croatian breeding colonies and non-breeding areas such as the Gulf of Trieste increased consistently from the 1980s to become a migratory movement at the present time. In order to characterise the patterns of this migration and the behaviour of first-y...

CapsuleShags move between breeding and non-breeding areas and this is associated with a significant change in diet. AimsTo determine whether the diet of Shags nesting on islets off the Croatian coast is the same as their diet after the post-breeding move to the Gulf of Trieste. Methods Diet was determined by the analysis of 611 regurgitated food pe...

The fine link between a particular dive pattern and a specific prey item represents a challenging task in the analysis of marine predator–prey relationships. There is growing evidence that prey type affects diving seabirds’ foraging strategies, dive shapes and underwater activity costs. This study investigates whether a generalist diver, the Great...

From the 1980s, Mediterranean shags Phalacrocorax aristotelis desmarestii have become regular summer visitors in the Gulf of Trieste (N-E Italy), as post-breeding movements from Croatian breeding colonies. To characterize such a recent habit and to explore diving optimality models, we investigate foraging strategies and diving patterns at different...

This study examined nest-site selection of four woodpecker species living in the floodplain forests of the Isonzo river (Gorizia). 14 plots were examined for a total area of 278 ha. We estimated the number of pairs for the whole study area:60 of the Great Spotted Woodpecker Dendrocopos major, 30 of the Green Woodpecker Picus viridis, 13 of the Less...

The aim of this study was to determine the importance of different environments for Cormorant Phalacrocorax carbo biology in the Grado and Marano lagoon (Friuli Venezia Giulia, NE Italy, Upper Adriatic Sea), and to estimate the levels of fish removal within such areas. Data were collected on Cormorant abundance and the amount of fish consumed in tw...

The results of 12 monthly censuses of waterbirds, carried out with constant effort in the Grado-Marano Lagoon (Friuli Venezia Giulia) in the period June 2006 - May 2007, are reported. The data originate from the integration of terrestrial and aerial censuses, that were carried out at spring high tides. 184 1x1 km squares, corresponding to the study...

The purpose of this paper is to assess the influence of several biotic and abiotic factors on the abundance of waterbirds in the Grado-Marano Lagoon. The Grado-Marano Lagoon is situated in the Northeast of the Adriatic Sea with an extension of approximately 160 km2. ASTER satellite images were utilized to classify different types of morphologies an...

We recorded preferential use of the left and right monocular visual field in black-winged stilts, Himantopus himantopus, during predatory pecking and during courtship and mating behaviour in a naturalistic setting. The stilts had a population-level preference for using their right monocular visual field before predatory pecking; pecks that followed...

Nel 2001 e 2002 in provincia di Gorizia (loc. Isola della Cona, Riserva Naturale Regionale Foce dell?Isonzo) due giovani maschi di volpe sono stati marcati con radiocollari, al fine di raccogliere dati sulla loro dispersione. L?area di studio, di circa 20 km², presenta zone boscose, boscaglie golenali, prati umidi, canneti e barene, inserite, comun...

The predatory behaviour of four owl species, tawny owl (Strix aluco), long-eared owl (Asio otus), little owl (Athene noctua) and barn owl (Tyto alba), was compared. The birds were wild individ-uals temporarily in captivity for rehabilitation and were tested be-fore release into an outdoor pen. Between four and ten birds per species were individuall...

The predatory behaviour on mice by sample of seventeen captive barn owls (Tyto alba) was studied. The owls were divided into two groups according to their age when they entered the Rehabilitation Centre used for this study (either adults/subadults, i.e., with previous predatory experience in the wild, or as fledglings, without any experience of pre...

Questo lavoro, attualmente in corso di svolgimento, rientra nell'ambito del Progetto Transna-zionale INTERREG IIIA Transfrontaliero Adriatico dal titolo "Ruolo ecologico delle zone umide per la sosta e lo svernamento degli uccelli acquatici nell'Adriatico settentrionale: linee guida per la conservazione e la gestione del patrimonio naturale marino...