Behavioral defenses are a key adaptation across animals, but confirming decay under relaxed selection is challenging. If expression involves decision-making, then defenses may only be expressed when the right environmental cues are available (i.e., cryptic plasticity). Even if defenses wane, they could be quickly restored once selection resumes as animals can learn by observing others (i.e., social memory). Here we tested cryptic plasticity and social memory under relaxed selection in a cuckoo host, the common reed warbler, by manipulating perceived parasitism risk with social information in geographically distinct areas differing in allopatry (100-1,000 years). Despite predicting that social information of a cuckoo vs. a control would elicit otherwise cryptic behavioral defenses, only birds that mobbed model cuckoos prior to manipulation upregulated this defense, and only in the recently allopatric population. Social information also had no effect on low-to-absent rates of foreign egg rejection, a second line of defense common to cuckoo host species. These results contrast with parasitized locations where similar methods provoke mobbing and increase egg rejection 10-fold. Our study therefore suggests that, even when manipulating information to account for reaction norms, behavioral defenses may degrade rapidly under relaxed selection, demonstrating a process facilitating a geographic mosaic of coevolution.

The “Chiffchaff complex” is a group of species with several similar subspecies, whose post-breeding distribution remains poorly understood, particularly in southern Europe. This study combines morphological and molecular approaches to investigate the subspecific composition and phenological patterns of Chiffchaffs captured in eastern Sicily. A total of 380 individuals were biometrically measured, with particular focus on wing length of P8 feather, and 81 individuals were genetically analyzed using ND2 mitochondrial marker. Morphological analysis highlighted significant variation in P8 length between phenological groups. Assuming that a turnover of individuals from different origins may occur in the study area, genetic investigation was deemed necessary to further investigate this high morphological diversity. Phylogenetic analysis revealed high intraspecific genetic diversity and identified two subspecies in the study area: P. c. collybita (73%) and P. c. abietinus (27%). These findings genetically confirm for the first time the presence of P. c. abietinus in Sicily and suggest a complex pattern of seasonal co-occurrence between populations. This work contributes to the understanding of Chiffchaff migration ecology and underlines the importance of integrating ringing data with molecular tools in Mediterranean biodiversity hotspots.

Four marine bird species breeding in the circum-Sicilian islands were monitored during 2021-2024 with the aim of updating data on distribution, breeding success, and population size for the EU Marine Strategy Directive (MSFD 2008/56/CE). Counts allowed to assess population sizes, in terms of breeding pairs, for Audouin’s Gull (91-160), Scopoli’s Shearwater (14,825-15,925), Yelkouan Shearwater (610-720), and Mediterranean Storm Petrel (3,030-3,050). However, for the latter two species, data could provide underestimates, as some breeding sites, located in poorly accessible areas, require further research.

We describe the results of the first regional census of herons and other colonial waterbirds, including Great Cormorants Phalacrocorax carbo, Little Bitterns Ixobrychus minutus, Black-crowned Night Herons Nycticorax nycticorax, Squacco Herons Ardeola ralloides, Western Cattle Herons Bubulcus ibis, Grey Herons Ardea cinerea, Purple Herons Ardea purpurea and Little Egrets Egretta garzetta, carried out throughout Sicily from 2007 to 2022. We also collected data about Great Egrets Casmerodius alba and other waterbird species in Ardeidae colonies without any breeding evidence, as Eurasian Spoonbills Platalea leucorodia and Glossy Ibis Plegadis falcinellus. Collected data highlighted a regional widespread increase of the numbers in known colonies and nests of each species, especially of Bubulcus ibis that showed a sharp increase in number from 30 nests recorded for the whole region in 2007 up to 530 nests in 2022, mainly concentrated in eastern Sicily, in the province of Catania. Also A. ralloides, N. nycticorax and E. garzetta showed a positive trend with an increase in the number of colonized locations and nests recorded, with A. ralloides occupying the most of the Sicilian colonies with at least few pairs. On the other hand, A. cinerea showed a slight negative trend, with 45 nests recorded in 2007 and only 31 in 2022, at the end of the study; A. purpurea is an irregular breeder with an oscillating and unpredictable trend related to only 1–4 ascertained pairs maximum for the whole region. Despite the P. carbo is a regular breeding species in Sicily, it has not showed any sign of expansion in the last decade, remaining confined to a few historical locations near the Simeto River and Lentini Lake. All data here presented are related to the minimum and ascertained numbers of colonies and counted nests. Small colonies may not have been counted in some unmonitored locations, often inaccessible. It is highly recommended, in the near future, the creation of a coordinated survey network that would improve and make the census more in-depth and better standardized.

The Gelsari and Lentini marshes, in east-central Sicily, are wetland under heavy anthropogenic pressure. This area is regularly subjected to water withdrawals and agriculture is practiced. Periodic bird census activities had been conducted in this area between 2016 and 2022 with collected data being supplemented with the data from a previous survey conducted between 2010 and 2016. During the censuses, numerous photographs were collected, which were later used for counts. In total, 121 surveys were carried out, with visits occurring approximately 20 times per year, covering all seasons. The data collected, both from bibliography and unpublished observations, were organised in table. 120 species and subspecies have been reported, 41 of which are in Annex I of the Birds Directive. Between 2021 and 2022, a water column measurement was taken in a central area of the Lentini marsh and compared with rainfall data in the area. It was found that water removal, occurring in both marshes in different modes, produced different effects on habitat conservation. Of the two marshes, Lentini is the one in which the existing favorable conditions in its most depressed areas, located below sea level, have allowed for the adequate conservation of the wetland. This environmental improvement having occurred with respect to the previous period has restored to the marsh its historically recognized possibility of not drying up completely during the summer period, allowing permanence of numerous birds. The obtained results suggest total elimination of agriculture and discontinuation of water withdrawals in the Lentini marsh as well as regulation of withdrawals in the Gelsari marsh.

ABSTRACT Capsule The Eurasian Reed Warbler Acrocephalus scirpaceus from breeding sites in Italy has little genetic variability in the mitochondrial cytochrome b gene but shows morphological variation suggesting isolation of some populations. Aims To investigate the morphometric and genetic trait variation of Eurasian Reed Warbler populations at a large temporal and spatial scale. Methods We analysed morphometric traits and the mitochondrial cytochrome b (cyt b) gene of samples collected over 25 years, from populations at seven sites across the Italian peninsula and islands. Results While we found no genetic differences, we detected significantly smaller body sizes in individuals breeding in Sicily and Sardinia compared to those from mainland Italy. There were also significant body size differences between two Sicilian populations: one larger breeding on the southern coast and the other smaller at an inner highland site. Conclusion The morphometric data, together with the site fidelity of individuals, are consistent with there being isolation of some populations. Specifically, our results are consistent with an example of polyphenism, morphological plasticity, in the populations of the main Italian islands, Sicily and Sardinia.

Our aim was to investigate the among-populations diversity of prey composition in Eurasian Reed Warblers’ diets via their droppings, both to assess the ecological validity of this sampling method and to test whether the prey species most abundant in fecal samples were also the most present in the Italian study site. We collected fecal samples at four sites throughout Italy, for a total of 144 samples. Within reedbeds, the breeding habitat of the Eurasian Reed Warbler, we also collected arthropods by carrying out entomological sweepings at one of the study sites. Within the fecal samples, we identified dozens of prey species, belonging mainly to Araneae, Coleoptera, Diptera, Hymenoptera and Aphidoidea taxa, whose compositions were not statistically different among sites. The commonest prey species were Coleoptera in the droppings (68.5%) and Diptera in the reedbeds (31.3%), although the latter was less numerous in the fecal samples. The diets of different Italian populations of Eurasian Reed Warbler emerging from our study underline a strong Coleopteran presence, without differences across Italy. Fecal samples appear to be an exhaustive method to study variation in Eurasian Reed Warbler diet and its ecological importance; however, although potential caveats do exist, such as the possible under-representation of Diptera.

Mediterranean Crossbills are as much differentiated as L. scotica and L. pytyopsittacus. They are sedentary, linked to pine trees and have evolved a thicker bill to extract the seeds from Pine cones. Their decolorization could be due to dietary causes. The authors studied biometrics, breeding phenology, and primary food of Italian populations living in Calabria and Etna (Sicily) and compared them with the other Mediterranean populations. A coevolutive radiation between the different populations of Mediterranean Crossbills presently living in the three main peninsulas, adiacent islands and North Africa occurred separately and this may be demonstrated by their morphometrics, their sedentariness, as well as by songs and some genetic results recently published. They conclude that the same criteria followed to raise L. curvirostra scotica to the species rank as scotica occur also for the different Mediterranean populations.

Insects are known to represent a critical part of the White Stork Ciconia ciconia diet throughout its breeding range. Yet, the composition of the diet in the storks breeding in the Mediterranean regions remains poorly explored. Here, we investigated the diet of a population of white storks from Sicily through pellets collected in 2003, 2007, and 2020. A total of 1,928 prey items were identified and classified into six categories. Insects dominated the diet in all years and represented 99.06% of the whole prey number. Two orders of insects were mainly consumed, namely Orthoptera, which were the most frequent prey, followed by Coleoptera. Within these, carabid beetles were dominant, followed by tenebrionids. Aiming to extend the study of the diet to the post-breeding period, we carried out direct observations on migratory Storks in September 2021, during the migration period. In this period, White Storks were observed feeding in arable lands with high concentration of small crickets Grylloderes brunneri. Altogether, our study provides new insights on the diet of White Storks in the Mediterranean range and highlights how conserving areas that support high diversity of insect species may also favor organisms at higher levels of the trophic chain.

A new complete check-list of Birds of Sicily is presented in this paper, with a comparison with previous lists for a period of one hundred and fifty years.Further, an unknown manuscript by Joseph Whitaker "Birds of Sicily", dated back to ca. 1920, has been transcribed and is here presented integrally.Thus, lists of birds here presented have been separated as follows: i) Doderlein (

and 2019, a first monitoring of Odonata promoted by CUT-GANA was conducted inside the Nature Reserve named "Complesso Speleologico Villasmundo -S.Alfio", in Melilli (Syracuse), in south-eastern Sicily.A total of 18 different species were recorded, 6 belonging to the Zygoptera suborder and 12 to the Anisoptera suborder, including Onychogomphus uncatus and Libellula fulva.Some information on uncommon species recorded in the neighbouring areas are also reported.

The Kentish Plover Charadrius alexandrinus is a sensitive species whose national breeding population has been undergoing a sharp decrease, up to 50%, in 2010 compared to the previous decade. Due to the lack of updated data and fragmented knowledge about its current status and distribution in Sicily, a specific and accurate monitoring of this species was carried out during the years 2018 and 2019. About 230 km of coastline and 64 UTM squares 10x10 km were investigated during the breeding seasons, and a total of 205-287 pairs have been estimated for the whole region, distributed in 41 UTM squares (including the island of Favignana). Pairs are mainly concentrated in the complex of “Saline di Trapani and Stagnone di Marsala” and along the sandy coast of Gulf of Gela, with a higher abundance along the southeast coast of the region. Breeding population showed a decrease of 18-28% in number of pairs in comparison to the last estimation of 250-400 pairs reported for the years 2009-2010. After the investigation of 108 km of coastline and 46 UTM squares, the Sicilian wintering population has been estimated at 376- 563 ind., with wintering flocks mainly concentrated in the wetlands of “Mazara del Vallo” and along the coasts of Syracuse and the Gulf of Gela. These updated estimates place Sicily as the second most important Italian region for the wintering of this species, just after Sardinia. For the first time, the data collected have made it possible to draw up qualitative-quantitative maps of C. alexandrinus distribution in Sicily, providing an important instrument for the management and planning of specific conservation actions, which should be based on habitat protection and implementation of appropriate artificial ecological niches.

ABSTRACT Using data from a survey of Italian birdwatchers, we examined whether recreation specialization affects birders’ travel intention through a two-dimensional framework based on the “behavior” and “skills, knowledge, and commitment” constructs. The model was estimated through a partial least squares structural equation “spread” model. We implemented a second-stage analysis, using a seemingly unrelated regression (SURE) model to identify which birder characteristics, attitudes, and preferences significantly affected the path scores. The findings demonstrated a significant and positive relationship between recreation specialization and birders’ travel intention, and offer evidence that birders’ behavior and skills, knowledge, and commitment were statistically significant lower hierarchical order constructs of recreation specialization. The intensity of these connections varied according to the birder’s profile, the source of information used to choose the destination site and the reasons behind the choice of site for birdwatching.

Natural History Museums are places of scientific dissemination and informal education, and have a fundamental role in scientific research and in preserving the historical heritage of a territory and its biodiversity. The island of Sicily, thanks to its geographic position as an inter-continental bridge in the Mediterranean, presents a notable ornithological diversity, with both sedentary species and species that migrate between Africa and Europe. For this reason, and thanks to a strong hunting tradition, Sicilian collections also depict the avifaunal assemblage historically present in the region, particularly for birds of prey, the group we focus on because of its particular ecological characteristics and cultural interests. However, the partnership among museum institutions, generally and in Italy, is complex and fragmented, and thus a census of Sicilian raptors collections had not been attempted yet. This study presents data from 16 public museum institutions, reporting the presence in their collections more than 1800 specimens belonging to 64 species. This census presents a detailed estimate of the Sicilian museum patrimony regarding this charismatic group, which may constitute a starting point for future studies and contribute to the visibility, promotion and interconnection of the institutions involved.

From March to September 2018 and 2019, a first monitoring of Odonata promoted by CUTGANAwas conducted inside a site of Natura 2000 network, named “Vallone di Piano della Corte”, nearAgira (Enna), Sicily. A total of 21 different species were recorded, including Pyrrhosoma nym-phula (Sulzer, 1776), for which there are no stations reported for this side of Sicily.

Gelsari and Lentini marshes are two large wetlands extending along the southern coast of the Gulf of Catania, in Sicily (Italy), which have always been studied extensively by naturalists of the past for their undisputed environmental value. The draining works of these areas, which have occurred in the last century, has led to a loss of interest for the marshes, which were considered lost from the naturalistic point of view. Thus, the scientific studies ceased and, in particular, stopped the recording of avifauna data. In more recent times, the temporary breakdown of pumping stations, that occurred from 2008 to 2010, has enabled the marshes to take back a natural hydrological regime for a period of a few years, short but enough to make habitats of community interest and for an extremely important birdlife to reappear. Therefore, a monitoring activity has been started, allowing collecting in systematic way information on species present between 2010 and 2016. The aim of this work is to make known the situation regarding the presence of birds In recent years and compare it with what is available from historical data and to highlight its value, despite the anthropic pressure to which the area is subject. Finally, management proposals are put forward, aimed at fulfilling the full potential of this important site.

GIS spatial analysis of three indicators (vegetation value, faunal richness and landscape heterogeneity) was used to detect and map High-Value Biodiversity Areas (HVBAs), estimate the coverage of biodiversity in the Sicilian protected areas network, and identify new priority areas that could improve long-term biodiversity conservation outcomes. Findings indicated that only 32% of HVBAs are currently covered by the protected areas network. Hotspot analysis revealed that a modest expansion (less than 1%) in the current extent of protected areas would include a disproportionate amount (56%) of biodiversity hotspots, and identified prioritized candidates HVBAs for designation of new protected areas.

The Audouin’s Gull Larus audouinii Payraudeau, 1826 has never been recorded breeding in Sicily: the authors are here reporting the discovery of a breeding colony on the island of Vendicari, province of Siracusa, off the south-east coast of Sicily. An estimated 50 60 pairs have bred there in 2010 and 2011 and 100 to 130 pairs in the period 2012-2016. All the basic information on breeding attempts and success, egg-laying dates, number of eggs laid, number of chicks fledged, and characteristics of each nest was collected. During the breeding season of 2012-2016 a total of 19 ringed adults were observed at the colony: 11 of these originated from the same colony (Vendicari) while 8 came from other colonies, of which 6 from Italy and 2 from the Ebro delta in Spain. Those gulls ringed as chicks from the Vendicari colony have so far shown that they spend the winter months in Sicily and North Africa, while in the spring and summer months, these birds have been observed in Sicily, Calabria, Apulia and Campania. The data presented here demonstrate the ability of this species in occupying new territories, sometimes on the periphery, and a tendency of population increase in a very short period of time, presumably through recruitment of individuals originating from other colonies. The data collected confirm a strong nest-site tenacity and also show that a significant part of the individuals present in the colony consisted of birds in their third year of life.

Five roosts of Eurasian Magpie Pica pica have been studied in Siracusa city (Sicily, Italy). One of the roosts was monitored periodically, for a total of 34 visits. All these communal roost was used all year round, although the highest densities were detected during the non-breeding season. The following environmental characteristics of the wooded areas used as night roosts were registered: the location and the extent and composition of vegetation. Roosts features suggest an active preference for areas with a favourable microclimate during the cold season; Black-billed Magpies avoided north exposed areas as well as deciduous trees; on the other hand they selected safe areas (i.e. with scarce or no human presence). Significant correlations have been found between the mean daily temperatures and roost arrival time. In particular, roost arrival times are delayed during the coldest days, likely due to extended feeding activities. Significant correlations have also been found between the number of birds in the roosts and day length, temperature and wind speed. The data suggest that night roosting aggregations are influenced by environmental variables; long, cold and windy nights induce the birds flocking together, possibly also to reduce individual predation risk. At the same time, roosting behaviour could be advantageous at an individual level because these aggregations enable intraspecific interactions.