1,721,077 research outputs found
Nesting of the Spotless Starling, Sturnus unicolor, on the island of Favignana (Aegadian Islands, Sicily)
Full text linkThe presence of the Spotless Starling in Sicily was reported for the first time at the beginning of the XIX century, although the first nests for the province of Trapani are reported almost at the end of the XX century. As a breeder, the Spotless Starling remained absent from all the circumsicilian islands until the first report for the island of Pantelleria, in 2012. In 2020, the nest of Spotless Starling was observed on the island of Favignana, within a hole on an antenna. The couple fed the chicks with Ligia italica crustacean isopod of the family Ligiidae. The nesting on the island of Favignana confirms the continuous expansion of the species in Sicil
Habitat Determinants and Density of the Endemic Sicilian Rock Partridge Alectoris graeca whitakeri on Mt. Etna, Sicily, Italy
No full textThe assessment of the conservation status of a species is the first step to prevent local extinction and to plan appropriate, effective and scientifically sound conservation actions, hence knowledge of the distribution, population trends and characteristics of preferred habitat is crucial for the conservation of a species. Galliformes are facing
increasing threats related to overhunting, habitat loss and fragmentation, and human disturbance. The Sicilian Rock Partridge (hereafter Rock Partridge) Alectoris graeca whitakeri is a significant conservation unit endemic to Sicily (Italy) classified as Near Threatened by the IUCN due to a decreasing population. Few studies have been conducted on the occurrence and population density of this subspecies. Here, we estimated its population density and identified which habitat factors drive the occurrence of this species on Mt. Etna. We used a combination of sampling methods (speciesspecific play-back calls, distance sampling, camera-trapping) to collect count and presence/absence data, which were then integrated into a single habitat model (presence vs. absence). We obtained 24 responses from play-back calls (plus 8 individuals observed while performing the play-back calls), 8 sightings from distance sampling, 6 detections from
camera-trapping. Probability of occurrence of Rock Partridge on Mt. Etna was positively driven by shrub and meadow vegetation, whereas its occurrence decreased with an increase in both woody areas (coniferous and deciduous) and elevation.
Population density estimated using play-back call data resulted in 0.80 pairs/km2 (95% CI: 0.17–2.22) over an area of 53.7 km2. The density of Rock Partridge on Mt. Etna appeared to have slightly declined and its distribution undergone a contraction since the previous survey. Several potential threats to the Rock Partridge in Sicily are currently increasing and should be mitigated to ensure the long-term survival of this unique population on Mt. Etna, as well as in the whole island of Sicily
The spreading of the invasive italian wall lizard on Vulcano, the last island inhabited by the critically endangered aeolian wall lizard
Full text link[EN] The Aeolian Wall Lizard (Podarcis raffoneae) is an endemic species of the Aeolian Archipelago of Italy (Mediterranean Sea). Its distribution is limited to three islets and two relict populations on a relatively large island: Vulcano (a population on the summit of Gran Cratere volcano and another on Capo Grosso promontory). The critically endangered Aeolian Wall Lizard is threatened by the introduction of the Italian Wall Lizard (Podarcis siculus), which successfully competes and hybridizes with the endemic lizard. The invasive lizard is widespread on Vulcano, although the literature does not provide the exact distribution. Our first aim was updating the distribution of the Italian Wall Lizard on Vulcano, with special attention to the last enclaves of the Aeolian Wall Lizard. Our second purpose was investigating the factors determining this distribution range. In the spring of 2016, we surveyed the Italian Wall Lizard distribution on Vulcano, considering 10 human-related and 10 natural areas, including Gran Cratere volcano and Capo Grosso promontory. We recorded the presence of the invasive Italian Wall Lizard in each survey area. As a consequence, the Aeolian Wall Lizard populations of Vulcano face an imminent extinction risk. The main factors increasing the presence probability of this invasive lizard on Vulcano were the nearness to the harbor (the introduction gateway) and the urbanization degree (the invasion pathway). Therefore, we suggest the implementation of a control plan simultaneously acting on the areas of sympatry (mostly Capo Grosso promontory), the introduction gateway (Vulcano harbor), and the source populations (urban areas).[IT] La Lucertola delle Eolie (Podarcis raffoneae) è una specie endemica dell’Arcipelago Eoliano (Italia, Mar Mediterraneo). La sua distribuzione è limitata a tre isolotti e due popolazioni relitte in un’isola relativamente grande: Vulcano (una popolazione sulla sommità del vulcano Gran Cratere e un’altra sul promontorio di Capo Grosso). La Lucertola delle Eolie, una specie in pericolo critico d’estinzione, è minacciata dall’introduzione della Lucertola Campestre (Podarcis siculus), a causa della competizione e della possibilità di ibridazione. La Lucertola Campestre è ormai diffusa su tutta l’isola di Vulcano, ma la letteratura scientifica non fornisce l’esatta area di distribuzione. Il primo obiettivo di questo studio è attualizzare l’area di distribuzione conosciuta della Lucertola Campestre su Vulcano, prestando speciale attenzione alle ultime enclavi della Lucertola delle Eolie. Il secondo obiettivo è comprendere i fattori che determinano l’attuale area di distribuzione di questa specie nella nostra area di studio. Nella primavera del 2016, abbiamo monitorato la distribuzione della Lucertola Campestre su Vulcano, considerando 10 aree antropizzate e 10 aree naturali, includendo il vulcano Gran Cratere e il promontorio di Capo Grosso. Abbiamo registrato la presenza della Lucertola Campestre in ogni area monitorata. Come conseguenza, le popolazioni di Lucertola delle Eolie di Vulcano affrontano un rischio d’estinzione imminente. I principali fattori che influenzano positivamente la probabilità di presenza della Lucertola Campestre su Vulcano sono la vicinanza al porto (il portale d’entrata di questa specie) e il grado di urbanizzazione. Quindi, suggeriamo l’implementazione di un piano di controllo che agisca simultaneamente nelle aree di simpatria (soprattutto Capo Grosso), nel portale d’entrata (il porto di Vulcano), e sulle popolazioni sorgente (nelle aree urbane).Peer reviewe
New data about Chiropterofauna of the “
Full text linkThis work increase the knowledge related to bat fauna present in the “Monte Pellegrino” Nature Reserve in the Palermo municipality. The acoustic sampling took place in the summer/autumn season using the D500X Bat detector in 22 samples. The identified signals were attributed to 8 species and one genus. The Taxa with the most passes in the reserve are: Tadarita teniotis followed by Pipistrellus kuhlii, Hypsugo savii (100% of Costancy), Pipistrellus pygmaeus, Pipistrellus pipistrellus, Plecotus sp., Miniopterus schreibersii and last with a single recording Rhinolophus ferrumequinum and Rhinolophus hipposideros. The dendrogram of similarity shows 3 distinct bats cenosis. Two samples present intense activity in almost all time slots and three samples, close to each, show a peak increase in the intermediate time slots for the three most abundant species. The analysis carried out on the environmental preferences shows that among the 13 Corine Land Cover (CLC) habitats, the highest number of passes is recorded in Artificial lakes (code 5122), Orchards (code 222) and Arid limestone grassland (code 3211). The Arid limestone grassland habitat (code 3211) has the highest Shannon Index value, while the Mastic stain habitat (code 32312) has the lowest diversity value. The dendrogram of similarity shows two clusters. In the first there are Gorse (code 32231), Mediterranean scrub (code 31111), Orchards (code 222), Mosaic of agricultural plots (code 242), while the second cluster contains the remaining habitats
Sexing adult Cory's Shearwater by discriminant analysis of body measurements on Linosa Island (Sicilian Channel), Italy
No full textMales and females of many avian species may show no plumage dimorphism, but often can be sexed by differences in body measurements. Sex determination of many Cory's Shearwaters Calonetris diomedea, was possible by multiplying bill length by bill depth. In this study, discriminant analysis of six measurements (bill length, bill depth, wing, tail, tarsus and mass) was performed on Cory's Shearwaters breeding on Linosa Island (Sicilian Channel), Italy and the efficiency of sex determination was compared with the univariate method. Results show the advantages of the discriminant functions. Bill depth is the best parameter (up to 92% correct classification), followed by mass (84% correct classification); using mass is simple and causes less disturbance to the birds. Received 10 August 2000, accepted 2 February 2001
Indagini sulla variazione fenotipica in ambienti insulari e microinsulari delle specie di Podarcis Wagler, 1820 (Reptilia, Lacertidae) presenti in Sicilia e in alcune isole circumsiciliane.
No full textGoing Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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