Volume 48
2024


Layout by Roberto Brembilla

Avocetta
Volume 48 continuous publishing



  1. Editorial - The pitfalls and potential of citizen science in ornithology

    Arianna Passarotto & Alessandra Costanzo

    Abstract     Read Article       Download
    297 387
  2. The humble Stonechat Saxicola rubicola and the species neglected by ornithological research in Italy

    Maurizio Sarà

    Abstract     Read Article       Download
    271 376

    The query of one of the major online scientific research databases returned quite worrying data, because a large group of species breeding in Italy, 47 out of 270 (17%) has never been studied and this number grows further (56 species, 20.7% of the total) if we consider that 9 species with published papers have 0 h-index (i.e. do not yet have any citations). These species neglected by Italian ornithological research have been called ‘zero species’. Bird species without indexed studies are 87.2% native and mostly migratory (66.0%). They live mainly in wetlands (36.2%) and forest habitats (27.7%) and generally have an increasing population trend (44.7%). Furthermore, the majority of these species are classified as least concern by the Italian Red List (44.7%), with a lower percentage of threatened species (34.0%). Zero species are more unprotected than protected ones (61.7% vs 38.3%). Finally, 42.6% of them belong to passerines and have a very restricted geographical range (83.0%). Some examples of zero species are reported and discussed, such as the Stonechat Saxicola rubicola, the Common redpoll Acanthis flammea or the Red Kite Milvus milvus, highlighting some of their interesting traits that could stimulate research aimed at conservation.

  3. Territory selection of breeding Golden Eagles Aquila chrysaetos in a low-density population

    Andrea Mazzarano, Riccardo Mattea, Gianluca Damiani

    Abstract     Read Article       Download
    239 330

    Territory selection by birds of prey is an essential process influencing survival and productivity. For Golden Eagle Aquila chrysaetos, research in Europe has focused primarily upon migrating and high-density populations, and rarely on the territory selection in low-density populations. We analysed Golden Eagle breeding sites in Central Apennines (Italy), spanning from 29 sites in 1980 up to 38 sites in 2020, verifying in 4 different years (1980, 1990, 2000 and 2020) their status of occupancy or vacancy, through cross-checking data from available literature and field observations. In the chosen years, each site was characterized by land use and neighbouring distances variables, to individuate the presence of a possible common selection process. The different protection status of each area (unprotected or Natural/National Parks) was tested, assuming that habitat protection could have positive effects on Eagles’ territory selection. The so obtained panel data was statistically analysed by means of t-test, χ2 test and probit models. In one hand, Golden Eagles in the Apennines showed a continuous recolonization of territories, including seven previously vacant and two undiscovered sites. On the other hand, half of the vacant sites remain unoccupied. Our results suggest that Golden Eagles, in a low-density population, tend to minimize the effect of lower quality habitats by choosing a breeding territory which can guarantee low intra-specific interferences: 35% of 2020 breeding pairs have, at least, one nearby vacant territory. Depending on the quality of the available breeding habitat, Individual Adjustment Hypothesis (IAH) supports or replaces Habitat Heterogeneity Hypothesis (HHH).

  4. Diet of Golden Eagle (Aquila chrysaethos) nestlings in Central Apennines, Italy

    Gianluca Damiani, Andrea Mazzarano, Silvia Dancali, Paolo Forconi

    Abstract     Read Article       Download
    140 218

    The diet of animal species reflects important evolutionary and behavioural adaptations that may affect the viability of populations. The reproductive success, the habitat selection, and the spatial distribution of individuals are often related to trophic resources. By studying the diet of a predator, it is possible to better understand the ecological interactions between different species at a local scale. We studied the nestlings’ diet of six Golden Eagle (Aquila chrysaetos) breeding pairs in Central Apennines (Italy), through the analysis of pellets and prey remains (2000-2004) and integrated them with visual observations (2000-2022). While data from pellets and prey remains allowed for estimates in biomass and diet breadth, nest visual observations provided new qualitative insights into the species’ hunting behaviour. We were able to identify 16 species of mammals, 14 species of birds and 2 species of reptiles among prey items. The application of the Levins index on the 21 families detected produced a value of 8.45, indicating a rather wide trophic niche. The dominant preys were hares (Lepus europaeus and Lepus corsicanus), with a 25% frequency and 43% of the total estimated biomass. Notably, it appears that wild boars and corvids are becoming more important for the diet of the golden eagle’s nestlings, which is in agreement with the recent expansion of such species in the study regions, coupled with the decline of hares and Phasianids.

  5. Moult strategies and morphometric precisions in the Lilford's woodpecker Dendrocopos leucotos lilfordi

    Patrice Urbina-Tobias, Jean-Louis Grangé

    Abstract     Read Article       Download
    125 179

    This article presents a study of the plumage of the Lilford’s woodpecker Dendrocopos leucotos lilfordi. The species performs a partial post-juvenile moult for the first-year birds and a complete post-nuptial moult regularly arrested for adults. The criteria presented make it possible to differentiate the two age-classes of a bird in hand. Furthermore, a difference in wing shape via the wing formula appears between females and males, suggesting a different internuptial or post-juvenile dispersal behaviour depending on the sexes.

  6. Occurrence of Laminosioptes cysticola (Acariformes: Laminosioptidae) in Ardea alba egretta from the peri-urban area of Belém, Pará-Brazil

    David F. Conga, Gerson B. Oliveira, Amanda A. Figueiredo, Ana Sílvia S. Ribeiro, Washington L.A. Pereira

    Abstract     Read Article       Download
    57 87

    Mites of the genus Laminosioptes have been reported in domestic Galliformes birds and pigeons in some countries. They specifically infest the subcutaneous tissue of the host generating granulomatous lesions. In the current study, we reported the presence of Laminosioptes cysticola in the pectoral muscle of a specimen of Great Egret, Ardea alba egretta, found in the peri-urban area of Belém, Pará, Brazil. We discuss the role of this individual as vector of mites between domestic and wild birds and we recommend ornithologists and veterinaries to carry out careful observations of live and dead birds because small parasites such as the mites L. cysticola can easily remain undetected.

  7. The State of Sombre Tit Poecile lugubris Temminck, 1820 in Armenia

    Karen Aghababyan, Gurgen Khanamirian, Viktorya Gevorgyan, Asya Ghazaryan

    Abstract     Read Article       Download
    50 104

    The Sombre Tit Poecile lugubris is very little studied species, and within Armenia, it occurs only in the south-eastern regions of the country. The current study aims at providing data for the next assessment of the conservation status of Sombre Tit in Armenia, based on the data collected from 2003-2019. The obtained data show that Sombre Tits have slightly expanded their distribution to the north; their current Area of Occupancy makes 94 km2, while the Extent of Occurrence covers 1,065 km2. The population of Sombre Tit makes from 910 to 1,350 breeding pairs. During observed 17 years (2003-2019), the population trend of the species computed for the Meghri region of Armenia can be considered stable (Imputed Overall Slope: Additive = 0.0017 ± 0.0109; Multiplicative = 1.0017 ± 0.0109; P > 0.05), although demonstrates relatively strong fluctuations. The conservation status of Sombre Tit in Armenia should be revised, as it can correspond to the category Endangered, according to criteria C2a(ii). The main factors that can influence the species in Armenia are forest fires, which are relatively common in south-eastern Armenia, and the use of pesticides for forest pest control.

  8. Laying eggs on the same nest: unusual mixed-species clutch among three colonial shorebirds

    Paolo Salvador, Stefano Sponza

    Abstract     Read Article       Download
    63 61

    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 Giulia. To our knowledge, it is the first record with more than two species among Charadriiformes. We discuss the possible explanation concerning the limited suitable nesting space in a human-made breeding habitat. These findings are rarely reported despite their importance for comprehending the phenomenon from an ecological perspective.

  9. Long-term population trends of bird communities in artificially-protected wetlands of Northern Italy

    Stefano Borghi, Carlo Giannella, Andrea Ravagnani, Rossella Casari, Alessio Farioli, Giuseppe Rossi, Matteo Dal Zotto, Nunzio Grattini, Daniela Campobello

    Abstract     Read Article       Download
    24 33

    Artificial wetlands have become a common conservation approach to contrast the decline of biodiversity globally, as a result of the ongoing loss and fragmentation of natural habitats. Assessments on the trend of the avian biodiversity in artificial wetlands are essential to understand their conservation value. This study aims to analyse temporal changes in the abundance of bird guilds and species in small artificial wetlands in Northern Italy. We surveyed bird populations over the 2005-2019 period from three adjacent wetlands, and examined temporal trends of species as both single species and grouped in guilds. We found the water systems analysed supported a high diversity of species. Overall, we found Swans and Geese, Cormorants, Raptors and Large wading birds had an increasing trend between 2005 and 2019, while Gulls and Terns were stable, Ducks, Rails and Cranes, and Grebes and Divers were uncertain, and Shorebirds decreased. Species-specific trends were revealed: Circus cyaneus (+13.40%) and Falco vespertinus (+21.32%) increased, while Calidris pugnax decreased (-7.91%) and Aythya nyroca was uncertain (+6.30%). Furthermore, dominant species had mainly a stable abundance (e.g. Larus ridibundus and Anas platyrhynchos), while Anas crecca increased (+2.97%), Vanellus vanellus decreased (-3.65%), and Fulica atra had an uncertain trend. We described these local systems as of vital importance to sustain the local and regional avian biodiversity, also urging to ensure national and international functional connectivity between natural and artificial systems.

  10. New extra-Amazonian records of the Black-billed Cuckoo Coccyzus erythropthalmus (Cuculidae) for Brazil

    Fabio Schunck, Luis Katsumi Yabase, Marta Yabase, Guilherme Alves Serpa, Mateus Rocha Ribas, Pedro Scherer-Neto, Gérard Baudet, Eduardo Carrano, Tomas Sigrist, Guilherme Renzo Rocha Brito

    Abstract     Read Article       Download
    9 7

    The breeding grounds of the Black-billed Cuckoo Coccyzus erythropthalmus encompass a wide area in northern North America. During the austral winter individuals migrate to non-breeding areas in South America. There had been only three known locations for the species in Brazil, two in the Amazon Forest and one in the Atlantic Forest. Here, we aim to present new records in Brazil and to organize the available literature recovering historical data. The new records are in the Southeast and South regions and thus represent the first documented records outside the Brazilian Amazon. These findings indicate an expansion of the area considered nomadic for the species. All extra-Amazonian records were made in strong El Niño years, a climate phenomenon that may be changing bird migration patterns in South America, which requires further investigation.

  11. To change not to drown: Eurasian Oystercatchers Haematopus ostralegus adopt pole tops as safe nesting sites in the Lagoon of Venice

    Roberto G. Valle, Francesco Scarton

    Abstract     Read Article       Download
    121 228

    Eurasian Oystercatchers have increasingly adopted pole tops in the last decade in the Lagoon of Venice (NE Italy). At the end of the study, 7% of the breeding population of the Lagoon (n = 180) nested on pole tops. Nests built in these structures are safe from flooding due to extremely high tides, thus allowing a high hatching success: 42 clutches out of 43 (97.7%) hatched. We hypothesise that this is an adaptive behaviour to the increased frequency of extreme high tides in the last decade and is a good omen for the species. The good availability of pole tops suitable for nesting in the Lagoon allows breeding in areas otherwise unsuitable for nesting due to the lack of sites safe from flooding. Placement of artificial nests on pole tops is also feasible and could be an easy and cheap strategy for the conservation of the breeding population of Oystercatchers in the Lagoon of Venice as extreme high tides and spring storms will likely increase in the future

  12. The Golden Eagle Aquila chrysaetos in the northern Marches Apennines (Central Italy). Long-term monitoring (1983-2023) in the mountains of Pesaro-Urbino

    Maurizio Saltarelli, Marco Pantalone

    Abstract     Read Article       Download
    8 8

    This study describes the monitoring work related to the nesting of the Golden Eagle Aquila chrysaetos in Northern Marches Apennines (Central Italy), in province of Pesaro-Urbino. Monitoring took place between 1983-2023, when a minimum of 1 and a maximum of 5 breeding pairs nested in the research area. The 16 nesting sites used by the Golden Eagle were located on cliffs with niches, ledges and high shallow caves, at an average height of 744.43 m (±249.7 m) a.s.l. The average number of nests per territory was 3.2 (±2.28 SD). The exposure of nest sites was heterogeneous. The maximum density for the species was 0.60 pairs/100 km2 and the Nearest Neighbor Distance was 8.84 km ±2.5. Most of the first incubations occurred in March and within the study period, at least one incubation was always observed. Incubation and fledging periods lasted on average 44.70 days (±1.78 d) and 81.76 days (±6.45 d), respectively. Over the study period, the breeding pairs raised a total of 98 chicks, of which 75 fledged successfully. Across the 41 years of monitoring, the productivity rate recorded was 0.65 (N. fledglings /N. pairs), the reproductive success 0.94 (N. fledglings /N. pairs with confirmed incubation), the fledging success 1.14 (fledglings/N. success pairs) and the nestling mortality was 23.5%.  In 13.6% of the total successful breeding events, two fledglings were raised per nest. Only in three years of monitoring, no fledgling was raised.

  13. Forum - Conservation experiences, evidence, and opinions: Conservation front lines need experienced troops: the role of a scientific trust in a changing world

    Corrado Battisti, Roberto Ambrosini, Giacomo Assandri, Rosario Balestrieri, Enrico Bassi, Gaia Bazzi, Alessandro Berlusconi, Chiara Bettega, Giuseppe Bogliani, Letizia Campioni, Benedetta Catitti, Gianpasquale Chiatante, Alessandra Costanzo, Davide Dominoni, Giulia Masoero, Alessandro Montemaggiori, Flavio Monti, Michelangelo Morganti, Arianna Passarotto, Samuele Ramellini, Gloria Ramello, Maurizio Sarà

    Abstract     Read Article       Download
    122 104

    The active participation of scientific trusts, including CISO (Centro Italiano Studi Ornitologici), in applied conservation actions plays a crucial role in addressing the challenges faced by natural and semi-natural landscapes, which are increasingly impacted by improper land-use and land-cover. This is particularly true for those landscapes where Large Infrastructures and Big Events (LIBEs) are planned. In these circumstances, researchers, professionals, and environmentalists typically express their concerns on the impacts of LIBEs through mediatic campaigns, often highlighting the ecological importance of vulnerable areas. These actions form the first, useful level of engagement in conservation. However, we advocate for a more proactive role of scientific trusts, which should entail forming task forces of conservation experts and providing scientific support in management decisions when LIBEs are being considered. In our opinion, scientists should locally produce original field studies by using effective sampling designs such as Before-After-Control-Impact surveys. We highlight that such a targeted level of action may support the public agencies when authorizing (or not) LIBEs, by providing evidence-based information about the ecological value of the target area and the potential impacts of LIBEs on ecosystem functions and local biodiversity. The aim is to avoid emotion-based social media loops, conflicts, and polarizations in the discussions about the ecological impacts of LIBEs.

  14. Population size and breeding success of the Scopoli’s Shearwater on Lampione Islet

    Antonella Di Gangi, Vittoria Roatti, Federico Ottoveggio, Bruno Massa & Giacomo Dell'Omo

    Abstract     Read Article       Download
    45 39

    The islet of Lampione, located in the archipelago of the Pelagie islands
    (Sicily channel), is known to be the Italian southernmost breeding site for the
    Scopoli’s Shearwater Calonectris diomedea. So far, there was little
    information on the number of Shearwaters attending the islet and on the status
    of this breeding population. Therefore, during an eight-year study period, we
    determined the active nests used by the birds and assessed the annual breeding
    success of the population on a subset of study nests. Counts of the active
    nests and of the birds attending the rafts at sea revealed a breeding
    population of approx. 230 pairs, which makes the islet the fifth-largest
    breeding colony among the Italian islands. Breeding success on Lampione ranged
    from 39.7% and 70.8% and was about 30% lower compared to that measured in the
    nearby colony of Linosa. Breeding failure on Lampione in 2018 was mainly due to
    predation on chicks by Yellow-legged Gulls Larus michaellis, but
    predation was later reduced by improving the concealing of existing burrows and
    the construction of artificial nests. We also observed intraspecific
    competition for nest sites. Our findings show the importance of the islet of
    Lampione, and of the Pelagie archipelago, for the conservation of this species.

  15. Nesting tree selection in urban Woodpigeon; applications in urban planning to reduce the conflicts with human activities 

    Eduardo Gil, Anika Meyer, Diego Villanúa

    Abstract     Read Article       Download
    34 35

    The urban populations of Woodpigeon (Columba palumbus) is
    increasing throughout Europe, generating conflicts with humans associated with
    damage resulting from their feces deposition or with their role in the
    maintenance of zoonotic diseases. Despite this, the species has a significant
    conservation value, as it is an important part of the diet of various
    threatened raptors like the Bonelli´s (Aquila fasciata) and Iberian
    Imperial Eagle (Aquila adalberti). Also, it is a game species whose
    hunting generates large income in certain regions. 
    In the present work, we assessed
    the habitat selection during the nesting period, analyzing the tree species
    used for nesting and nest distribution patterns in streets and urban
    parks. It has been verified how the location of the nest is not random,
    with a percentage of them in evergreen trees significantly higher than expected
    and with a significant selection of certain tree species like Pinus sp.,
    Robinia pseudoacacia 
    or Ulmus sp …) while
    others like Prunus sp., Melia azedarach or Populus
    sp 
    were avoided. Significant differences were also found in the
    density of nests, being significantly greater in the streets (12.3 ±11.6
    nest/ha) than in parks (5.7 ±3.7 nest/ha). It is discussed
    how  the plantations in areas with benches or vehicle parking of tree
    species negatively selected by Woodpigeons for nesting and tree species
    positively selected by Woodpigeons in the rest of the park areas might lead to
    a reduction of the species associated conflicts while guaranteeing its conservation.

  16. Preliminary data on the activity of male and female common pheasants Phasianus colchicus during the breeding period in a Mediterranean area

    Andrea Viviano, Lorenzo Lazzeri, Alessandro Vitale, Emiliano Mori

    Abstract     Read Article       Download
    19 18

    Assessing patterns of activity rhythms in wildlife is pivotal for species conservation. In this work, we aimed at determining the curve of activity rhythms of male and female common pheasants Phasianus colchicus in a Mediterranean area in central Italy. We used camera-trapping and we computed the inter-sexual temporal overlap of activity rhythms in the breeding period. We collected 129 independent records of common pheasants (males, N = 90; females, N = 39). Males were mostly active in the morning, whereas female activity was mostly concentrated at dawn and dusk, showing an intermediate overlap of diurnal activity rhythms (Δ1 = 0.55).  Recorded patterns of activity rhythms confirmed the importance of ecotones for the conservation of this species, which represent an important prey for several native carnivores.

  17. Vocal and territorial behaviour of Puff-throated Babbler, a South-Asian duetting passerine

    Ekaterina M. Shishkina, Nguyen Van Linh, Alexey S. Opaev

    Abstract     Read Article       Download
    6 0

    Territorial songbirds use singing as an interactive social signal during territorial interactions. Considerable information has been accumulated about the communication of passerine birds in the context of territorial competition. Most of such data, however, were gathered in the northern temperate zone. Only a few studies have been conducted in the tropical zone. In this study, we describe for the first time the vocal and territorial behaviour of the Puff-throated Babbler Pellorneum ruficeps, a South Asian tropical resident bird. We recorded spontaneous vocalization simulated territorial intrusion by broadcasting different vocalizations at territories.  We played back different types of conspecific vocalizations to territorial males: (1) male simple song, (2) male complex song, and (3) duet. Depending on context, there were three types of male vocalizations: simple song, complex song, and subsong. While singing spontaneously, males produced a simple song of 2–3 elements, repeated at a rate of 10–12 songs per minute. Males could respond to playback with complex songs, which are much more elaborate and longer (up to 5–10 seconds) vocalization emitted at a rate of approximately one song per minute. Subsong is the most commonly heard vocalization during playback-simulated territorial intrusion. Females could acoustically respond to playback along with the males, forming a duet. While duetting, females produced a sequence of identical broadband elements (trills) overlapping the male complex song. In response to simple song playback, males sang, approached the loudspeaker, and flew around it. Males reacted much more strongly when presented with the playback of complex songs. They sang more complex songs, performed more flyovers, and produced subsongs. Therefore, complex songs are an aggressive signal used in the context of territorial competition. We observed male-female duets in response to complex song playback only. Males sang more actively and performed more flyovers in response to duets than to complex songs. We thus assumed that the duet is a more aggressive signal than the complex song.