Volume 44 - N. 1
June 2020

Avocetta
Volume 44 - N. 1
Volume 44, N°1 - 2020



  1. Editorial  - COVID-19 and ornithology: will 2020 be a sad gap in our data?

    Roberto Ambrosini, Editor-in-Chief

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  2. Avian brood parasitism in Italy: another perspective

    Daniela Campobello, Spencer G. Sealy

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    We present a quantitative analysis of the data reported in the only published review of parasitism frequency on hosts of Common
    Cuckoo Cuculus canorus in a Mediterranean area. We first eliminated a bias potentially introduced by the method by which data
    were recorded. Of the initial potential 70 species parasitized in Italy, only 44 were confirmed as host species, of which only 10 species
    had more than 10% of their total nests parasitized. We highlighted differential parasitism on host species according to geographic area,
    but the analysis suggested results were strongly biased because nest location was generally not reported and the number of records steeply
    decreased from North to South.

  3. The historical and current distribution of Dalmatian Pelican Pelecanus crispus and Great White Pelican Pelecanus onocrotalus in Greece and adjacent areas: 1830-2019

    George Handrinos and Giorgos Catsadorakis

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    Evidence about the historical breeding distribution of Dalmatian Pelicans Pelecanus crispus and Great White Pelicans Pelecanus onocrotalus in Greece and an adjacent zone was sought in all historical scientific literature containing references to pelicans, starting from the antiquity. Pelicans were familiar to ancient Greeks, although the two species were not distinguished. Aristotle was the first to observe and describe their migration movements in the Balkans. Subsequently, nothing was mentioned for pelicans until the 16th century observations and writings of Pierre Belon du Mans. In mid-19th century the first scientific data for both species appeared and nesting of the Dalmatian Pelicans was noted for the period 1830- 1900 in seven wetlands at Peloponnese and south mainland Greece and six at northern Greece and adjacent areas along latitude 41oN. It is impossible to evaluate the actual status of pelicans in the region during 1900-1950 as none of the few contemporary ornithological publications mentioned anything about nesting of pelicans in Greece. The breeding range of Dalmatian Pelicans had probably shrunk dramatically, although it is unlikely that all the old colonies were exterminated. Until the end of 1970s, many of the wetlands where Dalmatian pelicans bred were drained or heavily altered and the number of known colonies was reduced from seven to three, with two of them in Greece, at Amvrakikos and Lake Mikri Prespa and one at Karavasta in Albania. Scientific and conservation work initiated in 1983 mainly by the “International Pelican Research and Conservation Project” and conservation organisations, led at the turn of the century to a manyfold increase of the Amvrakikos and the Lake Mikri Prespa Dalmatian pelican colonies, which subsequently gave rise to four new colonies in the period 2003-2015: Lake Kerkini, Messolonghi lagoons, Karla Reservoir and Lake Chimaditis. The overall breeding population rose from 100-120 pairs and two colonies in the late ‘60s to over 2100 pairs and six colonies in the end of the 2010s. Simultaneously, the Great White Pelican breeding population rose from less than 100 pairs and one colony to over 700 pairs and three colonies.

  4. Loss of graded enemy recognition in a Whitehead population allopatric with brood-parasitic Long-tailed Cuckoos

    Shelby L. Lawson, Nora Leuschner, Brian J. Gill, Janice K. Enos and Mark E. Hauber

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    Many avian hosts of brood parasitic birds discriminate between various types of threats at the nest and may respond with categorically different, specifically anti-predatory or anti-parasitic behaviors. Alternatively, hosts may adjust their responses to threat level in a graded manner, responding more aggressively to brood parasites during the laying and incubation stages of nesting, when nests are most susceptible to parasitism, and more aggressively to nest predators during the nestling and fledgling stages when predation would be more costly than parasitism. In New Zealand, endemic host Whiteheads Mohoua albicilla act inconspicuously around their nests in the presence of sympatric Long-tailed Cuckoos Urodynamis taitensis, their obligate brood parasite, perhaps to avoid disclosing nest location. We tested behavioral responses of a Whitehead population on Tiritiri Matangi Island that has been breeding allopatrically from cuckoos for 17 years. We also presented models of the allopatric parasite, a sympatric predator (Morepork Owl, Ninox novaeseelandiae), and a sympatric, non-threatening, introduced heterospecific (Song Thrush, Turdus philomelos) during the egg and chick stages, and to groups of cooperatively breeding Whiteheads. We compared responses across nest stages and stimulus types. We found that, unlike sympatric Whiteheads elsewhere in New Zealand, Whiteheads on Tiritiri Matangi produced alarm calls in response to the cuckoo model. Furthermore, the rate of alarm calling was similar towards the cuckoo and the owl, and across the egg and chick stages, and higher than to the control stimulus. Despite the limitations of the study, these results are consistent with allopatric Whiteheads having lost their specific anti-parasitic defense tactics in response to brood parasitic cuckoos.

  5. Short Note - Current distribution and population size of the Barred Warbler Sylvia nisoria in South Tyrol (Italy)

    Francesco Ceresa, Matteo Anderle, Leo Hilpold, Roberto Maistri, Oskar Niederfriniger, Renato Sascor and Petra Kranebitter

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    The Barred Warbler Sylvia nisoria is a critically endangered breeding species in Italy, given the severe decline suffered in the last decades and the reduced population size. South Tyrol, an inner Alpine region, is the northernmost Italian breeding area of this warbler, but we lacked recent information about the distribution and population size. In this study, based on surveys carried out in the year 2019 and other recent observations, we assessed a very restricted current distribution of this warbler, and we estimated a population size of 10-30 pairs. We also observed a singing male at unusually high elevation. A comparison of our results to historical data suggests a strong reduction in distribution compared to the 1980s/1990s. The changes in agricultural practices of the last decades might have contributed to determine such decline. Appropriate conservation measures are urgently needed to try to avoid the local extinction of the species.

  6. Short Note - Past and present distribution of the Common Myna Acridotheres tristis in Italy: a review

    Emiliano Mori, Susana Saavedra, Mattia Menchetti and Giacomo Assandri

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    Biological invasions represent one of the main causes of the current biodiversity loss. Assessing distribution of invasive species is therefore pivotal to design effective management plans. In this work, we reviewed the current distribution of the Common Myna Acridotheres tristis in Italy. The Myna is recorded as an invasive species in many other countries worldwide. We used citizen-science and online platforms, to obtain a reliable map of the distribution of breeding populations, as very few data have been published on the distribution of this bird in Italy. We found 34 occurrences of the Common Myna in Italy, and breeding has been confirmed in two areas in Campania (Southern Italy), i.e. in the provinces of Salerno and Caserta. To prevent this species to become invasive in Italy, given the current limited distribution of breeding populations, a rapid removal of free-ranging individuals should be recommended in the short-term period.

  7. Short Note - Three-phase transformer arcing horns; neglected deadly components to birds

    Mahmood Kolnegari, Richard E. Harness

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    Unprotected power transformers are known to create electrocution problems for wildlife. However, the role of three-phase transformer arcing horns and bird electrocutions has not been investigated. Arcing horns are rigid conductors sometimes deployed to protect insulators by providing a gap for lightning to jump across without damaging the equipment. To identify how birds are electrocuted by arcing horns we submitted a survey to 32 Iranian utility companies and examined 562 opportunistic utility outage records of bird electrocutions between 2018 to 2019. We documented 59 electrocuted birds and classified five types of arcing horn electrocutions based on where the carcasses were discovered. To mitigate such problems utilities sometimes remove arcing horns but doing so can be problematic to the power network. Using insulation is not entirely effective because the point of the upper rod can produce an electrical discharge to the head of a bird perching on the lower grounded rod. We provide alternative solutions.

  8. Short Note - Response behaviour in wintering wigeon (Mareca penelope) due to motor/electric boat disturbance: explorative data suggest a recurrent pattern

    Corrado Battisti

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    The behavioural response of a wintering focal flock of Wigeon Mareca penelope in relation to the periodic passage of the motor/
    electric boats was studied during an Environmental Impact Assessment. A recurring escape model emerged. At each passage of the
    boats, birds resting in the fields along the lake banks first flew to the neighbouring waters (averaged escape distance: 116.6 m ± 25.8),
    then (ii) flew away, (iii) returned in the waters (near the banks) and, finally, (iv) returned in the neighbouring fields. These first data could
    stimulate further research on the escape behaviour from this anthropogenic disturbance.

  9. Bird News - June 2020

    Gaia Bazzi (ed.)

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    Interesting sightings about birds of the world for unusual behaviour, phenology or other features