Volume 44 - N. 2
December 2020

Avocetta
Volume 44 - N. 2
Volume 44 - N.2, December 2020



  1. Editorial - The times they are a-changin’

    Davide Dominoni

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    Editorial by Davide Dominoni, Associate Editor of Avocetta, University of Glasgow

  2. Nesting ecology of Lesser Grey and Woodchat Shrikes in Apulia, southern Italy

    Gianpasquale Chiatante

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    True shrikes (family Laniidae, genus Lanius) are birds highly associated with open and farmed landscapes and have suffered significant declines all over the world, especially due to increasingly intense agriculture and climatic fluctuations. In Italy, three species breed: Red-backed Shrike Lanius collurio, Lesser Grey Shrike Lanius minor and Woodchat Shrike Lanius senator. All three are threatened and considered Vulnerable (the first two species) or Endangered (the latter species) in Italy. The purpose of this study was to provide new insights on the nesting ecology of Lesser Grey and Woodchat Shrikes in Italy by territory mapping in six sampling areas in Apulia in 2009-2013. I also collected data on nest location and breeding success. I mapped 93 territories of Lesser Grey Shrike (for 127 breeding attempts) and 84 territories of Woodchat Shrike (for 107 breeding attempts) and noted a decline in shrike numbers over the five years. Most territories of Lesser Grey Shrikes were used for one nesting attempt (71.0%) and the remainder used twice, showing a clear site fidelity. Similarly for the Woodchat Shrike, more than 20% of territories were used for two nesting attempts. Both species formed solitary pairs, but 5% of Lesser Grey Shrike formed two-pair clusters and I found only a single two-pair cluster of Woodchat Shrikes. Lesser Grey Shrikes nested in isolated trees (mainly oaks, elms, almond, and olive trees), building a nest at 4.2 m above the ground, partially hidden and placed in a distal position respect the tree trunk. The first record of Macedonian Oak and Olive being used for nest support was obtained. I found only three nests of the Woodchat Shrike. Fledged broods of Lesser Grey Shrike composed on average 2.3 juveniles; for the Woodchat Shrike this value is 1.9 juveniles.
  3. Combined use of radar and mist net trapping to detect species composition of nocturnal migrants

    Ivan Maggini, Giuseppe Cortone, Carlo Catoni and Giacomo Dell’Omo

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    The Strait of Messina, in southern Italy, is a well-known migration hotspot for diurnal migrants such as raptors. Radar studies have also shown that there is a considerable rate of nocturnal passage of migrants during spring migration. During the spring season 2015, we combined mist net trapping with radar observations
    at a site on the Calabrian side of the Strait, to characterize the species composition of nocturnally migrating passerines, and to investigate the relationship between the numbers of birds flying over and the ones stopping at the study site. Despite the radar counted nearly four millions tracks of birds flying overhead, only
    242 individuals were captured with mist nets during the same period. Of these, only 70 (28.9 %) were potential migrants. There was no correlation between the number of daily captures and the number of tracks recorded by radar on the previous night. The application of radar observations clearly shows that a large proportion of passing migrants may go undetected when relying on counts of birds at a watchpoint for diurnal observations only. The Strait of Messina seems to be a passage site for nocturnally migrating birds including songbirds. However, most favourable stopover sites for these birds might be found further South, possibly not far from our study site.

  4. Monitoring of a community of nesting birds in an agro-ecosystem with high environmental heterogeneity

    Roberto Pollo

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    An agroecosystem with high environmental heterogeneity located in the low Veronese Po plain (Italy) was monitored over a seven-year period, from 2013 to 2019. In the study area three transects representative of three types of environment were selected: arboreal-shrubby hedge, cultivated land, and linear wood. Using a line transect method, five visits were made in each breeding season. For each habitat type, the following indices were calculated: Richness, Relative species frequency, I.K.A., Abundance and Density of territorial males, and Shannon Diversity. A total of 39 breeding species were registered. Whittaker’s diagrams highlighted the presence of high levels of richness and diversity in the linear wood and arboreal-shrubby hedge environments. The cultivated area hosts species considered as bioindicators of highly extensive agricultural environments. The characteristics of the arboreal-shrubby hedge seemed optimal to support a well-structured and
    stable bird community, and some typical species of hedges such as Sylvia communis and Luscinia megarhynchos had reached I.K.A. comparable to the highest recorded in Italy. The trends of the main parameters of all three communities did not show statistically significant fluctuations in the years of sampling. The results show a high degree of general ecological interest and conservation importance of the study area, also in comparison of other similar Italian agroecosystems, since we found 14 breeding species of high conservation concern, among which three included in Annex 1 of the 2009 Directive / 147 / EC.

  5. Short Communication - First Record of Eurasian Spoonbills Platalea leucorodia feeding on Branchiopoda in a temporary wetland

    Salvatore Surdo

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    The diet of the Eurasian Spoonbill Platalea leucorodia is poorly documented with only the most common prey groups known, namely small fishes, amphibians, reptiles, crustaceans, molluscs, worms, leeches and plant material. Here, three small crustaceans, Branchiopoda Triops cancriformis (Notostraca), Chirocephalus diaphanus (Anostraca), and Cyzicus tetracerus (Spinicaudata) are documented as prey of the Eurasian Spoonbill in a temporary wetland near the San Teodoro salt pan (Marsala, western Sicily). These observations provide a new insight into the foraging ecology of the species, showing its extreme opportunism in targeting small prey when feeding in a temporary wetland system.

  6. Short communication - Sepia cuttlebones pecked by birds along a Mediterranean beach: patterns, frequency and a possible conservation implication

    Corrado Battisti

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    Birds require calcium carbonate for skeleton and egg development. For this reason, cuttlebones of Sepia cuttlefish can be considerate a dietary supplement and often bear signs of pecking by birds (mainly gulls and other seabirds). Due to the different structure of cuttlebones (dorsal vs. ventral regions), I hypothesized that birds peck more intensely the anterior and ventral part these being softer and thicker. On a sample of 89 cuttlebones of Sepia cuttlefish, a relatively high percentage (88.8%) showed pecking signs by birds. All cuttlebones pecked showed signs on the ventral part while signs on the dorsal part were observed in significantly lower frequency. In the ventral part, no significant differences were found between the anterior and the posterior region. The longest cuttlebones showed a significant higher frequency of pecking signs, likely because of the longest cuttlebones are also those with greater thickness (and, therefore, with higher availability of
    calcium aragonite). These are the first evidences from Mediterranean area. Since expanded polystyrene, an increasingly abundant anthropogenic debris in natural environments, was often pecked because confused with cuttlebones, our first data may have conservation implications in the disciplinary arena of marine/beach
    litter research.

  7. Retraction letter:  “Quantifying the global legal trade in live CITES-listed raptors and owls for commercial purposes over a 40-year period”

    Connor T. Panter, Eleanor D. Atkinson & Rachel L. White

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    Subsequent to the publication of the following paper in Avocetta, the authors were made aware of an error in the dataset affecting the results presented in Table 4. After re-analysing the data, the new dataset failed to uphold the original conclusions and the authors have requested a retraction of the original manuscript to sustain the integrity of their findings.

    Panter, C.T., Atkinson, E.D. & White, R.L. 2019. Quantifying the global legal trade in live CITES-listed raptors and
    owls for commercial purposes over a 40-year period. Avocetta 43(1): 23-36. Doi: https://doi.org/10.30456/
    AVO.2019104

  8. Forum - Conservation Evidence Do the weaknesses and strengths of experts and local volunteers affect the conservation actions focused on nesting plovers? Constructive considerations from the Italian beachfront line

    Corrado Battisti, Marco Gustin, Alessandro Polinori

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    Both the high-level strategies promoted by experts of public Conservation Agencies, and the small-scale tactics implemented by local conservation groups show strengths, weaknesses, opportunities and threats that can affect the effectiveness of the efforts aimed at the conservation of plovers nesting on sand dunes
    (Charadrius alexandrinus and Charadrius dubius). Here we propose a SWOT analysis, focusing on critical conditioning factors that should contribute towards rendering effective the local conservation strategies: (1) experts should learn the tools of project management, thus avoiding both ‘analysis-paralysis’ and ‘epistemic arrogance’
    towards local volunteers, and using a simplified scientific language to communicate smart operational guidelines to the people; (2) editorial times necessary to draft guidelines should be shortened because sand-dune bird species urgently need tools for rapid actions; (3) in conservation strategies, ‘monitoring’ means verifying
    changes in an environmental target in the expected direction defined by specific project objectives (it is not only a periodical field sampling of biodiversity targets). In this regard, experts should monitor not only the status of plovers (pairs, nests and chicks) but above all the effectiveness of conservation actions carried out; (4)
    local volunteers, often highly motivated towards these charismatic species, have scarce knowledge, lack skill and funding availability; therefore constituting an underutilized human potential whichshould be supported and adequately trained by technicians in order to allow a fine-grained pervasive conservation of these declining species.

  9. Bird News - December 2020

    Gaia Bazzi (ed.)

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    This column aims to collect a series of interesting observations and to make it accessible to the scientific community in future. We collect observations without time, space or species limitation but we focus on a limited series of category of interest. See more on Avocetta website: https://www.avocetta.org/bird-news-column

  10. Book reviews - December 2020

    Roberto Ambrosini and Benedetta Catitti

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    Review of the recently published books:
    “The kestrel: ecology, behaviour and conservation of an open-land predator.” Cambridge University Press, Cambridge by David Costantini and Giacomo Dell’Omo 2020
    “European Breeding Bird Atlas 2: Distribution, Abundance and Change.” Edited by: European Bird Census Council & Lynx Edicions, Barcelona. Authors: Keller, V., Herrando, S., Voříšek, P., Franch, M., Kipson, M., Milanesi, P., Martí, D., Anton, M., Klvaňová, A., Kalyakin, M.V., Bauer, H.-G. & Foppen, R.P.B., 2020