Photo: Woodpigeons during migration- Central Italy. Denis Bianchi - Club Italiano del Colombaccio

Ornithology Heresy

Monitoring the 2017 Autumn Migration of the Woodpigeon (Columba palumbus): Take-off Decision making and Forecasting

Enrico Cavina, Denis Bianchi, Vasco Feligetti, Graziano Giovanetti and Rinaldo Bucchi

An innovative experimental app (Monitoring Woodpigeons Live - MCL) performs real time monitoring of the arrivals and transits of woodpigeons in Italy. Analysis of the migratory samples provided via the app with special focus on the Mesola stop-over and take-off provide clear evidence of the relationships between the "decision making" to migrate and atmospheric pressure jumps 12 to 24 hours before in a given area. The take-offs were often successfully forecasted. A video-film was made which supports this thesis. The authors underline the value of prediction in research as a fundamental aspect of the scientific method.

Posted: 30 November 2017

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The Paratympanic Organ of Vitali in migratory birds: Research failure or challenge ?

by E. Cavina

The discovery of the Paratympanic Organ (PTO) in birds by Giovanni Vitali in 1911 was once considered for the Nobel Prize, but the story of the "organ of flight" has almost been forgotten.

Posted: 17 December 2016

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Earthquakes, geomagnetism and the reversed sense of direction of woodpigeons (Columba palumbus) during their 2016 October migration in Central Italy.

by E. Cavina

During the recent strong earthquake sequence in Central Italy a "reversed migration" of woodpigeons was observed by members of the Club Italiano del Colombaccio. The phenomenon could be related to new temporary electro-magnetic local sources due to earth fracture movements influencing the migratory senses of the birds.

Posted: 7 November 2016

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THE PARA-TYMPANIC ORGAN of VITALI: the challenge of bird sensory physiology.

by E. Cavina

On the basis of the preceding paper concerning the Eurasian Woodpigeon's autumn migration, we analyzed abiotic factors on the origin Scandinavian-Russian breeding areas for four more bird species in addition to the Woodpigeon. We have selected 60 migratory mass peaks of transit of the Eurasian Siskin, the Chaffinch/Brambling, the Common Starling, the Common Woodpigeon and the Barnacle Goose. The detailed relationship between mass take-off and changes in Atmospheric Pressure (plus other abiotic factors ) 48-12 hours before starting has been analyzed .
(A) 6 peaks not significant
(B) 6 peaks moderately significant ( 7-10 hPa difference)
(C) 48 peaks strongly significant ( 10-20 hPa difference)
The role of the Para-Tympanic Organ of Vitali is underlined and further investigated.

Posted: 26 January 2016

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Decision making of autumn migrations of woodpigeons (Columba palumbus)

by E. Cavina

In this paper we have tried to detect all the possible abiotic effects on the autumn migration of woodpigeons (Columba palumbus). Three transit areas of were considered: Falsterbo Sweden, the French Pyrenees and the Appennine mountains and valleys of Italy. Our focus was to identify the main abiotic factor related to the weather that can be defined as the proximate cause or "finger-pressing-the-button" for the take-off flights of the autumn migration from nesting areas near transit areas. The analysis was conducted on census data in transit, in the archives of various institutions. The total quantity of birds counted in migration over 40 years (from 1973 to 2014 ) was 42,936,667. Over the past 15 years (1999-2013) 47 peak days-of-migration were identified in Sweden, 42 peaks in the Pyrenees and 12 in Italy, i.e. 101 peaks in total. These peaks were compared with the weather conditions recorded day by day and hour by hour. The analysis revealed that the most likely finger-pressing-the-button is the rising of the atmospheric pressure at all three sites (92.62% Sweden, 92.85% in the Pyrenees and 91,00% in Italy). Variations were above 10 hPa in 75.80% of the peaks for the interval "36/24 h" and 76.19% for the sector "18 h" preceding the take-off. The global analysis of all the abiotic factors makes it possible to construct a number of hypotheses for the interpretation of why this happens. The sensory input which detects these variations of atmospheric pressure is identified as the Para-Tympanic Organ of Vitali, a possible "biological barometer".

Posted: 14 September 2015

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