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Genetic Investigation of Italian Domestic Pigeons

 D. Bigi (University of Bologna) et al,

'Genetic investigation of  Italian domestic pigeons increases knowledge about the long-bred history of Columba livia (Aves: Columbidae)' 

Italian Journal of  Zoology, 2016, 173-182, Vol. 73, No. 2, http://www.tandfonline.com/doi/full/10.1080/11250003.2016.1172121

In a study published in 2016, an Italian research group investigated the relationships between eight Italian and eleven foreign breeds, two of the Italians being subdivided into subgroups (Fig. 1). Not very well known abroad are the Italian breeds Piacentino, Romagnol and Sotobanca. These are large pigeons for which a weight of 800 is given for Piacentino and 850 g for the other two breeds.

Italian Breeds Foreign Breeds
Italian Owls Birmingham Roller
Italian Owls Rondone Rostov Tumbler
Italienian Beauty Homer Vienna Tumbler
Piacentino Fantail
Romagnol Frillback
Runt Old Dutch Cauchine
Sotobanco English Carrier
Florentine Racing Homer
Triganino Schietto Modena
Triganino Gazzo German Modena
  French Mondain

Fig. 1: Breeds and Sub-groups selected for the investigation

As an indicator for the genetic similarity or distance, FST values ​​were calculated which give information about the frequency of alleles at the genotypes in question in the populations. At a value of zero, no difference can be detected. Within the sample, Frillbacks took an outsider roll, which partly relied on the lack of color pigeons genetically closer to them. On average, a distance of 0.34 to the others was calculated. The smallest distances were 0.04 between the two groups of Italian Owls and also between the two Triganino groups. The distances between the Triganinio and the English Modena were slightly higher with 0,06 (Schietti) and 0,05 (Gazzi), and slightly higher between Triaganino and the German Modenese with 0,09 and 0,08 respectively.

Fig. 2: Modena, Modenes Flying Pigeon (Wright 1879), Triganino Gazzi, German Modena

Racing Homers had the smallest distance to the Italian Beauty Homers who were raised from them (0,06). They were followed by Birmingham Rollers (0,08), which had already been assigned by Stringham et al. (2012) a great proximity. A distance of 0.08 only also had Piacentini.

As a result of the analysis, it is stated in the abstract that it has been confirmed that the Racing Homer is derived from the English carrier. However, the implicit assumption that serious sources have asserted or proved that, is false.

In the interpretation of the matrix of the distances between the individual breeds and the condensation of information on clusters and representation in dendograms, the authors do not seem to be aware of the limitations and the pitfalls of the methods. Cluster analysis is about grouping selected objects - here selected pigeon breeds - into subgroups (clusters) so that the breeds within a cluster are more similar than they are to those in another group. In general, the objects are distributed so that the distance within a group is small and the distance between the groups is large. Clustering is seen as a discovering 'data mining' that is meant to arouse creative ideas. There are not one, but several systematic procedures (algorithms) for generating clusters. So there are also different results that can tell a different story. In the interpretation, caution, or even creativity, is appropriate. Whether two objects in the same cluster end up depends in some algorithm not only on the directly measured kinship. It also depends on which objects are still present in the sample, or are not present.

Two objects that are found in a sample with other objects in the same cluster can be separated by adding, removing, or replacing objects. Clustering thus is not only an instrument for gaining knowledge, but also for the manipulation of the reader. Depending on the chosen algorithms and the composition of the group, two objects that have the smallest distance bilaterally can optically end up in the dendogram even in far-off branches. This is the case here.

A very plausible result is obtained for the four Modenese breeds or groups (Fig. 2), which form a cluster very early in the sample (Fig. 5). Not so for the Racing Homers for different reasons. Racing Homer (RH) and Italian Beauty Homers (IH) are quickly combined in the dendogram.

Siegerin von Sattledt 604 km 5337 Tauben.JPG Carrier-Ulm-web.jpg 

Fig. 3: Winner from the Nationalflight from  Sattledt 604 km with an entry of 5337 pigeons. Clocked in time at 10 flights in 2013 (Bernhard Beumer and Theodor Sandbothe, RV Beckhum, photo Gerhard Blum; English Carrier at the VDT-Show Ulm 2014 at the right.

Birminham-Roller-web.jpg Tippler-web.jpg Tuerkische Taube web.jpg

Fig. 4: Pied Birmingham-Roller, Tippler und Turkish Pigeon (now extinct) from about 1890 at the Brunswick National Historic Museum

The genetic distance of both breeds to the English Carrier (EC) at 0.13 and 0.16 is significantly greater than the distance of the Birmingham Roller (BR) with 0.08 and 0.10 respectively. Nevertheless, in the chosen method, the first three breeds are summarized, and the Birmingham Roller remains far apart in the dendogram (Fig. 5). If input errors can be excluded during the data preparation, the selected cluster method will be the cause. In contrast to classical clustering methods, the clustering of the clusters in a Bayesian approach is not based on similarities, but on the basis of a variance criterion for the whole group (Heller et al.). The method chosen for this study and for other comparable studies may react particularly sensitively to the composition of the samples and should be questioned in general with regard to the meaningfulness.

Fig. 5: Dendogram for the relationship of selected breeds

The authors try to support their conclusion of the origin of the Racing Homer from the English Carrier implicitly by confirmations in the literature. As a reference for the thesis an investigation by Stringham et al. (2012) is quoted (p. 180). If we expect to find a small distance between Carrier and Racing Homer compared to other pigeon breeds we are in error. Stringham et al. report a Nei's FST value of 0.107 between the two breeds, larger than that of the Racing Homer x Birmingham Roller (0.093) and far greater than the distance to the Tippler (0.065). A lower distance was only recorded for a feral population in Utah, which had formed from escaped Racing Homers (0,049). Italian Owls (0,115) and Old German Owls (0,116) exceeded the distance of the English carrier and the Racing Homer only a little. We may conclude, information may also be misrepresented by omissions.

Levi (1963) is also mentioned as a further proof for the descent of the Racing Homer from the carrier (p. 180, 181). The quote is incorrect and probably results from volatile reading. The authors refer to the English Carrier. Also Levi knows the English Carrier, with the addition 'Exhibition Bird'. However, in depicting the descent of the Racing Homer Levi writes of the "Eastern Carrier". The Eastern Carrier is considered by some authors identical or the ancestor of the Horseman and the Dragoon. It is the pigeon that Willughby (1678, p. 181) described as the messenger (carrier) of the Turkish Empire. On the continent it was called the Turkish Pigeon. The Turkish Pigeon is also one of the ancestors of the English Carrier, but in the figure at Levi (1969, p. 85) correctly shown as a 'dead branch' with regard to the formation of the Racing Homer (here Fig. 6). Levi did not claim that the Racing Homer was derived from the English carrier, but explicitly showed the opposite

Fig. 6: The ancestors of the Racing Homer according to Levi 1969, p. 85.

By the way, on the basis of the molecular-genetically determined distances it must be assumed that Levi in his description of the development of the Racing Homer underestimated the importance of long-beaked highfliers, to whom also the Tippler and Roller go back, (compare Sell 2009, 2014, pp. 121f.).

However interesting molecular-genetic investigations may be, the picture is clouded if, as a result of carelessness, existing false ideas get reinforced. Already the well-known ornithologist Tegetmeier blamed on the name 'Carrier' in 1871 (p. 44), since no one could visit a show without someone who was deceived by the name of them as the true messenger (Fig, 7).

Fig. 7: Tegetmeier on the name carrier for the exhibition carrier (1871, p. 44)

 

A look into the book from Fulton 1876 (268 ff.) might also help to get things right.

Literature:

Bigi, D. u.a. (2016), 'Genetic investigation of  Italian domestic pigeons increases knowledge about the long-bred history of Columba livia (Aves: Columbidae)' Italian Journal of  Zoology, 2016, 173-182, Vol. 73, No. 2, http://www.tandfonline.com/doi/full/10.1080/11250003.2016.1172121

Fulton, R. (1876), The Illustrated Book of Pigeons. London, Paris, New York and Melbourne.

Heller, Katherine A., und Zoubin Ghahramani, University College London,  http://www.gatsby.ucl.ac.uk/~heller/bhcnew.pdf

Levi, W.M. (1969), The Pigeon, Sumter South Carolina 1941, revised 1957, reprinted with minor changes and additions 1963, reprinted 1969.

Sell, A. (2009), Taubenrassen. Herkunft, Verwandtschaften, Achim.

Sell, A. (2012), Pigeon Genetics, Achim.

Sell, A. (2014), Brieftauben und ihre Verwandten, Achim.

Stringham et al. (2012), Divergence, Convergence, and the Ancestry of Feral Populations in the Do­mestic Rock Pigeons, Currently Biology (2012), doi: 10.1016/j.cub.2011.12.045.

Tegetmeier, W.B. (1871), The homing or carrier Pigeon, London

Willughby, F. (1676), Ornithologia, Libres Tres, Londini.

 

Axel Sell, August 2017