<abstract xmlns="http://www.w3.org/1999/xhtml">In this paper, a complex morphological comparison of four Common Nightingale groups <italic>(Luscinia megarhynchos)</italic> is demonstrated. In total, 121 territorial nightingales were mist-netted and measured individually on four study areas called ‘Bódva’, ‘Felső-Tisza’, ‘Szatmár-Bereg’ and ‘Bátorliget’ in the North-Eastern part of Hungary in 2006–2013. To distinguish groups by morphology, C<italic>lassification and Regression Trees</italic> (CART), <italic>Random Forest</italic> (RF) and <italic>Linear Discriminant Analysis</italic> (LDA) methods were used. Comparison of the four studied Common Nightingale groups shows substantial morphological differences in the length of the second, the third and the fourth primaries (P2, P3, P4), in bill length (BL) and bill width (BW), while other characteristics showed greater similarities. Based on the results of all the applied classification methods, birds originated from Szatmár-Bereg were clearly distinguishable from the others. The differences in morphology can be explained by interspecific competition or phenotypic plasticity resulting from the change of ecological, environmental parameters. Our case study highlights the advantageous differences of the classification methods to distinguish groups with similar morphology and to choose important variables for classification. In conclusion, broad application of the classification methods RF and CART is highly recommended in comparative ecological studies.</abstract>

In this paper, a complex morphological comparison of four Common Nightingale groups (Luscinia megarhynchos) is demonstrated. In total, 121 territorial nightingales were mist-netted and measured individually on four study areas called ‘Bódva’, ‘Felső-Tisza’, ‘Szatmár-Bereg’ and ‘Bátorliget’ in the North-Eastern part of Hungary in 2006–2013. To distinguish groups by morphology, Classification and Regression Trees (CART), Random Forest (RF) and Linear Discriminant Analysis (LDA) methods were used. Comparison of the four studied Common Nightingale groups shows substantial morphological differences in the length of the second, the third and the fourth primaries (P2, P3, P4), in bill length (BL) and bill width (BW), while other characteristics showed greater similarities. Based on the results of all the applied classification methods, birds originated from Szatmár-Bereg were clearly distinguishable from the others. The differences in morphology can be explained by interspecific competition or phenotypic plasticity resulting from the change of ecological, environmental parameters. Our case study highlights the advantageous differences of the classification methods to distinguish groups with similar morphology and to choose important variables for classification. In conclusion, broad application of the classification methods RF and CART is highly recommended in comparative ecological studies.

Morphological classification of conspecific birds from closely situated breeding areas – A case study of the Common Nightingale

Department of Evolutionary Zoology and Human Biology, University of Debrecen, 4032 Debrecen, Egyetem tér 1., Hungary

Department of Biomathematics and Informatics, Faculty of Veterinary Sciences, Szent István University, 1078 Budapest, István utca 2., Hungary

Ornis Hungarica

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

In this paper, a complex morphological comparison of four Common Nightingale groups (Luscinia megarhynchos) is demonstrated. In total, 121 territorial...

Morphological classification of conspecific birds from closely situated breeding areas – A case study of the Common Nightingale

Published Online: Jan 13, 2016

Page range: 20 - 30

DOI: https://doi.org/10.1515/orhu-2015-0011

Keywords
classification and regression trees, random forest, linear discriminant analysis, morphological classification

© 2015 Dávid Kováts et al., published by De Gruyter Open

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Morphological classification of conspecific birds from closely situated breeding areas – A case study of the Common Nightingale

Published Online: Jan 13, 2016

Page range: 20 - 30

DOI: https://doi.org/10.1515/orhu-2015-0011

Keywordsclassification and regression trees, random forest, linear discriminant analysis, morphological classification

© 2015 Dávid Kováts et al., published by De Gruyter Open

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Keywords
classification and regression trees, random forest, linear discriminant analysis, morphological classification