Biometric variability and sexual size dimorphism in the Great Knot Calidris tenuirostris

The Great Knot is a species from the Scolopacidae family of waders migrating within the East Asian-Australasian Flyway, and studies on this species have contributed greatly to understanding of migration ecophysiology and migration strategies in long-distance migrants. In this paper, we provide the f...

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Bibliographic Details
Published in:The European Zoological Journal
Main Authors: D. Dorofeev, A. Ivanov, E. Khudyakova, Y. Verkuil, T. Piersma, W. Meissner
Format: Article in Journal/Newspaper
Language:English
Published: Taylor & Francis Group 2024
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Online Access:https://doi.org/10.1080/24750263.2023.2293120
https://doaj.org/article/86ad488902294b2ab4423792fa7bab7b
Description
Summary:The Great Knot is a species from the Scolopacidae family of waders migrating within the East Asian-Australasian Flyway, and studies on this species have contributed greatly to understanding of migration ecophysiology and migration strategies in long-distance migrants. In this paper, we provide the first description of biometric variability and sexual size dimorphism in Great Knots. During the study on the Kamchatka Peninsula, 683 adults and 229 juveniles were measured and sexed molecularly. In adults, the mean measurements of females were larger than in males, except for tarsus length. In juveniles, at the early stage of migration from breeding to wintering grounds, apparently growth was not complete. Sexual dimorphism was small, with only wing length being significantly longer in females than in males. All dimensions of juveniles were smaller than those of adults, especially in bill length. The most sexually dimorphic trait in both adults and juveniles was wing length, and the most effective discriminant function with wing length as a single predictor correctly identified the sex of 76% of birds in both age classes. However, molecular sexing is the method of choice for reliable sexing, especially in juveniles.