Biometrics of ruffs Philomachus pugnax migrating in spring through southern Belarus with special emphasis on the occurrence of ‘faeders’

• Published in: Ringing & Migration
• Main Authors: Karlionova, Natalia, Pinchuk, Pavel, Meissner, Włodzimierz, Verkuil, Yvonne
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2007
• Subjects: lena river; Philomachus pugnax; Ruff
• Online Access: https://hdl.handle.net/11370/9a3cf535-0288-4c84-a3ae-957590d6f734; https://research.rug.nl/en/publications/9a3cf535-0288-4c84-a3ae-957590d6f734; https://doi.org/10.1080/03078698.2007.9674359; http://www.scopus.com/inward/record.url?scp=34250351873&partnerID=8YFLogxK

In spring, the Ruff Philomachus pugnax passes through European inland sites in large numbers. Birds from eastern and western parts of the breeding range may differ in biometrics, but data on this species in eastern Europe are scarce. The aim of this study was to describe the biometrics of Ruffs migrating through southern Belarus in spring. In 2004, 242 birds were sexed by DNA analysis. Three birds sexed as males had female plumage but wing lengths intermediate between females and breeding-plumage males, and were identified as cryptic males or ‘faeders’. Between 2001 and 2005, 2, 237 Ruffs were ringed at the study site (1, 310 males in breeding plumage, 911 females and 14 faeders). There was a strong seasonal variation in sex ratio. For adult Ruffs wing length was the best predictor of sex. Total head length and tarsusplus-toe length distributions overlapped slightly between the sexes. There was evidence for slight bimodality in the distributions of wing, bill and tarsus-plus-toe length in non-faeder males and in wing and bill length distributions for females. Mean wing lengths of Ruffs passing through the Belarus study site were similar to those birds from other locations in Europe and North Africa, but different from birds from South Africa, Yamal and the middle Lena River, suggesting that Ruffs have at least two different breeding populations.