AVIS-IBIS

Birds of Indian Subcontinent

Use of Morphometric Measurements to Differentiate between Species and Sex of King and Clapper Rails

Publication Type:Journal Article
Year of Publication:2009
Authors:Perkins, M, King, SL, Travis, SE, Linscombe, J
Journal:Waterbirds
Volume:32
Issue:4
Date Published:2009
ISBN Number:1524-4695
Keywords:Rallidae, Rallus, Rallus crepitans, Rallus elegans, Rallus longirostris
Abstract:Abstract. King Rails (Rallus elegans) and Clapper Rails (Rallus longirostris) are large, secretive waterbirds whose ranges overlap in brackish marshes along the Atlantic and Gulf Coasts. King and Clapper Rails are difficult to separate by physical appearance and there is currently no reliable method to distinguish between the two species. Here, the relative effectiveness of using discriminant analysis of morphometric measurements to identify and sex King and Clapper Rails was examined. Mean measurements of wing, tarsus, and weight were different between male King and Clapper Rails and between female King and Clapper Rails. However, for all measurements except culmen, male Clapper Rails and female King Rails were not different. Discriminate analysis of morphometric measurements revealed that wing, tarsus, and culmen measurements differentiated between King and Clapper Rails, but cross-validation results for male Clapper Rails were only 73%. Male King Rails were larger than female King Rails for all morphometric measurements and male Clapper Rails were larger than female Clapper Rails for all morphometric measurements except for the tail. Wing and tarsus measurements differentiated between male and female King Rails and wing, tarsus, and culmen measurements differentiated between male and female Clapper Rails.Abstract. King Rails (Rallus elegans) and Clapper Rails (Rallus longirostris) are large, secretive waterbirds whose ranges overlap in brackish marshes along the Atlantic and Gulf Coasts. King and Clapper Rails are difficult to separate by physical appearance and there is currently no reliable method to distinguish between the two species. Here, the relative effectiveness of using discriminant analysis of morphometric measurements to identify and sex King and Clapper Rails was examined. Mean measurements of wing, tarsus, and weight were different between male King and Clapper Rails and between female King and Clapper Rails. However, for all measurements except culmen, male Clapper Rails and female King Rails were not different. Discriminate analysis of morphometric measurements revealed that wing, tarsus, and culmen measurements differentiated between King and Clapper Rails, but cross-validation results for male Clapper Rails were only 73%. Male King Rails were larger than female King Rails for all morphometric measurements and male Clapper Rails were larger than female Clapper Rails for all morphometric measurements except for the tail. Wing and tarsus measurements differentiated between male and female King Rails and wing, tarsus, and culmen measurements differentiated between male and female Clapper Rails.
URL:http://dx.doi.org/10.1675/063.032.0411
Short Title:Waterbirds
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith