Specimen Shrinkage in Cinnamon Teal

—Body size measurements from freshly collected birds and dried museum specimens were used to evaluate specimen shrinkage in Cinnamon Teal (Anas cyanoptera). Six of seven body measurements of female Cinnamon Teal differed significantly after specimen drying, whereas five of seven male body measurements differed. The largest amount of shrinkage was in bill height, bill width, and tarsus length. Bill length at nares showed no significant shrinkage suggesting it is a more conservative measurement than exposed culmen and, therefore, a more reliable method for accurately measuring bill length. Correction values for body size measurements are reported for future waterfowl studies combining measurements of both live birds and museum specimens. Received 1 March 2007. Accepted 6 September 2007. Specimen shrinkage during the process of drying is common. Shrinkage can cause analytical problems if not properly corrected in studies involving live or freshly killed birds and museum specimens (e.g., Winker 1996). Correction for shrinkage is needed before applying to live birds when developing classification criteria for gender, subspecies, or species based on morphological features from museum specimens (Greenwood 1979, Jenni and Winkler 1989, Winker 1993). For example, Mueller (1990) reported that a shrinkage value of 1.72% would comprise 34% of wing length differences between male and female Northern Saw-whet Owls (Aegolius acadicus). In addition, the amount of shrinkage varies among body parts and species (Winker 1993). Shrinkage values from one taxon may have limited use outside that particular taxon or similar morphological species because of the morphological diversity of birds and variety of preparation techniques (Jenni and Winkler 1989, Winker 1993). Specimen shrinkage in waterfowl has yet to be investigated. This pa1 Institute of Arctic Biology, Department of Biology and Wildlife, and University of Alaska Museum, University of Alaska, Fairbanks, AK 99775, USA. 2 Corresponding author; e-mail: [email protected] per reports shrinkage values for Cinnamon Teal (Anas cyanoptera), which may be used to develop correction values for similar size ( 350–550 g) waterfowl.