Measurements of adult Red Crossbills. Data shown as mean ± SE (n). For Call Types and the distribution of birds giving them, see Figures 4-17. Data for Types 1, 2, 3, 4, 5, and 7 from (Groth 1993b). Groth's designation of the call type based on one archival recording. Data for types 6, 8, and 11 from Benkman's measurements of museum specimens. Data for Type 10 from Irwin's measurements of live birds (Irwin 2010). All measurements were made in a comparable manner.

Data from Groth (); no data from known Type 8 birds; Groth’s designation of the call type based on one archival recording. Red Crossbill Flight Calls recorded in 1970 by CSA (see Fig. 3) match the Type 8 call presented by Groth (). Griscom () gives a range of measurements of adult male specimens taken in Newfoundland: wing, 91–96.5; culmen 17–19; bill depth 10.3–11.5. Griscom’s data presented only for rough comparison with Groth’s data. Groth’s measurements were made on birds of known call type, but Griscom’s data were taken from museum specimens only and may not have been measured as Groth measured his birds.