Appendix 1—table 2. List of the different methods used to estimate bib size in all studies (published and unpublished) testing the relationship between dominance rank and bib size in male house sparrows (N = 19 studies).

Note that some studies used more than one method to estimate bib size.

Method to estimate bib size	Number of times used	Order of preference‡
Area*	8	1
Møller, 1987’s equation	6	2
Length and width†	3	2
Length only	2	3
Møller, 1987’s drawings	1	4
Veiga, 1993’s equation	1	5

*Area was measured from pictures (N = 5 studies), by tracing and weighing (N = 2 studies), and by tracing and ranking (N = 1 study).

†If length and width were available, we estimated bib area using Møller, 1987’s equation.

‡Order of preference used for the analyses (see main text). The order of preference was determined based on how frequently the method was used in previous studies.