Table 3. The percentage of males and females based on data sources of different bird-based recreation projects in the UK and USA. The chi-square statistics computed for each data source were greater than the critical value, P(χ2 ≥ 3.841) = 0.05. Test 1 and Test 2 differ in the population used to compute the expected value, with Test 1 using the 49M:51F ratio of the general population and Test 2 using the gender ratio specific to the recreation project that is likely the source population for a particular project. † indicate recreation projects that involve listing. N is the number of individuals in each recreation project for which gender was known or assigned.

Degree of Competition or Authority Recreation Project %M %F Test 1
X2		 Test 2
X2		 (df, N) Skew
Supportive
CLO members 45 55 210 N/A (1, 32872) F
Audubon subscribers 37 63 9548 N/A (1, 1657000) F
RSPB members 48 52 354 N/A (1, 883774) F
BTO members 60 40 629 N/A (1, 13000) M
Participatory
†CUB 30 70 132 83 (1, 912) F
HFDS 36 64 134 65 (1, 1982) F
NestWatch 38 62 138 56 (1, 2846) F
†Project FeederWatch 34 66 652 354 (1, 7246) F
CamClickr 33 67 167 95 (1, 1626) F
†Breeding Bird Atlas 62 38 239 412 (1, 3529) M
BFL 57 43 10 22 (1, 371) M
†CBC 63 37 3023 11178 (1, 38544) M
†eBird 57 43 241 547 (1, 9410) M
†Garden BirdWatch 42 58 268 1843 (1, 13649) F
†BBS, UK 82 18 1001 463 (1, 2296) M
Nest Record Scheme 83 17 324 155 (1, 701) M
Competitive
†ABA List Report 80 20 217 4199 (1, 563) M
†UK400Club 99.02 0.08 6562 92 (1, 6416) M
Authoritative
†eBird state reviewers 93 7 135 92 (1, 174) M
†CBC Regional Editors 93 7 33 17 (1, 43) M
†Recent Birding Advice Book 72 28 8 N/A (1, 39) M