Seasonal variation in mean cloacal protuberance and testis size in red crossbills
Season
.
N
.
Cloacal protuberance length (mm)
.
Left testis length (mm)
.
Winter (21 Dec-20 Mar)
30
4.7±0.2a,b
3.8±0.3a
Spring (21 Mar-20 Jun)
47
4.7±0.2a,b
4.3±0.2a
Summer (21 Jun-20 Sep)
190
5.1±0.1a
5.0±0.1b
Autumn (21 Sep-20 Dec)
41
4.4±0.1b
2.5±0.2c
Season
.
N
.
Cloacal protuberance length (mm)
.
Left testis length (mm)
.
Winter (21 Dec-20 Mar)
30
4.7±0.2a,b
3.8±0.3a
Spring (21 Mar-20 Jun)
47
4.7±0.2a,b
4.3±0.2a
Summer (21 Jun-20 Sep)
190
5.1±0.1a
5.0±0.1b
Autumn (21 Sep-20 Dec)
41
4.4±0.1b
2.5±0.2c
Individual data are plotted in Fig. 2. Values are means ± s.e.m.; values indicated by the same superscript letter do not differ from each other (Tukey's post-hoctests).