Table 1. Sex and age classification of Black-headed gulls (Chroicocephalus ridibundus) captured from January 2019 to April 2019 at two bays.

Area (Bay)	Male/Adult	Female/Adult	Male/Yealinga)	Male/Yearlinga)
Tokyo-bay	36	30	2	0
Mikawa-bay	5	16	2	2

a) Yearling data was not available for statistical analysis due to the small sample size.