Two cases of year-to-year mate fidelity in Chiffchaff occurred in the
subpopulation of 6 males and their females in a region of South Bohemi
a. The first nesting of both females failed in the first season. One o
f them was secondary female in the first season. Both pairs renested i
n a new territory in the second season. The nesting of both of them wa
s successful in this season. This is probably the first record of rema
ting between seasons in this species.