Female Cuckoo Calls Are More Effective at Attracting Breeding Male Cuckoos and Their Hosts Than Male Cuckoo Calls

Vocalizations during the breeding season play a significant role in both intra- and inter-specific communications. There have been numerous studies on the calls and functions of the common cuckoo (<i>Cuculus canorus</i> [CC]). However, there is limited research on the calls and functions of female CCs. This study conducted a playback experiment of 90 sample sizes on actively breeding CCs and their hosts in Jilin Province, China, during the 2022 breeding season (May to August), with calls from female CCs, male CCs, and males of the Himalayan cuckoo (<i>C. saturates</i> [CS]) as control groups. The results showed that the calls of both male and female CCs attracted CCs and their hosts in the experimental area, while the control group did not attract any birds. The attracted CCs were predominantly males. Among the attracted hosts, there were Oriental reed warblers (<i>Acrocephalus orientalis</i>) and black-browed reed warblers (<i>Acrocephalus bistrigiceps</i>). Generalized linear mixed model analysis revealed that the number of individuals attracted by female CC calls was significantly higher than the number attracted by male CC calls, both for male CCs and hosts. Furthermore, male CCs were attracted by male and female CC calls to a significantly greater extent during the early stage than during the late stage, while there was no difference in the number of attracted host individuals. Our study showed that the calls of female CCs play an important role in the communication between male and female CCs, and hosts are more responsive to the calls of female CCs, suggesting that they perceive female cuckoos as more threatening. Our study reveals seasonally modulated male attraction and host sensitivity.