Function of note strings in Japanese Tit alarm calls to the Common Cuckoo: a playback experiment

Abstract

Background: Birds produce alarm calls to convey information about threats. Some Passerine alarm calls consist of several note strings, but few studies have examined their function. Previous studies have shown that Japanese Tits (Parus minor) can alter the calling rate and number and combination of notes in response to predators. We previously found the combinations of note types in Japanese Tit alarm calls to be significantly different in response to the Sparrowhawk (Accipiter nisus) and Common Cuckoo (Cuculus canorus). Methods:Through playback experiments, we tested whether the note strings in Japanese Tit alarm calls to the Common Cuckoo have different functions in conveying information. The note strings of selected alarm calls were divided into the categories of C and D, and different calls were then constructed separately based on the two note string categories. Original alarm calls (C-D), C calls and D calls were played back to male Japanese Tits during the incubation period.Results: Male Japanese Tits had a significantly stronger response to C calls than to C-D calls, and they showed a significantly stronger response to both C and C-D calls than to D calls, suggesting that Japanese Tits discriminated between the C and D calls. Conclusions:Our study demonstrated that the C-and D-category note strings of Japanese Tit alarm calls to the Common Cuckoo have different functions, which supports the previous finding that different note strings in an alarm call can provide different information to receivers. However, the exact meanings of these note strings are not yet known, and further investigation is therefore required.

Heterospecific alarm-call recognition in two warbler hosts of common cuckoos

“…Recording of alarm calls and behavior started when parent birds were observed within approximately 2 m of the specimen. Each recording lasted 5 min (Davies and Welbergen 2008; Yu et al 2017a). We recorded the dummy response of ORW and BRW as (1) the number of attacks of focal parent birds (we counted exactly the number of attacks indoor by playing back the video); and (2) the maximum number of ORW and BRW being attracted during experiments (the maximum number of simultaneously observed warblers).…”

“…While few rare hosts or non-hosts performed similar attack behavior on brood parasites, which look alike, they mistake parasites for predators (cuckoo–hawk mimicry, Davies and Welbergen 2008; Trnka et al 2015; but see Ma et al 2018a). However, Yu et al (2017a) showed that even rare host great tits ( Parus major ) could distinguish parasites, because tits produced different alarm calls in response to Eurasian sparrowhawks Accipiter nisus and common cuckoos ( Cuculus canorus ). These calls caused different response behaviors to conspecific receivers.…”

“…However, few studies have tested heterospecific alarm-call recognition of species under different intensity of selection. In this study, we first examined whether regular host oriental reed warblers ( Acrocephalus orientalis ) (hereafter ORWs) and rare host black-browed reed warblers ( Acrocephalus bistrigiceps ) (hereafter BRWs) have the ability to distinguish between common cuckoos and sparrowhawks using similar methods as Yu et al (2017a), and restrict their response behavior to conspecifics alarm calls. Heterospecific alarm-call recognition has been demonstrated experimentally through playback studies in several species (e.g.…”

Egg recognition in Cinereous Tits (Parus cinereus): eggshell spots matter

“…The mean altitude is 300 m, with a continental monsoon climate and four distinct seasons in the temperate zone. Vegetation is temperate needle broad-leaved mixed forest zone with secondary forest (Yu et al 2017). We monitored Cinereous Tits nesting in nest boxes during the breeding seasons each year.…”

“…We monitored Cinereous Tits nesting in nest boxes during the breeding seasons each year. The nest boxes were attached to trees about 3 m above the ground, facing in a random direction (Liang et al 2016;Yu et al 2017).…”