Online Resource 1: Rank order of the similarity to the begging calls of the parasitic shining cuckoo in New Zealand and its grey warbler host, for each acoustic distance measure. The parasite and its host are highlighted and the species of the genus Chalcites are marked (†). The names of the shining cuckoo hosts are in brackets and abbreviated for g.w.:grey warbler, w.t.:western thornbill and y.r.t.:yellow-rumped thornbill.

Rank / Spectro-temporal / Spectrogram / SAP / Sound features / Spectrogram
modulation / correlation / alignment
1 / shining cuckoo (g.w.) † / shining cuckoo (g.w.) † / shining cuckoo (g.w.) † / shining cuckoo (g.w.) † / shining cuckoo (g.w.) †
2 / grey warbler / tomtit / grey warbler / grey warbler / grey warbler
3 / H. bronze-cuckoo † / tui / saddleback / tomtit / tomtit
4 / fantail / bellbird / tomtit / bellbird / tui
5 / kokako / shining cuckoo (w.t.) † / robin / robin / silvereye
6 / tomtit / H. bronze-cuckoo † / tui / silvereye / H. bronze-cuckoo †
7 / silvereye / western thornbill / silvereye / shining cuckoo (w.t.) † / shining cuckoo (w.t.) †
8 / whitehead / grey warbler / bellbird / shining cuckoo (y.r.t.) † / western thornbill
9 / rifleman / robin / shining cuckoo (y.r.t.) † / tui / shining cuckoo (y.r.t.) †
10 / tui / long-tailed cuckoo / H. bronze-cuckoo † / H. bronze-cuckoo † / long-tailed cuckoo
11 / hihi / rock wren / whitehead / saddleback / bellbird
12 / kingfisher / silvereye / shining cuckoo (w.t.) † / western thornbill / robin
13 / pipit / brown creeper / rifleman / welcome swallow / yellowhead
14 / western thornbill / shining cuckoo (y.r.t.) † / pipit / whitehead / kokako
15 / shining cuckoo (w.t.) † / yellowhead / western thornbill / rifleman / rifleman
16 / bellbird / whitehead / welcome swallow / fantail / brown creeper
17 / long-tailed cuckoo / hihi / yellowhead / hihi / fantail
18 / yellowhead / fantail / brown creeper / brown creeper / hihi
19 / brown creeper / welcome swallow / fantail / yellowhead / whitehead
20 / welcome swallow / rifleman / parakeet / pipit / pipit
21 / shining cuckoo (y.r.t.) † / kokako / long-tailed cuckoo / rock wren / saddleback
22 / saddleback / saddleback / hihi / parakeet / welcome swallow
23 / rock wren / pipit / rock wren / kokako / rock wren
24 / parakeet / parakeet / kingfisher / long-tailed cuckoo / kingfisher
25 / robin / kingfisher / kokako / kingfisher / parakeet