Pair ID identifies particular pair of shrikes, which was confronted with all five intruders. In each pair responses of male and female were scored separately. There were five intruders, jay, kestrel, magpie, sparrowhawk and pigeon, all of them were stuffed dummies. Experiments were conducted at nests which contained eggs or chicks. We recorded three binomial responses, the parent guards the intruder (is present within a defined area - intruder guarding), the parent gives at least one alarm call (occurrence of alarm calling), the parent attacks the dummy at least once (occurrence of attack).