Host responses to experimental interspecific brood parasitism (IP) with model cuckoo eggs measured as (a) egg rejection, and latency to egg rejection in (b) blackbirds and (c) song thrush. IP was simulated by adding a blue or a spotted egg model (Figure 1). Responses were compared between areas in sympatry (CZ-S), micro-allopatry (CZ-A) and macro-allopatry (NZ-A) with common cuckoos (“CZ” – Czech Republic, “NZ” – New Zealand); see hypotheses (iv) and (v) in Introduction. Blackbirds (b) and song thrush (c) latencies to ejection (black) and to rejection (i.e., including desertion; grey) are presented as the raw data’s means ± SE. Sample sizes (nests) are given inside bars (a) or above x-axis (b,c).