When puncturing fails: nest desertion as an alternative egg rejection strategy in the Oriental Reed Warbler

This dataset documents host behavioural responses in an experimental brood parasitism study in which artificial or real eggs were introduced into host nests. A total of 63 experimental nests were monitored. For each nest, the type of experimental egg (real vs. fake) and a series of host responses were recorded, including acceptance, ejection, nest desertion, and rejection mistakes.

In addition to final behavioural outcomes, the dataset includes direct evidence of host inspection behaviour: whether the experimental egg showed peck marks. This variable (“recognize”) indicates whether the host physically pecked the experimental egg, which is often interpreted as an early-stage recognition or assessment behaviour prior to possible rejection decisions.

This dataset can be used to examine host recognition mechanisms, differences in defensive responses elicited by egg types, relationships among multiple rejection behaviours, and the frequency and causes of recognition or rejection errors.

The dataset includes key host responses such as whether the experimental egg was ejected (eject), whether the nest was deserted (desert), and whether the egg was rejected (reject). In addition, it records occurrences of “mistaken rejection” (mistake1), in which hosts erroneously rejected their own egg.

These data provide a basis for analysing the mechanisms underlying host recognition of parasitic eggs, the differential behavioural responses elicited by varying egg models, and the potential relationships among distinct defensive strategies.