Pleske’s grasshopper-warbler exhibits a characteristic skulking behaviour. It generally keeps close to the ground among thick vegetation, often making it difficult to detect (4). The breeding season typically runs from May to July, and the male usually arrives at the breeding site roughly two weeks before the female. During courtship and breeding the male often becomes much more conspicuous, perching on reed tops and singing loudly to attract a mate (4).
Unlike the female Pleske’s grasshopper-warbler, the male always re-uses the same breeding site (3), and in the majority of cases, only ever breeds with one female throughout its life (3). However in some cases the male may breed with more than one female at a time (7).
Generally, female Pleske’s grasshopper-warblers breed at different times during the breeding season, depending on their age. Younger females increase their survival rate by mating later in the breeding season, whereas older females tend to mate earlier to increase their reproductive rate. Females prefer males whose feathers have wider growth bands, as this represents a better nourished and healthier male than one with narrower growth bands (8).
Pleske’s grasshopper-warbler builds its nest low to the ground, usually below two metres, in willow thickets and shrubbery. Within the nest, Pleske’s grasshopper-warbler lays an average of four eggs, but the clutch size can range from three to six eggs. The female incubates the egg for around 14 days. The chicks leave the nest around 13 to 15 days after hatching (4).
Pleske’s grasshopper-warbler is primarily an insectivorous species (4).