A male destroying an egg in a cooperative breeding attempt in Lesser Spotted Woodpecker Dendrocopos minor

Abstract

A cooperative breeding case was found in Lesser Spotted Woodpecker (LSW) in which a male and three different females were involved. The contributions of each member of the cooperative breeding team were quantified during nest excavation and incubation. This is the first such report on LSW. During daytime, the nest was mainly occupied by the male during the final excavation phase, nest guarding, and egg laying. Aggressive interactions were recorded between two of the females during nest excavation, egg laying and incubation. The male was recorded destroying an egg presumably laid by the dominant female. The highest contribution during daytime incubation was made by the dominant female (39%), followed by the male (34%) and then by a second female (27%). The third female contributed very little at any stage. A picture of the male removing the egg was analyzed to estimate the egg maximum width, ruling out a possible runt egg. Motivations behind the behaviour of the male destroying the egg remain unclear.