Conspecific Egg Removal Behaviour in Eurasian Tree SparrowPasser montanus

Abstract

In farmland in central Honshu, Japan, conspecific infanticide was recorded in five out of 68 breeding attempts of Eurasian Tree Sparrow Passer montanus in 2011 and 2012 including one suspected case. The number of eggs lost by infanticide accounted for 20% in 2011 and for 24.1% in 2012 of the total egg and nestling losses. In three out of five cases, subsequent nesting took place in the nest box where infanticide had caused the loss of a clutch, twice by the perpetrator and once by unknown breeders. In this population, infanticide was a major cause of breeding failure.