The browser you are using is not supported by this website. All versions of Internet Explorer are no longer supported, either by us or Microsoft (read more here:

Please use a modern browser to fully experience our website, such as the newest versions of Edge, Chrome, Firefox or Safari etc.

Portrait of Henrik Smith. Photo.

Henrik Smith


Portrait of Henrik Smith. Photo.

Adoption or infanticide: Options of replacement males in the European starling


  • Henrik Smith
  • Liv Wennerberg
  • Torbjörn von Schantz

Summary, in English

The behaviour of a male bird towards a potential mate and her clutch may depend both on his expected paternity and on the likelihood that she will produce a replacement clutch if he commits infanticide. In this study we evaluate the choices made by replacement male European starlings Sturnus vulgaris. By removing males before and during laying, we induced other males, mainly neighbours, to mate with the reproductively active females. When the original male was removed before laying, a new male adopted the subsequent clutch in 14 out of 15 cases. When ten females were widowed during their laying period, replacement males never adopted their clutches. The paternity of replacement males was a function of when they replaced the former male. When replacement occurred more than 3 days before egglaying, the new male fathered nearly all offspring; when it occurred the day before laying, the new male still fathered more than every second young. When the original male was removed during his mate's laying period, in five out of ten cases a replacement male committed infanticide by throwing out the eggs, but this only occurred in one out of 15 cases when removal took place before laying. The evidence for infanticide actually being committed by the replacement male was circumstantial. Four out of six of the females affected by apparent infanticide produced replacement clutches in which the male presumably had higher paternity than in the original clutch. In all cases, the male adopted the replacement clutch. In five cases when the original male was removed during laying, the neighbours neither adopted the brood nor committed infanticide, although they sometimes were seen courting the widowed female and copulating with her. These cases occurred later during laying than those were males comitted infanticide. The time from infanticide to the laying of the replacement clutch tended to increase as infanticide was committed later in the laying sequence. We conclude that strategies of potential replacement males are influenced by their expected paternity in the current brood and the probability that the female will produce an early replacement clutch.


  • Biodiversity
  • Department of Biology
  • Molecular Ecology and Evolution Lab

Publishing year







Behavioral Ecology and Sociobiology





Document type

Journal article




  • Biological Sciences
  • Ecology


  • females
  • tree swallows
  • hirundo-rustica
  • sturnus-vulgaris
  • tropical house wrens
  • extra-pair paternity
  • dunnocks prunella-modularis
  • parental care
  • male
  • sexually selected infanticide
  • intraspecific brood parasitism
  • male investment
  • paternity
  • Sturnus vulgaris
  • adoption
  • infanticide



Research group

  • Molecular Ecology and Evolution Lab


  • ISSN: 1432-0762