An observation of parental infanticide in Dickcissels (Spiza americana): video evidence and potential mechanisms

Project Type: Graduate Student
Funds awarded in 2015: $9,977.00
Projected End Date: 12/31/2018
Grant Recipient: University of Illinois
Region: North Central
State: Illinois
Graduate Student:
Faculty Advisor:
Dr. James Miller
University of Illinois
Brood reduction by parents via infanticide is considered rare in passerine birds; however, this behavior may be underreported because of the difficulties observing behaviors at the nest and because researchers tend to attribute partial nestling loss to other causes. Here, we report a confirmed incidence of parental infanticide by Dickcissels (Spiza americana). While video-recording parental behavior, we documented a 4-day-old nestling being removed by a female Dickcissel. This bird was also observed brooding and feeding, so this event was likely a parental infanticide. We subsequently examined monitoring data from 162 hatched Dickcissel nests across 2 breeding seasons to identify instances of unexplained partial nestling loss, which could potentially be attributable to infanticide. Our data indicate that 9.1–12.7% of hatched nests experienced these events. Infanticide by genetic parents could (1) benefit survival of remaining brood mates by reducing food requirements, disease, or predation risk; (2) represent responses to cuckoldry or intraspecific brood parasitism; (3) represent cases of mistaken chick identity; or (4) be triggered by unusual stressors. We recommend that ecologists monitoring bird nests consider infanticide as a possible explanation for partial nestling loss.
Peer-reviewed Journal Article
Jaime J Coon, University of Illinois at Urbana-Champaign
Scott B Nelson, University of Illinois at Urbana-Champaign
Amy C West, University of South Dakota
Iris A Bradley, University of Illinois at Urbana-Champaign
James R Miller, University of Illinois at Urbana-Champaign
Target audience:
Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.