title: Artificial light at night desynchronizes strictly seasonal reproduction in a wild mammal.
abstract: Change in day length is an important cue for reproductive activation in seasonally breeding animals to ensure that the timing of greatest maternal investment (e.g. lactation in mammals) coincides with favourable environmental conditions (e.g. peak productivity). However, artificial light at night has the potential to interfere with the perception of such natural cues. Following a 5-year study on two populations of wild marsupial mammals exposed to different night-time levels of anthropogenic light, we show that light pollution in urban environments masks seasonal changes in ambient light cues, suppressing melatonin levels and delaying births in the tammar wallaby. These results highlight a previously unappreciated relationship linking artificial light at night with induced changes in mammalian reproductive physiology, and the potential for larger-scale impacts at the population level.
authors.affiliation: Department of Ecology, Environment and Evolution, La Trobe University, Melbourne 3086, Australia k.robert@latrobe.edu.au.
authors.forename: Kylie A
authors.identifier: http://orcid.org/0000-0002-8554-8440
authors.initials: KA
authors.lastname: Robert
authors.affiliation: Department of Ecology, Environment and Evolution, La Trobe University, Melbourne 3086, Australia.
authors.forename: John A
authors.identifier: http://orcid.org/0000-0001-5073-6954
authors.initials: JA
authors.lastname: Lesku
authors.affiliation: Max Planck Institute for Ornithology, Radolfzell 78315, Germany Department of Biology, University of Konstanz, Konstanz 78457, Germany.
authors.forename: Jesko
authors.initials: J
authors.lastname: Partecke
authors.affiliation: School of Animal Biology, The University of Western Australia, Perth 6009, Australia.
authors.forename: Brian
authors.initials: B
authors.lastname: Chambers
mesh_terms: D000818:Animals; D002947:Cities; D008027:Light / Q000009:adverse effects*; D007614:Macropodidae / Q000502:physiology*; D008550:Melatonin / Q000502:physiology*; D012098:Reproduction / Q000528:radiation effects*; D014904:Western Australia
chemical_list: D008550:Melatonin
keywords: Macropus eugenii; anthropogenic disturbance; circadian disruption; light pollution; melatonin; trophic mismatch