title: Differences in ultrasonic vocalizations between wild and laboratory California mice (Peromyscus californicus).
abstract: BACKGROUND
  Ultrasonic vocalizations (USVs) emitted by muroid rodents, including laboratory mice and rats, are used as phenotypic markers in behavioral assays and biomedical research. Interpretation of these USVs depends on understanding the significance of USV production by rodents in the wild. However, there has never been a study of muroid rodent ultrasound function in the wild and comparisons of USVs produced by wild and laboratory rodents are lacking to date. Here, we report the first comparison of wild and captive rodent USVs recorded from the same species, Peromyscus californicus.
  
  
  RESULTS
  We used standard ultrasound recording techniques to measure USVs from California mice in the laboratory (Peromyscus Genetic Stock Center, SC, USA) and the wild (Hastings Natural History Reserve, CA, USA). To determine which California mouse in the wild was vocalizing, we used a remote sensing method that used a 12-microphone acoustic localization array coupled with automated radio telemetry of all resident Peromyscus californicus in the area of the acoustic localization array. California mice in the laboratory and the wild produced the same types of USV motifs. However, wild California mice produced USVs that were 2-8 kHz higher in median frequency and significantly more variable in frequency than laboratory California mice.
  
  
  CONCLUSIONS
  The similarity in overall form of USVs from wild and laboratory California mice demonstrates that production of USVs by captive Peromyscus is not an artifact of captivity. Our study validates the widespread use of USVs in laboratory rodents as behavioral indicators but highlights that particular characteristics of laboratory USVs may not reflect natural conditions.
authors.affiliation: Department of Biology, University of North Carolina at Greensboro, Greensboro, North Carolina, USA. mckalcounisrueppell@gmail.com
authors.forename: Matina C
authors.initials: MC
authors.lastname: Kalcounis-Rueppell
authors.forename: Radmila
authors.initials: R
authors.lastname: Petric
authors.forename: Jessica R
authors.initials: JR
authors.lastname: Briggs
authors.forename: Catherine
authors.initials: C
authors.lastname: Carney
authors.forename: Matthew M
authors.initials: MM
authors.lastname: Marshall
authors.forename: John T
authors.initials: JT
authors.lastname: Willse
authors.forename: Olav
authors.initials: O
authors.lastname: Rueppell
authors.forename: David O
authors.initials: DO
authors.lastname: Ribble
authors.forename: Janet P
authors.initials: JP
authors.lastname: Crossland
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D019411:Clinical Laboratory Techniques / Q000592:standards; D051379:Mice; D010542:Peromyscus / Q000502:physiology*; D014465:Ultrasonics; D014828:Vocalization, Animal