Individual variation in the dear enemy phenomenon via territorial vocalizations in red squirrels Journal Article uri icon



  • Abstract; Territoriality arises when the benefits of resources exceed the costs of defending them. The dear enemy phenomenon, where familiar territorial neighbours refrain from intruding on one another and mutually reduce their defensive efforts, allows for reduction of these costs but requires discrimination between conspecifics. We hypothesized that territorial vocalizations in red squirrels (Tamiasciurus hudsonicus) are used for this discrimination. We performed a speaker replacement experiment where red squirrels () were temporarily removed from their territories and replaced with a speaker broadcasting their own call, an unfamiliar call, or silence. Contrary to our prediction, there were no differences in overall intrusion risk among our three playbacks, but the identity of intruders did vary. Existing variation in familiarity within territorial neighbourhoods should be considered, rather than the binary classification of familiar or stranger, when studying dear enemy effects. We also discuss the variable importance of silence in acoustic territorial populations.

publication date

  • January 1, 2018

has restriction

  • green

Date in CU Experts

  • January 12, 2021 2:55 AM

Full Author List

  • Robertson JG; Boutin S; Humphries MM; Dantzer B; Lane JE; McAdam AG

author count

  • 6

Other Profiles

International Standard Serial Number (ISSN)

  • 0005-7959

Electronic International Standard Serial Number (EISSN)

  • 1568-539X

Additional Document Info

start page

  • 1073

end page

  • 1096


  • 155


  • 13-15