Cookies Policy

This site uses cookies. By continuing to browse the site you are agreeing to our use of cookies.

I accept this policy

Find out more here

Red squirrel territorial vocalizations deter intrusions by conspecific rivals

No metrics data to plot.
The attempt to load metrics for this article has failed.
The attempt to plot a graph for these metrics has failed.
The full text of this article is not currently available.

Brill’s MyBook program is exclusively available on BrillOnline Books and Journals. Students and scholars affiliated with an institution that has purchased a Brill E-Book on the BrillOnline platform automatically have access to the MyBook option for the title(s) acquired by the Library. Brill MyBook is a print-on-demand paperback copy which is sold at a favorably uniform low price.

Access this article

+ Tax (if applicable)
Add to Favorites
You must be logged in to use this functionality

image of Behaviour

In many species, territory advertisement is thought to be one of the primary functions of acoustic communication. North American red squirrels are a territorial species in which ‘rattles’ have long been thought to be the principal signal communicating territory ownership. These vocalizations have been assumed to deter intruders, thus reducing energetic costs and the risk of injury associated with direct aggressive interactions. However, this hypothesis has not been directly tested. Here we used a speaker occupation experiment to test whether red squirrel rattles function to deter conspecific rivals. We studied 29 male squirrels and removed each individual from his territory twice in a paired design. During the experimental treatment, we simulated the owner’s presence after its removal by broadcasting the owner’s rattle from a loudspeaker at the centre of the territory once every 7 min. During the control treatment, the territory was left in silence following the temporary removal of the owner. We found that the presence of a speaker replacement reduced the probability of intrusion by 34% and increased the latency to first intrusion by 7%, providing support for the hypothesis that rattles play an active role in reducing intrusion risk. However, intrusions were not completely averted by the speaker replacement, indicating that for some individuals vocalizations alone are not a sufficient deterrent without other cues of the territory owner.

Affiliations: 1: aDepartment of Integrative Biology, University of Guelph, Guelph, ON, Canada ; 2: bSchool of Natural Resources and the Environment, University of Arizona, Tucson, AZ, USA ; 3: cDepartment of Biological Sciences, University of Alberta, Edmonton, AB, Canada ; 4: dDepartment of Natural Resource Sciences, Macdonald Campus, McGill University, Ste-Anne-de-Bellevue, QC, Canada ; 5: eDepartment of Psychology, University of Michigan, Ann Arbor, MI, USA ; 6: fDepartment of Ecology & Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA ; 7: gDepartment of Biology, University of Saskatchewan, Saskatoon, SK, Canada

*Corresponding author’s e-mail address:

Full text loading...


Data & Media loading...

1. Anderson P.K., Barclay R.M.R. (1995). "Acoustic signals of solitary dugongs: physical characteristics and behavioral correlates". — J. Mammal. Vol 76: 1226-1237. [Crossref]
2. Barlow K.E., Jones G. (1997). "Function of pipistrelle social calls: field data and a playback experiment". — Anim. Behav. Vol 53: 991-999. [Crossref]
3. Bass A.H., McKibben J.R. (2003). "Neural mechanisms and behaviors for acoustic communication in teleost fish". — Progr. Neurobiol. Vol 69: 1-26. [Crossref]
4. Bastos R.P., Alcantara M.B., Morais A.R. (2011). "Vocal behaviour and conspecific call response in Scinax centralis". — Herpetol. J. Vol 21: 43-50.
5. Berteaux D., Boutin S. (2000). "Breeding dispersal in female North American red squirrels". — Ecology Vol 81: 1311-1326. [Crossref]
6. Bradbury J.W., Vehrencamp S.L. (2011). Principles of animal communication, 2nd edn.Sinauer Associates, Sunderland, MA.
7. Brumm H., Robertson K.A., Nemeth E. (2011). "Singing direction as a tool to investigate the function of birdsong: an experiment on sedge warblers". — Anim. Behav. Vol 81: 653-659. [Crossref]
8. Cain K.E., Langmore N.E. (2015). "Female and male song rates across breeding stage: testing for sexual and nonsexual functions of female song". — Anim. Behav. Vol 109: 65-71. [Crossref]
9. Catchpole C.K. (1973). "The functions of advertising song in the sedge warbler (Acrocephalus schoenobaenus) and the reed warbler (A. scirpaceus)". — Behaviour Vol 46: 300-319. [Crossref]
10. Catchpole C.K. (1982). "The evolution of bird sounds in relation to mating and spacing behavior". — In: Acoustic communication in birds ( Kroodsma D.E., Miller E.H., eds). Academic Press, London, p.  297-319. [Crossref]
11. Catchpole C.K. (1983). "Variation in the song of the great reed warbler Acrocephalus arundinaceus in relation to mate attraction and territorial defence". — Anim. Behav. Vol 31: 1217-1225. [Crossref]
12. Catchpole C.K., Slater P.J.B. (2008). Bird song: biological themes and variations, 2nd edn.Cambridge University Press, Cambridge. [Crossref]
13. Conti C., Fonseca P.J., Picciulin M., Amorim M.C.P. (2015). "How effective are acoustic signals in territorial defence in the Lusitanian toadfish?" — J. Exp. Biol. Vol 218: 893-898. [Crossref]
14. Cox D.R. (1972). "Regression models and life tables". — J. Roy. Stat. Soc. Ser. B Vol 34: 187-220.
15. Cox D.R., Oakes D. (1984). Analysis of survival data. — Chapman & Hall, London.
16. Dantzer B., Boutin S., Humphries M.M., McAdam A.G. (2012). "Behavioral responses of territorial red squirrels to natural and experimental variation in population density". — Behav. Ecol. Sociobiol. Vol 66: 865-878. [Crossref]
17. Dantzer B., Newman A.E.M., Boonstra R., Palme R., Boutin S., Humphries M.M., McAdam A.G. (2013). "Density triggers maternal hormones that increase adaptive offspring growth in a wild mammal". — Science Vol 340: 1215-1217. [Crossref]
18. Darden S.K., Dabelsteen T. (2008). "Acoustic territorial signalling in a small, socially monogamous canid". — Anim. Behav. Vol 75: 905-912. [Crossref]
19. Digweed S.M., Rendall D., Imbeau T. (2012). "Who’s your neighbor? Acoustic cues to individual identity in red squirrel Tamiasciurus hudsonicus rattle calls". — Curr. Zool. Vol 58: 758-764. [Crossref]
20. Donald J., Boutin S. (2011). "Intraspecific cache pilferage by larder-hoarding red squirrels (Tamiasciurus hudsonicus)". — J. Mammal. Vol 92: 1013-1020. [Crossref]
21. Falls J.B. (1988). "Does song deter territorial intrusion in white-throated sparrows (Zonotrichia albicollis)?" — Can. J. Zool. Vol 66: 206-211. [Crossref]
22. Gorrell J., McAdam A., Coltman D., Humphries M., Boutin S. (2010). "Adopting kin enhances inclusive fitness in asocial red squirrels". — Nature Commun. Vol 1: 22. [Crossref]
23. Grinnell J., McComb K. (2001). "Roaring and social communication in African lions: the limitations imposed by listeners". — Anim. Behav. Vol 62: 93-98. [Crossref]
24. Grinnell J., Packer C., Pusey A.E. (1995). "Cooperation in male lions: kinship, reciprocity or mutualism?" — Anim. Behav. Vol 49: 95-105. [Crossref]
25. Harrington F.H., Mech D.L. (1979). "Wolf howling and its role in territory maintenance". — Behaviour Vol 68: 207-249. [Crossref]
26. Hayes S.A., Kumar A., Costa D.P., Mellinger D.K., Harvey J.T., Southall B.L., Le Boeuf B.J. (2004). "Evaluating the function of the male harbour seal, Phoca vitulina, roar through playback experiments". — Anim. Behav. Vol 67: 1133-1139. [Crossref]
27. Huang P., Sieving K.E., St. Mary C.M. (2012). "Heterospecific information about predation risk influences exploratory behavior". — Behav. Ecol. Vol 23: 463-472. [Crossref]
28. Kramer H.G., Lemon R.E. (1983). "Dynamics of territorial singing between neighboring song sparrows (Melospiza melodia)". — Behaviour Vol 85: 198-223. [Crossref]
29. Krebs C.J., Boutin S.A., Boonstra R. (2001). Ecosystem dynamics of the boreal forest: the Kluane project. — Oxford University Press, New York, NY.
30. Krebs J.R. (1977). "Song and territory in the great tit Parus major". — In: Evolutionary ecology ( Stonehouse B., Perrins C., eds). University Park Press, Baltimore, MD, p.  47-62.
31. Krebs J., Ashcroft R., Webber M. (1978). "Song repertoires and territory defence in the great tit". — Nature Vol 271: 539-542. [Crossref]
32. Lair H. (1990). "The calls of the red squirrel: a contextual analysis of function". — Behaviour Vol 115: 254-281. [Crossref]
33. McAdam A., Boutin S., Sykes A.K., Humphries M.M. (2007). "Life histories of female red squirrels and their contributions to population growth and lifetime fitness". — Ecoscience Vol 14: 362-369. [Crossref]
34. McDonald M.V. (1989). "Function of song in Scott’s seaside sparrow, Ammodramus maritimus peninsulae". — Anim. Behav. Vol 38: 468-485. [Crossref]
35. Morais A.R., Siqueira M.N., Bastos R.P. (2015). "How do males of Hypsiboas goianus (Hylidae: Anura) respond to conspecific acoustic stimuli?" — Zoologia (Curitiba) Vol 32: 431-437. [Crossref]
36. Morton E.S. (1977). "On the occurrence and significance of motivation-structural rules in some bird and mammal sounds". — Am. Nat. Vol 111: 855-869. [Crossref]
37. Myrberg A.A. (1997). "Sound reduction by a coral reef fish (Pomacentrus partitus): evidence for a vocal, territorial “keep-out” signal". — Bull. Mar. Sci. Vol 60: 1017-1025.
38. Nowicki S., Hughes M., Searcy W. (1998). "The territory defense function of song in song sparrows: a test with the speaker occupation design". — Behaviour Vol 135: 615-628. [Crossref]
39. Odom K.J., Mennill D.J. (2010). "Vocal duets in a nonpasserine: an examination of territory defence and neighbour-stranger discrimination in a neighbourhood of barred owls". — Behaviour Vol 147: 619-639. [Crossref]
40. Peek F.W. (1972). "An experimental study of the territorial function of vocal and visual display in the male red-winged blackbird (Agelaius phoeniceus)". — Anim. Behav. Vol 20: 112-118. [Crossref]
41. Penteriani V. (2002). "Variation in the function of eagle owl vocal behaviour: territorial defence and intra-pair communication?" — Ethol. Ecol. Evol. Vol 14: 275-281. [Crossref]
42. Pereira R., Rismondo S., Caiano M., Pedroso S.S., Fonseca P.J., Amorim M.C.P. (2013). "The role of agonistic sounds in male nest defence in the painted goby Pomatoschistus pictus". — Ethology Vol 120: 53-63. [Crossref]
43. Price K., Boutin S., Ydenberg R. (1990). "Intensity of territorial defense in red squirrels: an experimental test of the asymmetric war of attrition". — Behav. Ecol. Sociobiol. Vol 27: 217-222. [Crossref]
44. R Core Team (2016). R: a language and environment for statistical computing. — R Foundation for Statistical Computing, Vienna, available online at
45. Reby D., Cargnelutti B., Hewison A.J.M. (1999). "Contexts and possible functions of barking in roe deer". — Anim. Behav. Vol 57: 1121-1128. [Crossref]
46. Seyfarth R., Cheney D. (1990). "The assessment by vervet monkeys of their own and another species’ alarm calls". — Anim. Behav. Vol 40: 754-764. [Crossref]
47. Sharpe D.J., Goldingay R.L. (2009). "Vocal behaviour of the squirrel glider (Petaurus norfolcensis)". — Aust. J. Zool. Vol 57: 55-64. [Crossref]
48. Shonfield J., Taylor R., Boutin S., Humphries M., McAdam A. (2012). "Territorial defence behaviour in red squirrels is influenced by local density". — Behaviour Vol 149: 369-390. [Crossref]
49. Shonfield J., Gorrell J.C., Coltman D.W., Boutin S., Humphries M.M., Wilson D.R., McAdam A.G. (2017). "Using playback of territorial calls to investigate mechanisms of kin discrimination in red squirrels". — Behav. Ecol. Vol 28: 382-390. [Crossref]
50. Smith C.C. (1968). "The adaptive nature of social organization in the genus of three squirrels Tamiasciurus". — Ecol. Monogr. Vol 38: 31-64. [Crossref]
51. Smith C.C. (1978). "Structure and function of the vocalizations of tree squirrels (Tamiasciurus)". — J. Mammal. Vol 59: 793-808. [Crossref]
52. Smith D.G. (1979). "Male singing ability and territory integrity in red-winged blackbirds (Ageliaus phoeniceus)". — Behaviour Vol 68: 193-206. [Crossref]
53. Soard C.M., Ritchison G. (2009). "‘Chick-a-dee’ calls of Carolina chickadees convey information about degree of threat posed by avian predators". — Anim. Behav. Vol 78: 1447-1453. [Crossref]
54. Templeton C.N., Greene E., Davis K. (2005). "Allometry of alarm calls: black-capped chickadees encode information about predator size". — Science Vol 308: 1934-1937. [Crossref]
55. Therneau T.M. (2015). Mixed effects Cox models (R package version 2.2-5). — Available online at
56. Waser P.M. (1975). "Experimental playbacks show vocal mediation of intergroup avoidance in a forest monkey". — Nature Vol 255: 56-58. [Crossref]
57. Weeden J.S., Falls J.B. (1959). "Differential responses of male ovenbirds to recorded songs of neighboring and more distant individuals". — Auk Vol 76: 343-351. [Crossref]
58. Wells K.D. (1977). "The social behaviour of anuran amphibians". — Anim. Behav. Vol 25: 666-693. [Crossref]
59. Westcott D. (1992). "Inter-and intra-sexual selection: the role of song in a lek mating system". — Anim. Behav. Vol 44: 695-703. [Crossref]
60. Wilson E.O. (1975). Sociobiology: the new synthesis. — Harvard University Press, Cambridge, MA.
61. Wilson D.R., Goble A.R., Boutin S., Humphries M.M., Coltman D.W., Gorrell J.C., Shonfield J., McAdam A.G. (2015). "Red squirrels use territorial vocalizations for kin discrimination". — Anim. Behav. Vol 107: 79-85. [Crossref]
62. Yasukawa K. (1981). "Song and territory defense in the red-winged blackbird". — Auk Vol 98: 185-187.
63. Yasukawa K. (1990). "Does the “teer” vocalization deter prospecting female red-winged blackbirds?" — Behav. Ecol. Sociobiol. Vol 26: 421-426. [Crossref]

Article metrics loading...



Can't access your account?
  • Tools

  • Add to Favorites
  • Printable version
  • Email this page
  • Subscribe to ToC alert
  • Get permissions
  • Recommend to your library

    You must fill out fields marked with: *

    Librarian details
    Your details
    Why are you recommending this title?
    Select reason:
    Behaviour — Recommend this title to your library
  • Export citations
  • Key

  • Full access
  • Open Access
  • Partial/No accessInformation