March 2016 - We have launched a new Citizen Science Project on recording White-throated Sparrow song across North America. To get involved, grab a cell phone and check out the whitethroatsong.ca website for instructions!
Ecosystem Science & Management Program
Natural Resources and Environmental Studies
University of Northern BC
3333 University Way, Prince George, BC, Canada, V2N 4Z9
phone (250) 960 5019
fax (250) 960 5539
My main area of research is animal behaviour, particularly in avian reproductive behaviour and communication. My work with chickadees assesses the impact of habitat disturbance and urbanization on the normal breeding and communication behaviours of animals, and most recently the potential for this to result in inter-species hybridization. Starting in 2013, much of this work is focusing a joint research project that Dr. Matt Reudink (Thompson Rivers University) and I have been establishing in the parks and woods around Kamloops, BC with a focus on mountain chickadees. Since 2005, I have also been working with industry, the Canadian Wildlife Service and faculty at UNBC to assess migratory movement patterns of birds around wind farms and airports, and we are extending this work to other areas of bird tracking.
Most of my students work in our lab - the Avian Behaviour & Conservation Research Lab, more colloquially referred to as the "Bird Cave". This name came from the fact that we use to be housed in a windowless room in the basement that was rather cavernous. We have since moved to a lab with windows out of the basement, but the name (and logo) has stuck.
The work in the lab follows a general theme of determining how habitat alteration impacts the condition, communication and, ultimately, reproduction of birds. The research started off looking at the impacts of settling in poor habitat in black-capped chickadees, and has branched into looking at similar issues in owls (Western Screech and Northern Saw-whet) and white-throated sparrows (work being done with Scott Ramsay at Wilfrid Laurier University). Work on chickadees is branching out to look at effects of urban development, as well as interspecific interactions and hybridization. The most recent focus is looking at the impact of wind farm construction on altering bird migration patterns and landscape use (for breeding or for migratory stop-overs). We are also beginning to address these same issues of spatial movement and collision risk of birds at airports, as well as developing new techniques to track birds across forest gaps.
So despite the logo, we haven't started on wrens yet (I just like this drawing and we figured Troglodytes troglodytes was a good species for a 'bird cave').
Graduate students (MSc and PhD) in my lab are part of the Natural Resources and Environmental Studies Graduate Program (NRES) and postdocs would be able to apply to work within the NRES Institute. If you are interested in working in the lab, please contact me about current opportunities and funding potential.
Stefanie LaZerte, Postdoctoral Fellow
Stefanie completed her PhD in April 2015 on the effects of urbanization on avian signalling. Specifically, she looked at how the interaction between both a noisier environment and also changes to the physical characteristics of the environment affected signal transmission and detection. She also investigated whether species-specific signals may pre-dispose certain birds to being less compromised by urbanization than other species, and tested these predictions with several species of chickadees in urban and rural settings in British Columbia.
Since May 2016, Stefanie has continued this work as a Postdoctoral Fellow in the lab, and is branching out into getting involved in some of our other research projects, specifically those involving song dialects and migrational behaviour in white-throated sparrows. Despite now being a Research Fellow at Thompson Rivers University, we have managed to keep her working on a few of our local projects!
Check out the Citizen Science Project she has helped develop at whitethroatsong.ca
Kristen began work in Jan 2014 as the first student on a collaborative venture between our lab and Matt Reudink's lab at Thompson Rivers University. This venture will focus on the behaviour and communication of mountain chickadees in the Kamloops region facing two challenges - increasing urbanization into their habitat and secondary contact with dominant black-capped chickadees.
Erica Bonderud, MSc Student (Co-supervised with Matt Reudink, TRU)
Erica began her Masters in September 2015, and is interested in the breeding behaviour of Mountain Chickadees. She will be studying the effects of male dominance relationships on extra-pair paternity in Mountain Chickadee populations in the Kamloops area.
Jacob Bailey, MSc Student (Co-supervised with Matt Reudink, TRU)
Jacob will be investigating movement patterns of mountain chickadees. He will be using using RFID technology to track bird movements across fragmented landscapes in order to determine the effect they have on movement and dispersal of birds in these areas.
Paul Koch (BSc 2017) - The influence of genetics on neophobia: responses of wolves, wolfdogs and dogs to visual stimuli. B.Sc. Thesis, University of Northern BC
Stefanie LaZerte (PhD 2015) - Sounds of the city: the effects of urbanization and noise on mountain and black-capped chickadee communication. PhD Thesis, University of Northern BC.
Hannah Zimmerman (BSc. 2015) - Cultural evolution in white-throated sparrow song: regional variation through shift in terminal strophe type and length. B.Sc. Thesis, University of Northern BC
Isobel Hartley, Research Associate 2008-2014. Developing techniques for tracking bird movement patterns. www.unbc.ca/avian-movement
Angelique Grava (PhD 2012) -Interspecific interactions between mountain and black-capped chickadees within a contact zone. PhD Thesis, University of Northern BC.
Thibault Grava (PhD 2012) - Effect of habitat quality on communication and signalling in the black-capped chickadee. PhD Thesis, University of Northern BC.
Dustin Walsh (BSc 2011) - Nightvision monitoring of avian movement around wind farms. B.Sc. Thesis, University of Northern BC
Naira Johnston (MSc 2011, Research Associate 2012) - The associations between weather and topography on golden eagle flight behaviour at a wind farm in the Canadian Rockies. MSc. Thesis, University of Northern BC.
Katrina Wohlfarth (BSc. 2011) - The relationship between dominance and personality traits in chickadees. Independent Research Project. University of Northern BC
Laura Kennedy (BSc. 2011) - Relationship between grasshopper availability and crow movement patterns at the Prince George Airport. Independent Research Project. University of Northern BC
Andrea Pomeroy. (Postdoctoral Fellow 2007- 2009) - The use of metabolic assays to determine the indirect affect of wind development on migratory birds. NSERC Industrial Research and Development Fellow.
Sarina Loots. (Science Horizons Research Internship – Sept 2010-March 2011) - Development and testing of remote radars and radar tracking software (radR) for use in Avian Tracking at airports.
James Bradley (Research Associate - April 2009 – May 2012 part time) - Spatial movement of golden eagle migration in relation to weather patterns.
Regis Didier (Research Associate April to July 2009, April to July 2010) - Environmental effects on chickadee reproduction and food availability.
Veronica Mesias (Research Associate May to Sept 2009 (co-supervised with B. Murray) - Geographic variation in song dialects of white-throated sparrows in relation to genetic differentiation of migratory routes
Adrienne Labrosse (M.Sc. 2008) - Determining factors affecting carcass removal and searching efficiency during the post-construction monitoring of wind farms. MSc. Thesis, University of Northern BC.
Philippe Thomas (M.Sc. 2008) - Factors influencing avian movement patterns around proposed ridgeline wind farm sites in British Columbia, Canada. MSc. Thesis, University of Northern BC.
Laura Radigan (BSc. 2009) - Vegetation Trials and Bird Distribution Patterns at the Prince George Airport. USRA Project Student, University of Northern BC
Morgan Anderson (BSc. 2008) - Spatial and temporal patterns of avian movement around airports. USRA Project Student, University of Northern BC
Jeannine McCormack. (BSc. 2006) - Risk taking behaviour and winter foraging in chickadees – the effect of habitat. Independent Research Project. University of Northern BC.
Sarah Atherton. (BSc. 2005) - . The effect of urban lighting on dawn singing in chickadees. USRA Project Student 2004 and 2005, University of Northern BC
Eileen Brunsch (BSc. 2005) - Developing microsatellite techniques for black-capped chickadees. NSERC USRA project student 2004, and research assistant 2005/2006, University of Northern BC
Mark Keil (BSc. 2005) - The effects of windfarms on birds: a review. Independent Research Project. University of Northern BC.
Carmen Holschuh (M.Sc 2004) - Monitoring habitat quality and condition of Queen Charlotte saw-whet owls (Aegolius acadicus brooksi) using vocal individuality MSc. Thesis, University of Northern BC.
(BSc. 2001) - Behavioural compensation for habitat induced differences in black-capped chickadee song transmission. B.Sc. Thesis, University of Northern BC
Harry van Oort (M.Sc 2004) - Habitat selection and impacts of habitat disturbance on somatic and reproductive investments in the black-capped chickadee. MSc. Thesis. University of Northern BC.
Tania Tripp (M.Sc. 2004) - Use of bioacoustics for population monitoring in the western screech-owl (Megascops kennicottii). MSc. Thesis, University of Nothern BC.
Kevin Fort (M.Sc. 2003) - The effects of habitat disturbance on the reproductive behaviour of the black-capped chickadee (Poecile atricapilla).. MSc. Thesis, University of Northern BC.
Ingebjørg Jean Hansen (BSc 2003) - Communication breakdown: habitat influences on the communication networks and transmission of song in black-capped chickadee (Poecile atricapillus). B.Sc. Thesis, University of Northern BC
Zoe McDonell. (BSc. 2002) - Feeding rates and nesting behavoiur between disturbed and undisturbed woodlands in the black-capped chickadee. B.Sc. Thesis, University of Northern BC.
Kim Everett (BSc. 2001) - The influence of wildlife tree management on cavity nesting birds in Northern BC. B.Sc. Thesis, University of Northern BC
Marini, K.L.D, Otter, K.A., LaZerte, S.E. & Reudink, M.W. 2017. Urban environments are associated with earlier clutches and faster nestling feather growth compared to natural habitats. Urban Ecosystems. In press (Accepted May 2017)
LaZerte, S., Slabbekoorn, H. & Otter, K.A. 2017. Territorial black-capped chickadee males respond faster to high- than to low-frequency songs in experimentally elevated noise conditions. PeerJ 5:e3257; DOI 10.7717/peerj.3257
LaZerte, S., Otter, K.A., & Slabbekoorn, H. 2017. Mountain chickadees adjust songs, calls and chorus composition with increasing ambient and experimental noise. Urban Ecosystems. Published online Feb 2017. DOI 10.1007/s11252-017-0652-7
Hahn, A.H., Guillette, L.M, Hoeschele, M., Otter, K.A, Ratcliffe, L.M., & Sturdy, C.B. 2017. Discrimination of male black-capped chickadee songs: Relationship between acoustic preference and performance accuracy. Animal Behaviour 126: 107–121.
Snell, C.L., LaZerte, S.E., Reudink, M.W. & Otter, K.A. 2016. Sympatric song variant in mountain chickadees Poecile gambeli does not reduce aggression from black-capped chickadees Poecile atricapillus. European Journal of Ecology. 2(1): x-x, doi: 10.1515/eje-2016-0006
Zimmerman, H.D., Ramsay, S.M., Mesias, V., Mora, M., Murray, B. & Otter, K.A. 2016. Evolution in white-throated sparrow song: regional variation through shift in terminal strophe type and length. Behaviour 153: 1839–1861. [Chosen as COVER PHOTO for issue]
LaZerte, S.E., Slabbekoorn, H. & Otter, K.A. 2016. Learning to cope: vocal adjustment to urban noise is correlated with prior experience in black-capped chickadees. Proceedings of the Royal Society of London B. 283: 20161058. http://dx.doi.org/10.1098/rspb.2016.1058
Adams, R.V., LaZerte, S.E., Otter, K.A. & Burg, T.M. 2016. Influence of landscape features on the microgeographic genetic structure of a resident songbird. Heredity. 117: 63-72. link
Hahn, A.H., Hoeschele, M., Guillette, L.M., Hoang, J., McMillan, N., Congdon, J.V., Campbell, K.A., Mennill, D.J., Otter, K.A., Grava, T., Ratcliffe, L.M., & Sturdy, C.B. 2016. Black-capped chickadees categorize songs based on geographic information. Animal Behaviour 112: 93–104.
LaZerte, S.E., Slabbekoorn, H., & Otter, K.A. 2015. Sounds of the city: The effects of noise on communication in mountain and black-capped chickadees. Natural Resources & Environmental Studies Institute Research Extension Notes 10. University of Northern British Columbia. link
LaZerte, S.E., Otter, K.A. & Slabbekoorn, H. 2015. Improving urban acoustics: Urban noise is more detrimental than urban habitat to transmission of chickadee vocalizations. Bioacoustics 24: 233 -252. link
Ramsay, S.M. & Otter, K.A. 2015. Geographic variation in white-throated sparrow song may arise through epiphenomena selection. Journal of Ornithology 156:763–773.
Kennedy, L. & Otter, K.A. 2015. Grass management regimes to mitigate bird-aircraft collisions; reducing grasshopper availability and subsequently American crow (Corvus brachyrhynchos) activity at airports. Human–Wildlife Interactions 9: 58–66
Otter, K.A., Hartley, M.I., d’Entremont, M., Johnston, N.N., Walsh, D, Bradley, J., Willie M., & Pomeroy, A.C. 2014. Avian Movement at the Dokie 1 Wind Energy Project 2008-2012: analysis of potential conflict between wind development and avian migration in the northern Rocky Mountains. Natural Resources & Environmental Studies Institute (NRESi) Technical Report #1. University of Northern British Columbia. Prince George, B.C., Canada. (35 pages)
Johnston, N.N., Bradley, J.E. & Otter, K.A. 2014. Increased flight altitudes may suggest turbine avoidance by migrating golden eagles at a Rocky mountain wind installation. Plos ONE 9(3): e93030
Ainslie, B., Alexander, N., Johnston, N., Bradley, J., Pomeroy, A.C., Jackson, P.L., & Otter, K.A. 2014. Predicting spatial patterns of eagle migration using a mesoscale atmospheric model: a case study associated with a mountain-ridge wind development. International Journal of Biometeorology. 58: 17-30
Johnston, N.N., Bradley, J.E., Pomeroy, A.C. & Otter, K.A. 2013. Flight paths of migrating Golden Eagles and the risk associated with wind energy development in the Rocky Mountains. Avian Conservation & Ecology 8(2): 12. http://dx.doi.org/10.5751/ACE-00608-080212
Grava, T., Fairhurst G.D., Avey M.T., Grava A., Bradley J., Avis J.L., Bortolotti G.R, Sturdy C.B. & Otter K.A. 2013. Habitat quality affects early physiology and subsequent neuromotor development of juvenile black-capped chickadees. Plos ONE 8: e71852 (10 pages)
Grava, T., Grava A. & Otter K.A. 2013. Habitat-induced changes in song consistency affect perception of social status in male chickadees. Behavioral Ecology & Sociobiology. 67:1699-1707
Hahn, A.H., Guillet, L.M., Hoeschele, M., Mennill, D.J., Otter, K.A., Grava, T., Ratcliffe, L.M. & Sturdy, C.B. 2013. Dominance and geographic information contained within black-capped chickadee (Poecile atricapillus) song. Behaviour. 150: 1601-1622. DOI:10.1163/1568539X-00003111. (Article was highlighted with the coverphoto for this issue of the journal)
Grava, A., Otter, K.A Grava, T., & LaZerte, S. 2013. Character displacement in dawn chorusing behaviour of sympatric mountain and black-capped chickadees. Animal Behaviour 86: 177-187
Grava, A., Grava, T., & Otter, K.A. 2012. Differential response to interspecific and intraspecific signals amongst chickadees. Ethology 118: 711–720.
Grava, A., Grava, T, Didier, R., Lait, L., Koran, E., Dosso, J., Burg, T. & Otter, K.A. 2012. Interspecific dominance relationships and hybridization between black-capped and mountain chickadees. Behavioural Ecology 23: 566-572.
Grava, T. Grava, A & Otter, K.A. 2012. Vocal performance varies with habitat quality in the black-capped chickadee. Behaviour 149 : 35–50.
Otter, K.A., Murray, B.W., Holschuh, C.I. & Fort, K.T. 2011. Rare insights into intraspecific brood parasitism and apparent quasi-parasitism in black-capped chickadees. Animal Biodiversity & Conservation 34: 23-29
Thomas, P.J., Labrosse, A.K, Pomeroy, A.C. & Otter, K.A. 2011. Effects of weather on avian migration at proposed ridgeline wind energy sites. Journal of Wildlife Management. 75: 805-815
Lambrechts, M., Adriaensen, F., Ardia, D. R., Artemyev, A. V., Atiénzar, F., Bańbura, J., Barba, E., Bouvier, J.-C., Camprodon, J., Cooper, C. B., Dawson, R. D., Eens, M., Eeva, T., Faivre, B., Garamszegi, L. Z., Goodenough, A., Gosler, A., Grégoire, A., Griffith, S. C., Johnson, L. S., Kania, W., Keišs, O., Llambias, P. E., Mainwaring, M. C., Mänd, R., Massa, B., Mazgajski, T. D., Møller, A.P., Moreno, J., Naef-Daenzer, B., Nilsson, J.-Å., Norte, A. C., Otter, K. A., Park, C. R., Perrins, C. M., Pinowski, J., Porkert, J., Potti, J., Remes, V., Richner, H., Shiao, M.-T., Silverin, B., Slagsvold, T., Smith, H. G., Sorace, A., Stenning, M. J., Stewart, I., Thompson, C. F., Török, J., van Noordwijk, A. J., & Ziane, N. 2010. The design of artificial nestboxes for the study of secondary hole-nesting birds: a review of methodological inconsistencies and potential biases. Acta Ornithologica 45:1-26.
Hoeschele, M. Moscicki, M.K., Otter, K.A., van Oort, H., Fort, K.T., Farrell, T.M., Lee, H., Robson, S.W.J. & Sturdy, C.J. 2010. Dominance signalled in an acoustic ornament. Animal Behaviour 79: 657–664
Grava, T, Grava, A. & Otter, K.A. 2009. Supplemental feeding and dawn singing in black-capped chickadees. Condor 111: 560-564
Schubert, K.A., Kraus, C., Mennill, D.J., Ramsay, S.M., Otter, K.A. & Ratcliffe, L.M. 2008. Enhanced annual survival of high ranking male black-capped chickadees: a multi-strata modelling approach. Auk 125: 629-636.
Desrochers, A., Otter, K.A., Belisle, M. & Olson, J. 2007. Synopsis – Landscape ecology, conservation issues and behaviour. In. Otter, K. A. ed. Ecology and behavior of chickadees and titmice: an integrated approach. Pp. 293-298. Oxford University Press, Oxford.
Mennill, D.J. & Otter, K.A. 2007. Status signaling and communication networks in chickadees: Complex communication with a simple song. In. Otter, K. A. ed. Ecology and behavior of chickadees and titmice: an integrated approach. Pp. 215-233. Oxford University Press, Oxford.
Otter, K. A. ed. Ecology and behavior of chickadees and titmice: an integrated approach. Oxford University Press, Oxford.
Otter, K.A., van Oort, H. and Fort, K.T. 2007. Habitat quality, reproduction and behaviour in chickadees and titmice: insights on the use of habitat matrixes in conservation? In. Otter, K. A. ed. Ecology and behavior of chickadees and titmice: an integrated approach. Pp. 277-298. Oxford University Press, Oxford.
Otter, K.A., Atherton, S.E. & van Oort, H. 2007. Female food-solicitation calling, hunger levels and habitat differences in the black-capped chickadee. Animal Behaviour 74: 847-853
Ramsay, S.M., & Otter, K.A. 2007. Seasonal variation in the timing of reproduction in titmice and chickadees. In. Otter, K. A. ed. Ecology and behavior of chickadees and titmice: an integrated approach. Pp. 55-69. Oxford University Press, Oxford.
van Oort, H. Otter, K.A., Fort, K. & McDonell, Z. 2007. Habitat, dominance and the phenotypic quality of male black-capped chickadees. Condor 109: 88-96
Schubert, K.A., Mennill, D.J., Ramsay, S.M., Otter, K.A., Boag, P.T. & Ratcliffe, L.M. 2007. Variation in social rank acquisition influences lifetime reproductive success in black-capped chickadees. Biological Journal of the Linnaean Society 90: 89-95
Smulders, T.V., Lisi, M.D., Tricomi, E., Otter, K.A., Chruszcz, B., Ratcliffe, L.M., & DeVoogd, T.J. 2006. Failure to detect seasonal changes in the song system nuclei of the black-capped chickadee (Poecile atricapillus). Journal of Neurobiology 66: 991-1001
Tripp, T. & Otter, K.A. 2006. Vocal individuality as a potential long-term monitoring tool for adult male Western Screech Owls. Canadian Journal of Zoology 84: 744-753
van Oort, H., Otter, K.A., Fort, K. & Holschuh, C.I. 2006. Habitat quality, social dominance and dawn chorus song output in black-capped chickadees. Ethology 112:772-778
Hansen, I.J., Otter, K.A. & van Oort, H. 2005. Communication breakdown? Habitat influences on the communication networks in black-capped chickadees. Acta Ethologica 8: 111-120
Holschuh, C.I. & Otter K.A. 2005. Using vocal individuality to monitor Queen Charlotte Saw-whet Owls (Aegolius acadicus brooksi). Journal of Raptor Research 39:134-141
van Oort, H. & Otter, K.A. 2005. Natal nutrition and habitat selection among juvenile black-capped chickadees. Canadian Journal of Zoology 83: 1495-1501
Otter, K.A. & Ratcliffe, L. 2005. Enlightened decisions: female perspectives on communication networks. Pp. 133-151. In: Communication Networks (P.K. McGregor, ed). Cambridge University Press, Cambridge, UK.
Everett, K.T. & Otter, K.A. 2004. Presence of cavities in snags retained in forest cutblocks: Do management policies promote species retention? Canadian Field Naturalist 118: 354-359
Fort, K. & Otter, K.A. 2004a. Effects of habitat disturbance on reproduction in black-capped chickadees (Poecile atricapillus) in Northern British Columbia. Auk 121: 1070-1080
Fort, K. & Otter, K.A.. 2004b. Territorial breakdown of black-capped chickadees, Poecile atricapillus, in disturbed habitats? Animal Behaviour 68:407-415
Ramsay, S.M., Mennill, D., Otter K.A. & Ratcliffe, L.M.. 2003. Offspring sex ratio in relation to rank in the black-capped chickadee. Journal of Avian Biology 34:134-139
Otter, K.A., Ratcliffe, L., Njegovan, M. & Fotheringham, J. 2002. The importance of frequency and temporal matching in aggressive vocal signalling of black-capped chickadees: evidence from interactive playback. Ethology 108: 181-191
Otter, K., Stewart, I.K., McGregor, P.K., Terry, A.M.R., Dabelsteen, T. & Burke, T. 2001. Extra-pair paternity in great tits in relation to manipulation of male signals. Journal of Avian Biology 32: 338-344
Doutrelant, C., Leitao, A., Otter, K. & Lambrechts, M.M. 2000. Interspecific competition and geographic song variation in the blue tit. Behavioral Ecology and Sociobiology 48: 119-124
McGregor, P.K., Otter, K.A. & Peake, T.M. 2000. Communication networks: receiver and signaller perspectives. Pp. 361-372. In: Animal Signals. Adaptive Significance of Signalling and Signal Design in Animal Communication. (Y. Espmark, T. Amundsen & G. Rosenqvist, eds), Proc. Fifth Int. Kongsvoll Symp., September 15-20, 1998. Tapir Publishers, Trondheim, Norway.
Peake, T.M., Otter, K., Terry, A.M.R., & McGregor, P.K. 2000. SCREECH: an interactive playback program for PCs. Bioacoustics. 11: 69-75
Ramsay, S.M., Otter, K., Mennill, D.J. & Ratcliffe, L. 2000. Divorce & extrapair mating in female black-capped chickadees (Poecile atricapillus): seperate strategies with a common target. Behavioral Ecology and Sociobiology 49: 18-23
Otter, K., McGregor, P.K., Terry, A.M.R., Burford, F.R.L., Peake, T.M. & Dabelsteen, T. 1999. Do female great tits (Parus major) assess males by eavesdropping? A field study using interactive song playback. Proceedings of the Royal Society of London, Series B 266: 1305-1310
Otter K., Ramsay, S.M. & Ratcliffe, L. 1999. Enhanced reproductive success of female black-capped chickadees mated to high ranking males. Auk 116: 345-354
Otter, K. & Ratcliffe, L. 1999. Relationship of bib size to age and sex in the black-capped chickadee. Journal of Field Ornithology 70: 567-577
Ramsay, S.M, Otter, K. & Ratcliffe, L.M. 1999. Nest site selection by female black-capped chickadees: settlement based on social attraction. Auk 116: 604-617
Otter K., Ratcliffe, L., Michaud, D. & Boag, P.T. 1998. Do female black-capped chickadees prefer high ranking males as extra-pair partners? Behavioral Ecology and Sociobiology 43: 25-36
Otter, K., Chruszcz, B. & Ratcliffe, L. 1997. Honest advertisement and singing during the dawn chorus of Black-capped Chickadees, Parus atricapillus. Behavioral Ecology 8: 167-173
Otter, K. & Ratcliffe, L. 1996. Female initiated divorce in a monogamous songbird: abandoning mates for males of higher quality. Proc R Soc Lond 263: 351-354
Otter, K. 1996. Individual variation in the advertisement call of male Saw-whet owls. J Field Ornithol 67: 398-405
Ratcliffe, L. & Otter, K. 1996. Sex differences in song recognition. Pp. 339-355. In: Ecology and Evolution of Acoustic Communication among Birds. (D.E. Kroodsma & E.H. Miller, eds) Cornell University Press, Ithaca, New York
Otter, K., Ratcliffe, L. & Boag, P.T. 1994. Extra-pair paternity in the black-capped chickadee. Condor 96: 218-222
Otter, K., Njegovan, M., Naugler, C., Fotheringham, J. & Ratcliffe, L.. 1994. A simple technique for interactive playback experiments using a Macintosh Powerbook Computer. Bioacoustics 5: 303-310
Otter, K. 1994. The impact of potential predation upon foraging behaviour of eastern chipmunks. Canadian Journal of Zoology 72: 1858-1861
Otter, K. & Ratcliffe, L. 1993. Changes in the singing behaviour of male black-capped chickadees (Parus atricapillus) following mate removal. Behav Ecol Sociobiol 33: 409-414