L. Scott Johnson


Department of Biological Sciences

Towson University

Towson, MD 21252 USA

(410) 704-2587 (office)

(410) 704-2405 (fax)

sjohnson at towson.edu


LSJ Wyo 2008 2


B.A., Biology, St. Olaf College, 1981

M.S., Zoology, Northern Arizona Univ., 1985

Ph.D. Ecology, University of Calgary, 1992




image004proudly Canadian!




At the dinosaur (theropod) track site, Red Gulch area, Shell, Wyoming


Courses taught at Towson University:


BIOL 202 Introduction to Ecology and Evolutiono


BIOL 204- Educational and Career Planning for the Biologist


BIOL 371 Animal Behavior


BIOL 456 Ornithology


BIOL 484 Discussion Seminar in Ecology, Evolution, Behavior, and Conservation



Fields of Specialization: Animal Behavior, Ornithology, Behavioral Ecology


Research Interests: I am broadly interested in the reproductive biology and behavior of birds. Over the past 30+years, I have studied a wide variety of topics including:


  functions of song

  nestling growth and development

  effects of ectoparasites on nestlings

  parental care

  the process of nest-leaving (fledging)

  adaptive value of different egg shapes

  role of calcium availability in limiting

reproductive output

  evolution of plumage colouration

  criteria that females use in

choosing mates

  causes and consequences

of polygynous mating

  extra-pair mating behavior

  manipulation of offspring

sex ratios by females

  ovicide and infanticide

  effect of breeding at high altitudes

on life history strategies


US Map WY Red


Relief map WY










I do field work during the summer in northern Wyoming at sites in the Bighorn Mountains near the town of Sheridan.












Most of my research has involved one model species, the House Wren.













However, I also have worked with the

Tree Swallow and am now working on the Mountain Bluebird.



Adult HOWR tree

House Wren

(Troglodytes aedon)



Mountain Bluebird

(Sialia currucoides)





Winkler, D.W., Ringelman, K.M., Dunn, P.O., Whittingham, L., Hussell, D.J.T., Clark, R.G., Dawson, R.D. Johnson, L.S. et al. 2014. Clutch size and lay date changes across the Americas in Tachycineta swallows: What are the roles for direct selection, demography and organismal biology? Ecography (in press).


Thompson, C.F., S.K. Sakaluk, B.S. Masters, B.G.P. Johnson, L.A. Vogel, A.M. Forsman, and L.S. Johnson. 2014. Condition-dependent sex difference in nestling House Wren (Troglodytes aedon) response to phytohaemagglutinin injection. Canadian Journal of Zoology 92: 17.


Johnson, L.S., R.M. Hebert*, F.M. Napolillo* and A. Allen*. 2013. The process of fledging in the Mountain Bluebird. Journal of Field Ornithology 84: 367376.


Johnson, L.S., F.M. Napolillo*, D.Y. Kozlovsky*, R.M. Hebert*, and A. Allen*. 2013. Variation in incubation effort during egg-laying in Mountain Bluebirds and its association with hatching asynchrony. Journal of Field Ornithology 84: 244-252.

Johnson, L.S., S.M. Murphy, & G. Parrish. 2011. Lack of predator odor detection and avoidance in a songbird, the house wren (Troglodytes aedon). Journal of Field Ornithology 82: 150-157.


Stauffer, K.R. & L.S. Johnson. 2011. Cavity-nesting by the Black-billed Magpie (Pica hudsonia). Wilson Journal of Ornithology 123: 411-413.


Masters, B.S., L.S. Johnson, B.G.P. Johnson, J.L. Brubaker, S.K. Sakaluk, & C.F. Thompson. 2011. Evidence for heterozygote instability in microsatellite loci in house wrens. Biology Letters 7: 127-130.


Lambrechts, M. et al. 2010. Design of artificial nestboxes for the study of secondary hole-nesting birds: review of methodological inconsistencies and potential biases. Acta Ornithologica  45: 1-26.   


Masters, B.S., B.G.P. Johnson, C.J. Neely, K.L. Williams, & L.S. Johnson. 2009. Compatible alleles and extra-pair paternity: conclusions depend on the microsatellite loci used. The Condor (Journal of the Cooper Ornithological Society) 111: 365-369.


Johnson, L.S., J.L. Brubaker, B.G.P. Johnson, & B.S. Masters. 2009. Evidence for a maternal effect benefiting extra-pair offspring in a Wyoming population of the house wren. Journal of Avian Biology 40: 248-253.


Johnson, L.S., C.F. Thompson, S.K. Sakaluk, M. Neuhuser, B.G.P. Johnson, S.S. Soukup, S.J. Forsythe, & B.S. Masters. 2009. Extra-pair young in house wren broods are more likely to be male than female. Proceedings of the Royal Society of London, Series B. 276: 2285-2289.


Balenger, S.L., L.S. Johnson, H. Mays, B.S. Masters. 2009. Extra-pair paternity in the socially monogamous mountain bluebird (Sialia currucoides) and its effect on the potential for sexual selection. Journal of Avian Biology 40: 173-180.


Balenger, S.L., L.S. Johnson, and B.S. Masters. 2009. Sexual selection in a socially monogamous bird: male color predicts paternity success in the mountain bluebird, Sialia currucoides. Behavioral Ecology and Sociobiology 63: 403-411.


Johnson, L.S., J.L. Brubaker, and B.G.P. Johnson. 2008. How males in the house wren, a cavity-nesting songbird, discover that eggs have hatched and transition to provisioning nestlings. Behaviour 145: 781-1796.


Forsman, A.M., L.A. Vogel, S.K. Sakaluk, B.G. Johnson, B.S. Masters, L.S. Johnson, C.F. Thompson. 2008. Female house wrens (Troglodytes aedon) increase the size, but not immunocompetence, of their offspring through extra-pair mating. Molecular Ecology 17: 3697-3706.


Newhouse, M.J., P.P. Marra, and L.S. Johnson. 2008. Reproductive success of house wrens in suburban and rural landscapes. Wilson Journal of Ornithology 120:99-104.


Balenger, S.L., Johnson, L.S., Brubaker, J. and Ostlind, E. 2007. Parental effort in relation to structural plumage coloration in the mountain bluebird (Sialia currucoides). Ethology 113: 838-846.


Johnson, L.S., J.L. Brubaker, S.L. Balenger, and E. Ostlind. 2007. Effect of altitude on male parental expenditure in Mountain Bluebirds (Sialia currucoides): are higher altitude males more attentive fathers? Journal of Ornithology 148: 9-16.


Shawkey, M., S. Balenger, G. Hill, L.S. Johnson, A. Keyser, L. Seifferman. 2006. Mechanisms of change in structural plumage colouration among bluebirds (Sialia spp.). Journal of the Royal Society Interface 3: 527-532.


Johnson, L. S., L. E. Wimmers, B. G. Johnson, R. Molinaro, R. C. Milkie, B. S. Gallagher and B. S. Masters,. 2005. Sex manipulation within broods of house wrens: a second look. Animal Behaviour 70: 1323-1329.


Masters, B.S., B.G. Hicks, L.S. Johnson, and L.A. Erb. 2003. Genotype and extra-pair paternity in the house wren: a rare male effect? Proceedings of the Royal Society of London B, Biological Sciences. 270: 1393-1397.


Johnson, L.S., L. E. Wimmers, S. Campbell, and L. Hamilton. 2003. Growth rate, size, and sex ratio of last-laid, last-hatched offspring in the Tree Swallow Tachycineta bicolor. Journal of Avian Biology 34:35-33.


Johnson, L.S., B.G. Hicks and B.S. Masters. 2002. Increased cuckoldry as a cost of breeding late in the house wren, Troglodytes aedon. Behavioral Ecology 13(5):670-675.


Albrecht, D.A. and L.S. Johnson 2002. Manipulation of offspring sex ratio by second-mated female house wrens. Proceedings of the Royal Society of London, Series B 269(1490) 461-465.


Morrison, B.L. and L.S. Johnson. 2002. Effect of nestling ectoparasites on parental feeding rates in the House Wren. The Condor (Journal of the Cooper Ornithological Society). 104: 183-187.


Johnson, L.S., J.E. Leyhe and C. Werner. 2001. The shape of eggs in different-sized clutches of the house wren (Troglodytes aedon). Canadian Journal of Zoology 79: 1527-1531


OBrien, E., B. L. Morrison, and L.S. Johnson. 2001. Assessing the effects of haematophagous ectoparasites on the health of nestling birds: haematocrit vs. haemoglobin levels in house wrens parasitized by blow fly larvae. Journal of Avian Biology 32: 73-76.


Lago, K., L. S. Johnson, and D. J. Albrecht. 2000. Growth of late-hatched, competitively disadvantaged nestling house wrens relative to their older, larger nestmates. Journal of Field Ornithology 71: 676-685.


Czapka, S.J. and L. S. Johnson. 2000. Consequences of mate sharing for first-mated females In a polygynous songbird, the house wren. Wilson Bulletin (Journal of the Wilson Ornithological Society) 112: 72-81.


Johnson, L. S. and J. Wise. 2000. Wintering grounds of North American house wren as revealed by band recoveries. Journal of Field Ornithology 71:501-505.


Dutta, C., L. S. Johnson, D. Larkin, and L.P. Mangurian. 1998. Extent of skeletal development at the time of fledging in house wrens. The Condor (Journal of the Cooper Ornithological Society) 100: 568-573.


Johnson, L.S. 1998. House Wren (Troglodytes aedon). In: The Birds of North America No. 380. (A. Poole and F. Gill, eds). The Birds of North America, Inc., Philadelphia, PA.


Ziolkowski, D., L. S. Johnson, K. M. Hannam, and W. A. Searcy. 1997. Coordination of female nest attentiveness with male song output in the cavity-nesting house wrens (Troglodytes aedon). Journal of Avian Biology 28: 9-14.


Johnson, L. S. and W. A. Searcy. 1996. Female attraction to male song in house wrens (Troglodytes aedon). Behaviour 133: 357-366.


Johnson, L. S. 1996. Removal of old nest material from the nesting sites of house wrens: effects on nest site attractiveness and ectoparasite loads. Journal of Field Ornithology 67: 212-221.


Johnson, L. S. and R. M. R. Barclay. 1996. Effect of supplemental calcium on the reproductive output of a small passerine bird, the house wren Troglodytes aedon. Canadian Journal of Zoology 74:278-282.


Johnson, L. S. and L. S. Kermott. 1994. Nesting success of cavity‑nesting birds using natural cavities. Journal of Field Ornithology 65: 36‑51.


Johnson, L. S., L. H. Kermott, and M. R. Lein. 1994. Territorial polygyny in house wrens: are females sufficiently compensated for the costs of mate sharing? Behavioral Ecology 5: 98-104.


Johnson, L. S. and W. A. Searcy. 1993. Female choice, nest site quality, and polygyny in the house wren Troglodytes aedon. Ethology 95: 265-277.


Johnson, L. S. and L. H. Kermott. 1993. Why is reduced male parental assistance detrimental to the reproductive success of secondary females in the house wren (Troglodytes aedon)? Animal Behaviour 46: 1111-1120.


Johnson, L. S., L. H. Kermott, and M. R. Lein. 1993. The cost of polygyny in the house wren Troglodytes aedon. Journal of Animal Ecology 62: 669‑682.


Johnson, L. S. and D. J. Albrecht. 1993. Does the cost of polygyny in house wrens include reduced male assistance in defending offspring? Behavioural Ecology and Sociobiology 33: 131-136


Johnson, L. S. and D. A. Albrecht. 1993. Effects of haematophagous ectoparasites on nestling house wrens, Troglodytes aedon: who pays the cost of parasitism? Oikos 66: 255-262.


Johnson, L. S., M. S. Merkle, and L. H. Kermott. 1992. Experimental evidence for the importance of male parental care in monogamous house wrens. The Auk 109: 662-664.


Johnson, L. S. and L. H. Kermott. 1992. Why do male house wrens feed their incubating mates so rarely? American Midland Naturalist 127:200-203.


Johnson, L. S., M. D. Eastman, and L. H. Kermott. 1991. Effect of ectoparasitism by larvae of the blow fly, Protocalliphora parorum (Diptera: Calliphoridae) on nestling house wrens, Troglodytes aedon. Canadian Journal of Zoology 69: 1441‑1446.

Kermott, L. H., L. S. Johnson, and M. S. Merkle. 1991. Experimental evidence for the function of mate replacement and infanticide by males in a north‑temperate population of house wrens. The Condor 93: 630-636.


Johnson, L. S. and L. H. Kermott. 1991. Effect of nest-site supplementation on polygynous behavior in the house wren. The Condor 93: 784-787.


Johnson, L. S. and L. H. Kermott. 1991. The functions of song in male house wrens (Troglodytes aedon). Behaviour 116: 190-209.


Johnson, L. S. and L. H. Kermott. 1990. Possible causes of territory takeovers in a north-temperate population of house wrens. The Auk 107: 781‑784.


Johnson, L. S. and L. H. Kermott. 1990. The structure and context of female song in a north-temperate house wren population. Journal of Field Ornithology 61: 273-284.


Kermott, L. H. and L. S. Johnson. 1990. Brood adoption and apparent infanticide in a north-temperate house wren population. Wilson Bulletin 102: 333-336.


Johnson, L. S. and L. H. Kermott. 1989. Territorial intrusions in the house wren Troglodytes aedon: evidence for the sperm competition hypothesis. Ornis Scandinavica 20: 89-92.


Eastman, M. D., L. S. Johnson and L. H. Kermott. 1989. Ectoparasitism of nestling house wrens Troglodytes aedon by larvae of the blow fly Protocalliphora braueri (Hendel). Canadian Journal of Zoology 67: 2358-2362.


Johnson, L. S. 1987. Pattern of song type use for territorial defence in the Plain Titmouse Parus inornatus. Ornis Scandinavica 18: 24-32.


Johnson, L. S., J. M. Marzluff and R. P. Balda. 1987. Handling of pinon pine seeds by the Clark's Nutcracker. The Condor 89: 117-125.


Johnson, L. S. 1983. Effect of mate loss on song performance in the Plain Titmouse. The Condor 85: 378-380.