I am a behavioural ecologist with broad interests in sexual selection, mating system evolution, sperm biology and the effects of human-induced change on the reproductive ecology and behaviour of animals. Overall, my research programme investigates both genetic and environmental effects on behaviour and reproductive fitness. We currently use zebrafish, tree weta, stag beetles, and triplefins in our research, but I am open to working with different study systems.
Postgraduate students
I am currently accepting students interested in working on insect conservation and behaviour or transgenerational acclimation in fishes.
The University of Otago offers PhD scholarships to candidates with excellent academic records (irrespective of nationality). Please feel free to contact me if you are interested my research and would like to do your PhD in New Zealand. More information can be found on the Scholarships page.
Current students
Luna Thomas (PhD Zoology), The mating system of the endemic stag beetle, Geodorcus helmsi. Supervisors: Johnson, Jenny Jandt
Yasmin Foster (PhD Zoology), Integrating genomic and epigenomic approaches for kākāpō conservation. Supervisors: Robertson, Gossner, Dutoit, Johnson
Melita Busch (MSc Zoology). Foraging and defending in Vespula wasps. Supervisors: Jenny Jandt, Johnson
Breana Riordan (MSc Zoology). Thermal tolerances of triplefins fishes. Supervisors: Johnson, Tony Hickey
Zhuali Lim (MSc Ecology). Pollination and nesting behaviour of native NZ bees. Supervisors: Johnson, Janice Lord
Previous students
Mateus Detoni (PhD Zoology), Social wasp behavioural ecology and genomics. Supervisors: Jandt, Johnson
Meg Kelly (MSc Zoology), Examining behavioural differences between predator aware and predator naive tree wētā. Supervisors: Johnson, Priscilla Wehi
Fletcher Munsterman (MSc, Zoology), Impacts of microplastics on triplefin behaviour. Supervisors: Johnson, Bridie Allan
Dominque Harris (MSc, Zoology), Can territorial fish recognise each other as individuals? Supervisors: Closs, Johnson
Brad Lamont (MSc Marine Science), Investigating how a high predation environment during embryogenesis affects larval characteristics in triplefin fish using chemical alarm cues. Supervisors: Allan, Johnson
Adele Parli (MSc Zoology), Behavioural effects of brodifacoum bait exposure on Wellington tree wētā. Supervisors: Johnson, Priscilla Wehi, Anne Besson
Hilary Thomson (MSc Zoology), Repeatability of zebrafish personality traits. Supervisor: Johnson
Simon Lamb (MSc Zoology), Effects of atrazine on transgenerational epigenetics in zebrafish. Supervisor: Johnson
Carlos Lara Vasquez (PhD Zoology), Immunity, quality, and fitness in a bird with a variable mating system. Supervisors: Nakagawa, Robertson, Johnson
Benedikt Holtmann (PhD Zoology), Animal personality and social networks in a species with variable mating systems, the Dunnock. Supervisors: Nakagawa, Robertson, Johnson
Jordan Aria Housiaux (MSc Marine Sciences), Ecology of sevengill sharks using mark/recapture and connectivity analyses. Supervisors: Rayment, Hepburn, Johnson
Sanghvi, K., Vega-Trejo, R., Nakagawa, S., Gascoigne, S. J. L., Johnson, S. L., Salguero-Gómez, R., … Sepil, I. (2024). Meta-analysis shows no consistent evidence for senescence in ejaculate traits across animals. Nature Communications, 15, 558. doi: 10.1038/s41467-024-44768-4
Journal - Research Article
Besson, A., Johnson, S. L., Nakagawa, S., Meylan, S., & Cree, A. (2023). Do personality traits co-vary with baseline concentrations of glucocorticoids in a viviparous lizard? In D. J. Wilson & J. M. Monks (Eds.), Recent developments in research on the herpetofauna of Aotearoa New Zealand: Proceedings of the 18th Biennial Conference of the Society for Research on Amphibians and Reptiles in New Zealand (SRARNZ) 2021: DOC Research and Development Series 369. 2.4. Retrieved from https://www.doc.govt.nz/about-us/science-publications/series/doc-research-and-development-series
Conference Contribution - Published proceedings: Abstract
Thompson, L., Doogan, H., Thompson, C., Wehi, P., & Johnson, S. (2023). Are there differences in behaviour between the two colour morphs of the mountain stone wētā, Hemideina maori? New Zealand Journal of Zoology. Advance online publication. doi: 10.1080/03014223.2023.2249408
Journal - Research Article
Kelly, M., Wehi, P. M., & Johnson, S. L. (2023). Behavioural differences in predator aware and predator naïve Wellington tree wētā, Hemideina crassidens. Current Research in Insect Science, 3, 100058. doi: 10.1016/j.cris.2023.100058
Journal - Research Article
Detoni, M., Johnson, S. L., Adams, C. I. M., Bengston, S., & Jandt, J. M. (2023). Older, but not wiser: Social wasp colony defensive behavior decreases with time, not experience. Insectes Sociaux, 70, 81-96. doi: 10.1007/s00040-022-00893-1
Journal - Research Article
Paul, J., Johnson, S., & Iremonger, K. (2022, August-September). Developing a zebrafish (Danio rerio) model to study behavioural and neuroendocrine responses to stress. Verbal presentation at the 16th New Zealand Medical Sciences Congress (MedSci), Queenstown, New Zealand.
Conference Contribution - Verbal presentation and other Conference outputs
Schenk, S., Horsfield, J., & Johnson, S. (2022). Zebrafish on "P": Behavioural effects of methamphetamine. In K. Horne (Ed.), Proceedings of the 38th International Australasian Winter Conference on Brain Research (AWCBR). (pp. 95). Retrieved from https://www.queenstownresearchweek.org
Conference Contribution - Published proceedings: Abstract
Ragsdale, A., Ortega-Recalde, O., Dutoit, L., Besson, A. A., Chia, J. H. Z., King, T., Nakagawa, S., Hickey, A., Gemmell, N. J., Hore, T., & Johnson, S. L. (2022). Paternal hypoxia exposure primes offspring for increased hypoxia resistance. BMC Biology, 20, 185. doi: 10.1186/s12915-022-01389-x
Journal - Research Article
Divers, S. L., Johnson, S. L., & Lokman, P. M. (2022). Sperm quality of artificially matured shortfinned eel is not affected by human chorionic gonadotropin dose and route of administration. PeerJ, 10, e13742. doi: 10.7717/peerj.13742
Journal - Research Article
Johnson, S. L., Borziak, K., Kleffmann, T., Rosengrave, P., Dorus, S., & Gemmell, N. J. (2020). Ovarian fluid proteome variation associates with sperm swimming speed in an externally fertilising fish. Journal of Evolutionary Biology, 33, 1783-1794. doi: 10.1111/jeb.13717
Journal - Research Article
Lara, C. E., Grueber, C. E., Holtmann, B., Santos, E. S. A., Johnson, S. L., Robertson, B. C., … Nakagawa, S. (2020). Assessment of the dunnocks’ introduction to New Zealand using innate immune-gene diversity. Evolutionary Ecology, 34, 803-820. doi: 10.1007/s10682-020-10070-0
Journal - Research Article
Sasson, D. A., Johnson, S. L., Smith, M. D., & Brockmann, H. J. (2020). Seasonal variation in reproduction of horseshoe crabs (Limulus polyphemus) from the Gulf Coast of Florida. Biological Bulletin, 239, 24-39. doi: 10.1086/709876
Journal - Research Article
Ragsdale, A. K., Dutoit, L., Besson, A. A., King, T., Gemmell, N. J., Hore, T., & Johnson, S. L. (2020). Paternal hypoxia exposure primes offspring for increased hypoxia resistance. Integrative & Comparative Biology, 60(Suppl. 1), (pp. E192). doi: 10.1093/icb/icaa006
Conference Contribution - Published proceedings: Abstract
Thomson, H. R., Lamb, S. D., Besson, A. A., & Johnson, S. L. (2020). Long-term repeatability of behaviours in zebrafish (Danio rerio). Ethology, 126, 903-911. doi: 10.1111/eth.13038
Journal - Research Article
Lamb, S. D., Chia, J. H. Z., & Johnson, S. L. (2020). Paternal exposure to a common herbicide alters the behavior and serotonergic system of zebrafish offspring. PLoS ONE, 15(4), e0228357. doi: 10.1371/journal.pone.0228357
Journal - Research Article
Parli, A., Besson, A., Wehi, P., & Johnson, S. (2020). Sub-lethal exposure to a mammalian pesticide bait alters behaviour in an orthopteran. Journal of Insect Conservation, 24, 536-546. doi: 10.1007/s10841-020-00222-6
Journal - Research Article
Ragsdale, A., Dutoit, L., Chia, J., Gemmell, N., & Johnson, S. (2019). It's in your head: How echoes of the past shape future progeny. Proceedings of the Genetics Society of Australasia (GSA) Conference. Retrieved from https://event.crowdcompass.com/gsa2019
Conference Contribution - Published proceedings: Abstract
Johnson, S. L., Zellhuber-McMillan, S., Gillum, J., Dunleavy, J., Evans, J., Nakagawa, S., & Gemmell, N. J. (2018). Evidence that fertility trades off with early offspring fitness as males age. Proceedings of the Royal Society B, 285(1871), 20172174. doi: 10.1098/rspb.2017.2174
Journal - Research Article
Thomson, H., & Johnson, S. (2017). Genetic effects on social isolation anxiety in zebrafish (Danio rerio). Proceedings of the Annual Conference of the Genetics Society of Australasia (GSA) with the New Zealand Society for Biochemistry and Molecular Biology (NZSBMB). 539. Retrieved from http://gen2017.w.events4you.currinda.com
Conference Contribution - Published proceedings: Abstract
Ragsdale, A., Hore, T., & Johnson, S. (2017). DNA methylation and aging in zebrafish. Proceedings of the Annual Conference of the Genetics Society of Australasia (GSA) with the New Zealand Society for Biochemistry and Molecular Biology (NZSBMB). 531. Retrieved from http://gen2017.w.events4you.currinda.com
Conference Contribution - Published proceedings: Abstract
Johnson, S. L., & Lamb, S. D. (2017). Intergenerational effects of atrazine exposure suring juvenile development in zebrafish. Proceedings of the Annual Conference of the Genetics Society of Australasia (GSA) with the New Zealand Society for Biochemistry and Molecular Biology (NZSBMB). 704. Retrieved from http://gen2017.w.events4you.currinda.com
Conference Contribution - Published proceedings: Abstract
Lamb, S. D., Taylor, H. R., Holtmann, B., Santos, E. S. A., Tamayo, J. H., Johnson, S. L., Nakagawa, S., & Lara, C. E. (2017). Coprophagy in Dunnocks (Prunella modularis): A frequent behavior in females, infrequent in males, and very unusual in nestlings. Wilson Journal of Ornithology, 129(3), 615-620. doi: 10.1676/16-059.1
Journal - Research Article
Gessner, C., Johnson, S. L., Fisher, P., Clarke, S., Rutherford, K., Symonds, J., & Gemmell, N. J. (2017). Male-female relatedness at specific SNP-linkage groups influences cryptic female choice in Chinook salmon (Oncorhynchus tshawytscha). Proceedings of the Royal Society B, 284(1859), 20170853. doi: 10.1098/rspb.2017.0853
Journal - Research Article
O'Dea, R. E., Noble, D. W. A., Johnson, S. L., Hesselson, D., & Nakagawa, S. (2016). The role of non-genetic inheritance in evolutionary rescue: Epigenetic buffering, heritable bet hedging and epigenetic traps. Environmental Epigenetics, 2(1), dvv014. doi: 10.1093/eep/dvv014
Journal - Research Other
Holtmann, B., Grosser, S., Lagisz, M., Johnson, S. L., Santos, E. S. A., Lara, C. E., Robertson, B. C., & Nakagawa, S. (2016). Population differentiation and behavioural association of the two 'personality' genes DRD4 and SERT in dunnocks (Prunella modularis). Molecular Ecology, 25(3), 706-722. doi: 10.1111/mec.13514
Journal - Research Article
Flynn, T., Signal, B., Johnson, S. L., & Gemmell, N. J. (2016). Mitochondrial genome diversity among six laboratory zebrafish (Danio rerio) strains. Mitochondrial DNA, 27(6), 4364-4371. doi: 10.3109/19401736.2015.1089536
Journal - Research Article
Senior, A. M., Johnson, S. L., & Nakagawa, S. (2016). Sperm traits of masculinized fish relative to wild-type males: A systematic review and meta-analyses. Fish & Fisheries, 17(1), 143-164. doi: 10.1111/faf.12096
Journal - Research Article
Brockmann, H. J., Johnson, S. L., Smith, M. D., & Sasson, D. (2015). Mating tactics of the American horseshoe crab (Limulus polyphemus). In R. H. Carmichael, M. L. Botton, P. K. S. Shin & S. G. Cheung (Eds.), Changing global perspectives on horseshoe crab biology, conservation and management. (pp. 321-351). Cham, Switzerland: Springer. doi: 10.1007/978-3-319-19542-1_19
Chapter in Book - Research
Sasson, D. A., Johnson, S. L., & Brockmann, H. J. (2015). Reproductive tactics and mating contexts affect sperm traits in horseshoe crabs (Limulus polyphemus). Behavioral Ecology & Sociobiology, 69(11), 1769-1778. doi: 10.1007/s00265-015-1989-7
Journal - Research Article
Yund, P. O., Collins, C., & Johnson, S. L. (2015). Evidence of a Native Northwest Atlantic COI haplotype clade in the cryptogenic colonial ascidian Botryllus schlosseri. Biological Bulletin, 228(3), 201-216.
Journal - Research Article
Vasquez, M. C., Johnson, S. L., Brockmann, H. J., & Julian, D. (2015). Nest site selection minimizes environmental stressor exposure in the American horseshoe crab, Limulus polyphemus (L.). Journal of Experimental Marine Biology & Ecology, 463, 105-114. doi: 10.1016/j.jembe.2014.10.028
Journal - Research Article
Johnson, S. L., Dunleavy, J., Gemmell, N. J., & Nakagawa, S. (2015). Consistent age-dependent declines in human semen quality: A systematic review and meta-analysis. Ageing Research Reviews, 19, 22-33. doi: 10.1016/j.arr.2014.10.007
Journal - Research Article
Johnson, S. L., Villarroel, M., Rosengrave, P., Carne, A., Kleffmann, T., Lokman, P. M., & Gemmell, N. J. (2014). Proteomic analysis of Chinook salmon (Oncorhynchus tshawytscha) ovarian fluid. PLoS ONE, 9(8), e104155. doi: 10.1371/journal.pone.0104155
Journal - Research Article
Johnson, S. L., & Brockmann, H. J. (2013). Parental effects on early development: Testing for indirect benefits of polyandry. Behavioral Ecology, 24(5), 1218-1228. doi: 10.1093/beheco/art056
Journal - Research Article
Johnson, S. (2012). Cryptic female choice in salmon: Does sperm motility require a female’s touch? Proceedings of the Centre for Reproduction and Genomics 4th Annual Research Colloquium. (pp. 8). Retrieved from http://www.otago.ac.nz/crg/news/colloquium/
Conference Contribution - Published proceedings: Abstract
Johnson, S. L., & Brockmann, H. J. (2012). Alternative reproductive tactics in female horseshoe crabs. Behavioral Ecology, 23(5), 999-1008. doi: 10.1093/beheco/ars063
Journal - Research Article
Sasson, D. A., Johnson, S. L., & Brockmann, H. J. (2012). The role of age on sperm traits in the American horseshoe crab, Limulus polyphemus. Animal Behaviour, 84(4), 975-981. doi: 10.1016/j.anbehav.2012.07.023
Journal - Research Article
Johnson, S. L., & Gemmell, N. J. (2012). Are old males still good males and can females tell the difference?: Do hidden advantages of mating with old males off-set costs related to fertility, or are we missing something else? BioEssays, 34(7), 609-619. doi: 10.1002/bies.201100157
Journal - Research Article
Brockmann, H. J., & Johnson, S. L. (2011). A long-term study of spawning activity in a Florida Gulf coast population of horseshoe crabs (Limulus polyphemus). Estuaries & Coasts, 34(5), 1049-1067. doi: 10.1007/s12237-011-9419-1
Journal - Research Article
Johnson, S. L., & Brockmann, H. J. (2010). Costs of multiple mates: An experimental study in horseshoe crabs. Animal Behaviour, 80(5), 773-782. doi: 10.1016/j.anbehav.2010.07.019
Journal - Research Article
Johnson, S. L., & Yund, P. O. (2009). Effects of fertilization distance on male gain curves in a free-spawning marine invertebrate: A combined empirical and theoretical approach. Evolution, 63(12), 3114-3123. doi: 10.1111/j.1558-5646.2009.00784.x
Journal - Research Article
Johnson, S. L., & Yund, P. O. (2008). Mulitple paternity and subsequent fusion-rejection interactions in a kin-structured population. Marine Ecology Progress Series, 364, 129-134. doi: 10.3354/meps07500
Journal - Research Article
Johnson, S. L. (2007). Mating system dynamics in a free-spawning colonial ascidian (PhD). University of Maine, Orono, ME.
Awarded Doctoral Degree
Yund, P. O., Murdock, K., & Johnson, S. L. (2007). Spatial distribution of ascidian sperm: Two -dimensional patterns and short vs. time-integrated assays. Marine Ecology Progress Series, 341, 103-109.
Journal - Research Article
Johnson, S. L., & Yund, P. O. (2007). Variation in multiple paternity in natural populations of a free-spawning marine invertebrate. Molecular Ecology, 16(15), 3253-3262. doi: 10.1111/j.1365-294X.2007.03366.x
Journal - Research Article