R. David


Academic Title

Professor, Biology

Research Interests
  • Animal Behavior
  • Animal Physiology
  • Evolutionary Biology
  • Marine Biology
Research Summary

My research combines ethological, evolutionary, ecological and phylogenetic approaches to investigate animal behavior. Using experimental and observational methods, my interests focus on the elicitation, control, function and evolution of behavior in fishes. Projects investigate visual signals and the mechanisms by which they control and mediate courtship, aggression and other social behaviors. Much of my research involves experimental studies on mate choice, sexual selection and aggression in Poeciliid fishes. I also hold a strong interest in marine mammal behavior, ecology and conservation.

I am an associate scientist with the Blue Ocean Society for Marine Conservation, a nonprofit organization dedicated to marine mammal research, conservation and education centered in Portsmouth, New Hampshire. During the summer, I serve as “naturalist” aboard whale-watch vessels, collecting behavioral and physical data on whale and dolphin populations in the Gulf of Maine, including Stellwagen Bank National Marine Sanctuary, while educating the public on marine mammal ecology and conservation. This work involves mentoring undergraduates conducting research at Merrimack and/or interning with Blue Ocean. As part of this collaboration, Blue Ocean provides competitive internship opportunities to Merrimack students.

  • Ph.D., Ecology and Evolutionary Biology, Indiana University
  • B.A. Biology, University of Maine, Farmington
Areas of Expertise
  • Behavior, Ecology and Conservation of Marine Mammals in the Gulf of Maine.
  • Investigating the Effects of Environmentally Realistic Herbicide and Pharmaceutical Exposure on Hormone Concentrations, Reproductive and Aggressive Behavior in Fish.
  • The Role of Sexual Selection in Fish Evolution
Recent Publications

MacLaren, RD. 2019. Evidence of an emerging female preference for an artificial male trait and the potential for spread via mate choice copying in Poecilia latipinna. Ethology. DOI: 10.1111/eth.12885

MacLaren, RD, Wisniewski, K, and MacLaren, C. 2018. Medicine in our waters – so what? Environmental Science Journal for Kids. http://www.sciencejournalforkids.org/science-articles/medicine-in-our-waters-so-what

MacLaren, RD, Wisniewski, K, and MacLaren, C. 2018. Environmental concentrations of metformin exposure affect aggressive behavior in the Siamese fighting fish, Betta splendens. PLoS One. https://doi.org/10.1371/journal.pone.0197259.

MacLaren, RD. 2017. “Effects of Male Apparent Length on Female Preference for Absolute Body Size in Xiphophorus helleri.” Acta Ethol. 20(1), 27-36. DOI 10.1007/s10211-016-0245-0.

MacLaren, RD. 2016. “Social Environment Affects Female Preference for Male Body Color During Development in Artificially Selected Varieties of Poecilia latipinna.” Ethology, Ecology and Evolution. DOI: 10.1080/03949370.2016.1220427.

MacLaren, RD, *Fontaine, A. 2013. Incongruence Between the Sexes in Preferences for Body and Dorsal Fin Size in Xiphophorus variatus.” Behavioural Processes 92, 99-106: 10.1016/j.beproc.2012.10.013.

MacLaren, R.D., Schulte, D. and Kennedy, J. 2012. “Field Research Studying Whales in an Undergraduate Animal Behavior Laboratory.” Bioscene Journal of College Biology Teaching.

MacLaren, R.D. and *Fontaine, A. 2012. “Female Bias for Male Lateral Projection Area in Poecilia reticulata.” Environmental Biology of Fishes. Vol. 93, Issue 1, 105-119.

MacLaren, R.D., *He, R., and *Gagnon, J. 2011. “Bias for Enlarged Male Body and Dorsal Fins in Female Xiphophorus variatus.” Behavioural Processes 87, 197-202.

MacLaren, R.D. and *Daniska, D. 2008. “Female Preferences for Dorsal Fin and Body Size in Xiphophorus helleri: Further Investigation of the LPA Bias in Poeciliid Fishes.” Behaviour. 145, 897-913.

MacLaren, R.D. 2007. “Female Preference in Xiphophorus helleri: Further Investigation of the LPA Bias in Poeciliid Fishes.” 2007 Annual Animal Behavior Society Conference Abstracts.

MacLaren, R.D. 2006. “The Effects of Male Proximity, Apparent Size and Absolute Size on Female Preference in the Sailfin Molly Poecilia latipinna.” Behaviour. 143, 1457-1472.

MacLaren, R.D. and Rowland, W.J. 2006a. “Female Preference for Male Lateral Projection Area in the Shortfin Molly Poecilia mexicana: Evidence for a Pre-existing Bias.” Ethology. 112, 678-690.

MacLaren, R.D. and Rowland, W.J. 2006b. “Differences in Female Preferences for Male Body Size in Poecilia latipinna Using Simultaneous vs. Sequential Stimulus Presentation Designs.” Behaviour. 143, 273-292.

MacLaren, R.D., Rowland, W.J., and *Morgan, N. 2004. “Female Preferences for Sailfin and Body Size in the Sailfin Molly Poecilia latipinna.” Ethology.110, 363-379.

Honors and Awards
  • Faculty Development Grants, Merrimack College, 2009, 2011-15 and 2017-19.
  • Center for Excellence in Teaching and Learning/Davis Grant Research Award, Merrimack College, 2015-16.
  • Paul E. Murray Fellowships, Merrimack College, 2011 and 2016.
  • Provost Innovation Fund Grants, Merrimack College, 2012-15 and 2018.