R. David Maclaren
R. David MacLaren, Ph.D.
Associate Professor of Biology
B.A. Biology, University of Maine at Farmington
Ph.D. Ecology and Evolutionary Biology, Indiana University
Office: Mendel 270
Tel: 978-837-3543
Email: maclarenr@merrimack.edu
Courses Taught at Merrimack: Principles of Biology I labs, Principles of Biology II lecture & labs, Comparative Animal Anatomy & Physiology, Evolution, Animal Behavior, Marine Biology, and Senior Thesis Research in Biology.
Dr. MacLaren is President of the Marine Studies Consortium (http://www1.assumption.edu/msc/courses.html) and Program Coordinator for Merrimack College. He is also Coordinator of the Merrimack College Campus Environmental Sustainability Initiative . 
Research Interests
I have two research foci: 1) The role of sexual selection in fish evolution, and 2) Behavior, ecology, and conservation of marine mammals in the Gulf of Maine.
1. Fish 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. Current projects investigate visual signals and the mechanisms by which they control and mediate courtship, aggression, and other social behaviors. Much of my research to date involves experimental studies on mate choice and sexual selection in Poeciliid fishes. Through studies of mate choice in these species, students learn first hand about the powerful roles sexual selection plays in guiding the process of evolution by natural selection. Recent projects include an on-going series of experiments examining the evolutionary basis of preference for male fin elaborations in the family of live-bearing fishes known as the Poecilidae (e.g. mollies, swordtails, platies, & guppies). Female preference for sexually dimorphic male fin elaborations in this family may be driven by a preexisting perceptual bias for increased overall size or lateral projection area (LPA) that has existed since the lineages diverged from a common ancestor. The LPA bias hypothesis suggests that a male with greater LPA (i.e. larger body and/or fin size) projects a larger image onto the female’s retina at a given viewing distance, eliciting a greater sensory and thus behavioral response to the stimulus. Support for the preexisting bias hypothesis requires phylogenetic evidence that the female preference evolved within the lineage before the male trait. Our research takes a comparative phylogenetic approach using dummy males to examine female preferences for dorsal fin size, body size and fin:body size ratio in multiple species of poeciliid fishes, including species whose males naturally possess an LPA-enhancing enlarged dorsal fin, species whose males possess alternative forms of LPA-enhancing fin elaboration (fantails and swordtails), as well as species whose males possess no fin elaborations.
2. I also hold a strong interest in marine mammal behavior, ecology, and conservation. In Spring 2009 I established a partnership in research and education with the Blue Ocean Society for Marine Conservation (http://www.blueoceansociety.org/), a non-profit organization dedicated to marine mammal research, conservation, and education centered in Portsmouth, NH. During the summer months I serve as “Naturalist” aboard whale watch vessels, collecting behavioral and physical data on the whale, dolphin, and sea bird populations in the Jeffreys Ledge region of the Gulf of Maine while educating the public on marine mammal ecology and conservation. This work involves mentoring undergraduate students conducting summer research at Merrimack and/or interning with Blue Ocean. All the data collected are added to Blue Ocean’s data base, which we then analyze during the off season. As part of this collaboration, Blue Ocean provides competitive internship/research opportunities to Merrimack students interested in marine mammal ecology, behavior & conservation.
Current Research
My students and I are currently working on several research projects, including the following:
· An examination of male preferences for fin elaborations in conspecific females, addressing the question of whether there is congruence between the sexes in a preexisting bias for increased LPA in a sexually monomorphic Poeciliid fish.
· My research students and I are collaborating with Blue Ocean scientists in the analysis of 13+ years of marine mammal data from the Jeffreys Ledge region of the Gulf of Maine. Data mining efforts include addressing such topics/questions as:
1. Relationships between number of sightings of particular species (especially right, humpback, fin, minke, pilot and sei whales, Atlantic white-sided dolphin, and harbor porpoise) and time of year.
2. Covariance in appearances of particular species (e.g. Right and sei whales) in our sightings data.
3. Are there any particular individual fin or humpback whales that are "associated" with one and other more often than we would expect by chance, and if so, are these individuals related, same sex or opposite sex?
4. Relationships between major behavior observed (e.g. breaching) and various aspects of weather both current and in the 24hrs prior to documenting the behavior.
5. Relationships between major behavior observed (e.g. breaching) and particular individuals. Are there particular individual humpback or fin whales that are observed exhibiting a particular behavior or suite of behaviors more often than expected when compared with the typical behavior patterns of other whales?
6. Examining the relationships between particular major behaviors observed and the AGE and or SEX of the whale exhibiting them (e.g. Relationship between humpback age and frequency of bubble feeding behavior).
7. Mining for ANY relationships/correlations/predictors (be it weather related, presence of other species, and/or time of year) of right whale occurrence/sightings in the Jeffreys Ledge region.
8. Mine the GPS data looking for predictable changes in the distribution/presence/absence of particular whale species over the course of the summer research season.
9. Research fisheries data on various sorts of regulatory moratoria (e.g. banning mid-water trawling for herring on Jeffreys Ledge) with the goal of assessing how such measures have influenced the seasonal abundance of particular species such as humpback and fin whales.
Selected Publications
* denotes undergraduate researcher
MacLaren, R.D. and *Fontaine, A. Female bias for male lateral projection area in Poecilia reticulata. 2011 In press Environmental Biology of Fishes.
MacLaren, R.D., *Gagnon, J. and *He, R. Female bias for enlarged male body and dorsal fins in Xiphophorus varietus. 2011 In press. Behavioural Processes.
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. 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 preexisting 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.
Rowland, W.J., *Grindle, N., MacLaren, R.D., and Granquist, R. 2002. Male preference for a subtle posture cue that signals spawning readiness in female sticklebacks. Animal Behaviour. 63, 743-748.
R. David MacLaren, Ph.D.
Associate Professor of Biology
maclarenr@merrimack.edu