The Rollinson Lab 

Evolutionary ecology, long-term data, environmental change


38) Rollinson, N. A simple explanation for the evolution and maintenance of temperature-dependent sex determination.    

37) Rollinson N., Terebiznik M., Edge C.B., Nancekivell E.G., Brooks R.J. Maternal and environmental effects give rise to predictable sex-specific variation in hatchling size in a reptile with ancient TSD.

36) Lawson L., Rollinson N. Artificial incubation of species with temperature-dependent sex determination: How hot is too hot?

35) De Lisle S.P., Punzalan D., Rollinson N., Rowe L. Extinction and the temporal distribution of macroevolutionary bursts.

In Press

34) Burton T., Rollinson N., Stewart D., Armstrong J., Metcalfe, N. in press. Adaptive maternal investment in the wild? Links between maternal growth trajectory and offspring size, growth and survival in contrasting environments. The American Naturalist

33) Rollinson N., Nilsson-Örtman V., Rowe, L. in press. Density-dependent offspring interactions do not explain macroevolutionary scaling of adult size and size and independence. Evolution

32) Moldowan P.*, Smith M.*, Baldwin A., Bartley T., Rollinson N., Wynen, H. in press. Nature’s pitfall trap: Salamanders as rich prey for carnivorous plants in a nutrient-poor northern bog ecosystem. Ecology

*Author contribution was equal

31) Rollinson N., Massey, M., Meron, M. in press. A low cost, efficient, and precise technique to quantify key life cycle events in nests of oviparous reptiles. Journal of Herpetology

30) Hawkshaw, D.M., P.D. Moldowan, J.D. Litzgus, R.J. Brooks, and Rollinson N. in press. Discovery and description of a novel sexual weapon in the world’s most widely-studied freshwater turtle. Evolutionary Ecology

29) Francis, E.A., Moldowan, P. D., Greischar, M.A., Rollinson N. in press Anthropogenic nest sites provide warmer incubation environments than natural nest sites in a population of oviparous reptiles near their northern range limit. Oecologia.

28) Rouleau, C.*, Massey, M. D. *, Rollinson N. in press. Temperature does not affect hatch timing in snapping turtles (Chelydra serpentina). Undergoing second revision for Journal of Herpetology.

*Author contribution was equal

27) Massey, M. Congdon, J.C., Davy, C., Rollinson N. in press. First evidence of metabolic heating in a freshwater turtle, the snapping turtle. Chelonian Biology and Conservation.


26) Massey M., Nancekivell G., Brooks R., Rollinson N. 2019. Measurement and modelling of primary sex ratios in species with temperature dependent sex determination. Journal of Experimental Biology. jeb.190215

25) Santilli J., Rollinson, N. 2018. Toward a general explanation for latitudinal clines in body size among chelonians. Biological Journal of the Linnean Society. 124:381-393 pdf

24) Rollinson N., Rowe L. 2018. Temperature-dependent oxygen limitation and the rise of Bergmann's Rule in species with aquatic respiration. Evolution 72:977-988 pdf

23) Rollinson N., Rowe L. 2018. Oxygen limitation at the larval stage and the evolution of maternal investment per offspring in aquatic environments. The American Naturalist 191:604-619 pdf

22) Rollinson, N*., Holt, S*., Massey, M. Holt, R., Nancekivell, G., Brooks, RJ. 2018. A new method of estimating thermal performance of embryonic development rate yields accurate prediction of embryonic age in wild reptile nests. Journal of Thermal Biology 74:187-194 pdf
*Author contributions were equal

21) Armstrong D., Keevil M., Rollinson N., Brooks R.J., 2018. Subtle variation in indeterminate growth leads to major variation in survival and lifetime reproductive output in a long-lived reptile. Functional Ecology 32:752-761  pdf

20) Edge C.B.*, Rollinson N.*, Brooks R.J., Congdon J., Iverson J., Janzen F., and Litzgus J.  2017 Phenotypic plasticity of nest timing in a post-glacial landscape: how do long-lived reptiles adapt to thermal time constraints?  Ecology. 98 512-524 pdf
*Author contribution was equal

19) Rollinson N., Rowe L. 2016. The positive correlation between maternal size and offspring size: fitting pieces of a life-history puzzle. Biological Reviews 91:1134-1148

18) Rollinson N., Rowe L. 2015. Persistent directional selection on body size and a resolution to the paradox of stasis.  Evolution 69:2441-2451

17) Rollinson N., Hackett D. 2015. Experimental assessment of agonistic behavior, chemical communication, spacing, and intersexual associations of the red-backed salamanders near its northern range limit. Canadian Journal of Zoology 93:773-781

16) Rollinson N*., Keith D.A.*, Debes P.V., Houde A.L.S., McBride M., Hutchings J.A. 2014. Risk assessment of inbreeding and outbreeding depression in a captive breeding program.
Conservation Biology. 28:529–540      
*Author contribution was equal

15) Rollinson N., Hutchings J.A. 2013. Environmental quality predicts optimal egg size in the wild. The American Naturalist. 182:76–90

14) Rollinson N.*, Edge C.B.*, Brooks R.J. 2013. Recurrent violations of invariant rules for offspring size: evidence from turtles and the implications for small clutch size models. Oecologia.  172: 973–982
*Author contribution was equal

13) Stahlschmidt Z.R., Rollinson N., Acker M., Adamo S.A. 2013. Are all eggs created equal? Food availability and the fitness tradeoff between reproduction and immunity. Functional Ecology. 27:800–806

12) Rollinson N., Hutchings J.A. 2013. The relationship between offspring size and fitness: integrating theory and empiricism. Ecology. 94: 315–324

11) Congdon J.D., Gibbons J.W. , Brooks R.J., Rollinson N., Tsaliagos R.N. 2013. Indeterminate growth in long-lived freshwater turtles as a component of individual fitness. Evolutionary Ecology. 27: 445–459

10) Rollinson N., Farmer R.G., Brooks R.J. 2012. Widespread reproductive variation in North American turtles: temperature, egg size and optimality. Zoology. 115:160-169
*Featured on the cover of Zoology (June 2012)

9) Rollinson N., Hutchings J.A. 2011. Body size-specific maternal effects on the offspring environment shape juvenile phenotypes in Atlantic salmon. Oecologia. 166:889-98
8) Rollinson N., Hutchings J.A. 2011. Why does egg size of salmonids increase with the mean size of popultion spawning gravels?  Canadian Journal of Fisheries and Aquatic Sciences. 68:1307-1315

7) Rollinson N., Hutchings J.A. 2010. Why does egg size increase with maternal size? Effects of egg size and egg density on offspring phenotypes. Evolutionary Ecology Research. 12:949-960
6) Rollinson N., Brooks R.J. 2008. Optimal offspring provisioning when egg size is 'constrained’: a case study with the painted turtle. Oikos. 117:144-151
5) Rollinson N., Brooks R.J. 2008. Sources and significance of among individual reproductive variation in a northern population of painted turtles. Copeia. 2008:533-541

4) Rollinson N., Tattersall G.J., Brooks R.J. 2008. Overwintering habitats of a northern population of Painted Turtles (Chrysemys picta): winter temperature selection and dissovled oxygen concentrations. Journal of Herpetology. 42:312-321
3) Carrière M.A., Rollinson N., Suley A.N., Brooks R.J. 2008. Thermoregulation when the growing  season is short: sex-biased basking patterns in a northern population of painted turtles.
Journal of Herpetology. 42:206-209

2) Rollinson N., Brooks R.J. 2007. Marking nests increases the frequency of nest depredation in a northern population of painted turtles. Journal of Herpetology. 41:174-176
1) Rollinson N., Brooks R.J. 2007. Proximate constraints on reproductive output in a northern population of painted turtles: an empirical test of the bet-hedging paradigm.
Canadian Journal of Zoology. 85:177-184

News Archive

Summer 2018
Melanie Massey defends her extraordinary MSc thesis!! (and immediately begins a PhD in evo devo at Dalhousie U.!). Well done Melanie.

Spring 2018
The Original Bug Shirt Company ( generously contributes to our long-term studies in Algonquin Park. The bugs are bad up here, and the Rollinson group greatly appreciates your contribution!

Winter 2018
Njal is appointed to the Amphibians and Reptiles Species Specialist Subcommittee of COSEWIC

Spring 2017
Patrick Moldowan wins a prestigious Alexander Graham Bell CGS-Doctoral Award!

Melanie Massey wins a prestigious Alexander Graham Bell CGS-M Award!

December 16th, 2016
Melanie Massey wins UofT's TA of the year award - congrats Melanie!

September 1st, 2016

Hollis Dahn wins a prestigious Connaught Scholarship. Congrats Hollis!

April 22nd 2016
Njal is awarded the 2016 Canadian Society for Ecology and Evolution Early Career Award.  This award recognizes outstanding accomplishments and promising future research potential in ecology and evolution by scientists early in their careers.

September 11th, 2015
New paper "Persistent directional selection on body size and a resolution to the paradox of stasis" is covered on the eco-evo blog.

August 15th, 2014

This entry is a plug for the excellent programs offered by NIMBioS. Last week Njal attended a NIMBioS tutorial on evolutionary quantitative genetics at the University of Tennessee. The workshop was amazing, both in terms of content and instruction. Njal strongly encourage all evolutionary ecologists to check out the NIMBioS website, and the ongoing tutorials they offer.