Ducks Unlimited Canada
Institute for Wetland & Waterfowl Research
PO Box 1160
Stonewall, Manitoba, Canada
R0C 2Z0

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Llwellyn Armstrong


Designing, analyzing and sharing research results.

Llwellyn Armstrong has been the statistician for IWWR since 1998. She consults extensively with staff on issues of study design, sampling methodology and statistical analyses, and helps ensure the results of analyses are appropriately disseminated. As the need arises, she also conducts research into the use of innovative biostatistical techniques.

Llwellyn is on the Board of the Statistical Society of Canada and a member of the American Statistical Association.


  • M.Sc., Statistics, University of Manitoba
  • B.Sc., Statistics, University of Manitoba

Llwellyn’s Publications (organized by year)

Devries, J.H., L.M. Armstrong, D.W. Howerter, and R.B. Emery. 2023. Waterfowl distribution and productivity in the Prairie Pothole Region of Canada: Tools for conservation planning. Wildlife Monographs 211:e1074.

Bortolotti, L.E., R.B. Emery, P.D. Kowal, L.M. Armstrong, V.B. Harriman, H.V. Singer, M.J. Anteau, F.B. Baldwin, C. Meuckon, and D.A. Wrubleski. 2023. Migrating ducks and submersed aquatic vegetation respond positively after invasive common carp (Cyprinus carpio) exclusion from a freshwater coastal marsh. Wetlands 43:25.

Kowal, P.D., P. Badiou, R.B. Emery, L.G. Goldsborough, D.A. Wrubleski, L.M. Armstrong, and B. Page. 2022. Improvement in water clarity and submersed aquatic vegetation cover after exclusion of invasive common carp from a large coastal wetland, Delta Marsh, Manitoba. Frontiers in Environmental Science 10:992690.

Wasko, J.D., T.P. McGonigle, L.G. Goldsborough, D.A. Wrubleski, P.H. Badiou, and L.M. Armstrong. 2022. Use of shoot dimensions and microscopic analysis of leaves to distinguish Typha latifolia, Typha angustifolia, and their invasive hybrid Typha xglauca. Wetlands Ecology and Management 30:19-33.

Bortolotti, L.E., R.B. Emery, L.M. Armstrong, and D.W. Howerter. 2022. Landscape composition, climate variability, and their interaction drive water waterfowl nest survival in the Canadian Prairies. Ecosphere 13:e3908.

Hammell, G.S., H.V. Singer, and L.M. Armstrong. 2021. Comparative reproductive parameters of sympatric lesser scaup (Aythya affinis) and ring-necked duck (Aythya collaris) in parkland Manitoba. Canadian Field Naturalist 135:278-292.

Wasko, J.D., T.P. McGonigle, L.G. Goldsborough, D.A. Wrubleski, P.H. Badiou, and L.M. Armstrong. 2021. Use of shoot dimensions and microscopic analysis of leaves to distinguish Typha latifolia, Typha angustifolia, and their invasive hybrid Typha xglauca. Wetlands Ecolgy and Management: In Press.

Zhang, Z., L.E. Bortolotti, Z. Li, L.M. Armstrong, T.W. Bell, and Y. Li. 2021. Heterogeneous changes to wetlands in the Canadian prairies under future climate. Water Resources Research 57:e2020WR028727.

Davis, S.K., D.A. Kirk, L.M. Armstrong, J.H. Devries, and R.J. Fisher. 2020. Shifting from spring wheat to winter wheat: A potential conservation strategy for grassland songbirds in cultivated landscapes? Biological Conservation 245:108530.

Singer, H.V., S.M. Slattery, L. Armstrong, and S. Witherly. 2020. Assessing breeding duck population trends relative to anthropogenic disturbances across the Boreal Plains of Canada, 1960-2007. Avian Conservation and Ecology 15:1.

Devries, J.H., R.G. Clark, and L.M. Armstrong. 2018. Dynamics of habitat selection in birds: Adaptive response to nest predation depends on multiple factors. Oecologia 187: 305-318.

Davis, S.K., J.H. Devries, and L.M. Armstrong. 2017. Variation in passerine use of burned and hayed planted grasslands. Journal of Wildlife Management 81: 1494-1504.

Singer, H.V., D.R. Luukkonen, L.M. Armstrong, and S.R. Winterstein. 2016. Influence of weather, wetland availability, and mallard abundance on productivity of Great Lakes mallards (Anas platyrhyncos). Wetlands 36:969-978.

Coluccy, J.M., M.V. Castelli, P.M. Castelli, J.W. Simpson, S.R. McWilliams and L. Armstrong. 2015. True metabolizable energy in American black duck foods. Journal of Wildlife Management 79:344-348.

Howerter, D.W., M.G. Anderson, J.H. Devries, B.L. Joynt, L.M. Armstrong, R.B. Emery, and T.W. Arnold. 2014. Variation in mallard vital rates in Canada Aspen Parklands: The Prairie Habitat Joint Venture assessment. Wildlife Monographs 188:1-37.

Bloom, P.M., R.G. Clark, D.W. Howerter, and L.M. Armstrong. 2013. Multi-scale habitat selection affects offspring survival in a precocial species. Oecologia 173:1249-1259.

Bloom, P.M., D.W. Howerter, R.B. Emery, and L.M. Armstrong. 2013. Relationships between grazing and waterfowl production in the Canadian prairies. Journal of Wildlife Management 77: 534-544.

Garvey, M.E., E. Nol, D.W. Howerter, and L.M. Armstrong. 2013. A spatial analysis of factors affecting nesting success of shorebirds in the Canadian prairies. Condor 115: 58-66.

Baschuk, M.S., M.D. Ervin, W.R. Clark, L.M. Armstrong, D.A. Wrubleski, and G.L. Goldsborough. 2012. Using satellite imagery to assess macrophyte response to water-level manipulations in the Saskatchewan River delta, Manitoba. Wetlands 32:1091-1102.

Bloom, P. M., R. G. Clark, D. W. Howerter, and L. M. Armstrong. 2012. Landscape-level correlates of mallard duckling survival: implications for conservation programs. Journal of Wildlife Management 76:813-823.

Bloom, P. M., D. W. Howerter, J. H. Devries, L. M. Armstrong, and R. G. Clark. 2012. Radiomarking brood-rearing mallard females: implications for juvenile survival. Wildlife Society Bulletin 36:582–586.

Petrie, M.J., R.D. Drobney, D.T. Sears, and L.M. Armstrong. 2012. Evidence for mallard Anas platyrhyncos and American black duck Anas rubripes competition in western New Brunswick, Canada. Wildfowl 62: 146-164.

Devries, J. H. and L. M. Armstrong. 2011. Impact of management treatments on waterfowl use of dense nesting cover in the Canadian prairie parklands. Journal of Wildlife Management 75:340-1349.

Gurney, K.E.B., R.G. Clark, S.M. Slattery, N.V. Smith-Downey, J. Walker, L.M. Armstrong, S.E. Stephens, M. Petrula, R.M. Corcoran, K.H. Martin, K.A. DeGroot, R.W. Brook, A.D. Afton, K. Cutting, J.M. Warren, M. Fournier, and D.N. Koons. 2011. Time constraints in temperate-breeding species: influence of growing season length on reproductive strategies. Ecography 34:628-636.

Coluccy, J.M., T. Yerkes, R. Walling, J.W. Simpson, L. Armstrong, and J. Davis. 2008. Population dynamics and sensitivity analyses of breeding mallards in the Great Lakes states. Journal of Wildlife Management 72:1181-1187.

Devries, J. H., L. M. Armstrong, R. J. MacFarlane, L. Moats, and P. T. Thoroughgood. 2008. Waterfowl nesting in fall-seeded and spring-seeded cropland in Saskatchewan. Journal of Wildlife Management 72:1790-1797.

Howerter, D. W., J. J. Rotella, M. G. Anderson, L. M. Armstrong, and J. H. Devries. 2008. Mallard nest-site selection in an altered environment: predictions and patterns. Israel Journal of Ecology & Evolution 54:437–460

Arnold, T.W., L.M. Craig-Moore, L.M. Armstrong, D.W. Howerter, J.H. Devries, B.L. Joynt, R.B. Emery, and M.G. Anderson. 2007. Waterfowl use of dense nesting cover in the Canadian prairie parklands. Journal of Wildlife Management 71:2542-2549.

Raven, G.H., L.M. Armstrong, D.W. Howerter, and T.W. Arnold. 2007. Wetland selection by mallard broods in Canada’s prairie-parklands. Journal of Wildlife Management 71:2527-2531.

Raven, G.H., T.W. Arnold, D.W. Howerter, and L.M. Armstrong. 2007. Mallard brood movements in the Canadian prairie parklands. Prairie Naturalist 39:1-13.

Yerkes, T., R. Paige, R. Macleod, L. Armstrong, G. Soulliere, and R. Gatti. 2007. Predicted distribution and characteristics of wetlands used by mallard pairs in five Great Lake states. American Midland Naturalist 157:356-364.

Emery, R.B., D.W. Howerter, L.M. Armstrong, M.G. Anderson, J.H. Devries, and B.L. Joynt. 2005. Seasonal variation in waterfowl nest success and its relation to cover management in the Canadian prairies. Journal of Wildlife Management 69:1181-1193.

Turner, M.A., D.B. Huebert, D.L. Findlay, L.L. Hendzel, W.A. Jansen, R.A. Bodaly, S.E.M. Kasian, and L.M. Armstrong. 2005. Divergent impacts of experimental lake-level drawdown on planktonic and benthic plant communities in a boreal forest lake. Canadian Journal of Fisheries and Aquatic Sciences 62:991-1003.

Hoekman, S.T., T.S. Gabor, R. Maher, H. Murkin, and L.M. Armstrong. 2004. Factors affecting survival of mallard ducklings in southern Ontario. Condor 106:485-495.

McPherson, R., T.W. Arnold, L. Armstrong, and C.J. Schwarz. 2003. Estimating the number of nests initiated by radiomarked mallards. Journal of Wildlife Management 67:843-851.

Podruzny, K.M., J.H. Devries, L. Armstrong, and J.J. Rotella. 2002. Long-term response of northern pintails to changes in wetlands and agriculture in the Canadian prairie pothole region. Journal of Wildlife Management 66:993-1010.

Rosenberg, D.M., A.P. Wiens, B. Bilyj, and L. Armstrong. 2001. Peatland chironomidae (diptera): effects of flooding on emergence from Lake 979, Experimental Lakes Area, Ontario. Journal of the North American Benthological Society 20:448-467.

Trumble-Waddell, J.E., M.L. Campbell, L. Armstrong, and B.D. Macpherson. 1998. Reliability and validity of the three-day estimated record of food intake provided by parents and caregivers of preschool children in dual-earner families. Journal of Dietetic Practice and Research 59:83-89.

Diamant, R.M.F., M.J.M. Grunau, M.L. Campbell, and L. Armstrong. 1996. Cross Lake harvest and consumption study: historical consumption survey. Technical report for the Cross Lake First Nation, Manitoba Hydro and Manitoba Northern Affairs.

Malcolmson, L.J., M. Vaisey-Genser, R. Przybylski, D. Ryland, N.A.M. Eskin, and L. Armstrong. 1996. Characterization of stored regular and low-linolenic canola oils at different levels of consumer acceptance. Journal of the American Oil Chemists’ Society 73:1153-1160.

Wong, P.L., L. Armstrong, C.L. Betze, P. Wilkinson, and W.L. Lockhart. 1996. Analysis of the effects of the Pine Falls pulp mill on the benthic invertebrates in the Winnipeg River. Manitoba technical report for the Freshwater Institute.

Rosenberg, D.M., A.P. Wiens, B. Bilyj, and L. Armstrong. 1995. Experimental acidification of a poor fen in northwestern Ontario: effects on emergence of chironomidae (diptera). Canadian Journal of Fisheries and Aquatic Sciences. 52:2229-2237.

Vaisey-Genser, M., L.J. Malcolmson, D. Ryland, R. Przybylski, N.A.M. Eskin, and L. Armstrong. 1994. Consumer acceptance of canola oils during temperature-accelerated storage. Food Quality and Preference 5:237-243.