Understanding the factors that influence population abundance requires knowledge of how events are linked throughout the migratory cycle. The primary obstacle, thus far, has been the inability to track individuals over large geographic distances. Part of the research in the Norris lab has been devoted to developing intrinsic markers, such as stable isotopes and trace elements, identifying and understanding the mechanisms behind sources of variance in isotopes and trace elements, and developing statistical tools to assign individuals to specific locations. The development of such markers has provided us with the ability to develop a species-specific isotopic basemap of North America that includes strontium isotopes, a trace element basemap for a migratory shorebird, and a range-wide connectivity map for a migratory songbird.
Bairlein, F, Norris, DR, Voight, C, Dunn, EH & Hussell, DJT. 2016. Using stable-hydrogen isotopes to reveal immigration in an Arctic-breeding songbird population. Movement Ecology 4:16.
Fairhurst, G, Berzins, LL, Bradley, DW*, Romano, A, Romano, M, Ambrosini, R, Dawson, RD, Dunn, PO, Hobson, KA, Liechti, F, Marchant, TA, Norris, DR, Rubolini, D, Saino, N, Shutler, D, Whittingham, LA & Clark RG. 2015. Assessing costs of carrying geolocators using feather corticosterone in two species of aerial insectivore. Royal Society Open Science 2: 150004.
Flockhart, DTT, Kyser, TK, Chipley, D, Miller, N & Norris, DR. 2015. Applying strontium isotopes (87Sr/86Sr) for tracking wildlife: experimental evidence shows no fractionation between soil, plants, and herbivores. Isotopes in Environmental & Health Studies 51(3): 372-381.
Gomez, J, Michelson, CI, Bradley, DW, Norris, DR, Berzins, L, Dawson, RD, Clark, RG. 2013. Effects of geolocators on reproductive performance and annual return rates of a migratory songbird. Journal of Ornithology 155: 37-44.
Storm-Suke, A, Wassenaar, LI, Nol, E & Norris, DR. 2012. The influence of metabolic rate on the contribution of stable-hydrogen and -oxygen isotopes in drinking water to Quail blood plasma and feathers. Functional Ecology 26: 1111-1119.
Storm-Suke, A, Norris, DR, Wassenaar, LI, Chin, E & Nol, E. 2012. Factors influencing the turnover and net isotopic discrimination of hydrogen isotopes in proteinaceous tissue: experimental results using Japanese quail. Physiological & Biochemical Zoology 85: 376-384.
Rae, L, Mitchell, GW, Guglielmo, CG, Mauck, RM & Norris, DR. 2009. Radio transmitters do not affect the body condition of Savannah sparrows during the fall pre-migratory period. Journal of Field Ornithology 80: 434-441.
Betini, GS, Hobson, KA, Wassenaar, LI & Norris, DR. 2009. Stable-hydrogen isotope values in songbird nestlings: effects of temperature, body size, and diet. Canadian Journal of Zoology 87: 767-772.
Sellick, MJ, Kyser, TK, Wunder, MB, Chipley, D & Norris, DR. 2009. Geographic variation in strontium and hydrogen isotopes in avian tissues: implications for tracking migration. Public Library of Science, One 4(3): e4735.
Wunder, MB & Norris, DR. 2008. Improved estimates of certainty in stable isotope-based geographic assignments for tracking migratory animals. Ecological Applications 18: 549-559.
Wunder, MB & Norris, DR. 2008. Analysis and design of isotope-based studies of migratory animals. Pages 107-128 In: Tracking Animal Migration using Stable Isotopes (Eds. KA Hobson & LI Wassenaar). Elsevier, New York.
Langin, KM, Reudink, MW, Marra, PP, Norris, DR, Kyser, TK & Ratcliffe, LM. 2007. Hydrogen isotopic composition of known-origin migratory birds: implications for geographic assignment. Oecologia 152: 449-457.
Norris, DR, Lank, DB, Pither, J, Chipley, D, Ydenberg, RC & Kyser, TK. 2007. Trace elements identify wintering populations of a migratory shorebird. Canadian Journal of Zoology 85: 579-583.