What are they?
Stable isotopes are non-radioactive forms of elements that have similar chemical properties but vary in their atomic mass due to differences in the number of neutrons. The differences in atomic mass cause separation among isotopes of the same element during geochemical and metabolic processes. This phenomenon is known as isotopic fractionation.
Useful isotopes for migratory connectivity
Approximately two thirds of the known elements have more than one stable isotope, but isotopes of carbon (13C), nitrogen (15N), and hydrogen (also know as Deuterium, D) are among the most useful for studying migratory connectivity. There are two reasons for this.
- Their patterns of isotopic fractionation are well understood and vary predictably across broad spatial scales.
- They are naturally abundant, allowing them to be be detected in biological tissues.
Each of the aforementioned isotopes offers different clues about a bird’s molt location. Some of the most informative research on migratory connectivity uses multiple stable isotopes or uses stable isotopes in combination with genetic markers.
- Stable-hydrogen isotopes vary strongly with latitude.
- Stable-carbon isotopes show a similar pattern due to broad scale differences in water-use efficiency and photosynthesis strategy by plants.
- Stable-sulfur isotopes differ between marine and terrestrial environments, making it possible to measure longitudinal origins of molt in species whose habitats extend to coastal regions.
Feathers (claws, blood and muscle can also be used) are the most commonly used tissue in stable isotope investigations of migratory connectivity. Most species of migratory birds undergo a complete molt once each year between July and September on or near their breeding areas, and the isotopic signatures of foods eaten during this time become incorporated into feathers. Because isotopic signatures are mostly inert once stored in feather tissue, samples collected later on in the year provide information about the geographic origin of birds during molt.
Stable isotopes are analyzed using isotope ratio mass spectrometry, and sample results are expressed relative to a standard of known isotopic composition.
Stable isotope resources link
Using a variety of approaches strengthens connectivity research. Often an isotopic component would be useful but a scientist is not set up to carry out the analyses in their own lab. The labs listed below routinely carry out isotopic analyses of population connectivity.
Edited by Peter Marra, Smithsonian Migratory Bird Center, firstname.lastname@example.org.
- Adams, J., and S. Flora. 2010. Correlating seabird movements with ocean winds: linking satellite telemetry with ocean scatterometry. Marine Biology 157: 915-929
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- Amstrup, S.C., G.M. Durner, T.L. McDonald, D.M. Mulcahy, and G.W. Garner. 2001. Comparing movement patterns of satellite-tagged male and female polar bears. Canadian Journal of Zoology 79 (2): 2147-2158
- Angerbjörn, A., P. Börjesson, and K. Brandberg. 2006. Stable isotope analysis of harbour porpoises and their prey from the Baltic and Kattegat/Skagerrak Seas. Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory,. Marine Biology Research 2: 411-419
- Anker-Nilssen, T., and T. Aarvak. 2009. Satellite telemetry reveals post-breeding movements of Atlantic puffins Fratercula arctica from Røst, North Norway. Polar Biology 32 (1): 1657-1664
- Barrette, C., M.O. Hammill, and A.-M. Goulet. 1999. Quality of satellite telemetry locations of gray seals (Halichoerus grypus). Marine Mammal Science 15: 589-594
- Bowen, G., L. Wassenaar, and K. Hobson. 2005. Global application of stable hydrogen and oxygen isotopes to wildlife forensics. Oecologia 143: 337-348
- Brodeur, S., J.-P.L. Savard, M. Robert, R.D. Titman, G. Fitzgerald, and L. Savard. 2008. Failure time and fate of harlequin ducks implanted with satellite transmitters. Waterbirds 31 (Special Publication 2): 183-187
- Bustnes, J.O., A. Mosbech, C. Sonne, and G.H. Systad. 2010. Migration patterns, breeding and moulting locations of king eiders wintering in north-eastern Norway. Polar Biology 33: 1379-1385
- Byrne, R., J. Fish, T.K. Doyle, and J.D.R. Houghton. 2009. Tracking leatherback turtles (Dermochelys coriacea) during consecutive inter-nesting intervals: Further support for direct transmitter attachment. Journal of Experimental Marine Biology & Ecology 377: 68-75
- Cadahía, L., P. López-López, V. Urios, Á. Soutullo, and J.J. Negro. 2009. Natal dispersal and recruitment of two Bonelli’s Eagles Aquila fasciata: a four-year satellite tracking study. Acta Ornithologica 44: 193-198
- Campbell, H.A., M.E. Watts, S. Sullivan, M.A. Read, S. Choukroun, S.R. Irwin, and C.E. Franklin. 2010. Estuarine crocodiles ride surface currents to facilitate long-distance travel. Journal of Animal Ecology 79: 955-964
- Chaloupka, M., D. Parker, and G. Balazs. 2004. Modelling post-release mortality of loggerhead sea turtles exposed to the Hawaii-based pelagic longline fishery. Marine EcologyProgress Series 280: 285-293
- Chevallier, D., F. Jiguet, T. Nore, F. Baillon, and P. Cavallin. 2010. Satellite tracking of a Booted Eagle Aquila pennata during migration. Ringing & Migration 25: 62-64
- Conrath, C.L., and J.A. Musick. 2008. Investigations into depth and temperature habitat utilization and overwintering grounds of juvenile sandbar sharks, Carcharhinus plumbeus: the importance of near shore North Carolina waters. Environmental Biology of Fishes 82: 123-131
- Crawford, K., R.A. McDonald, and S. Bearhop. 2008. Applications of stable isotope techniques to the ecology of mammals. Mammal Review 38: 87-107
- De La Cruz, S.E.W., J.Y. Takekawa, M.T. Wilson, D.R. Nysewander, J.R. Evenson, D. Esler, W.S. Boyd, and D.H. Ward. 2009. Spring migration routes and chronology of surf scoters (Melanitta perspicillata): a synthesis of Pacific coast studies. Canadian Journal of Zoology 87 (1): 1069-1086
- Devineau, O., T.M. Shenk, G.C. White, P.F. Doherty Jr., P.M. Lukacs, and R.H. Kahn. 2010. Evaluating the Canada lynx reintroduction programme in Colorado: patterns in mortality. Journal of Applied Ecology 47: 524-531
- Dubinin, M., A. Lushchekina, and V.C. Radeloff. 2010. Performance and accuracy of Argos transmitters for wildlife monitoring in Southern Russia. European Journal of Wildlife Research 56: 459-463
- Durbec, M., L. Cavalli, J. Grey, R. Chappaz, and B. Nyuyen. 2010. The use of stable isotopes to trace small-scale movements by small fish species. Hydrobiologia 641: 23-31
- Forero, M.G., and K.A. Hobson. 2003. Using stable isotopes of nitrogen and carbon to study seabird ecology: Applications in the Mediterranean seabird community. Scientia Marina 67 (Supplement 2): 23-32
- Gilg, O., H. Strøm, A. Aebischer, M.V. Gavrilo, A.E. Volkov, C. Miljeteig, and B. Sabard. 2010. Post-breeding movements of northeast Atlantic ivory gull Pagophila eburnea populations. Journal of Avian Biology 41: 532-542
- Guelinckx, J., J. Maes, L. de Brabandere, F. Dehairs, and F. Ollevier. 2006. Migration dynamics of clupeoids in the Schelde estuary: A stable isotope approach. Estuarine Coastal & Shelf Science 66 (4): 612-623
- Guest, M.A., R.M. Connolly, S.Y. Lee, N.R. Loneragan, and M.J. Breitfuss. 2006. Mechanism for the small-scale movement of carbon among estuarine habitats: organic matter transfer not crab movement. Oecologia 148: 88-96
- Haas, H.L., C.J. Freeman, J.M. Logan, L. Deegan, and E.F. Gaines. 2009. Examining mummichog growth and movement: Are some individuals making intra-season migrations to optimize growth?. Journal of Experimental Marine Biology & Ecology 369: 8-16
- Hatch, S.A., V.A. Gill, and D.M. Mulcahy. 2010. Individual and colony-specific wintering areas of Pacific northern fulmars (Fulmarus glacialis). Canadian Journal of Fisheries & Aquatic Sciences 67: 386-400
- Hauser, N., A.N. Zerbini, Y. Geyer, M.-P. Heide-Jørgensen, and P. Clapham. 2010. Movements of satellite-monitored humpback whales, Megaptera novaeangliae, from the Cook Islands. Marine Mammal Science 26: 679-685
- Hays, G.C., C.J.A. Bradshaw, M.C. James, P. Lovell, and D.W. Sims. 2007. Why do Argos satellite tags deployed on marine animals stop transmitting?. Journal of Experimental Marine Biology & Ecology 349: 52-60
- Hazel, J. 2009. Evaluation of fast-acquisition GPS in stationary tests and fine-scale tracking of green turtles. Journal of Experimental Marine Biology & Ecology 374: 58-68
- Heide-Jørgensen, M.P., R. Dietz, K.L. Laidre, P. Nicklen, E. Garde, P. Richard, and J. Orr. 2008. Resighting of a narwhal (Monodon monoceros) instrumented with a satellite transmitter. Arctic 61: 395-398
- Heithaus, M.R., A.J. Wirsing, L.M. Dill, and L.I. Heithaus. 2007. Long-term movements of tiger sharks satellite-tagged in Shark Bay, Western Australia. Marine Biology 151: 1455-1461
- Higuchi, H., J.P. Pierre, V. Krever, V. Andronov, G. Fujita, K. Ozaki, O. Goroshko, M. Ueta, S. Smirensky, and N. Mita. 2004. Using a remote technology in conservation: satellite tracking white-naped cranes in Russia and Asia. Conservation Biology 18: 136-147
- Hobson, K.A., L.I. Wassenaar, B. Milá, I. Lovette, C. Dingle, and T.B. Smith. 2003. Stable isotopes as indicators of altitudinal distributions and movements in an Ecuadorean hummingbird community. Oecologia 136: 302-308
- Hobson, K.A. 1999. Tracing origins and migration of wildlife using stable isotopes: a review. Oecologia 120: 314-326
- Hupp, J.W., J.A. Schmutz, C.R. Ely, Jr., E.E. Syroechkovskiy, A.V. Kondratyev, W.D. Eldridge, and E. Lappo. 2007. Moult migration of emperor geese Chen canagica between Alaska and Russia. Journal of Avian Biology 38: 462-470
- Hussey, N.E., M.A. MacNeil, and A.T. Fisk. 2010. The requirement for accurate diet-tissue discrimination factors for interpreting stable isotopes in sharks. Hydrobiologia 654: 1-5
- Iverson, S.A., W.S. Boyd, D. Esler, D.M. Mulcahy, and T.D. Bowman. 2006. Comparison of the effects and performance of four types of radiotransmitters for use with scoters. Wildlife Society Bulletin 34: 656-663
- Kelly, B.P., O.H. Badajos, M. Kunnasranta, J.R. Moran, M. Martinez-Bakker, D. Wartzok, and P. Boveng. 2010. Seasonal home ranges and fidelity to breeding sites among ringed seals. Polar Biology 33: 1095-1109
- Kerr, L.A., A.H. Andrews, G.M. Cailliet, T.A. Brown, and K.H. Coale. 2006. Investigations of 14C, 13C, and 15N in vertebrae of white shark (Carcharodon carcharias) from the eastern North Pacific Ocean. Environmental Biology of Fishes 77 (4): 337-353
- Lake, S., H. Burton, and S. Wotherspoon. 2006. Movements of adult female Weddell seals during the winter months. Polar Biology 29: 270-279
- Latty, C.J., T.E. Hollmén, M.R. Petersen, A.N. Powell, and R.D. Andrews. 2010. Abdominally implanted transmitters with percutaneous antennas affect the dive performance of common eiders. Condor 112: 314-322
- Liminana, R., A. Soutullo, and V. Urios. 2007. Autumn migration of Montagu’s harriers Circus pygargus tracked by satellite telemetry. Journal für Ornithologie 148: 517-523
- Litvin, S.Y., and M.P. Weinstein. 2004. Multivariate analysis of stable-isotope ratios to infer movements and utilization of estuarine organic matter by juvenile weakfish (Cynoscion regalis). Canadian Journal of Fisheries & Aquatic Sciences 61: 1851-1861
- Macneale, K.H., B.L. Peckarsky, and G.E. Likens. 2004. Contradictory results from different methods for measuring direction of insect flight. Freshwater Biology 49: 1260-1268
- Maisonneuve, C., and G. Cabana. 2003. Tracing movement of double-crested cormorant between estuarine, riverine, and upland lakes with stable isotopes. Vogelwarte 42 (2): 56
- Mazerolle, D.F., and K.A. Hobson. 2005. Estimating origins of short-distance migrant songbirds in North America: contrasting inferences from hydrogen isotope measurements of feathers, claws, and blood. Condor 107: 280-288
- McClellan, C.M., J. Braun-McNeill, L. Avens, B.P. Wallace, and A.J. Read. 2010. Stable isotopes confirm a foraging dichotomy in juvenile loggerhead sea turtles. Journal of Experimental Marine Biology & Ecology 387 (2): 44-51
- McKinley, J.O., and B. Mattox. 2010. Winter site fidelity of migratory raptors in southwestern Idaho. Journal of Raptor Research 44: 240-243
- McMahon, K.W., M.L. Fogel, T.S. Elsdon, and S.R. Thorrold. 2010. Carbon isotope fractionation of amino acids in fish muscle reflects biosynthesis and isotopic routing from dietary protein. Journal of Animal Ecology 79: 1132-1141
- Meyburg, B.-U., and C. Meyburg. 2007. Quinze annees de suivi de rapaces par satellite. [15 years’ satellite tracking of raptors.]. Alauda 75: 265-286
- Meyer, C.G., Y.P. Papastamatiou, and K.N. Holland. 2010. A multiple instrument approach to quantifying the movement patterns and habitat use of tiger (Galeocerdo cuvier) and Galapagos sharks (Carcharhinus galapagensis) at French Frigate Shoals, Hawaii. Marine Biology 157: 1857-1868
- Nicholls, D.G., and C.J.R. Robertson. 2007. Assessing flight characteristics for the Chatham albatross (Thalassarche eremita) from satellite tracking. Notornis 54: 168-179
- Oppel, S., and A.N. Powell. 2010. Age-specific survival estimates of king eiders derived from satellite telementry. Condor 112: 323-330
- Oppel, S., D. Dickson, and A. Powell. 2009. International importance of the eastern Chukchi Sea as a staging area for migrating king eiders. Polar Biology 32: 775-783
- Pade, N.G., N. Queiroz, N.E. Humphries, M.J. Witt, C.S. Jones, L.R. Noble, and D.W. Sims. 2009. First results from satellite-linked archival tagging of porbeagle shark, Lamna nasus: Area fidelity, wider-scale movements and plasticity in diel depth changes.” Journal of Experimental Marine Biology & Ecology 370: 64-74
- Papastamatiou, Y.P., A.M. Friedlander, J.E. Caselle, and C.G. Lowe. 2010. Long-term movement patterns and trophic ecology of blacktip reef sharks (Carcharhinus melanopterus) at Palmyra Atoll. Journal of Experimental Marine Biology & Ecology 386: 94-102
- Pauli, J.N., M. Ben-David, S.W. Buskirk, J.E. DePue, and W.P. Smith. 2009. An isotopic technique to mark mid-sized vertebrates non-invasively. Journal of Zoology 278: 141-148
- Peske, L., and M.J. McGrady. 2005. From the Field: A system for locating satellite-received transmitters (PTTs) in the field. Wildlife Society Bulletin 33: 307-312
- Petersen, M.R., B.J. McCaffery, and P.L. Flint. 2003. Post-breeding distribution of long-tailed ducks Clangula hyemalis from the Yukon-Kuskokwim Delta, Alaska. Wildfowl 54: 103-113
- Powell, L.A. 2004. A multistate capture-recapture model using a posteriori classification to enhance estimation of movement rates. Condor 106: 761-767
- Puetz, K., C. Rahbek, P. Saurola, K.T. Pedersen, R. Juvaste, and A.J. Helbig. 2007. Satellite tracking of the migratory pathways of first-year lesser black-backed gulls Larus fuscus departing from the breeding grounds of different subspecies. Die Vogelwelt 128: 141-148
- Quakenbush, L.T., J.J. Citta, J.C. George, R.J Smal, and M.P. Heide-Jørgensen. 2010. Fall and winter movements of bowhead whales (Balaena mysticetus) in the Chukchi Sea and within a potential petroleum development area. Arctic 63: 289-307
- Ramos, R., J. González-Solís, and X. Ruiz. 2009. Linking isotopic and migratory patterns in a pelagic seabird. Oecologia 160: 97-105
- Reichlin, T.S., K.A. Hobson, L.I. Wassenaar, M. Schaub, D. Tolkmitt, D. Becker, L. Jenni, and R. Arlettaz. 2010. Migratory connectivity in a declining bird species: using feather isotopes to inform demographic modelling. Diversity & Distributions 16: 643-654
- Richter, H.V., and G.S. Cumming. 2008. First application of satellite telemetry to track African straw-coloured fruit bat migration. Journal of Zoology 275: 172-176
- Sasamal, S.K., and R.C. Panigraphy. 2006. Influence of eddies on the migratory routes of the sea turtles in the Bay of Bengal. International Journal of Remote Sensing 27 (5-16): 3115-3122
- Sheaffer, S.E., R.A. Malecki, B.L. Swift, J. Dunn, and K. Scribner. 2007. Management implications of molt migration by the Atlantic Flyway resident population of Geese, Branta canadensis. Canadian Field-Naturalist 121: 313-320
- Sherrill-Mix, S.A., M.C. James, R.A. Myers, and M. Elgar. 2008. Migration cues and timing in leatherback sea turtles. Behavioral Ecology 19: 231-236
- Smith, A.D., and A.M. Dufty, Jr. 2005. Variation in the stable-hydrogen isotope composition of Northern Goshawk feathers: relevance to the study of migratory origins. Condor 107: 547-558
- Söhle, I. S. 2003. Effects of satellite telemetry on Sooty Shearwater, Puffinus griseus, adults and chicks. Emu 103: 373-379
- Soutullo, Alvaro, Luis Cadahía, Vicente Urios, Miguel Ferrer, and Juan José Negro. 2007. Accuracy of lightweight satellite telemetry: a case study in the Iberian Peninsula. Journal of Wildlife Management 71: 1010-1015
- Steenhof, K., K.K. Bates, M.R. Fuller, M.N. Kochert, J.O. McKinley, and P.M. Lukacs. 2006. Effects of radiomarking on prairie falcons: attachment failures provide insights about survival. Wildlife Society Bulletin 34: 116-126
- Thomas, K., J.T. Harvey, T. Goldstein, J. Barakos, and F. Gulland. 2010. Movement, dive behavior, and survival of California sea lions (Zalophus californianus) posttreatment for domoic acid toxicosis. Marine Mammal Science 26: 36-52
- Thorup, K., R.A. Holland, A.P. Tøttrup, and M. Wikelski. 2010. Understanding the migratory orientation program of birds: extending laboratory studies to study free-flying migrants in a natural setting. Integrative & Comparative Biology 50: 315-322
- Torres Dowdall, J., A. Farmer, and E.H. Bucher. 2006. Uso de isotopos estables para determinar conectividad migratoria en aves: alcances y limitaciones. [Using stable isotopes to determine migratory connectivity in birds: extent and limitations.]. Hornero 21: 73-84
- Udevitz, M.S., C.V. Jay, A.S. Fischbach, and J.L. Garlich-Miller. 2009. “Modeling haul-out behavior of walruses in Bering Sea ice. Canadian Journal of Zoology 87 (2): 1111-1128
- Villers, A., A. Millon, F. Jiguet, J.-M. Lett, C. Attie, M.B. Morales, and V. Bretagnolle. 2010. Migration of wild and captive-bred Little Bustards Tetrax tetrax: releasing birds from Spain threatens attempts to conserve declining French populations. Ibis 152: 254-261
- Whiting, S.D. 2008. Movements and distribution of dugongs (Dugong dugon) in a macro-tidal environment in northern Australia. Australian Journal of Zoology 56: 215-222