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Stable isotopes reflect the ecological stability of two high-elevation mammals from the late Quaternary of Colorado

Published online by Cambridge University Press:  20 January 2017

Bryan S. McLean  and
Steven D. Emslie
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Abstract

The vertebrate fossil record of Cement Creek Cave, Colorado, spans from ≫ 45,000 yr ago to the present and represents the richest stratified series of high-elevation (≫ 2900 m) mammal remains known from the late Quaternary of North America. Stable carbon and oxygen isotope analyses of tooth enamel were used to assess potential ecological responses of two species found commonly throughout the cave, Yellow-bellied marmots (Marmota flaviventris) and Bushy-tailed woodrats (Neotoma cinerea), to late Quaternary climate and environmental changes of the Southern Rocky Mountains. Results indicate that despite such perturbations, the dietary ecologies of both species were maintained across this period. Neither taxon shifted to consuming C4 taxa or different C3 functional groups; similarly, no significant shifts in surface water use were detected. Variations in enamel δ13C were observed, however, that represent the physiological responses of high-elevation plants to changing levels of late Quaternary atmospheric CO2. While our findings extend both the geographic and elevational record of this plant CO2 response, they simultaneously highlight the ecological stability of high-elevation M. flaviventris and N. cinerea during climate changes of late Quaternary magnitude.

Keywords

Marmota flaviventrisNeotoma cinereaCement Creek CaveMiddle WisconsinSouthern Rocky MountainsTooth enamelδ13Cδ18OAtmospheric CO2
Type
Original Articles
Information
Quaternary Research , Volume 77 , Issue 3 , May 2012 , pp. 408 - 417
Copyright
University of Washington

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References

Ahn, J., Brook, E.J., (2008). Atmospheric CO2 and climate on millennial time scales during the last glacial period. Science. 322, 83–85.CrossRefGoogle ScholarPubMed
Ambrose, S., Norr, L., (1993). Experimental evidence for the relationship of carbon isotope ratios of whole diet and dietary protein to those of bone collagen and carbonate. Lambert, J., Grupe, G., Prehistoric Human Bone: Archaeology at the Molecular Level, Springer-Verlag, Berlin, 1–37.Google Scholar
Andersen, D.C., Armitage, K.B., Hoffmann, R.S., (1976). Socioecology of marmots: female reproductive strategies. Ecology. 57, 552–560.CrossRefGoogle Scholar
Arens, N.C., Jahren, A.H., Amundson, R., (2000). Can C3 plants faithfully record the carbon isotopic composition of atmospheric carbon dioxide?. Paleobiology. 26, 137–164.2.0.CO;2>CrossRefGoogle Scholar
Armstrong, D.M., (1972). Distribution of Mammals in Colorado. Museum of Natural History, University of Kansas, Lawrence, Kansas.CrossRefGoogle Scholar
Aucour, A.-M., Hillaire-Marcel, C., Bonnefille, R., (1994). Late Quaternary biomass changes from 13C measurements in a highland peatbog from equatorial Africa (Burundi). Quaternary Research. 41, 225–233.Google Scholar
Barnosky, A.D., (2004). Biodiversity Response to Climate Change in the Middle Pleistocene. University of California Press, Berkeley.Google Scholar
Barnosky, A.D., Hadly, E.A., Bell, C.J., (2003). Mammalian response to global warming on varied temporal scales. Journal of Mammalogy. 84, 354–368.Google Scholar
Barnosky, A.D., Bell, C.J., Emslie, S.D., Goodwin, H.T., Mead, J.I., Repenning, C.A., Scott, E., Shabel, A.B., (2004). Exceptional record of mid-Pleistocene vertebrates helps differentiate climatic from anthropogenic ecosystem perturbations. Proceedings of the National Academy of Sciences of the United States of America. 101, 9297–9302.Google Scholar
Barrell, J., (1969). Flora of the Gunnison Basin: Gunnison, Saguache and Hinsdale Counties, Colorado; a Study in the Distribution of Plants. National Land Institute, Rockford, Illinois.Google Scholar
Barry, R.G., (1983). Late-pleistocene climatology. Porter, S.C., Late-Quaternary Environments of the United States. 1, University of Minnesota Press, Minneapolis, 390–407.Google Scholar
Beniston, M., (2003). Climatic change in mountain regions: a review of possible impacts. Climatic Change. 59, 5–31.CrossRefGoogle Scholar
Betancourt, J.L., Van Devender, T.R., Martin, P.S., (1990). Packrat Middens: The Last 40,000 Years of Biotic Change. The University of Arizona Press, Tucson.Google Scholar
Bond, G., Broecker, W., Johnsen, S.J., McManus, J., Labeyrie, L., Jouzel, J., Bonani, G., (1993). Correlations between climate records from North Atlantic sediments and Greenland ice. Nature. 365, 143–147.Google Scholar
Briles, C.E., Whitlock, C., Meltzer, D.J., (2012). Last glacial"interglacial environments in the southern Rocky Mountains, USA and implications for Younger Dryas-age human occupation. Quaternary Research. 77, 96–103.CrossRefGoogle Scholar
Brooks, J.R., Flanagan, L.B., Buchmann, N., Ehleringer, J.R., (1997). Carbon isotope composition of boreal plants: functional grouping of life forms. Oecologia. 110, 301–311.CrossRefGoogle ScholarPubMed
Brugger, K.A., (2007). Cosmogenic 10Be and 36Cl ages from late Pleistocene terminal moraine complexes in the Taylor River drainage basin, central Colorado, USA. Quaternary Science Reviews. 26, 494–499.Google Scholar
Brugger, K.A., (2010). Climate in the southern Sawatch Range and Elk Mountains, Colorado, U.S.A., during the Last Glacial Maximum: inferences using a simple degree-day model. Arctic, Antarctic, and Alpine Research. 42, 164–178.CrossRefGoogle Scholar
Bryant, J.D., Froelich, P.N., (1995). A model of oxygen isotope fractionation in body water of large mammals. Geochimica et Cosmochimica Acta. 59, 4523–4537.Google Scholar
Bump, J.K., Fox-Dobbs, K., Bada, J.L., Koch, P.L., Peterson, R.O., Vucetich, J.A., (2007). Stable isotopes, ecological integration and environmental change: wolves record atmospheric carbon isotope trend better than tree rings. Proceedings of the Royal Society B: Biological Sciences. 274, 2471–2480.CrossRefGoogle ScholarPubMed
Cerling, T.E., Harris, J.M., MacFadden, B.J., Leakey, M.G., Quade, J., Eisenmann, V., Ehleringer, J.R., (1997). Global vegetation change through the Miocene/Pliocene boundary. Nature. 389, 153–158.Google Scholar
Collatz, G.J., Berry, J.A., Clark, J.S., (1998). Effects of climate and atmospheric CO2 partial pressure on the global distribution of C4 grasses: present, past, and future. Oecologia. 114, 441–454.Google Scholar
Coltrain, J.B., Harris, J.M., Cerling, T.E., Ehleringer, J.R., Dearing, M., Ward, J., Allen, J., (2004). Rancho La Brea stable isotope biogeochemistry and its implications for the palaeoecology of late Pleistocene, coastal southern California. Palaeogeography Palaeoclimatology Palaeoecology. 205, 199–219.CrossRefGoogle Scholar
Connin, S.L., Betancourt, J., Quade, J., (1998). Late Pleistocene C4 plant dominance and summer rainfall in the southwestern United States from isotopic study of herbivore teeth. Quaternary Research. 50, 179–193.Google Scholar
Cooper, D.J., (2004). The modern environment, flora, and vegetation of South Park, Colorado. Barnosky, A.D., Biodiversity Response to Climate Change in the Middle Pleistocene: the Porcupine Cave Fauna from Colorado, University of California Press, Berkeley, 27–38.CrossRefGoogle Scholar
Dansgaard, W., Johnsen, S.J., Clausen, H.B., Dahl-Jensen, D., Gundestrup, N.S., Hammer, C.U., Hvidberg, C.S., Steffensen, J.P., Sveinbjornsdottir, A.E., Jouzel, J., Bond, G., (1993). Evidence for general instability of past climate from a 250-kyr ice-core record. Nature. 364, 218–220.Google Scholar
Dawson, T.E., Mambelli, S., Plamboeck, A.H., Templer, P.H., Tu, K.P., (2002). Stable isotopes in plant ecology. Annual Review of Ecology and Systematics. 33, 507–559.Google Scholar
Dongmann, G., Nurnberg, H.W., Forstel, H., Wagener, K., (1974). On the enrichment of H2 18O in the leaves of transpiring plants. Radiation and Environmental Biophysics. 11, 41–52.CrossRefGoogle ScholarPubMed
Ehleringer, J.R., Cerling, T.E., Helliker, B.R., (1997). C4 photosynthesis, atmospheric CO2, and climate. Oecologia. 112, 285–299.CrossRefGoogle ScholarPubMed
Emslie, S.D., (2002). Fossil shrews (Insectivora: Soricidae) from the late Pleistocene of Colorado. The Southwestern Naturalist. 47, 62–69.Google Scholar
Fall, P.L., (1997). Timberline fluctuations and late Quaternary paleoclimates in the Southern Rocky Mountains, Colorado. Geological Society of America Bulletin. 109, 1306–1320.Google Scholar
Farquhar, G.D., Ehleringer, J.R., Hubick, K.T., (1989). Carbon isotope discrimination and photosynthesis. Annual Review of Plant Physiology and Plant Molecular Biology. 40, 503–537.Google Scholar
Feranec, R.S., Hadly, E.A., Paytan, A., (2010). Isotopes reveal limited effects of middle Pleistocene climate change on the ecology of mid-sized mammals. Quaternary International. 217, 43–52.Google Scholar
Finley, R.B., (1958). The wood rats of Colorado: distribution and ecology. University of Kansas Publications, Museum of Natural History. 10, 213–552.Google Scholar
Fitzgerald, J.P., Meaney, C.A., Armstrong, D.M., (1994). Mammals of Colorado. Denver Museum of Natural History and University Press of Colorado, Niwot.Google Scholar
Fluckiger, J., Monnin, E., Stauffer, B., Schwander, J., Stocker, T.F., Chappellaz, J., Raynaud, D., Barnola, J.-M., (2002). High-resolution Holocene N2O ice core record and its relationship with CH4 and CO2 . Global Biogeochemical Cycles. 16, 1010.Google Scholar
Francey, R.J., Allison, C.E., Etheridge, D.M., Trudinger, C.M., Enting, I.G., Leuenberger, M., Langenfelds, R.L., Michel, E., Steele, L.P., (1999). A 1000-year high precision record of δ13C in atmospheric CO2 . Tellus. 51B, 170–193.CrossRefGoogle Scholar
Frase, B.A., Hoffmann, R.S., (1980). Marmota flaviventris . Mammalian Species. 135, 1–8.Google Scholar
Fricke, H.C., O'Neil, J.R., ('Neil, 1996). Inter- and intra-tooth variation in the oxygen isotope composition of mammalian tooth enamel phosphate: implications for palaeoclimatological and palaeobiological research. Palaeogeography Palaeoclimatology Palaeoecology. 126, 91–99.Google Scholar
Friedli, H., Lotscher, H., Oeschger, H., Siegenthaler, U., Stauffer, B., (1986). Ice core record of the 13C/12C ratio of atmospheric CO2 in the past two centuries. Nature. 324, 234–238.Google Scholar
Graham, R.W., Lundelius, E.L., Graham, M.A., Schroeder, E.K., Toomey, R.S., (1996). Spatial response of mammals to late Quaternary environmental fluctuations. Science. 272, 1601–1606.Google Scholar
Hall, E.R., (1981). The Mammals of North America. John Wiley and Sons, New York.Google Scholar
Harris, A.H., (1985). Late Pleistocene Vertebrate Paleoecology of the West. University of Texas Press, Austin.Google Scholar
Helliker, B.R., Ehleringer, J.R., (2000). Establishing a grassland signature in veins: 18O in the leaf water of C3 and C4 grasses. Proceedings of the National Academy of Sciences of the United States of America. 97, 7894–7898.CrossRefGoogle ScholarPubMed
Higgins, P., MacFadden, B.J., (2004). “Amount effect” recorded in oxygen isotopes of late glacial horse (Equus) and bison (Bison) teeth from the Sonoran and Chihuahuan deserts, southwestern United States. Palaeogeography Palaeoclimatology Palaeoecology. 206, 337–353.Google Scholar
Holmgren, C.A., Norris, J., Betancourt, J.L., (2007). Inferences about winter temperatures and summer rains from the late Quaternary record of C4 perennial grasses and C3 desert shrubs in the northern Chihuahuan Desert. Journal of Quaternary Science. 22, 141–161.CrossRefGoogle Scholar
Huang, Y., Street-Perrott, F.A., Perrott, R.A., Metzger, P., Eglinton, G., (1999). Glacial–interglacial environmental changes inferred from molecular and compound-specific 13C analyses of sediments from Sacred Lake, Mt. Kenya. Geochimica et Cosmochimica Acta. 63, 1383–1404.Google Scholar
IPCC, , (2007). Climate change 2007: the physical science basis. Solomon, S., Qin, D., Manning, M., Chen, Z., Marquis, M., Averyt, K.B., Tignor, M., Miller, H.L., Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Cambridge University Press, Cambridge and New York.Google Scholar
Keeling, C.D., Mook, W.G., Tans, P.P., (1979). Recent trends in the 13C/12C ratio of atmospheric carbon dioxide. Nature. 277, 121–123.Google Scholar
Keeling, C.D., Piper, S.C., Bacastow, R.B., Wahlen, M., Whorf, T.P., Heimann, M., Meijer, H.A., (2005). Atmospheric CO2 and 13CO2 Exchange with the Terrestrial Biosphere and Oceans from 1978 to 2000: Observations and Carbon Cycle Implications. Ehleringer, J.R., Cerling, T.E., Dearing, M., A History of Atmospheric CO2 and its Effects on Plants, Animals, and Ecosystems, Springer-Verlag, New York, 83–113.Google Scholar
Koch, P.L., (2007). Isotopic study of the biology of modern and fossil vertebrates. Michener, R., Lajtha, K., Stable Isotopes in Ecology and Environmental Science, Blackwell Publishing, Malden, 99–154.Google Scholar
Koch, P.L., Tuross, N., Fogel, M.L., (1997). The effects of sample treatment and diagenesis on the isotopic integrity of carbonate in biogenic hydroxylapatite. Journal of Archaeological Science. 24, 417–429.Google Scholar
Koch, P.L., Hoppe, K.A., Webb, S.D., (1998). The isotopic ecology of late Pleistocene mammals in North America Part 1. Florida. Chemical Geology. 152, 119–138.Google Scholar
Kohn, M.J., Welker, J.M., (2005). On the temperature correlation of δ18O in modern precipitation. Earth and Planetary Science Letters. 231, 87–96.Google Scholar
Kohn, M.J., Schoeninger, M.J., Valley, J.W., (1996). Herbivore tooth oxygen isotope compositions: effects of diet and physiology. Geochimica et Cosmochimica Acta. 60, 3889–3896.Google Scholar
Land, L.S., Lundelius, E.L., Valastro, S., (1980). Isotopic ecology of deer bones. Palaeogeography Palaeoclimatology Palaeoecology. 32, 143–151.CrossRefGoogle Scholar
Legg, T.E., Baker, R.G., (1980). Palynology of Pinedale sediments, Devlins Park, Boulder County, Colorado. Arctic and Alpine Research. 12, 319–333.Google Scholar
Leuenberger, M., Siegenthaler, U., Langway, C.C., (1992). Carbon isotope composition of atmospheric CO2 during the last ice age from an Antarctic ice core. Nature. 357, 488–490.Google Scholar
Longinelli, A., (1984). Oxygen isotopes in mammal bone phosphate: a new tool for paleohydrological and paleoclimatological research?. Geochimica et Cosmochimica Acta. 48, 385–390.Google Scholar
Lundelius, E.L., Graham, R.W., Anderson, E., Guilday, J., Holman, J.A., Steadman, D.W., Webb, S.D., (1983). Terrestrial vertebrate faunas. Porter, S.C., Late-Quaternary Environments of the United States. 1, University of Minnesota Press, Minneapolis, 311–353.Google Scholar
Luz, B., Lolodny, Y., Horowitz, M., (1984). Fractionation of oxygen isotopes between mammalian bone-phosphate and environmental drinking water. Geochimica et Cosmochimica Acta. 48, 1689–1693.CrossRefGoogle Scholar
MacFadden, B.J., Cerling, T.E., (1996). Mammalian herbivore communities, ancient feeding ecology, and carbon isotopes: a 10 million-sequence from the Neogene of Florida. Journal of Vertebrate Paleontology. 16, 103–115.CrossRefGoogle Scholar
MacFadden, B.J., Cerling, T.E., Harris, J.M., Prado, J., (1999). Ancient latitudinal gradients of C3/C4 grasses interpreted from stable isotopes of New World Pleistocene horse (Equus) teeth. Global Ecology and Biogeography. 8, 137–149.CrossRefGoogle Scholar
Marino, B.D., McElroy, M.B., (1991). Isotopic composition of atmospheric CO2 inferred from carbon in C4 plant cellulose. Nature. 349, 127–131.Google Scholar
Marino, B.D., McElroy, M.B., Salawitch, R.J., Spaulding, W.G., (1992). Glacial-to-interglacial variations in the carbon isotopic composition of atmospheric CO2 . Nature. 357, 461–466.Google Scholar
Markgraf, V., Scott, L., (1981). Lower timberline in central Colorado during the past 15,000 yr. Geology. 9, 231–234.Google Scholar
Marshall, J.D., Zhang, J., (1994). Carbon isotope discrimination and water-use efficiency in native plants of the North-Central Rockies. Ecology. 75, 1887–1895.Google Scholar
Marshall, J.D., Brooks, J.R., Lajtha, K., (2007). Sources of variation in the stable isotopic composition of plants. Michener, R., Lajtha, K., Stable Isotopes in Ecology and Environmental Science, Blackwell Publishing, Malden, 22–60.Google Scholar
McGuire, K., McDonnell, J., (2007). Stable isotope tracers in watershed hydrology. Michener, R., Lajtha, K., Stable Isotopes in Ecology and Environmental Science, Blackwell Publishing, Malden, 334–374.Google Scholar
Medina, E., Minchin, P., (1980). Stratification of δ13C values of leaves in Amazonian rain forests. Oecologia. 45, 377–378.CrossRefGoogle ScholarPubMed
Monnin, E., Indermuhle, A., Dallenbach, A., Fluckiger, J., Stauffer, B., Stocker, T.F., Raynaud, D., Barnola, J.-M., (2001). Atmospheric CO2 concentrations over the last glacial termination. Science. 291, 112–114.Google Scholar
Munson, P.J., (1984). Teeth of juvenile woodchucks as seasonal indicators on archaeological sites. Journal of Archaeological Science. 11, 395–403.Google Scholar
(2004). NGRIP Members High-resolution record of Northern Hemisphere climate extending into the last interglacial period. Nature. 431, 147–151.Google Scholar
O'Leary, M.H., ('Leary, 1981). Carbon isotope fractionation in plants. Phytochemistry. 20, 553–567.Google Scholar
Passey, B.H., Robinson, T.F., Ayliffe, L.K., Cerling, T.E., Sponheimer, M., Dearing, M.D., Roeder, B.L., Ehleringer, J.R., (2005). Carbon isotope fractionation between diet, breath CO2, and bioapatite in different mammals. Journal of Archaeological Science. 32, 1459–1470.CrossRefGoogle Scholar
Petit, J.R., Jouzel, J., Raynaud, D., Barkov, N.I., Barnola, J.M., Basile, I., Bender, M., Chappellaz, J., Davis, M., Delaygue, G., Delmotte, M., Kotlyakov, V.M., Legrand, M., Lipenkov, V.Y., Lorius, C., Pepin, L., Ritz, C., Saltzman, E., Stievenard, M., (1999). Climate and atmospheric history of the past 420,000 years from the Vostok ice core, Antarctica. Nature. 399, 429–436.CrossRefGoogle Scholar
Pierce, K.L., (2003). Pleistocene glaciations of the Rocky Mountains. Development in Quaternary Science. 1, 63–76.Google Scholar
Quade, J., Cerling, T.E., Barry, J.C., Morgan, M.E., Pilbeam, D.R., Chivas, A.R., Lee-Thorp, J.A., Van der Merwe, N.J., (1992). A 16-Ma record of paleodiet using carbon and oxygen isotopes in fossil teeth from Pakistan. Chemical Geology. 94, 183–192.Google Scholar
(2011). R Development Core Team R: A Language and Environment for Statistical Computing. R Foundation for Statistical Computing, Vienna, http://www.R-project.org/.Google Scholar
Richmond, G.M., (1986). Stratigraphy and Correlation of Glacial Deposits of the Rocky Mountains, the Colorado Plateau and the Ranges of the Great Basin. Sibrava, V., Bowen, D.Q., Richmond, G.M., Quaternary Glaciations in the Northern Hemisphere, Pergamon Press, Elmsford, 99–127.Google Scholar
Richmond, G.M., Fullerton, D.S., (1986). Summation of quaternary glaciations in the United States of America. Sibrava, V., Bowen, D.Q., Richmond, G.M., Quaternary Glaciations in the Northern Hemisphere, Pergamon Press, Elmsford, 183–196.Google Scholar
Sage, R.F., Coleman, J.R., (2001). Effects of low atmospheric CO2 on plants: more than a thing of the past. Trends in Plant Science. 6, 18–24.Google Scholar
Sare, D.T.J., Millar, J.S., Longstaffe, F.J., (2005). Tracing dietary protein in red-backed voles (Clethrionomys gapperi) using stable isotopes of nitrogen and carbon. Canadian Journal of Zoology. 83, 717–725.CrossRefGoogle Scholar
Schoeninger, M.J., DeNiro, M.J., (1982). Carbon isotope ratios of apatite from fossil bone cannot be used to reconstruct diets of animals. Nature. 297, 577–578.Google Scholar
Sigman, D.M., Boyle, E.A., (2000). Glacial/interglacial variations in atmospheric carbon dioxide. Nature. 407, 859–869.Google Scholar
Sikes, R.S., Gannon, W.L., (2011). Animal Care and Use Committee of the American Society of Mammalogists. Guidelines of the American Society of Mammalogists for the use of wild animals in research, Journal of Mammalogy, 92, 235–253.Google Scholar
Smith, F.A., (1997). Neotoma cinerea . Mammalian Species. 564, 1–8.Google Scholar
Spaulding, W.G., Leopold, E.B., Van Devender, T.R., (1983). Late Wisconsin Paleoecology of the American Southwest. Porter, S.C., Late-Quaternary Environments of the United States. 1, University of Minnesota Press, Minneapolis, 259–293.Google Scholar
Stafford, T.W., Semken, H.A., Graham, R.W., Klippel, W.F., Markova, A., Smirnov, N.G., Southon, J., (1999). First accelerator mass spectrometry 14C dates documenting contemporaneity of nonanalog species in late Pleistocene mammal communities. Geology. 27, 903–906.Google Scholar
Street-Perrott, F.A., Huang, Y., Perrott, R.A., Eglinton, G., Barker, P., Khelifa, L.B., Harkness, D.D., Olago, D.O., (1997). Impact of lower atmospheric carbon dioxide on tropical mountain ecosystems. Science. 278, 1422–1426.Google Scholar
Teeri, J.A., Stowe, L.G., (1976). Climatic patterns and the distribution of C4 grasses in North America. Oecologia. 23, 1–12.Google Scholar
Thewissen, J.G.M., Cooper, L.N., Clementz, M.T., Bajpai, S., Tiwari, B.N., (2007). Whales originated from aquatic artiodactyls in the Eocene epoch of India. Nature. 450, 1190–1194.CrossRefGoogle ScholarPubMed
Thompson, R.S., Whitlock, C., Bartlein, P.J., Harrison, S.P., Spaulding, W.G., (1993). Climatic changes in the Western United States since 18,000 yr B.P. Wright, H.E., Kutzbach, J.E., Webb, T., Ruddiman, W.F., Street-Perrott, F.A., Bartlein, P.J., Global Climates since the Last Glacial Maximum, University of Minnesota Press, Minneapolis, 468–513.Google Scholar
Van de Water, P.K., Leavitt, S.W., Betancourt, J.L., (1994). Trends in stomatal density and 13C/12C ratios of Pinus flexilis needles during last glacial–interglacial cycle. Science. 264, 239–243.Google Scholar
Van der Merwe, N.J., (1982). Carbon isotopes, photosynthesis, and archaeology. American Scientist. 70, 596–606.Google Scholar
Vaughan, T.A., (1990). Ecology of living packrats. Betancourt, J.L., Van Devender, T.R., Martin, P.S., Packrat Middens: the Last 40,000 Years of Biotic Change, The University of Arizona Press, Tucson, 14–27.Google Scholar
Vogel, J., (1978). Recycling of carbon in a forest environment. Oecologia Plantarum. 13, 89–94.Google Scholar
Wang, Y., Cerling, T.E., (1994). A model of fossil tooth and bone diagenesis: implications for paleodiet reconstruction from stable isotopes. Palaeogeography Palaeoclimatology Palaeoecology. 107, 281–289.Google Scholar
Ward, J.K., Harris, J.M., Cerling, T.E., Wiedenhoeft, A., Lott, M.J., Dearing, M.-D., Coltrain, J.B., Ehleringer, J.R., (2005). Carbon starvation in glacial trees recovered from the La Brea tar pits, southern California. Proceedings of the National Academy of Sciences of the United States of America. 102, 690–694.Google Scholar
Webb, R.H., Betancourt, J.L., (1990). The spatial and temporal distribution of radiocarbon ages from packrat middens. Betancourt, J.L., Van Devender, T.R., Martin, P.S., Packrat Middens: The Last 40,000 Years of Biotic Change, The University of Arizona Press, Tucson, 85–102.Google Scholar
Welker, J.M., (2000). Isotopic (δ18O) characteristics of weekly precipitation collected across the USA: an initial analysis with application to water source studies. Hydrological Processes. 14, 1449–1464.Google Scholar
Wilson, D.E., Reeder, D.M., (2005). Mammal Species of the World. Johns Hopkins University Press, Baltimore.Google Scholar
Wright, H.E., Bent, A.M., Hansen, B.S., Maher, L.J., (1973). Present and past vegetation of the Chuska Mountains, northwestern New Mexico. Geological Society of America Bulletin. 84, 1155–1180.2.0.CO;2>CrossRefGoogle Scholar
Yurtsever, Y., Gat, J., (1981). Atmospheric water. Gat, J.R., Gonfiantini, R., Stable Isotope Hydrology, Deuterium and Oxygen-18 in the Water Cycle, International Energy Agency, Vienna, 103–142.Google Scholar