Stable isotope measurements are increasingly being used to gain insights into the nutritional ecology of many wildlife species and their role in ecosystem structure and function. Such studies require estimations of trophic discrimination factors (i.e. differences in the isotopic ratio between the consumer and its diet). Although trophic discrimination factors are tissue- and species-specific, researchers often rely on generalized, and fixed trophic discrimination factors that have not been experimentally derived. In this experimental study, captive wild boar (Sus scrofa) were fed a controlled diet of corn (Zea mays), a popular and increasingly dominant food source for wild boar in the Czech Republic and elsewhere in Europe, and trophic discrimination factors for stable carbon (Δ13C) and nitrogen (Δ15N) isotopes were determined from hair samples. The mean Δ13C and Δ15N in wild boar hair were -2.3‰ and +3.5‰, respectively. Also, in order to facilitate future derivations of isotopic measurements along wild boar hair, we calculated the average hair growth rate to be 1.1 mm d(-1). Our results serve as a baseline for interpreting isotopic patterns of free-ranging wild boar in current European agricultural landscapes. However, future research is needed in order to provide a broader understanding of the processes underlying the variation in trophic discrimination factors of carbon and nitrogen across of variety of diet types.

Department of Ecology Faculty of Environmental Sciences Czech University of Life Sciences Prague Prague Czech Republic

Department of Game Management and Wildlife Biology Faculty of Forestry and Wood Sciences Czech University of Life Sciences Prague Prague Czech Republic

Zobrazit více v PubMed

Adams LG, Farley SD, Stricker CA, Demma DJ, Roffler GH, Miller DC, et al. Are inland wolf-ungulate systems influenced by marine subsidies of Pacific salmon? Ecol Appl. 2010;20: 251–262. PubMed

Codron D, Codron J, Lee-Thorp JA, Sponheimer M, De Ruiter D, Brink JS. Stable isotope characterisation of mammalian predator-prey relationships in a South African savanna. Eur J Wildl Res. 2007;53: 161–170.

Ben-David M, Flaherty EA. Stable isotopes in mammalian research: a beginner’s guide. J Mammal. 2012;93: 312–328.

Wurster CM, Robertson J, Westcott DA, Dryden B, Zazzo A, Bird MI. Utilization of Sugarcane Habitat by Feral Pig (Sus scrofa) in Northern Tropical Queensland: Evidence from the Stable Isotope Composition of Hair. PLoS ONE. 2012; 7 10.1371/journal.pone.0043538 PubMed DOI PMC

DeNiro MJ, Epstein S. Influence of diet on the distribution of carbon isotopes in animals. Geochim Cosmochim Acta. 1978;42: 495–506.

DeNiro MJ, Epstein S. Influence of diet on the distribution of nitrogen isotopes in animals. Geochim Cosmochim Acta. 1981;45: 341–351.

Hobson KA. Tracing origins and migration of wildlife using stables isotopes: a review. Oecologia. 1999;120: 314–326. PubMed

Post DM. Using stable isotopes to estimate trophic position: models, methods, and assumptions. Ecology. 2002;83: 703–718.

Bassham JA, Benson AA, Kay LD, Harris AZ, Wilson AT, Calvin M. The path of carbon in photosynthesis XXI. The cyclic regeneration of carbon dioxide acceptor. J Am Chem Soc. 1953;76: 1760–1770.

Hatch MD, Slack CR, Johnson HS. Further studies on a new pathway of photosynthetic CO2 fixation in sugarcane and its occurrence in other plant species. J Biochem. 1967; 102: 417–422. PubMed PMC

Farquhar GD, Ehleringer JR, Hubick KT. Carbon isotope discrimination and photosynthesis. Annu Rev Plant Physiol Plant Mol Biol. 1989; 40: 503–537.

O'Leary MH. Carbon isotopes in photosynthesis. BioScience. 1988;38: 328–336.

Craine JM, Elmore AJ, Aidar MP, Bustamante M, Dawson TE, Hobbie EA, et al. Global patterns of foliar nitrogen isotopes and their relationships with climate, mycorrhizal fungi, foliar nutrient concentrations, and nitrogen availability. New Phytol. 2009; 183: 980–992. 10.1111/j.1469-8137.2009.02917.x PubMed DOI

Ambrose SH. Effects of diet, climate and physiology on nitrogen isotope abundances in terrestrial foodwebs. J Archaeol Sci. 1991;18: 293–317.

Tieszen LL, Boutton TW, Tesdahl KG, Slade NA. Fractionation and turnover of stable carbon isotopes in animal tissues: implications for δ 13C analysis of diet. Oecologia. 1983;57: 32–37. PubMed

Peterson BJ, Fry B. Stable isotopes in ecosystem studies. Annu Rev Ecol Syst. 1987;18: 293–320.

Hilderbrand GV, Farley SD, Robbins CT, Hanley TA, Titus K, Servheen C. Use of stable isotopes to determine diets of living and extinct bears. Can J Zool. 1996;74: 2080–2088.

Schwertl M, Auerswald K, Schnyder H. Reconstruction of the isotopic history of animal diets by hair segmental analysis. Rapid Commun Mass Spectrom. 2003;17: 1312–1318. PubMed

Cerling TE, Viehl K. Seasonal diet changes of the forest hog (Hylochoerus meinertzhageni Thomas) based on the carbon isotopic composition of hair. Afr J Ecol. 2004;42: 88–92.

Iacumin P, Davanzo S, Nikolaev V. Short-term climatic changes recorded by mammoth hair in the arctic environment. Palaeogeogr Palaeoclimatol Palaeoecol. 2005;218: 317–324.

Cerling TE, Wittemyer G, Rasmussen HB, Vollrath F, Cerling CE, Robinson TJ, et al. Stable isotopes in elephant hair documents migration patterns and diet changes. Proc Natl Acad Sci USA. 2006;103: 371–373. PubMed PMC

Fry B. Stable isotope ecology. Springer; New York; 2006.

Phillips DL. Converting isotope values to diet composition: the use of mixing models. J Mammal. 2012;93: 342–352.

Ben-David M, Schell DM. Mixing models in analyses of diet using multiple stable isotopes: a response. Oecologia. 2012;127: 180–184. PubMed

McCutchan JH Jr, Lewis WM, Kendall C, McGrath CC. Variation in trophic shift for stable isotope ratios of carbon, nitrogen, and sulfur. Oikos. 2003; 102(2): 378–390.

Sponheimer M, Robinson T, Ayliffe L, Passey B, Roeder B, Shipley L, et al. An experimental study of carbon-isotope fractionation between diet, hair, and feces of mammalian herbivores. Can J Zool. 2003;81: 871–876.

Martínez del Rio C, Wolf N, Carleton SA, Gannes LZ. Isotopic ecology ten years after a call for more laboratory experiments. Biol Rev. 2009;84: 91–111. 10.1111/j.1469-185X.2008.00064.x PubMed DOI

Parng E, Crumpacker A, Kurle CM. Variation in the stable carbon and nitrogen isotope discrimination factors from diet to fur in four felid species held on different diets. J Mammal. 2014;95(1): 151–159.

Dalerum F, Angerbjörn A. Resolving temporal variation in vertebrate diets using naturally occurring stable isotopes. Oecologia. 2005;144: 647–58. PubMed

Caut S, Angulo E, Courchamp F. Caution on isotopic model use for analyses of consumer diet. Can J Zool. 2008;86: 438–445.

Bond A, Diamond AW. Recent Bayesian stable-isotope mixing models are highly sensitive to variation in discrimination factors. Ecol Appl. 2011;21: 1017–1023. PubMed

Caut S, Angulo E, Courchamp F. Discrimination factors (Δ15N and Δ13C) in an omnivorous consumer: effect of diet isotopic ratio. Funct Ecol. 2007;22: 255–263.

Kelly DJ, Robertson A, Murphy D, Fitzsimons T, Costello E, Gormley E, et al. Trophic Enrichment Factors for Blood Serum in the European Badger (Meles meles). PLoS ONE. 2012;7 10.1371/journal.pone.0053071 PubMed DOI PMC

Kurle CM, Koch PL, Tershy BR, Croll DA. The effects of sex, tissue type, and dietary components on stable isotope discrimination factors (Δ13C and Δ15N) in mammalian omnivores. Isotopes Environ Health Stud. 2014;50: 307–321. 10.1080/10256016.2014.908872 PubMed DOI

Hobson KA, Quirk TW. Effect of age and ration on diet-tissue isotopic (Δ13C, Δ15N) discrimination in striped skunks (Mephitis mephitis). Isotopes Environ Health Stud. 2014;50(3). 10.1080/10256016.2014.867852 PubMed DOI

Felicetti LA, Schwartz CC, Rye RO, Haroldson MA, Gunther KA, Phillips DL, et al. Use of sulfur and nitrogen stable isotopes to determine the importance of whitebark pine nuts to Yellowstone grizzly bears. Can J Zool. 2003;81: 763–770.

Nardoto GB, Godoy PB, Ferraz ESB, Ometto JPHB, Martinelli LA. Stable carbon and nitrogen isotopic fractionation between diet and swine tissues. Sci Agric. 2006;63: 579–582.

Warinner C, Tuross N. Alkaline cooking and stable isotope diet-tissue discrimination in swine: archaeological implications. J Archaeol Sci. 2009;36:1690–1697.

Schley L, Roper TJ. Diet of wild boar Sus scrofa in Western Europe, with particular reference to consumption of agricultural crops. Mammal Rev. 2003;33: 43–56.

Ballari SA, Barrios-García MN. A review of wild boar Sus scrofa diet and factors affecting food selection in native and introduced ranges. Mammal Rev. 2013;44: 124–134.

Herrero J, García-Serrano A, Couto S, Ortuño V, García-González R. Diet of wild boar Sus scrofa L. and crop damage in an intensive agroecosystem. Eur J Wildl Res. 2006;52: 245–250.

Amici A, Serrani F, Rossi CM, Primi R. Increase in crop damage caused by wild boar (Sus scrofa L.): the “refuge effect”. Agron Sustain Dev. 2012;32: 683–692.

Keuling O, Stier N. How endangered is the maize? Movement pattern of wild boar in autumn. In: 8th Symposium on wild boar and other suids; 2010.

Wildauer L, Reimoser F. Wild boar (Sus scrofa) management—what can we learn from history? In: XXVIIIth International Union of Game Biologists Congress; 2007.

Jones RJ, Ludlow MM, Troughton JH, Blunt CG. Changes in the natural carbon isotope ratios of the hair from steers fed diets of C4, C3 and C4 species in sequence. Search. 1981;12: 85–87.

Zazzo A, Harrison S, Bahar B, Moloney A, Monahan F, Scrimgeour CM, et al. Experimental determination of dietary carbon turnover in bovine hair and hoof. Can J Zool. 2007;85: 1239–1248.

van Scott EJ, Reinertson RP, Steinmuller R. The growing hair roots of the human scalp and morphologic changes therein following amethopterin therapy. J Invest Dermatol. 1957;29: 197–204. PubMed

Venables WN, Ripley BD. Modern applied statistics with S. 4th ed Springer Science & Business Media; 2002.

Therrien JF, Fitzgerald G, Gauthier G, Bêty J. Diet-tissue discrimination factors of carbon and nitrogen stable isotopes in blood of Snowy Owl (Bubo scandiacus). Can. J. Zool. 2011;89: 343–347.

Darr RL, Hewitt DG. Stable Isotope Trophic Shifts in White-Tailed Deer. J. Wildl. Manag. 2008;72: 1525–1531.

Marques TS, Bassetti LAB, Lara NRF, Araújo MS, Piňa CI, Camargo PB, et al. Isotopic Discrimination Factors (Δ13C and Δ15N) between Tissues and Diet of the Broad-Snouted Caiman (Caiman latirostris). J Herpetol. 2014;48: 332–337.

R Core Team. A language and environment for statistical computing. Version 3.0.3 [computer program] R Foundation for Statistical Computing. Vienna, Austria: Available: http:/www.R-project.org; 2014. Accessed 10 April 2014.

Lynfield YL, Macwilliams P. Shaving and hair growth. J Invest Dermatol. 1970;55: 170–172. PubMed

West A, Ayliffe L, Cerling T, Robinson TF, Karren B, Dearing MD, et al. (2004) Short-term diet changes revealed using stable carbon isotopes in horse tail-hair. Funct Ecol. 2004;18: 616–624.

Bradfield RB. Effect of undernutrition upon hair growth In: Orfanos CE, Montagna W, Stuttgen G, editors. Hair Research: Status and Future Aspects. Springer-Verlag, Berlin; 1981. pp. 251–256.

Johnson E. Environmental effects on the hair follicle In: Jarrett A, editor. Physiology and Pathophysiology of the Skin. Academic Press, London; 1977. pp. 1237–1249.

Mohn MP. The effects of different hormonal states on the growth of hair in rats In: Montagna W, Ellis RA, editors. The Biology of Hair Growth. Academic Press, New York; 1958; pp. 336–398.

Lecomte N, Ahlstrøm Ø, Ehrich D, Fuglei E, Ims RA, Yoccoz NG. Intrapopulation Variability Shaping Isotope Discrimination and Turnover: Experimental Evidence in Arctic Foxes. PLoS ONE. 2011;6 10.1371/journal.pone.0021357 PubMed DOI PMC

Caut S, Angulo E, Courchamp F. Variation in discrimination factors (Δ15N and Δ13C): the effect of diet isotopic values and applications for diet reconstruction. J Appl Ecol. 2009;46: 443–453.

Arentson RA, Zimmerman DR. True digestibility of amino acids and protein in pigs with 13C as a label to determine endogenous amino acid excretion. J Anim Sci. 1995;73: 1077–1085. PubMed

Codron D, Codron J, Sponheimer M, Bernasconi SM, Clauss M. When animals are not quite what they eat: diet digestibility influences 13C-incorporation rates and apparent discrimination in a mixed-feeding herbivore. Can J Zool. 2011;89: 453–465.

Murray PJ, Witt GB, Moll EJ. Wool, isotopes and diet selection in grazing sheep. Recent Advances in Animal Nutrition in Australia. 1997;14: 253.

Robbins CT, Felicetti L, Florin S. The impact of protein quality on stable nitrogen isotope ratio discrimination and assimilated diet estimation. Oecologia. 2010;162: 571–579. 10.1007/s00442-009-1485-8 PubMed DOI

Hemmer H. Domestication: The Decline of Environmental Appreciation. Cambridge University Press, Cambridge, UK; 1990.

Jones GF. Genetic aspects of domestication, common breeds and their origin In: Rothschild MF, Ruvinsky A, editors. The Genetics of the Pig. CAB International, Wallingford, UK; 1998. pp. 17–50.

Giuffra E, Kijas JMH, Amarger V, Carlborg O, Jeon JT, Andersson L. The origin of the domestic pig: Independent domestication and subsequent introgression. Genetics. 2000;154: 1785–1791. PubMed PMC

Weiler U, Appell HJ, Kremser M, Hofäcker S, Claus R. Consequences of Selection on Muscle Composition. A Comparative Study on Gracilis Muscle in Wild and Domestic Pigs. Anat Histol Embryol. 1995;24: 77–80. PubMed