Professor of Wildlife Ecology
Assistant Unit Leader, USGS BRD
Wisconsin Cooperative Wildlife Research Unit
204 Russell Labs
1630 Linden Drive
Madison, WI 53706-1598
Assistant Unit Leader, USGS BRD
The epidemiology of wildlife disease involves a complex interplay among the disease agent, the environment, and the ecology of host species. In a broad sense, understanding key components of the dynamics within and interactions among these three components are crucial to an improved understanding of wildlife disease ecology. Dr. Samuel’s research program combines a variety of laboratory analyses, field investigations, and epidemiology modeling tools to address a broad range of applied research on the ecology of wildlife disease. Recent and current projects concentrate on increased understanding the complexity of disease ecology affecting wildlife species and the development of effective management strategies. Research topics typically involve questions related to disease transmission, disease reservoirs, host ecology, impacts of disease of wildlife populations, and epidemiological modeling.
|BS||University of California-Berkeley||Computer Science||1973|
|MS||University of California-Davis||Ecology
Thesis: A population dynamics model of California sea otters: identification of critical life history stages and management implications.
|MS||University of Idaho||Applied Statistics
Thesis: Nonresponse Horvitz-Thompson methods for aerial surveys of wildlife populations.
|Ph.D||University of Idaho||Wildlife Management
Dissertation: An evaluation of elk sightability in north central Idaho with application to aerial census and herd composition counts.
The Wildlife Society, The Wildlife Disease Association, The Biometrics Society
Walsh, D. P., and M. D. Samuel. 2012. Factors affecting chronic wasting disease: a deer is not a deer is not a deer. Pages 1-9 in D. P. Walsh, ed. Enhanced surveillance strategies for detecting and monitoring chronic wasting disease in free-ranging cervids: U.S. Geological Survey Open-File Report 2012–1036.
Hobbelen, P. H. F., M. D. Samuel, D. Foote, L. Tango, and D. A. LaPointe. 2012. Modeling the impacts of global warming on predation and biotic resistance: mosquitoes, damselflies, and avian malaria in Hawaii. Theoretical Ecology. DOI 10.1007/s12080-011-0154-9.
Hart, P. J., B. L. Woodworth, R. Camp, K. Turner, K. McClure, K. Goodall, C. Henneman, C. Spiegel, J. LeBrun, E. Tweed, J. Citta, and M. Samuel. 2011. Bird and resource variability across and elevational gradient in Hawaii. The Auk 128:113-126.
Henaux, V., and M. D. Samuel. 2011. Avian influenza shedding patterns in waterfowl: Implications for surveillance, environmental transmission, and disease spread. Journal of Wildlife Diseases 47:566-578.
Shorey, R. I., K. T. Scribner, J. Kanefsky, M. D. Samuel, and S. V. Libants. 2011. Inter-continental gene flow among Western Arctic populations of lesser snow geese. Condor 113:735-746.
Piazza, T. M., D. S. Blehert, F. M. Dunning, B. M. Berlowski-Zier, F. N. Zeytin. M. D. Samuel, and W. C. Tucker. 2011. In vitro detection and quantification of botulinum neurotoxin type E activity in avian blood. Applied and Environmental Microbiology 77:7815-7822.
Rogers, K. G., S. J. Robinson, and M. D. Samuel. 2011. Diversity and distribution of white-tailed deer mtDNA lineages in CWD outbreak areas in southern Wisconsin, USA. Journal of Toxicology and Environmental Health 74:1521-1535.
Samuel, M. D., P. H. F. Hobbelen, F. DeCastro, J. A. Ahumada, D. A. LaPointe, C. T. Atkinson, B. L. Woodworth, P. J. Hart, and D. C. Duffy. 2011. The dynamics, transmission, and population impacts of avian malaria in native Hawaiian birds: a modeling approach. Ecological Applications 21:2960-2973.
Storm, D. J., M. D. Samuel, T. R. Van Deelen, K. D. Malcolm, R. E. Rolley, N. A. Frost, D. P. Bates, and B. J. Richards. 2011. Comparison of Visual-based Helicopter and Fixed-wing Forward-looking Infrared Surveys for Counting White-tailed Deer. Wildlife Biology 17:431-440.
Hénaux, V., M. D. Samuel, R. J. Dusek, J. P. Fleskes, and H. S. Ip. Presence of Avian Influenza Viruses in Waterfowl and Wetlands during Summer 2010 in California: Are Resident Birds a Potential Reservoir? PLoS ONE: e31471. doi:10.1371/journal.pone.0031471
Atkinson, C.A., and M.D. Samuel. 2010. Avian Malaria (Plasmodium relictum) in Native Hawaiian Forest Birds: Epizootiology and Dempgraphic Impacts on Apapane (Himatione sanguinea). Journal of Avian Biology 41:357-366.
Henaux, V., M.D. Samuel, and C.M. Bunck. Model-Based Evaluation of HP and LP Avian Influenza Dynamics in Wild Birds. PLoS ONE 5(6):e10997. doi:10.1371/journal.pone.0010997
Grear, D.A., M.D. Samuel, K.T. Scribner, B.V. Weckworth, and J.A. Langenberg. 2010. Influence of genetic relatedness and spatial proximity on chronic wasting disease infection among female white-tailed deer. Journal of Applied Ecology 74:532-540
Ahumada, J. A., M. D. Samuel, D. C. Duffy, A. Dobson, and P. H. F. Hobbelen. 2009. Modeling the epidemiology of avian malaria and pox Hawaii. Page 331-335 in Conservation Biology of Hawaiian Forest Birds. T. K. Pratt, C. T. Atkinson, P. C. Banko, J. Jacobi, and B. L. Woodworth (eds.). Yale University Press, New Haven.
Cross, P. C., J. Drewe, V. Patrek, G. Pearce, M. D. Samuel, and R. J. Delahay. 2009. Host population structure and implications for disease management.Pages 9-29 in R. J. Delahay, G. C. Smith, and M. R. Hutchings (eds.) Management of Disease in Wild Mammals. Springer-Verlag Tokyo, Inc. Tokyo.
Blanchong, J. A., D. M., Heisey, K. T. S. Libants, Scribner, C. Johnson, J. M. Aiken, J. A. Langenberg, and M. D. Samuel. 2009. Genetic susceptibility to chronic wasting disease in free-ranging white-tailed deer: Complement component C1q and Prnp polymorphisms. Infection, Genetics, and Evolution 9:1329-1335.
Jennelle, C. S., M. D. Samuel, C. A. Nolden, and E. A. Berkley. 2009. White-tailed deer carcass decomposition and potential exposure of scavengers to chronic wasting disease. Journal of Wildlife Management 73:655-662.
Jennelle, C. S., M. D. Samuel, C. A. Nolden, D. P. Keane, D. J. Barr, C. Johnson, J. P. Vanderloo, and J. M. Aiken. 2009. Surveillance for transmissible spongiform encephalopathy in scavengers of white-tailed deer carcasses in the chronic wasting disease area of Wisconsin. Journal of Toxicology and Environmental Health 72:1018-1024
Joly, D. O., M. D. Samuel, J. A. Langenberg, R. E. Rolley, and D. P. Keane. 2009. Surveillance to detect chronic wasting disease in Wisconsin white-tailed deer. Journal of Wildlife Diseases 45:989-997
Docherty, D.E., M.D. Samuel, K.F. Egstad, K.M. Griffin, C.A. Nolden, L. Karwal, and H.S. IP. 2009. Changes in West Nile seroprevalence and antibody titers among Wisconsin mesopredators 2003-2006. American Journal of Tropical Medicine and Hygiene 81:177-179
Joly, D.O., D.M. Heisery, M.D. Samuel, C.A. Ribic, N. Thomas, S.D. Wright, and I.E. Wright. 2009. Estimating cause-specific mortality rates using data derived from recovered carcasses. Journal of Wildlife Diseases 45:122-127
Osnas, E.E, D.M. Heisey, R.E. Rolley, and M.D. Samuel. 2009. Spatial and temporal patterns of an emerging epidemic: fine scale mapping of a wildlife epidemic in Wisconsin. Ecological Applications 19:1311-1322.
Wasserberg, G., E. E. Osnas, R.E. Rolley, and M.D. Samuel. 2009. Host culling as an adaptive management tool for chronic wasting disease – a modeling study. Journal of Applied Ecology 46:457-466.
Keane, D. P., D. J. Barr, P. N. Bochsler, S. M. Hall, T. Gidlewski, K. I. O’Rourke, T. R. Spraker, and M. D. Samuel. Chronic wasting disease in a Wisconsin white-tailed deer farm. Journal of Veterinary Diagnostic Investigation 20:698-703.
Hill, D. E., M. D. Samuel, C. A. Nolden, N. Sundar, D. S. Zarlenga, and J. P. Dubey. 2008. Tichinella murrelli in scavenging mammals from south-central Wisconsin, USA. Journal of Wildlife Diseases 44: 629-635.
Dubey, J. P., N. Sundar, C. A. Nolden, M. D.Samuel, G. V. Velmurugan, L. A. Bandini, O. C. H. Kwok, B. Bodenstein, and C. Su. 2007. Characterization of Toxoplasma gondii from raccoons (Procyon lotor), coyotes (Canis latrans), and stripped skunks (Mephitis mephitis) in Wisconsin identified several atypical genotypes. Journal of Parasitology 93:1524-1527.
Thompson, A. K., and M. D. Samuel. 2007. Alternative bait marker systems for white-tailed deer. Pages 223-231 in Proceedings of the 12th Wildlife Damage Management Conference.
Blehert, D. S., K. L. Jefferson, D. M. Heisey, M. D. Samuel, B. M. Berlowski, and D. J. Shadduck. 2008. Using amplified fragment length polymorphism analysis to differentiate isolates of Pasteurella multocida Serotype 1. Journal of Wildlife Diseases 44:209-225.
Williams, C. K., M. D. Samuel, V. V. Baranyuk, E. G. Cooch, and D. Kraege. Winter fidelity and apparent survival of lesser snow goose populations in the Pacific flyway. Journal of Wildlife Management 72: 159-167.
Thompson, A. K, M. D. Samuel, and T. R. Van Deelen. Alternative feeding strategies and potential disease transmission in Wisconsin white-tailed deer. Journal of Wildlife Management 72: 416-421.
Sundar, N., I. M. Asmundsson, N. J. Thomas, M. D. Samuel, J. P. Dubey, and B .M. Rosenthal. 2008. Modest genetic differentiation among North American populations of Sarcocystis neurona may reflect expansion in its geographic range
Blanchong, J. A., M. D. Samuel, K. T. Scribner, B. V. Weckworth, J. A. Langenberg, and K. Filcek. 2007. Landscape genetics and the spatial distribution of chronic wasting disease. Biology Letters. doi:10.1098/rsbl.2007.0523
Conner M. M. et al. 2007. Scale-dependent approaches to modeling spatial epidemiology of chronic wasting disease.
Anderson, J. L. et al. 2007. Mycobacterium avium subsp. paratuberculosis in Scavenging Mammals in Wisconsin. Journal of Wildlife Diseases, 43(2), pp. 302-308.
Samuel, M. D., R. G. Botzler, and G. A. Wobeser. 2007. Avian Cholera. Chapter 12.
Samuel, M. D. and B. J. Richards. 2007. Chronic Wasting Disease in Free-Ranging North American Cervids. Proc. 22nd Vertebr. Pest Conf.
Blanchong, J.A., D.O. Joly, M.D. Samuel, J.A. Langenberg, R.E. Rolley, and J.F. Sausen. 2006. White-tailed deer harvest from the chronic wasting disease zone in south-central Wisconsin. Wildlife Society Bulletin 34:725-731.
Docherty, D.E., M.D. Samuel, C.A. Nolden, K.E. Egstad, and K.M. Griffin. 2006. West Nile Virus Antibody Prevalence in Medium-sized mammals in southern Wisconsin. Emerging Infectious Diseases 12:1978-1980.
Joly D.O., M.D. Samuel, J.A. Langenberg, J.A. Blanchong, C.A. Batha, R.E. Rolley, D.P. Keane, and C.A. Ribic. 2006. Spatial epidemiology of chronic wasting disease in Wisconsin white-tailed deer. Journal of Wildlife Diseases 42:578-588.
Grear, D.A., M.D. Samuel, J.A. Langenberg, and D. Keane. 2006. Demographic patterns and harvest vulnerability of CWD infected white-tailed deer in Wisconsin. Journal of Wildlife Management 70:546-545.
Blanchong, J. A., M. D. Samuel, and G. Mack. 2006. Multi-species patterns of Avian Cholera mortality in Nebraska’s rainwater basin. Journal of Wildlife Diseases, 42(1) pp. 81-91..
Blanchong, J. A., M. D. Samuel, D. R. Goldberg, D. J. Shadduck, and M. A. Lehr. 2006. Persistence of Pasteurella Multocida in wetlands following avain cholera outbreaks. Journal of Wildlife Diseases, 42(1) pp. 33-39.
Blanchong, J. A. et al. 2006. Wetland environmental conditions associated with the risk of Avian Cholera outbreaks and the abundance of pasteurella multocida. Journal of Wildlife Management 70(1).
Woodworth, B. L. et al. 2005. Biocomplexity of introduced Avian Diseases in Hawaii. Threats to biodiversity of native Forest Ecosystems. Fact Sheet
Samuel, M. D., D. J. Shadduck, and D. R. Goldberg. 2005. Avian cholera exposure and carriers in greater white-fronted geese breeding in Alaska, USA. J. Wildlife Disease 41(3) pp. 498-502.
Lehr, M. A., R. G. Botzler, M. D. Samuel, and D. J. Shandduck. 2005. Associations between water quality, pasteurella multocida, and avian cholera at Sacramento National Wildlife Refuge. Journal of Wildlife Diseases, 41(2), pp. 291-297.
Atkinson, C. T., J. K. Lease, R. J. Dusek, and M. D. Samuel. 2005. Prevalence of Pox-like lesions and malaria in forest bird communities on Leeward Mauna Loa Volcano, Hawaii. The Condor 107:537-546.
Samuel, M.D., D.J. Shadduck, D.R. Goldberg, and W.P. Johnson. 2005. Avian cholera in waterfowl: the role of lesser snow and Ross’s geese as disease carriers in the Playa Lakes Region. J. Wildlife Disease 41:48-57.
Ahumada, J.A., D. Lapointe, and M.D. Samuel. 2004. Modeling the Population Dynamics of Culex quinquefasciatus (Diptera: Culicidae), along an Elevational Gradient in Hawaii. J. Med. Entomol. 41(6): 1157-1170.
Goldberg, D. R., M. D. Samuel, T. E. Rocke, K. M. Johnson, and G. Linz. 2004. Could blackbird mortality from avicide DRC-1339 contribute to avian botulism outbreadks in North Dakota? Wildlife Society Bulletin, 32(3):870-880.
Conn, P. B., W. L. Kendall, and M. D. Samuel. 2004. A General Model for the Analysis of Mark-Resight, Mark-Recapture, and Band-Recovery Data under Tag Loss. Biometrics 60, 900-909
Samuel, M. D., D. J. Shadduck, D. R. Goldberg. 2004. Are Wetlands the Reservoir for Avian Cholera? Journal of Wildlife Diseases,40(3), pp. 377-382.
Bollinger, T., P. Caley, E. Merrill, F. Messier, M.W. Miller, M.D. Samuel, and E. Vanopdenbosch. 2004. Chronic Wasting Disease in Canadian Wildlife: An Expert Opinion on the Epidemiology and Risks to Wild Deer. Canadian Cooperative Wildlife Health Centre.
Samuel, M. D., D. J. Shadduck, D. R. Goldberg, M. A. Wilson, D. O. Joly, and M. A. Lehr. 2003. Characterization of Pasteurella Multocida Isolates from Westland Ecosystems During 1996 To 1999. Journal of Wildlife Diseases, 39(4) pp. 798-807
Joly, D.O., C.A. Ribic, J.A. Langenberg, K. Beheler, C.A. Batha, B.J. Dhuey, R.E. Rolley, G. Bartelt, T. Van Deelen, and M.D. Samuel. 2003. Chronic wasting disease in wild Wisconsin white-tailed deer. Emerging Infectious Diseases 9: 599-601. (pdf reprints)
Samuel, M.D., D.O. Joly, M.A. Wild, S.D. Wright, D. Otis, R. Werge, and M. Miller. 2003. Surveillance strategies for detecting chronic wasting disease in free-ranging deer and elk: results of a CWD surveillance workshop, December 10-12, 2002. USGS-National Wildlife Health Center. (pdf version)
Samuel, M. D., D. J. Shadduck, D. R. Goldberg, and W. P. Johnson. 2003. Comparison of Methods to Detect Pasteurella Multocida in Carrier Waterfowl. Journal of Wildlife Diseases 39(1) pp. 125-135.
Ruth, J. M., D. R. Petit, J. R. Sauer, M. D. Samuel, F. A. Johnson, M. D. Fornwall, C. E. Korschgen, and J. P. Bennett. 2003. Science for avian conservation: Priorities for the new millennium. The Auk 120(1): 204-211.
Harvell, C. D., C. E. Mitchell, J. R. Ward, S. Altizer, A. P. Dobson, R. S. Ostfeld, and M. D. Samuel. 2002. Climate warming and disease risks for terrestrial and marine biota. Science. Vol. 296.
Samuel. M. D., D. R. Goldberg, A. E. Smith, V. V. Baranyuk, and E. G. Cooch. 2001. Neckband retention for lesser snow geese in the western arctic. Journal of Wildlife Management. 65(4):797-807.
Samuel, M. D., K. A. Convirse, and K. J. Miller. 2001. Disease mortality events involving Ross’ geese. Pages 33-42 in T. J. Moser, edition. The Status of Ross’s Geese – Report of the Arctic Goose Joint Venture Ross’ Goose Subcommittee.
Kenow, K. P., R. G. Wright, M. D. Samuel, and P. W. Rasmussen. 2001. Integrating SAS and GIS software to improve habitat-use estimates from radiotelemetry data. Wildlife Society Bulletin Vol. 29, no.3, Fall
Samuel, M. D. and E. F. Bowers. 2001. Lead exposure in American black ducks after implementation of non-toxic shot. Journal of Wildlife Management 64(4):947-953.
Rocke, T. E., M. D. Samuel, P. K. Swift, and G. S. Yarris. 2000. Efficacy of a type C botulism vaccine in green-winged teal. Journal of Wildlife Diseases. 36(3).
Samuel. M. D., J. Y. Takekawa, V. V. Baranyuk, and D. L. Orthmeyer. 1999. Effects of avian cholera on survival of lesser snow geese anser caerulescens: an experimental approach. Bird Study. 46 (suppl.), S239-247.
Samuel, M. D., J. Y. Takekawa, G. Samelius, and D. R. Goldberg. 1999. Avian cholera mortality in lesser snow geese nesting on Banks Island, Northwest Territories. 1999. Wildlife Society Bulletin vol. 27, no. 3.
Samuel, M. D., D. J. Shadduck, D. R. Goldberg, V. Baranyuk, L. Sileo, and J. I. Price. 1999. Antibodies against pasteurella multocida in snow geese in the western arctic. Journal of Wildlife Diseases, 35(3), pp. 440-449.
Rocke, T. E. and M. D. Samuel. 1999. Water and sediment characteristics associated with avian botulism outbreaks in wetlands. Journal of Wildlife Management 63(4):1249-1260.
Rocke, T. E., N. H. Euliss, Jr., M. D. Samuel. 1999. Environmental characteristics associated with the occurrence of avian botulism in wetlands of a northern California refuge. Journal of Wildlife Management 63(1):358-368.
Moore, M. K., D. J. Shadduck, D. R. Goldberg, and M. D. Samuel. 1998. A cryopreservation method for pasteurella multocida from wetland samples. Journal of Wildlife Diseases, 34(1), pp. 182-185.
Samuel, M. D., D. R. Goldberg, D. J. Shadduck, J. I. Price, and E. G. Cooch. 1997. Pasteurella multocida serotype 1 isolated from a lesser snow goose: evidence of a carrier state. Journal of Wildlife Diseases, 33(2), pp. 332-335.
Samuel, M. D., D. R. Goldberg, C. B. Thomas, P. Sharp, J. R. Robb, G. L. Krapu, B. N. Nersessian, K. P. Kenow, C. E. Korschgen, W. H. Chipley, and M. J. Conroy. 1996. Exposure of wild waterfowl to mycoplasma anatis. Journal of Wildlife Diseases, 32(2), pp. 331-337.
Korschgen, C. E., K. P. Kenow, W. L. Green, D. H. Johnson, M. D. Samuel, and L. Sileo. 1996. Survival of radiomarked canvasback ducklings in northwestern Minnesota. Journal Wildlife Management, 60(1):120-132.
Korschgen C. E., K. P. Kenow, W. L. Green, M. D. Samuel, and L. Sileo. 1996. Technique for implanting radio transmitters subcutaneously in day-old ducklings. Journal Field Ornithology, 67(3):392-397.
Samuel, M. D., D. R. Goldberg, C. B. Thomas, and P. Sharp. 1995. Effects of mycoplasma anatis and cold stress on hatching success and growth of mallard ducklings. Journal of Wildlife Diseases, 31(2), pp. 172-178.
Goldberg, D. R., M. D. Samuel, C. B. Thomas, P. Sharp, G. L. Krapu, J. R. Robb, K. P. Kenow, C. E. Korschgen, W. H. Chipley, M. J. Conroy, and S. H. Kleven. 1995. The occurrence of mycoplasmas in selected wild north American waterfowl. Journal of Wildlife Diseases, 31(3), pp. 364-371.
DeStefano, S., C. J. Brand, and M. D. Samuel. 1995. Seasonal ingestion of toxic and nontoxic shot by Canada geese. Wildlife Society Bulletin 23:502-506.
Conroy, M. J., M. D. Samuel, and G. C. White. 1995. Journal news. Journal of Wildlife Management 59:196-198.
Samuel, M. D. and M. R. Fuller. 1994 Wildlife Radiotelemetry: equipment and data analysis. Pages 370-418 in Wildlife Management Techniques Manual, 5th edition, T. Bookhout (ed).
Samuel, M. D. and E. O. Garton. 1994. Horvitz-Thompson survey sample methods for estimating large-scale animal abundance. Trans. 59th No. Am. Wildl. & Natur. Resour. Conf.
Sandler, R. J., T. E. Rocke, M. D. Samuel, and T. M. Yuill. 1993. Seasonal prevalence of clostridium botulinum type C in sediments of a northern California wetland. Journal of Wildlife Diseases, 29(4), pp. 533-539.
Samuel, M. D. and K. P. Kenow. 1992. Evaluating habitat selection with radio-telemetry triangulation error. Journal Wildlife Management 56(4):725-734.
Samuel, M. D. 1992. Influence of Disease on a population model of Mid-continent mallards. Trans. 57th N. A. Wildl. & nat. Res. Conf.
Samuel, M. D., E. F. Bowers, and J. C. Franson. 1992. Lead exposure and recovery rates of black ducks banded in Tennessee. Journal of Wildlife Diseases, 28(4), pp. 555-561.
Koford R. R., J. Sauer, D. H. Johnson, J. D. Nichols, and M. D. Samuel. 1992. Stochastic Population Model of Mid-Continental Mallards Pages 170-181 in Wildlfie 2001: Populations, D. R> McCullough and R. H. Barrett (eds). Elsevier Science Publishers, LTD, London, England.
Weiss, N. T., M. D. Samuel, D. H. Rusch, and F. D. Caswell. 1991. Effects of resighting errors on capture-resight estimates for neck-banded. Journal Field Ornithology, 62(4):464-473.
Samuel. M. D., D. H. Rusch, K. F. Abraham, M. M. Gillespie, and J. P. Prevett. 1991. Fall and winter distribution of Canada geese in the Mississippi flyway. Journal Wildlife Management, 55(3):449-456.
Rocke, T. E. and M. D. Samuel. 1991. Effects of lead shot ingestion on selected cells of the mallard immune system. Journal of Wildlife Diseases, 27(1), pp. 1-9.
Rocke, T. E. and M. D. Samuel. 1991. Brain Acetylcholinesterase activity in botulism-intoxicated mallards. Journal of Wildlife Diseases, 27(2), pp. 317-319.
Sileo, L., P. R. Sievert, and M. D. Samuel. 1990. Causes of mortality of albatross chicks at midway atoll. Journal of Wildlife Diseases, 26(3), pp. 329-338.
Samuel, M. D. 1990. Procedures for Publication of computer software. Wildl. Soc. Bull. 18:360.
Samuel, M. D., N. T. Weiss, D. H. Rusch, S. R. Craven, R. E. Trost, and F. D. Caswell. 1990. Neck-Band retention for Canada geese in the Mississippi flyway. Journal Wildlife Management, 54(4):612-621.
Samuel, M. D. and R. E. Green. 1988. A revised test procedure for identifying core areas within the home range. Journal of Animal Ecology, 57, 1067-1068.