Mark Ricca


Dr. Ricca (Mark) is a Wildlife Biologist with the USGS-Western Ecological Research Center. His work focuses broadly to address science needs of resource managers and agencies across a wide range of ecosystems by integrating concepts from population, community, and ecosystem ecology. He works in a diverse array of ecological systems ranging from desert wetlands in California to sub-artic islands in Alaska to sagebrush steppe in the Great Basin. 




2013                Ph.D.   Ecology, University of California, Davis         

2000                M.S.     Wildlife Science, Oregon State University

1995                B.S.     Wildlife, Humboldt State University

1991                A.A.      Biology, Allan Hancock College



2002-present   Wildlife Biologist, USGS Western Ecological Research Center

2000-2002       Biological Science Technician, USGS Western Ecological Research Center

1999                Faculty Research Assistant, Oregon State University

1996-1999       Graduate Research Assistant, Oregon State University

1994-1996              Field Biologist, California Department of Fish and Game



In Press. Ricca MA, AK Miles, DH Van Vuren, VT Eviner. Impacts of introduced Rangifer on maritime-tundra ecosystem processes on sub-arctic islands. Ecosphere.


Provisional. Coates PS, ML Casazza, MA Ricca, BE Brussee, EJ Blomberg, KB Gustafson, D Davis, L Niell, SP Espinosa, SC Gardner, DJ Delehanty. Multiscale Integration of Data Sources to Improve Distribution Modelling for Greater Sage-Grouse. Journal of Applied Ecology.


2015. Starns HD, FW Weckerly, MA Ricca, A Duarte. Vegetation changes associated with a population irruption by Roosevelt elk. Ecology and Evolution. 5:109-120.


2014. Casazza ML, MA Ricca, CT Overton, JY Takekawa, AM Merritt, JT Ackerman. Dietary mercury exposure to endangered California Clapper Rails in San Francisco Bay. Marine Pollution Bulletin. 86:254-260.


2014. Starns HD, MA Ricca, A Duarte, FW Weckerly. Climatic and density influences on recruitement in an irruptive population of Roosevelt elk. Journal of Mammalogy

2014. Ricca, MA, DH Van Vuren, FW Weckerly, JC Williams, AK Miles. Irruptive dynamics of introduced caribou on Adak Island, Alaska: an evaluation of Riney-Caughley model. Ecosphere. 5-94.

2014. Weckerly FW, MA Ricca. Aggression and coexistence in female caribou. Arctic.


2012. Ricca MA, FW Weckerly, A Duarte. Range expansion of nonindigenous caribou in the Aleutian archipelago of Alaska. Biological Invasions. 14:1179-1784.

2012.  Duarte A,  DM Wolcott, TE Chow, MA Ricca. Identifying and prioritizing suitable habitat for the endangered Aleutian shield fern. Journal of Fish and Wildlife Management. 3:303-310.


2010.  Ricca MA, AK Miles, BE Ballachey, JL Bodkin, D Esler, and KA Trust. PCB exposure in sea otters and harlequin ducks in relation to history of contamination by the Exxon Valdez oil spill. Marine Pollution Bulletin. 60:861-872.


2010.  Miles AK, and MA Ricca. Temporal and Spatial Distribution of Sediment Mercury at Salt Pond Wetland Restoration Sites, San Francisco Bay, CA, USA. Science of the Total Environment. 408:1154-1165. 


2009.  Molina KC, MA Ricca, AK Miles, and C Schoneman. Use of a nesting platform by gull-billed terns and black skimmers at the Salton Sea, California. Western Birds. 40:267-277.


2009.  Miles AK, MA Ricca, RG Anthony, and JA Estes. 2009. Organochlorine contaminants in fishes from coastal waters west of Amukta Pass, Aleutian Islands, Alaska. Environmental Toxicology and Chemistry. 28:1643-1654.  


2008.  Ricca MA, AK Miles, and RG Anthony. Sources of organochlorine contaminants and mercury in seabirds from the Aleutian archipelago of Alaska: inferences from spatial and trophic variation. Science of the Total Environment. 406:308-323.


2008.  Anthony RG, JA Estes, MA Ricca, AK Miles, and ED Forsman. Bald eagles and sea otters in the Aleutian Archipelago: Indirect effects of trophic cascades. Ecology. 89:2725-2735.


2007.  Miles AK, PL Flint, KA Trust, MA Ricca, SE Spring, DE Arrieta, T Hollmen, and BW Wilson. Polycyclic aromatic hydrocarbon exposure in Steller’s Eiders and Harlequin Ducks in the eastern Aleutian Islands,Alaska. Environmental Toxicology and Chemistry. 26:2694-2703


2007.  Ricca MA, AK Miles, RG Anthony, X Deng, and SSO Hung. Effect of lipid extraction on analyses of stable carbon and stable nitrogen isotopes in coastal organisms of the Aleutian    archipelago. Canadian Journal of Zoology. 85:40-48.


2007.  Anthony RG, AK Miles, MA Ricca, and JA Estes. Environmental contaminants in bald eagle eggs from the Aleutian archipelago. Environmental Toxicology and Chemistry. 26:1843-1855.     


2004.  Ricca MA, RG Anthony, and JC Williams. Bald Eagles consume Emperor Geese during late-winter in the Aleutian Archipelago. Journal of Raptor Research. 38:81-85.


2004.  Weckerly FW, K McFarland, MA Ricca, and KP Meyer. Roosevelt elk density and social segregation: foraging behavior and females avoiding larger groups of males. American Midland Naturalist. 152:386-399.


2003.  Ricca MA, RG Anthony, DH Jackson, and SA Wolfe. 2003. Spatial use and habitat associations of Columbian white-tailed deer fawns in southwestern Oregon. Northwest Science. 77:72-80.


2003.  Weckerly FW, VC Bleich, CLB Chetkiewicz, and MA Ricca. Body weight and rumen-reticulum capacity in tule elk and mule deer. Journal of Mammalogy. 84:559-664.


2002.  Ricca MA, RG Anthony, DH Jackson, and SA Wolfe. Survival of Columbian white-tailed deer in western Oregon. Journal of Wildlife Management. 66:1255-1266.


2001.  Weckerly FW, MA Ricca, and KP Meyer. Sexual segregation in Roosevelt elk cropping rate and aggression in mixed sex groups. Journal of Mammalogy. 82:825-835.


2001.  Gresswell RE, DS Bateman, and MA Ricca. Patterns of fish distribution at the watershed scale. Wild Trout. 7:195-197.


2000.  Weckerly FW, and MA Ricca. Using presence of sign to measure habitats used by Roosevelt elk. Wildlife Society Bulletin. 28:146-153.


1996.  Ricca MA, FW Weckerly, and RD Semlitsch. Effects of soil moisture and temperature on overwintering survival of Curculio larvae (Coleoptera : Curculionidae). The American Midland Naturalist. 136:203-206.





2014. Coates, PS, ML Casazza, BE Brussee, MA Ricca, KB Gustafson, CT Overton, E Sanchez-Chopitea, T Kroger, K Mauch, L Niell, KB Howe, S Gardner, S Espinosa, DJ Delehanty. Spatially explicit modeling of Greater Sage-Grouse (Centrocercus urophasianus) habitat in Nevada and northeastern California—A decision-support tool for management: U.S. Geological Survey Open-File Report 2014-1163, 84 p.,


2012. Ricca MA, JC Williams, FW Weckerly, VT Tutiakoff.. Aerial survey of barren-ground caribou at Adak and Kagalaska Islands, Alaska in 2012. Data Summary: USGS-Western Ecological Research Center & USFWS Alaska Maritime National Wildlife Refuge Report # AMNWR 2012/03. Davis CA and Homer, AK. 15 pp.


2009.  Miles AK, MA Ricca, A Meckstroth, and SE Spring. Salton sea ecosystem monitoring project. U.S. Geological Survey Open File-Report 2009-1276. 156pp. Available at


2007.  Ricca MA and AK Miles. Gull-billed tern use of the permanent nesting platform in the Salton Sea, California during the 2007 breeding season. Final report to USFWS Migratory Bird Division, Portland OR. 6pp


2005.  Estes JA, RG Anthony, AK Miles, MA Ricca, SL Reese, and WM Jarman. Environmental contaminants in the nearshore ecosystem of the Adak Island and other islands in the Aleutian Archipelago: 199-2002. Final Report To U.S. Navy. USGS-Western Ecological Research Center, Davis CA. 467pp.


2000.  Ricca MA.  Movements, habitat associations, and survival of Columbian white-tailed deer in western Oregon. M.S. Thesis. Oregon State University, Corvallis. 159pp.


1995.  Weckerly FW, and MA Ricca. Developing a reliable population-monitoring program of Roosevelt elk occupying dense coniferous forests. California Department of Fish and Game and Rocky Mountain Elk Foundation Contract no. CA94244. 60pp.