Cooperative Fish and Wildlife Research Units Program: Headquarters
Education, Research and Technical Assistance for Managing Our Natural Resources

Headquarters Research Activities


Northern Pintail Drake at Colusa National Wildlife Refuge

The Cooperative Research Units Program conducts research on a wide range of disciplines related to fish, wildlife, and natural resource management. Our 40 Units collectively conduct research on virtually every type of North American ecological community. Most research projects are carried out by graduate students participating with and/or under the direction of unit or other university scientists. Collectively, the Units typically have more than 1,000 research projects under way and generate 250-300 scientific publications annually.

Unit research may be of local, regional, national, or international interest. The research programs conducted by units are approved as directed by the Coordinating Committee overseeing each unit.

Check out our current and completed research projects by clicking a link below. You can also find a complete list of publications by clicking on the Publications link on the main menu.

Project Completion Date
Fish community response to commercial operation of the Richard September 2007
Fish community response to commercial operation of the Richard B Russell pump-storage hydropower facility on the Savannah River, GA-SC September 2010
Control of sucker spawning migrations in a major tributary of the Gunnison River to increase the production of native sucker larvae September 2021
Assessing attitudes and impacts to society associated with the use of nontoxic ammunition for hunting on National Wildlife Refuges December 2019
Using Genomics to Understand Population Dynamics and Enhance the Management of Canada Lynx Populations in the Contiguous United States December 2019
Comparative Ecology and Conservation of Bears in North and South America December 2020
Research Publications Publication Date
Zhang, Y., Y. Feng, S. Wang, Z. Tang, Z. Zhai, R. Viegut, E. Webb, A. Raedeke and Y. Shang. Deep Learning Models for Waterfowl Detection and Classification in Aerial Images. Information | Abstract March 2024
Wirth, L., A. Rosenberger, A. Prakash, J. Margraf, and T. Hamazaki. 2012. A remote sensing/GIS-based approach to identify and model spawning habitat for fall chum salmon in a sub-arctic, glacially-fed river. Transactions of the American Fisheries Society 141:1349-1363. | Download December 2012
Williams, B.K., R.C. Szaro, and C.D. Shapiro. 2007. Adaptive Management: U.S. Department of the Interior Technical Guide. Adaptive Management Working Group, U.S. Department of the Interior, Washington, D.C. June 2007
Williams, B.K., M.D. Koneff, and D.A. Smith. 1999. Evaluation of waterfowl conservation under the North American Waterfowl Management Plan. Journal of Wildlife Management 63:417-440. | Abstract April 1999
Williams, B.K., M. Eaton, and D.R. Breininger. 2011. Adaptive resource management and the value of information. Ecological Modelling 222:3305-3456. September 2011
Williams, B.K. and J.D. Nichols. 2001. Systems identification and the adaptive management of waterfowl in the United States. Wildlife Biology 7:129-142. | Abstract September 2001
Williams, B.K. 2011. Resolving structural uncertainty in natural resources management using POMDP approaches. 222:1092-1102. | Abstract March 2011
Williams, B.K. 2011. Passive and active adaptive management: Approaches and an example. Journal of Environmental Management 92:1371-1378. | Abstract May 2011
Williams, B.K. 2011. Adaptive management of natural resources: Framework and issues. Journal of Environmental Management 2011:1346-1353. | Abstract May 2011
Williams, B.K. 2009. Markov decision processes in natural resources management: Observability and uncertainty. Ecological Modelling 220:830-840. | Abstract March 2009
Williams, B.K. 2007. Optimal management of non-Markovian biological populations. Ecological Modelling 200:234-242. | Abstract January 2007
Williams, B.K. 2006. Adaptive harvest management: where we are, how we got here, and what we've learned thus far. Transactions, North American Wildlife and Natural Resources Conference 71. June 2006
Williams, B.K. 2003. Policy, research, and adaptive management in avian conservation. The Auk 120:212-217. January 2003
Williams, B.K. 2003. A research agenda for bird conservation. Transactions, North American Wildlife and Natural Resources Conference 68: 304-311. June 2003
Williams, B.K. 2001. Uncertainty, learning, and optimization in wildlife management. Environmental and Ecological Statistics 8:269-288. | Abstract September 2001
Williams, B.K. 2000. Perspectives on regulation of the sport harvest of wildlife. Transactions, North American Wildlife and Natural Resources Conference 65:61-64. June 2000
Williams, B. K., and J. D. Nichols. 2001. Systems identification and the adaptive management of waterfowl in theUnited States. Wildlife Biology 7:129-142. September 2001
Williams, B. K., M. D. Koneff, and D. A. Smith. 1999. Evaluation of waterfowl conservation under the north american waterfowl plan. Journal of Wildlife Management. 63(2):417-440. January 2000
Williams, B. K., J. D. Nichols, and M. J. Conroy. 2002. Analysis and management of animal populations. Academic Press. April 2002
Williams, B. K., J. D. Nichols, and M. J. Conroy. 2002. Analysis and management of animal populations. Academic Press . April 2002
Williams, B. K. 2001. Uncertainty, learning, and the optimal management of wildlife. Env. Ecol. Stat. 8:269-288 June 2001
Williams, B. K. 2000. Perspectives on regulation of the sport harvest of wildlife. North American Wildlife and Natural Resources Conference 65:61-64. November 2000
White, H. B., T. Decker, M.J. O’Brien, J.F. Organ and N. M. Roberts. 2015. Trapping and furbearer management in North American wildlife conservation, International Journal of Environmental Studies, DOI: 10.1080/00207233.2015.1019297 March 2015
Viegut, R.A., E.B. Webb, A.H. Raedeke, Z. Tang, Y.Zhang and Y. Shang. Nonbreeding waterfowl behavioral response to crewed and uncrewed aerial surveys on conservation areas in Missouri. Journal of the Southeastern Association of Fish and Wildlife Agencies | Abstract June 2024
Viegut, R.A., E.B. Webb, A.H. Raedeke, Z. Tang, Y. Zhang, Z. Zhai, Z Liu, S. Wang J. Zheng and Y. Shang. Detection probability and bias in machine-learning-based unoccupied aerial system non-breeding waterfowl surveys. Drones | Abstract February 2024
Verheijen, B.H.F., E.B. Webb, M.G. Brasher and H.M. Hagy. 2024. Spatiotemporal dynamics of waterfowl harvest distributions in the Central and Mississippi Flyways from 1960–2019. The Journal of Wildlife Management February 2024
Verheijen, B.H.F., E.B. Webb, M.G. Brasher and H.M. Hagy. 2024. Long-term changes in autumn-winter harvest distributions vary among duck species, months, and subpopulations. Ecology and Evolution June 2024
Szaro, R.C. and B.K. Williams. 2008. Climate change: Environmental effects and management adaptations. In: Fenech, A., D. MacIver, and F. Dallmeier (eds.). Climate Change and Biodiversity in the Americas. Environment Canada, Toronto, Ontario. February 2008
Stolarski, J. T, F. J. Margraf, J. G. Carlson, and T. M. Sutton. Lipid and moisture content modeling of amphidromous Dolly Varden Char using bioelectrical impedance analysis. North American Journal of Fisheries Management. 34:471-481. April 2014
Snyder, S., C.S. Loftin, and A.S. Reeve. 2023. Predicting the presence of Groundwater Influenced Ecosystems in the northeastern United States with ensembled correlative distribution models. Water. 15, 4035. https://doi.org/10.3390/w15234035 November 2023
Snyder, S., C.S. Loftin, A.S. Reeve. Vulnerability assessment of groundwater influenced ecosystems in the Northeastern United States. Water, 2024, 16, 1366. https://doi.org/10.3390/w16101366 May 2024
Rolek, B.W., D.J. Harrison, D.W. Linden, C.S. Loftin, P.B. Wood. 2021. Habitat associations of breeding conifer-associated birds in managed and regenerating forested stands. Forest Ecology and Management. October 2021
Rogosch, J.S., H.I.A. Boehm, R.W. Tingley, K.D. Wright, E.B. Webb, C.P. Paukert. 2024. Evaluating effectiveness of restoration to address current stressors to riverine fish. Freshwater Biology, 69, 607-622. https://doi.org/10.1111/fwb.14232 | Abstract May 2024
Rayl, N.D., T.K. Fuller, J.F. Organ, J.E. McDonald, Jr., R.D. Otto, G. Bastille-Rousseau, C.E. Soulliere and S.P. Mahoney. 2015. Spatiotemporal variation in the distribution of potential predators of a resource pulse: black bears and caribou calves in Newfoundland. Journal of Wildlife Management 79(7): 1041-1050. August 2015
Powell, L.A., A.J. Tyre, M.J. Conroy, J.T. Peterson, and B.K. Williams. 2011 Integrating adaptive management into wildlife curricula. The Wildlife Professional 5(2): 74-76. April 2011
Oyler-McCance, S.J., Ryan, M.J., Sullivan, B.K. et al. Genetic connectivity in the Arizona toad (Anaxyrus microscaphus): implications for conservation of a stream dwelling amphibian in the arid Southwestern United States. Conserv Genet (2024). https://doi.org/10.1007/s10592-024-01606-w | Abstract | Download | Publisher Website March 2024
Organ, John F., and R.E. McCabe. 2018. History of state wildlife management and conservation. Chapter 1, pages 1 - 23 in T.J. Ryder, editor, State Wildlife management and Conservation. Johns Hopkins University Press, Baltimore, Maryland, USA. LCCN 2017017327 February 2018
Organ, J.F., T.A. Decker, and T.M. Lama. 2016. The North American model and captive cervid facilities-what is the threat? Wildlife Society Bulletin 40(1):10-13 March 2016
Organ, J.F. The North American model of wildlife conservation and wild turkey management: the future. Pages 19-23 in D.E. Miller, editor, Proceedings of the eleventh national wild turkey symposium. Allen Press, Lawrence, Kansas, USA. | Abstract December 2015
Organ, J.F. 2018. The North American model of wildlife conservation and the public trust doctrine. Chapter 13, pages 125 – 135 in B.D. Leopold, W.B. Kessler, and J.L. Cummins, eds., North American Wildlife Policy and Law. Boone and Crockett Club, Missoula, Montana, USA. DOI 10: 111234 August 2018
Organ, J.F. 2018. Federal aid in wildlife and fisheries conservation. Chapter 16, pages 163-175 in B.D. Leopold, W.B. Kessler, and J.L. Cummins, eds., North American Wildlife Policy and Law. Boone and Crockett Club, Missoula, Montana, USA. DOI: 10: 198765 August 2018
Organ, J.F. 2016. Book Review: Inside the Equal Access to Justice Act: Environmental Litigation and the Crippling Battle over America's Lands, Endangered Species, and Critical Habitats. Journal of Wildlife Management 80: early view June 2016
Nichols, J.D., M.D. Koneff, P.J. Heglund, M.G. Knutson, M.E. Seamans, J.E. Lyons, J.M. Morton, M.T. Jones, G.S. Boomer, and B.K. Williams. 2011. Climate change, uncertainty, and natural resource management. Journal of Wildlife Management 75:6-18. | Abstract January 2011
Nichols, J.D., M.C. Runge, F.A. Johnson, and B.K. Williams. 2007. Adaptive harvest management of North American waterfowl populations: A brief history and future prospects. Journal of Ornithology 148:S343-S349. | Abstract December 2007
Nichols, J.D. and B.K. Williams. 2006. Monitoring for conservation. Trends in Ecology and Evolution 21:668-673. | Abstract December 2006
Nichols, J. D., M. C. Runge, et al. 2006. Adaptive Harvest Management of North American Waterfowl Populations - Recent Successes and Future Prospects. Journal of Ornithology 147(5): 28-28. August 2006
Nestler, J. M., R. A. Goodwin, T. M. Cole, D. Degan, and D. Dennerline. 2002. Simulating movement patterns of blueback herring in a stratified southern impoundment. Transactions of the American Fisheries Society 131:55-69. January 2002
Nathaniel D. Rayl, Guillaume Bastille-Rousseau, John F. Organ, Matthew A. Mumma, Shane P. Mahoney, Colleen E. Soulliere, Keith P. Lewis, Robert D. Otto, Dennis L. Murray, Lisette P. Waits, and Todd K. Fuller. 2018. Spatiotemporal heterogeneity in prey abundance and vulnerability shapes the foraging tactics of an omnivore. Journal of Animal Ecology. DOI: 10.1111/1365-2656.12810 | Abstract March 2018
Mumma, M.A., J.D. Holbrook, N.D. Rayl, C.J. Zieminski, T.K. Fuller, J.F. Organ, S.P. Mahoney, and L.P. Waits. 2017. Examining spatial patterns of selection and use for an altered predator guild. Oecologia DOI 10.1007/s00442-017-3971-8 | Abstract October 2017
McGowan CP, Price Tack JL, Silvano A, Grand JB, In Review, Models for managing harvests to maintain deer and hunter populations, Review initiated, intended outlet, WIldlife Society Bulletin September 2023
Mason, J.R., L. Carpenter, M. Cox, J. Devos, J. Fairchild, D. Freddy, J.R. Heffelfinger, R. Kahn, S, McCorquodale, D. Pac, D. Summers, G.C. White, and B.K. Williams. 2006. The case for ungulate survey analysis and data management. Wildlife Society Bulletin 34(4):1238-1242. November 2006
Loman, Z., C.S. Loftin, C. Spiegel, and R. Boettcher. Trends in Atlantic Flyway Breeding Colony Sizes for Five Colonial Waterbird Species. CSS 155-2024. February 2024
La Peyre MK, Sable S, Marshall DA, Irwin E, Hanson C. The use of conceptual ecological models to identify critical data and uncertainties to support numerical modeling:The northern Gulf of Mexico eastern oyster (Crassostrea virginica) example. Marine and Coastal Fisheries: Dynamics, Management, and Ecosystem Science. 204;16:e10297 https://doi.org/10.1002/mcf2.10297. | Abstract May 2024
Julien Martin, Matthew S. Richardson, Davina L. Passeri, Nicholas M. Enwright, Simeon Yurek, James G. Flocks, Mitch J. Eaton, Sara L. Zeigler, Hadi Charkhgard, Bradley J. Udell, Elise R. Irwin. Decision science as a framework for combining geomorphological and ecological modeling for the management of coastal systems. Ecology and Society. April 2023
Johnson, F.A., and B.K. Williams. 1999. Protocol and practice in the adaptive management of waterfowl harvests. Conservation Ecology 3(1): 8. [online] URL: http://www.consecol.org/vol3/iss1/art8/ June 1999
Johnson, F., and K. Williams. 1999. Protocol and practice in the adaptive management of waterfowl harvests. Conservation Ecology. 3(1):8. [online] URL: http://www. consecol. org/vol3/iss1/art8 January 2000
Jennings, C. A., M. Allen, C. Belcher, R. Bringolf, D. Dennerline, T. Goar, K. Kuklinski, J. Long, P. Mazik, D. Riecke, and M. Rogers. Congratulations on Your Promotion to Management: Considerations for New Supervisory Biologists. 2020. Journal of the Southeastern Association of Fish and Wildlife Agencies 7:103-113. | Abstract | Publisher Website March 2020
Irwin, E, R. Ramesh and A. Alam 2022. Oyster restoration: acknowledgement of uncertainty and lessons learned for future decision-making. U.S. Department of Interior, Fish and Wildlife Service, Cooperator Science Series FWS/CSS-XXX-2022, Washington, D.C. March 2022
Hossack, Blake R., Oja, Emily B., Owens, Audrey K., Hall, David, Cobos, Cassidi, Crawford, Catherine L., Goldberg, Caren S., et al. 2023. “ Empirical Evidence for Effects of Invasive American Bullfrogs on Occurrence of Native Amphibians and Emerging Pathogens.” Ecological Applications 33(2): e2785. https://doi.org/10.1002/eap.2785 | Abstract | Publisher Website December 2022
Hossack, B. R., Hall, D., Crawford, C. L., Goldberg, C. S., Muths, E., Sigafus, B. H., & Chambert, T. (2023). Successful eradication of invasive American bullfrogs leads to coextirpation of emerging pathogens. Conservation Letters, 00, e12970. https://doi.org/10.1111/conl.12970 | Abstract | Download | Publisher Website July 2023
Horne, L., DeVries, D, Wright, R, Irwin, E, Staton, B, Abdelrahman, H, Stoeckel, J. 2022. Effects of increasing temperature on the potential metabolic activity of seven Alabama fishes. Submitted to: Experimental Zoology-A. October 2022
Hightower, J.E., W.J. Fleming and M.A. Hayman. 1999. Effects of contaminated sediments on brown bullhead condition, growth, and mortality in a North Carolina tidal creek. Proc. Catfish 2000 Symposia. January 1999
Goguen, A.D., S.J. Riley, J.F. Organ, and B.A. Rudolph. 2017. Wild-harvested venison yields and sharing by Michigan deer hunters. Human Dimensions of Wildlife DOI: 10.1080/10871209.2017.1409372 | Abstract | Download | Publisher Website December 2017
Freeman, MC, KR Bestgen, D Carlisle, EA Frimpong, NR Franssen, KB Gido, ER Irwin, Y Kanno, C Luce, SK McKay, MC Mims, JD Olden, NL Poff, DL Propst, L Rack, AH Roy, E Stowe, A Walters, and SJ Wenger. 2022. Towards improved understanding of streamflow effects on freshwater fishes. Fisheries 47:290-298. https://doi.org/10.1002/fsh.10731 | Download | Publisher Website March 2022
Fogelman, Kaelyn, Archambault, Jennifer, Irwin, Elise, Maureen Walsh, Brewer, Shannon, and Stoeckel, James A. 2023. A review of lethal thermal tolerance among freshwater mussels (Bivalvia: Unionida) within the North American faunal region. Environmental Reviews https://doi.org/10.1139/er-2022-0077 January 2023
Flammang, M. K., D. E. Shoup, P. H. Michaletz, and K. L. Pope. 2009. Warmwater fish in small standing waters. Pages 23-43 in S. A. Bonar, N. Mercado-Silva, and K. L. Pope, editors. Standard methods for sampling North American freshwater fishes, 2nd edition. American Fisheries Society, Bethesda, Maryland. September 2024
Duda, M.D., T. Beppler, and J.Organ. 2017. The growth of sport shooting participation: what does this mean for conservation revenue? The Wildlife Professional 11(2): 38-41. | Download March 2017
Du Clos, B., F.A. Drummond, and C.S. Loftin. Effects of an early mass‑flowering crop on wild bee communities and traits in power line corridors vary with blooming plants and landscape context. Landscape Ecology; https://doi.org/10.1007/s10980-022-01495-9 August 2022
Dennerline, D.E., C.A. Jennings, and D.J. Degan. 2012. Relationships between hydroacoustic derived density and gill net catch: Implications for Fish Assessments. Fisheries Research 123-124: 78-89. | Abstract | Publisher Website July 2012
Dennerline, D. E., and M. J. Van Den Avyle. 2000. Sizes of prey consumed by two pelagic predators in US reservoirs: implications for quantifying biomass of available prey. Fisheries Research 45:147-154. | Publisher Website March 2000
Decker, D.J., J.F. Organ, A.B. Forstchen, M.V. Schiavone, and A.K. Fuller. 2018. Wildlife management is science based: myth or reality? The Wildlife Professional 12(4): 30-32. July 2018
Decker, D.J., J.F. Organ, A.B. Forstchen, C.A. Jacobson, W.F. Siemer, C.A. Smith, P.E. Lederle, and M.V. Schiavone. 2017. Wildlife governance in the 21st century - will sustainable use endure? Wildlife Society Bulletin 41:821-826. DOI10.1002/wsb.830 | Abstract | Download December 2017
Decker, D.J., A.B. Forstchen, E.F. Pomeranz, C.A. Smith, S.J. Riley, C.A. Jacobson, J.F. Organ, and G.R. Batcheller. 2015. Stakeholder engagement in wildlife management: does the public trust doctrine imply limits? J. Wildl. Manage. 79:174-179. February 2015
Decker, D., C. Smith, A. Forstchen, D. Hare, E. Pomeranz, C. Doyle-Capitman, K. Schuler, and J. Organ. 2016. Governance principles for wildlife conservation in the 21st century. Conservation Letters. DOI: 10.1111/conl.12211 | Abstract | Download January 2016
Counihan, T.D., K.L. Bouska, S.K. Brewer, R. Jacobson, A.F. Casper, C.G. Colin, I.R. Waite, K. Sheehan, M. Pyron, E. Irwin, K. Riva-Murray, A. McKerrow, and J. Bayer. 2022. Identifying monitoring information needs that support the management of fish in large rivers. PLoS ONE 17(4): e0267113. https://doi.org/10.1371/journal.pone.0267113 April 2022
Buck, J.M. and B.K. Williams. 1999. Expenditures and opinions of Vermont residents participating in nonconsumptive wildlife-based recreation. Transactions, North American Wildlife and Natural Resources Conference 64:484-493. June 1999
Buck, J. M., and B. K. Williams. 1999. Expenditures and opinions of vermont residents participating in nonconsumptive wildlife-based recreation. Trans. No. Amer. Wildl., and Natur. Resour. Conf. 64:484-493. January 2000
Boxler, B., C.S. Loftin, and W.B. Sutton. Monarch Butterfly (Danaus plexippus) Roost Site-Selection Criteria and Locations East of the Appalachian Mountains. Journal of Insect Behavior. Journal of Insect Behavior https://doi.org/10.1007/s10905-023-09844-5. February 2024
Bissonette, J. A., C. S. Loftin, D. M. Leslie, Jr., L. A. Nordstrom, and W. J. Fleming. 2000. The cooperative research unit program and wildlife education: historic development, future challenges. Wildlife Society Bulletin 28:534-541. November 2000
Berry, C.R., D.E. Dennerline and R. Rulifson. 2013. Safety: Skills, Attitudes, Facts, and Equipment. In: Zale, A., D. Parrish and T. Sutton (eds.). Fisheries Techniques, 3rd Edition. American Fisheries Society, Bethesda, MD. January 2013
Presentations Presentation Date
Wirth, L., A. Rosenberger, A. Prakash, R. Gens, F.J. Margraf, and T. Hamazaki. A remote-sensing, GIS-based approach to identify spawning habitat for fall chum salmon in a Sub-Arctic, glacially-fed river. Oral Presentation given to the Alaska Chapter of the American Fisheries Society. October 2013
Winkelman, D. L., W. L. Kendall, and M. C. Dzul. 2019. Introduction to the symposium on the use of autonomous PIT tag antennas for modeling vital rates and movement. American Fisheries Society and The Wildlife Society 2019 Joint Annual Conference, Reno, Nevada, 29 Sep - 3 Oct 2019. October 2019
Williams, J., L. Webb, and J. Spurgeon. River-Floodplain Connectivity: Effects on Ecological Communities in Restored Wetlands along the Lower Missouri River. Midwest Fish & Wildlife Conference, January 2025. January 2025
Williams, J., L. Webb and J. Spurgeon. Impacts of River-Floodplain Connectivity on Biotic Communities in Restored Wetlands within the Missouri River Floodplain. Missouri Natural Resources Conference, February 2024 February 2024
Weller, F., E.B. Webb, W. Beatty, S. Fogenburg, D Kesler, R. Blenk, K. Ringelman, M. Miller and J. Eadie. 2024. Informing waterfowl conservation planning with an agent-based model: quantifying mallard response to wetland composition and configuration. 9th North America Duck Symposium, Portland Oregon. February 2024
Vogel, S.K., Loftin, C., Zydlewski, J.D. Investigating the scientific networks of the Maine CRU. [poster] Maine Cooperative Fish and Wildlife Research Unit Annual Meeting. July 12, 2022. Orono, ME. July 2023
Vogel, S.K., Loftin, C., Zydlewski, J.D. A (very) brief history of the Cooperative Research Units Program. [oral, invited keynote] Maine Cooperative Fish and Wildlife Research Unit Annual Meeting. July 12, 2022. Orono, ME. July 2023
Vogel, S., Loftin, C., and Zydlewski, J. 2021 A collaborative organizational network analysis of the Cooperative Research Units program. 151st Annual Meeting of the American Fisheries Society. Baltimore, MD. November 6. November 2021
Vogel, S., Loftin, C., and Zydlewski, J. (2022) Collaboration networks within the CRU program. 152st Annual Meeting of the American Fisheries Society. Spokane, WA. August 2022
Vogel, S., Loftin, C., and Zydlewski, J. (2022) A Collaborative Organizational Network Analysis of the Cooperative Research Units Program. 2022 Atlantic Salmon Ecosystems Forum. January 11. University of Maine, Orono, Maine. January 2022
Vogel, S., C.S. Loftin, and J. Zydlewski. 2021. A Collaborative Organizational Network Analysis of the Cooperative Research Units Program. the Wildlife Society Annual Meeting, 1-5 November, virtual format. November 2021
Viegut, R., Webb, E., Raedeke, A., Zhang, Y.,Tang, Z., Zhai, Z., Wang, S., Liu, Z., and Shang, Y. 2023. An Integrated System of Drones and Artificial Intelligence for Estimating Non-Breeding Waterfowl Abundance. Oral presentation at the North American Duck Symposium, Portland Oregon. February 2024
Verheijen, B.H.F., E.B. Webb, M.G. Brasher, and H.M. Hagy. 2024. Factors driving longterm changes in duck harvest distributions in the Central and Mississippi Flyways. The 85th Midwest Fish & Wildlife Conference. St. Louis, Missouri, 19-22 January 2025. January 2025
Verheijen, B.H.F., E.B. Webb, M.G. Brasher, and H.M. Hagy. 2024. Factors driving long-term changes in duck harvest distributions in the Central and Mississippi Flyways. The 9th North American Duck Symposium. Portland, Oregon, 5-9 February 2024. February 2024
Trowbridge, J., D. R. Diefenbach, T. A. Marques, T. M. McConnell, A. Van Buskirk, C. S. Rosenberry, W. D. Walter, and K. Lamp. Accounting for animal density gradients in distance sampling surveys. Southeast Deer Study Group Meeting, February 2024, Shepherdstown, WV. February 2024
Trowbridge, J., D. R. Diefenbach, T. A. Marques, T. M. McConnell, A. Van Buskirk, C. S. Rosenberry, W. D. Walter, and K. Lamp. Accounting for animal density gradients in distance sampling surveys. Pennsylvania Chapter of The Wildlife Society, March 2024, State College, PA March 2024
Tripp, H., R.A. Gitzen, A.L. Silvano, and J.B. Grand. 2017. Individual-based modeling to project viability of gopher tortoise populations under alternative management scenarios: a case study with two Alabama wildlife management areas. 71st Annual Conference of Southeastern Association of Fish and Wildlife Agencies. Louisville, KY, October 29-November 1, 2017, October 2018
Sweeney, C., E. Webb, J. Steevens and A. Messerman. Quantifying neonicotinoid concentrations and toxicity thresholds in aquatic macroinvertebrates: implications for wetland-dependent wildlife. Poster presentation at the 9th North American Duck Symposium. Portland Oregon, February 5-9, 2024 February 2024
Sweeney, C., E. Webb, J. Steevens and A. Messerman. Quantifying Clothianidin Persistence and Stability in Missouri Freshwater Sediments. Presentation at the Society of Environmental Toxicology and Chemistry Conference, Oct 23, 2024 October 2024
Stored information for travel access February 2024
Stewart, B.D., C.E. Moore, and J.B. Grand. 2019. Automated techniques for interpreting game camera images from surveys for Eastern Wild Turkeys. This is Auburn. February 2019
Stewart, B.D., C.E. Moore, and J.B. Grand. 2018. Automated techniques for interpreting game camera images from surveys for Eastern Wild Turkeys. 72nd SEAFWA Annual Conference. Mobile, AL October 28-30. October 2018
Stewart BD, Moore CE, and Grand JB. 2019. Determining Eastern Wild Turkey population response to 9-day delay in spring harvest season. SEAFWA, Hilton Head, South Carolina 27-30 October 2019 October 2019
Stewart BD, Moore CE, and Grand JB. 2019. Automated techniques for interpreting game camera images from surveys for Eastern Wild Turkeys. SEAFWA Hilton Head, SC, 27-30 October 2019 October 2019
Stewart BD, Moore CE, and Grand JB. 2019. Automated techniques for interpreting game camera images from surveys for Eastern Wild Turkeys. October 2019
Snyder, S., C.S. Loftin, and A.S. Reeve. 2023. Vulnerability assessment of groundwater influenced ecosystems in the northeastern United States. Northeast Association of Fish and Wildlife Agencies annual conference, April 30 - May 2., Hershey, PA. Oral presentation. April 2023
Snyder, S., C.S. Loftin, and A.S. Reeve. 2021. Predicting Probability of Groundwater Discharge to Stream Ecosystems with Landscape Variables in Maine, USA. Presentation at the Annual Meeting of the American Fisheries Society, Baltimore, MD, 6-10 November. November 2021
Snyder, S., C.S. Loftin, A.S. Reeve. 2022. Predicting the presence of Groundwater Influenced Ecosystems in the northeastern United States with ensembled correlative distribution models. The Maine Chapter of the Wildlife Society Meeting, 2 December, Orono, ME. December 2022
Snyder, S., C.S. Loftin, A.S. Reeve. 2022. Predicting the Presence of Groundwater Influenced Streams and Wetlands in the Northeastern US with Correlative Distribution Models with an Ensemble Approach. The American Fisheries Society Annual Meeting, 21-25 August, Spokane, WA. August 2022
Snyder, S., C. Loftin, and A Reeve. 2023. Identification of Groundwater Influenced Ecosystems. Maine Department of Inland Fisheries and Wildlife, Fisheries Division Annual Meeting, 13 September, Millinocket, ME. September 2023
Ruiz, J, D. Dennerline, D. Degan, W. Jabour, C. A. Jennings. 2008. Are blueback herring distributed within desired habitat during summer stratification? Annual Meeting of the GA Chapter - American Fisheries Society. Jan. 29-31. Eatonton, GA. January 2008
Rogosch, J.S., H.I.A Boehm, R.W. Tingley III, K.D. Wright, E.B. Webb, and C.P. Paukert. 2024. Are river restoration projects designed and evaluated to address current stressors to inland fishes? World Fisheries Congress, Seattle WA. Mar 3 - 7, 2024 March 2024
Rogosch, J. H. Boehm, R. Tingley, K. Wright, E. Webb, and C. Paukert. 2024. Are river restoration projects designed and evaluated to address current stressors to inland fishes? American Fisheries Society Annual Meeting, Honolulu, HI. September 2024
Radigan, W., M. Pegg, C. Longhenry, C. Goble, and K. L. Pope. 2024. Walleye and sauger acoustic telemetry in a mainstem Missouri River reservoir. 154th annual meeting, America Fisheries Society, Honolulu, Hawaii. September 2024
Ouimet, A., Vogel, S.K., Loftin, C., Zydlewski, J.D. Investigating collaborative networks: A Maine Co-op case study. [poster] Maine Cooperative Fish and Wildlife Research Unit Annual Meeting. July 12, 2022. Orono, ME. July 2023
Njuguna, E., C. Murphy, C. Loftin, M. Hunter, D. Courtemanch, S. Horn, and P. Njoroge. 2022. Developing a Biotic Index for the Upper Tana Watershed, Kenya, using Community Science. Annual Meeting of the Association of Field Ornithologists, Plymouth, MA, 17-21 October. October 2022
Njuguna, E. Murphy, C.A., Loftin, C., Hunter, M., McGill, B., Courtemanch, D., Njoroge, P. 2024. Bridging community science and standardized bird-based biotic indices to advance watershed monitoring. Presentation to Society for Freshwater Science Annual Meeting. Philadelphia, PA. June 2024
Mercado-Silva, N., K. L. Pope, and S. A. Bonar. 2024. AFS Standard methods for sampling freshwater fish: International collaboration for method implementation. 154th Annual Meeting of the American Fisheries Society, September 15-19, 2024. Honolulu, ​Hawaii.

September 2024
Mercado-Silva, N., K. L. Pope, and S. A. Bonar. 2024. AFS Standard Methods for Sampling Freshwater Fish: International Collaboration for Method Implementation. 154th Annual Meeting of the American Fisheries Society, September 15-19, 2024, Honolulu, Hawaii.

September 2024
McGowan CP, Price Tack JL, Grand JB, 2024. Models for linking hunter retention and recruitment to regulations and game populations, Wildlife Society Annual Meeting, Baltimore, MD, October 2024 October 2024
Margraf, F.J., K.J. Hartman, and A. Hafs. BIA: does it work or not? September 2013
Margadant, LE, CE Moore, and JB Grand. 2019. Habitat Selection by Female Eastern Wild Turkeys in Alabama. Southeastern Association of Fish and Wildlife Agencies, Hilton Head, South Carolina. 27-30 October 2019. October 2019
Margadant, LA,, Grand, JB, Stewart, BD, Keller, SR, and Moore, CE. 2019. March 2019
Margadant, L.A., C.E. Moore, and J.B. Grand. 2018.The effect of baited camera stations on eastern wild turkey home range and movement. 72nd SEAFWA Annual Conference. Mobile, AL October 28-30. October 2018
Lewis, M.A., L.R. Kline, L. Maher, D.H. Hayes, Identifying and C.S. Loftin. Quantifying Uncertainty in Manual Interpretations of Aerial Imagery of Seabird Nesting Islands. Oral presentation, American Ornithological Society and Birds Caribbean Joint Conference, 27 June - 2 July, San Juan, PR. June 2022
Leach, B., E. Webb, W. Beatty and P. Link. 2024. Non-breeding habitat selection of Blue-winged teal throughout the Central and Mississippi Flyways. 9th North American Duck Symposium, Portland Oregon, February 5-9, 2024. February 2024
Lama, T., J. Organ, S. DeStefano, and W. Johnson. 2018. Conservation genomics of Canada lynx. 70th Anniversary Meeting of the Massachusetts Unit, Westborough, MA. May 2018
Kline, L.R., M.A. Lewis, M. Brown, L. Maher, A. Revello, R.M. Turner, D.J. Hayes , and C.S. Loftin. 2022. Uncertainties in Artificial Intelligence Classifications of Colonial Nesting Seabirds in Plane-based Imagery. Northeast Natural History Conference, 22-24 April, Albany, NY. April 2022
Kline, L. R., Lewis, M. A., Brown, M., Maher, L., Revello, A., Turner, R. M., Hayes, D. J., & Loftin, C. S. 2022. It's a bird! It's a buoy! Uncertainties in artificial intelligence classifications of colonial seabirds in plane-based imagery. Oral presentation, American Ornithological Society and Birds Caribbean Joint Conference, 27 June - 2 July, San Juan, PR. June 2022
Kendall, W. L., D. L. Winkelman, M. C. Dzul, and C. B. Yackulic. 2019. Estimating vital rates and movement using autonomous PIT tag antennas: a design and analysis framework. American Fisheries Society and The Wildlife Society 2019 Joint Annual Conference, Reno, NV. October 2019
Keller, SR, CE Moore, and JB Grand. 2019. Comparing camera survey designs for monitoring eastern wild turkey populations. Southeastern Association of Fish and Wildlife Agencies, Hilton Head, South Carolina. 27-30 October 2019. October 2019
Keller, S.R., C.E. Moore, and J.B. Grand. 2018. Comparing camera survey designs for monitoring eastern wild turkey populations. 72nd SEAFWA Annual Conference. Mobile, AL October 28-30. October 2018
K. J. Fogelman, K. Coffman, J. Archambault, E. Irwin, M. Walsh, S. Brewer, and J. A. Stoeckel. A review of temperature, hypoxia, conductivity, and agricultural contaminant stressors to freshwater mussels. American Malacology Society 2023, Tuscaloosa, Alabama August 2023
K. J. Fogelman, K. Coffman, J. Archambault, E. Irwin, M. Walsh, S. Brewer, and J. A. Stoeckel. A REVIEW OF TEMPERATURE AND HYPOXIA STRESSORS TO FRESHWATER MUSSELS. FMCS 2023, Portland, OR April 2023
Guy, H., Vogel, S.K., Loftin, C., Zydlewski, J.D. Do state natural resource agencies prioritize DEI messaging? [poster] Maine Cooperative Fish and Wildlife Research Unit Annual Meeting. July 12, 2022. Orono, ME. July 2023
Grand, James B. 2019. Alabama Turkey Research Project Update. Full Fans and Sharp Spurs. Alabama Department of Conservation and Natural Resources. December 2018
Gingery, T.M., and Diefenbach, D.R. 2022. Fawn Survival Patterns: looking beyond predators.7-11 November 2022, The Wildlife Society Annual Meeting, Spokane, WA. November 2022
Fogelman, Kaelyn J., Susan Fuller, Jennifer Archambault, Elise Irwin, Maureen Walsh, Shannon Brewer, and James A. Stoeckel. A Review Of Temperature, Hypoxia, And Other Water Quality Stressors To Freshwater Mussels. Alabama Water Resources Conference, September 2023 September 2023
Fogelman, K, J. A. Archambault, E. Irwin, M. Walsh, S. Brewer, and J. A. Stoeckel. 2022. A review of North American freshwater mussel lethal thermal tolerance. Joint Aquatic Sciences Meeting, Grand Rapids. May 2022
Fleming, W.J. and D.R. Petit. September, 2000. Fluoride concentrations and effects on birds nesting near an aluminum reduction facility in Tennessee. The Wildlife Society 7th Annual Conference. Nashville, TN. September 2000
Flammang, M., D. Shoup, P. Michaletz, and K. L. Pope. 2024. Standard methods for sampling North American freshwater fishes, warmwater fish, small standing water. . 154th annual meeting, America Fisheries Society, Honolulu, Hawaii. September 2024
Flammang, M., D. Shoup, P. Michaletz, and K. L. Pope. 2024. Standard methods for sampling North American freshwater fishes, warmwater fish, small standing water. . 154th annual meeting, America Fisheries Society, Honolulu, Hawaii (poster). September 2024
Falconi, N., J. Organ, and S. DeStefano. 2018. Value of data sharing for conservation of the spectacled bear in Peru. Ecological Society of America, New Orleans, LA. August 2018
Falconi, N., J. Organ, and S. DeStefano. 2017. Value of data sharing for conservation: A study case of a large scale project of Spectacled bear (Tremarctos ornatus) in Peru. 25th International Conference on Bear Research & Management, Quito, Ecuador. November 2017
Edwards, J.W., E.B. Webb, D.N. Fowler, P. Link and B. Leach. Environmental factors influencing blue-winged teal spring migration initiation and subsequent migratory movements. 9th North American Duck Symposium, Portland, Oregon. February 2024 February 2024
Edwards, J.W., E. B. Webb, D. N. Fowler, P. T. Link, and C. Nicolai. 2025. Surfing the 'Mucky' Blue Wave: Is blue-winged teal nonbreeding season resource selection influenced by fine-scale variation in wetland availability? Annual conference of the Waterbird Society. January 6 -9, 2025. San Juan, Costa Rica. January 2025
Edwards, J. W., E. B. Webb, D. N. Fowler, P. T. Link, and C. Nicolai. 2025. Surfing the Blue Wave: Is blue-winged teal resource selection influenced by fine-scale variation in wetland availability?. 2025 Midwest Fish and Wildlife Conference, January 19-22, 2025. St. Louis, Missouri. January 2025
Dunham, KD, and JB Grand. 2019. Using integrated models to identify ecology and population dynamics of threatened arctic species. American Ornithological Society (137th Stated Meeting), Anchorage, Alaska, June 24, 2019 - June 28, 2019 February 2019
Dunham, KD, and Grand JB. 2019. Comparing the utility of integrated and non-integrated analysis results in a conservation decision context October 2019
Diefenbach, D. R., T. A. Marques, J. L. Laake, T. M. Gingery, A. Van Buskirk, C. S. Rosenberry, W. D. Walter, and K. Lamp. Accounting for animal density gradients in distance sampling surveys. The Wildlife Society Annual Conference, 6-10 November 2022, Spokane, WA November 2022
Dennerline, D.E., C.A. Jennings, and D. Degan. 2010. Evaluating relationships between hydroacoustic derived density and gillnet catch: Implications for Reservoir Fish Assessments. Fisheries Sampling with Active Methods Conference in Ceske Budejovice, Czech Republic, September 8-11, 2010. September 2010
Dennerline, D.E. and C.A. Jennings. 2019. Safety through the eyes of a supervisor, your new lens. Annual Meeting, Southern Division, American Fisheries Society, Galveston, Texas, 24-27 January 2019. January 2019
Dennerline, D., J. Peterson and D. Degan. 2007. Looking Both Ways at the Crosswalk. Joint Meeting of the South Carolina and Georgia Chapters of the American Fisheries Society, Tybee Island, GA. January 2007
Dennerline, D., J. Peterson and D. Degan. 2007. Looking Both Ways at the Crosswalk. American Fisheries Society, 4th International Reservoir Symposium: Balancing Fisheries Management and Water Uses for Impounded River Systems. Atlanta, GA., 6-9 June 2007. June 2007
Dennerline, D., C. Jennings, and D. Degan. 2009. Questions regarding the utility of gillnet catch as an index of abundance in reservoir fisheries assessments. 139th Annual Meeting, American Fisheries Society. Nashville, Tennessee, 31 August - 03 September, 2009 September 2009
Dennerline, D., C. Jennings and D. Degan. 2009. Questions Regarding the Utility of Gillnet Catch as an Index of Abundance in Reservoir Fisheries Assessments. Annual Meeeting of the Georgia Chapter of the American Fisheries Society, Perry, Georgia, 27-28 January 2009. January 2009
Dennerline, D. E. and C. A. Jennings. 2016. Evaluation of mean rank shift for discerning changes in reservoir fish assemblages. Annual Meeting, American Fisheries Society, Kansas City, Missouri, 21-25 August 2016. August 2016
Dennerline, D. E. and C. A. Jennings. 2016. Evaluation of mean rank shift for discerning changes in reservoir fish assemblages. Joint Meeting of the Georgia and Alabama Chapters of the American Fisheries Society, Columbus, Georgia, 9-11 February 2016. February 2016
Dennerline, D. E. and C. A. Jennings. 2014. Evaluating reservoir fish assemblages: how much sampling is enough? 2014 Annual Meeting, Southern Division of the American Fisheries Society, Charleston, South Carolina, 22-26 January 2014. January 2014
Dennerline, D. 2005. 'Access'orizing Your Data. Annual Meeting of the Georgia Chapter of the American Fisheries Society. January 2005
Cahill, C., S. DeStefano, J. Organ, and G. Batcheller. 2018. Transitioning to alternative ammunition on National Wildlife Refuges. 70th Anniversary Meeting of the Massachusetts Unit, Westborough, MA. May 2018
Brewer, D>E>, E.B. Webb, A.E, Mini and S.K. McKnight. Using Bayesian Network Analysis to identify habitat distribution for a secretive marsh bird of conservation concern. American Ornithological Society Conference, Estes Park, CO, October 2024. October 2024
Bonar, S. A., N. Mercado-Silva, and K. L. Pope. 2024. AFS Standard Methods for Sampling North American Freshwater Fishes 2nd Edition Overview. 154th Annual Meeting of the American Fisheries Society, September 15-19th, 2024, Honolulu, Hawaii.




September 2024
Bonar, S. A., N. Mercado-Silva and K. L. Pope. AFS Standard Methods for Sampling North American Freshwater Fishes 2nd Edition Overview. 154th Annual Meeting of the American Fisheries Society, September 15-19, 2024. Honolulu Hawaii,


September 2024
2022 Vogel, S.K., Loftin, C., Zydlewski, J.D. Collaborative networks within the CRU program. [oral, invited] Atlantic International Chapter of the American Fisheries Society Annual Conference. September 18, 2022. Newry, ME.
September 2022
2022 Vogel, S.K., Loftin, C., Zydlewski, J.D. Collaborative networks within the CRU program. [oral, invited] Atlantic International Chapter of the American Fisheries Society Annual Conference. September 18, 2022. Newry, ME. September 2022
Theses and Dissertations Publication Date
Trujillo, A. M. M.S. Assessment of the suitability of the northern karst region of Puerto Rico for the reintroduction of the Puerto Rican Parrot (Amazona vittata). December 2004, Allen R. Lewis-Co-Advisor). December 2004
Timmons, J. R. 2001. Effects of non-uniform application of phytase (simulated) on performance and bone quality of male boilers. Thesis, Master of Science, University of Maryland Eastern Shore, Princess Anne, MD. 76 pp. May 2001
Stolarski, J.T. 2013. Growth and energetic condition of Dolly Varden char in coastal Arctic waters. PhD Thesis, University of Alaska Fairbanks. 176 pp. May 2013
South-Wirth, L. 2010. Fall chum distribution and spawning habitat preferences in the Upper Tanana River. M.S. Thesis, University of Alaska, Fairbanks, AK. A.E. Rosenberger and J. Margraf, co-advisors. May 2010
South, Lisa. 2010. A remote sensing-GIS based approach to identify and model spawning habitat for fall chum salmon in a sub-arctic, glacially-fed river. MS thesis, University of Alaska Fairbanks, Fairbanks, AK. 76 pp. August 2010
Perschbacher, J. 2011. The use of aerial imagery to map in-stream physical habitat related to summer distribution of juvenile salmonids in a southcentral Alaskan stream. MS Thesis, University of Alaska Fairbanks. 64 pp. December 2011
Nack (Drossel), Jamie. 2002. Effective of Predators and cattle on ground-nesting grassland birds in southwestern Wisconsin pastures. M.S. Thesis. University of Wisconsin-Madison. May 2002
Moss, M. L. 2000. Development of recirculating systems for the American eel: potential low-cost options for enhancement of the Chesapeake Bay eel fishery. Thesis, Master of Science, University of Maryland Eastern Shore, Princess Anne, MD. 121 pp. December 2000
Gerken, J. 2009. Identification and characterization of inconnu spawning habitat in the Sulukna River, Alaska. MS Thesis, University of Alaska Fairbanks. December 2009
Feldhaus, J. 2006. Heat shock proteins and physiological stress in redband rainbow trout (Oncorhynchus mykiss gairdneri) in the South Fork John Day River, Oregon. April 2006
Esse, D.A. 2011. Characteristics of the Sulukna River spawning population of inconnue, Yukon River drainage, Alaska. MS Thesis, University of Alaska Fairbanks. 55 pp. December 2011
Dennerline, D. E. 2015. Evaluating novel approaches for sampling and assessing changes in reservoir fish assemblages. Ph.D. Dissertation submitted to the University of Georgia. Athens, GA. December 2015
Decker, S.K.S. 2010. Thermal limitations on chinook salmon spawning habitat in the northern extent of their range. MS Thesis, University of Alaska Fairbanks, Fairbanks, AK. 41 pp. May 2010
Benolkin, E. A. 2009. Variation in age and size at maturity of Lake Clark Alaska sockeye salmon. MS Thesis, University of Alaska Fairbanks. December 2009
Balcerzak, M.J. December 2001. Raptor Abundance and Diversity and Red-shouldered Hawk (Buteo lineatus) Habitat Characteristics on Reclaimed Mountaintop Mines in Southern West Virginia. MS thesis, WVU. http://etd.wvu.edu/templates/showETD.cfm?recnum=2234 December 2001
Technical Publications Publication Date
Ruiz, J., D. Dennerline, and C. Jennings. 2008. Fisheries Investigations (2007): Richard B. Russell and J. Strom Thurmond Reservoirs. Annual Project Report for Research Work Order No. 76. Prepared for the US Army Corps of Engineers, Savannah District. 179 pp. January 2008
Ruiz, J., D. Dennerline, and C. Jennings. 2007. Fisheries Investigations (2006): Ricahrd B. Russell and J. Strom Thurmond Reservoirs. Annual Report for Research Work Order No. 76. Prepared for the US Army Corps of Engineers, Savannah District. 179 pp. January 2007
Ruiz, J., D. Dennerline, and C. Jennings. 2006. Fisheries Investigations (2005): Richard B. Russell and J. Strom Thurmond Reservoirs. Annual Report for Research Work Order No. 76. Prepared for the US Army Corps of Engineers, Savannah District. 176 pp. February 2006
Organ, John F. 2014. Ding's Brilliant Idea. Fair Chase. 29(4): 36-38. December 2014
Bissonette, J. A., C. S. Loftin, D. M. Leslie Jr., L. A. Nordstrom, and W. J. Fleming. 2000. The Cooperative Research Unit Program and wildlife education: historic development, future challenges. The Wildlife Society Bulletin 28:534-541. January 2000
Type Citation Publication Date
Data Release Snyder, S.D., Loftin, C.S., and Reeve, A.S., 2023, Distribution Models Predicting Groundwater Influenced Ecosystems in the Northeastern United States: U.S. Geological Survey data release, https://doi.org/10.5066/P97DJ8E6. October 2024
Data Release Snyder, S.D., Loftin, C.S., and Reeve, A.S. 2023. Vulnerability of Groundwater Influenced Ecosystems in the Northeastern United States: U.S. Geological Survey data release, https://doi.org/10.5066/P1K7S2DI. April 2023
Data Release Kline, L., Lewis, M.A., Maher, L., and Loftin, C.S., 2023. Point locations and species and behavioral identifications of colonial nesting seabirds on Maine's coastal islands interpreted from 2019 plane-based imagery, U.S. Geological Survey data release: https://doi.org/10.5066/P92SL92P. February 2023
Data Release Diefenbach, D., Trowbridge, J., Van Buskirk, A., McConnell, T., Lamp, K., Marques, T., Walter, W., Wallingford, B., and Rosenberry, C., 2024, Data for Distance sampling accounting for density gradient and animal distribution: U.S. Geological Survey data release, https://doi.org/10.5066/P16QJRFW. July 2023