Return of the Swamp Rabbit: Sylvilagus aquaticus Occupancy Increased and Expanded Along the Northern Extent of Its Distribution Range

Abstract

Swamp rabbits (Sylvilagus aquaticus) are a bottomland hardwood specialist that have experienced range contraction at the northern and western extents of their range. While swamp rabbit distribution has been studied at the northern periphery of its range, drivers of change over time have not been investigated. Here, we analyzed data collected in 2010–2012 and 2022–2023 across 16 counties in southeastern Missouri, USA and reported environmental factors driving changes in occupancy states. Occupancy probability increased between decadal surveys (0.66–0.79). Occupancy probability was negatively influenced by site isolation and patch richness density but positively influenced by site area. Colonization and extinction probabilities were influenced by bottomland hardwood forest cover change and flooding effects. When ground latrines were included, we observed an increase in detection (0.68–0.84) and occupancy probabilities (0.95–1.00). Swamp rabbit populations appear to have expanded within southeastern Missouri following many decades of range contraction.

Keywords

colonization / distribution range / dynamic occupancy / extinction / lagomorphs / metapopulation

References

[1] Allen, A. W. 1985. “Habitat Suitability Index Models: Swamp Rabbit.” U.S. Fish and Wildlife Service Biological Report 82(10.107):20.

[2] Andersen, T. K., and J. Marshall Shepherd. 2013. “Floods in a Changing Climate.” Geography Compass 7, no. 2: 95–115. https://doi.org/10.1111/gec3.12025.

[3] Barbour, M. S., A. Woolf, and J. W. Porath. 2001. “Recent Trends and Future Outlook for the Swamp Rabbit (Sylvilagus aquaticus) in Illinois.” Transactions of the Illinois State Academy of Science 94, no. 3: 151–160.

[4] Bartoń, K. 2023. “MuMIn: Multi-Model Inference.” R package version 1.47.5. https://CRAN.R-project.org/package=MuMIn.

[5] Beger, M. 2021. “Accepting the Loss of Habitat Specialists in a Changing World.” Nature Ecology & Evolution 5, no. 5: 556–557. https://doi.org/10.1038/s41559-021-01402-6.

[6] Bennitt, R., and W. O. Nagel. 1937. “A Survey of the Resident Game and Fur-Bearers of Missouri.” University of Missouri 12: 1–215.

[7] Berkman, L. K., C. K. Nielsen, C. L. Roy, and E. J. Heist. 2018. “A Landscape Genetic Analysis of Swamp Rabbits (Sylvilagus aquaticus) Suggests Forest Canopy Cover Enhances Gene Flow in an Agricultural Matrix.” Canadian Journal of Zoology 96, no. 6: 622–632. https://doi.org/10.1139/cjz-2017-0116.

[8] Berkman, L. K., S. R. Timm, I. W. Vining, et al. 2025. “Stark Differences Across Flood Risk Zones in the Mississippi River Floodplain Landscape Are Revealed by an Occupancy Survey of Missouri Swamp Rabbits (Sylvilagus aquaticus).” Landscape Ecology 40, no. 2: 34. https://doi.org/10.1007/s10980-025-02044-w.

[9] Brakenridge, G. R. 2023. “Global Active Archive of Large Flood Events.” Dartmouth Flood Observatory, University of Colorado. http://floodobservatory.colorado.edu/Archives/.

[10] Broadfoot, W. M., and H. L. Williston. 1973. “Flooding Effects on Southern Forests.” Journal of Forestry 71, no. 9: 584–587. https://doi.org/10.1093/jof/71.9.584.

[11] Bromaghin, J. F., T. L. McDonald, and S. C. Amstrup. 2013. “Plausible Combinations: An Improved Method to Evaluate the Covariate Structure of Cormack-Jolly-Seber Mark- Recapture Models.” Open Journal of Ecology 03, no. 01: 11–22. https://doi.org/10.4236/oje.2013.31002.

[12] Burnham, K. P., and D. R. Anderson. 2002. Model Selection and Multimodel Inference: A Practical Information-theoretic Approach, 2nd ed. Springer-Verlag.

[13] Chapman, J. A., and G. A. Feldhamer. 1981. “Sylvilagus aquaticus.” Mammalian Species 151: 1.

[14] Chapman, S. S., J. M. Omernik, G. E. Griffith, W. A. Schroeder, T. A. Nigh, and T. F. Wilton. 2002. Ecoregions of Iowa and Missouri [Map]. U.S. Geological Survey.

[15] Cosgriff, R. J., J. C. Nelson, and Y. Yin. 2007. “Floodplain Forest Response to Large-Scale Flood Disturbance.” Transactions of the Illinois State Academy of Science 100, no. 1: 47–71.

[16] Crawford, J. C., C. K. Nielsen, and E. M. Schauber. 2018. “Survival and Habitat Use of Sympatric Lagomorphs in Bottomland Hardwood Forests.” Canadian Journal of Zoology 96, no. 7: 713–722. https://doi.org/10.1139/cjz-2017-0066.

[17] Dailey, T. V., T. M. Vangilder, and L. W. Burger. 1993. “Swamp Rabbit Distribution in Missouri.” Proceedings of the Annual Conference of the Southeast Association of Fish and Wildlife Agencies 47: 251–256.

[18] Devictor, V., R. Julliard, and F. Jiguet. 2008. “Distribution of Specialist and Generalist Species Along Spatial Gradients of Habitat Disturbance and Fragmentation.” Oikos 117, no. 4: 507–514. https://doi.org/10.1111/j.0030-1299.2008.16215.x.

[19] Dumyahn, J. B., and P. A. Zollner. 2010. “Home Range Characteristics of Swamp Rabbits (Sylvilagus aquaticus) in Southwestern Indiana and Northwestern Kentucky.” Proceedings of the Indiana Academy of Science 119, no. 1: 80–86.

[20] Dumyahn, J. B., P. A. Zollner, and W. P. Smith. 2015. “Microhabitat Comparison of Swamp Rabbit Sites Between Periphery and Core of the Species Range: Swamp Rabbit Microhabitat.” Journal of Wildlife Management 79, no. 7: 1199–1206. https://doi.org/10.1002/jwmg.939.

[21] Environmental Systems Research Institute [ESRI]. 2023. ArcGIS Desktop: Release 3.1. Environmental Systems Research Institute.

[22] Fantz, D. K., I. W. Vining, J. S. Scheibe, R. N. Gillespie, and P. H. Marley. 2017. “Swamp Rabbit Distribution on the Northern Edge of Their Range in Missouri.” Southeastern Naturalist 16, no. 4: 614–628. https://doi.org/10.1656/058.016.0410.

[23] Faulkner, S., W. Barrow, ., B. Keeland, S. Walls, and D. Telesco. 2011. “Effects of Conservation Practices on Wetland Ecosystem Services in the Mississippi Alluvial Valley.” Ecological Applications 21, no. sp1: S31–S48. https://doi.org/10.1890/10-0592.1.

[24] Fiske, I., and R. Chandler. 2011. “Unmarked: An R Package for Fitting Hierarchical Models of Wildlife Occurrence and Abundance.” Journal of Statistical Software 43, no. 10: 1–23. https://www.jstatsoft.org/v43/i10/.

[25] Flinders, J. T., and J. A. Crawford. 1977. “Composition and Degradation of Jackrabbit and Cottontail Fecal Pellets, Texas High Plains.” Journal of Range Management Archives 30, no. 3: 217–220.

[26] Fowler, A., and R. E. Kissell. 2007. “Winter Relative Abundance and Habitat Associations of Swamp Rabbits in Eastern Arkansas.” Southeastern Naturalist 6, no. 2: 247–258. https://doi.org/10.1656/1528-7092(2007)6[247:WRAAHA]2.0.CO;2.

[27] Gardiner, E. S., and J. M. Oliver. 2004. “ Restoration of Bottomland Hardwood Forests in the Lower Mississippi Alluvial Valley, U.S.A.” In Restoration of Boreal and Temperate Forests, edited by J. Stanturf and P. Madsen, 235–251. CRC Press.

[28] Hanberry, B. B., J. M. Kabrick, H. S. He, and B. J. Palik. 2012. “Historical Trajectories and Restoration Strategies for the Mississippi River Alluvial Valley.” Forest Ecology and Management 280: 103–111. https://doi.org/10.1016/j.foreco.2012.05.033.

[29] Hardie, D. C., and J. A. Hutchings. 2010. “Evolutionary Ecology at the Extremes of Species' Ranges.” Environmental Reviews 18: 1–20. https://doi.org/10.1139/A09-014.

[30] Hesselbarth, M. H. K., M. Sciaini, K. A. With, K. Wiegand, and J. Nowosad. 2019. “Landscapemetrics: An Open-Source R Tool to Calculate Landscape Metrics.” Ecography 42: 1648–1657. https://doi.org/10.1111/ecog.04617.

[31] Hillard, E. M., J. C. Crawford, C. K. Nielsen, J. W. Groninger, and E. M. Schauber. 2021. “Hydrogeomorphology Influences Swamp Rabbit Habitat Selection in Bottomland Hardwood Forests.” Journal of Wildlife Management 85, no. 3: 593–601. https://doi.org/10.1002/jwmg.22005.

[32] Hillard, E. M., C. K. Nielsen, and J. W. Groninger. 2017. “Swamp Rabbits as Indicators of Wildlife Habitat Quality in Bottomland Hardwood Forest Ecosystems.” Ecological Indicators 79: 47–53. https://doi.org/10.1016/j.ecolind.2017.03.024.

[33] Hillard, E. M., C. K. Nielsen, and J. W. Groninger. 2024. “Stand Conditions Drive Swamp Rabbit Habitat Use in a Managed Bottomland Hardwood Forest.” Southeastern Naturalist 23, no. 2: 135–150. https://doi.org/10.1656/058.023.0201.

[34] Hümann, M., G. Schüler, C. Müller, R. Schneider, M. Johst, and T. Caspari. 2011. “Identification of Runoff Processes—The Impact of Different Forest Types and Soil Properties on Runoff Formation and Floods.” Journal of Hydrology 409, no. 3–4: 637–649. https://doi.org/10.1016/j.jhydrol.2011.08.067.

[35] Hunt, T. P. 1959. “Breeding Habits of the Swamp Rabbit With Notes on Its Life History.” Journal of Mammalogy 40, no. 1: 82. https://doi.org/10.2307/1376118.

[36] Jeng, C. C. 2023. “Why a Variance Inflation Factor of 10 Is Not an Ideal Cutoff for Multicollinearity Diagnostics.” Journal of Educational Research 57, no. 2: 67–92. https://doi.org/10.53106/199044282023105702004.

[37] Kellner, K. F., A. D. Smith, J. A. Royle, M. Kéry, J. L. Belant, and R. B. Chandler. 2023. “The Unmarked R Package: Twelve Years of Advances in Occurrence and Abundance Modelling in Ecology.” Methods in Ecology and Evolution 14, no. 6: 1408–1415. https://doi.org/10.1111/2041-210X.14123.

[38] Kennedy, H. E., and R. M. Krinard. 1974. “1973 Mississippi River Flood's Impact on Natural Hardwood Forests and Plantations.” Research Note SO-RN-177, U.S. Department of Agriculture, Forest Service, Southern Forest Experiment Station.

[39] Kéry, M., and J. A. Royle. 2020. Applied Hierarchical Modeling in Ecology: Analysis of Distribution, Abundance and Species Richness in R and BUGS: Volume 2: Dynamic and Advanced Models. Academic Press.

[40] Korte, P. A. 1975. "Distribution and Habitat Requirements of the Swamp Rabbit in Missouri.” M.S. Thesis, University of Missouri.

[41] Korte, P. A., and L. H. Fredrickson. 1977. “Swamp Rabbit Distribution in Missouri.” Transactions of the Missouri Academy of Science 10: 72–77.

[42] Lowe, C. E. 1958. “Ecology of the Swamp Rabbit in Georgia.” Journal of Mammalogy 39, no. 1: 116–127. https://doi.org/10.2307/1376617.

[43] MacKenzie, D. I., J. D. Nichols, J. E. Hines, M. G. Knutson, and A. B. Franklin. 2003. “Estimating Site Occupancy, Colonization, and Local Extinction When a Species Is Detected Imperfectly.” Ecology 84, no. 8: 2200–2207. https://doi.org/10.1890/02-3090.

[44] MacKenzie, D. I., J. D. Nichols, G. B. Lachman, S. Droege, J. Andrew Royle, and C. A. Langtimm. 2002. “Estimating Site Occupancy Rates When Detection Probabilities Are Less Than One.” Ecology 83, no. 8: 2248–2255. https://doi.org/10.1890/0012-9658(2002)083[2248:ESORWD]2.0.CO;2.

[45] MacKenzie, D. I., J. D. Nichols, N. Sutton, K. Kawanishi, and L. L. Bailey. 2005. “Improving Inferences in Population Studies of Rare Species That Are Detected Imperfectly.” Ecology 86, no. 5: 1101–1113. https://doi.org/10.1890/04-1060.

[46] MacLean, S. A., and S. R. Beissinger. 2017. “Species' Traits as Predictors of Range Shifts Under Contemporary Climate Change: A Review and Meta-Analysis.” Global Change Biology 23, no. 10: 4094–4105. https://doi.org/10.1111/gcb.13736.

[47] Magura, T., M. Ferrante, and G. L. Lövei. 2020. “Only Habitat Specialists Become Smaller With Advancing Urbanization.” Global Ecology and Biogeography 29, no. 11: 1978–1987. https://doi.org/10.1111/geb.13168.

[48] Mantyka-pringle, C. S., T. G. Martin, and J. R. Rhodes. 2012. “Interactions Between Climate and Habitat Loss Effects on Biodiversity: A Systematic Review and Meta-Analysis.” Global Change Biology 18, no. 4: 1239–1252. https://doi.org/10.1111/j.1365-2486.2011.02593.x.

[49] Marquardt, D. W. 1980. “Comment: You Should Standardize the Predictor Variables in Your Regression Models.” Journal of the American Statistical Association 75, no. 369: 87–91. https://doi.org/10.1080/01621459.1980.10477430.

[50] Mattila, N., V. Kaitala, A. Komonen, J. Päivinen, and J. S. Kotiaho. 2011. “Ecological Correlates of Distribution Change and Range Shift in Butterflies.” Insect Conservation and Diversity 4, no. 4: 239–246. https://doi.org/10.1111/j.1752-4598.2011.00141.x.

[51] McCollum, R. C., and N. R. Holler. 1994. “Comparative Use of Floodplains by Swamp Rabbits.” Journal of the Alabama Academy of Science 65, no. 4: 263–275.

[52] MDPS SEMA. 2015a. “Disaster Number 4238: Severe Storms, Tornadoes, Straight-Line Winds, and Flooding.” https://sema.dps.mo.gov/maps_and_disasters/disasters/4238.php.

[53] MDPS SEMA. 2015b. “Disaster Number 4250: Heavy Rains, Widespread Flash Flooding, and Flooding.” https://sema.dps.mo.gov/maps_and_disasters/disasters/4250.php.

[54] MDPS SEMA. 2017. “Disaster Number 4317: Severe Storms, Tornadoes, Straight-Line Winds, and Flooding.” https://sema.dps.mo.gov/maps_and_disasters/disasters/4317.php.

[55] MDPS SEMA. 2019. “Disaster Number 4435: Severe Storms, Straight-Line Winds, and flooding.” https://sema.dps.mo.gov/maps_and_disasters/disasters/4435.php.

[56] Missouri Department of Public Safety State Emergency Management Agency [MDPS SEMA]. 2011. “Disaster Number 1980: Severe Storms, Tornadoes, and Flooding.” https://sema.dps.mo.gov/maps_and_disasters/disasters/1980.php.

[57] Morin, D. J., C. B. Yackulic, J. E. Diffendorfer, et al. 2020. “Is Your Ad Hoc Model Selection Strategy Affecting Your Multimodel Inference?” Ecosphere 11, no. 1: e02997. https://doi.org/10.1002/ecs2.2997.

[58] National Centers for Environmental Information [NCEI]. 2023. “Daily Observational Data [web application].” National Centers for Environmental Information. https://www.ncei.noaa.gov/maps/daily/.

[59] Natural Resources Conservation Service [NRCS]. 2023. “Web Soil Survey [web application].” National Resources Conservation Service. https://websoilsurvey.nrcs.usda.gov/app/WebSoilSurvey.aspx.

[60] NatureServe. 2023. “NatureServe Explorer [web application].” NatureServe. https://explorer.natureserve.org/.

[61] Newbold, T., L. N. Hudson, S. Contu, et al. 2018. “Widespread Winners and Narrow-Ranged Losers: Land Use Homogenizes Biodiversity in Local Assemblages Worldwide.” PLoS Biology 16, no. 12: e2006841. https://doi.org/10.1371/journal.pbio.2006841.

[62] Nielsen, C. K., and L. K. Berkman. 2018. “ Sylvilagus aquaticus (Bachman, 1837); Swamp Rabbit.” In Lagomorphs: Pikas, Rabbits, and Hares of the World, edited by A. T. Smith, C. H. Johnston, P. C. Alves and K. Hackländer, 117–120. Johns Hopkins University Press.

[63] Pajda-De La, O., J. Pradeep, and J. Scheibe. 2013. “Persistence of a Swamp Rabbit Metapopulation: The Incidence Function Model Approach.” International Journal of Ecology & Development 25, no. 2: 1–20.

[64] R Core Team. 2022. R: A Language and Environment for Statistical Computing. R Foundation for Statistical Computing. https://www.R-project.org/.

[65] Robinson, C. D., J. C. Crawford, L. Corcoran, E. M. Schauber, and C. K. Nielsen. 2016. “Metapopulation Viability of Swamp Rabbits in Southern Illinois: Potential Impacts of Habitat Change.” Journal of Mammalogy 97, no. 1: 68–79. https://doi.org/10.1093/jmammal/gyv154.

[66] Roy Nielsen, C. L., S. M. Wakamiya, and C. K. Nielsen. 2008. “Viability and Patch Occupancy of a Swamp Rabbit Metapopulation at the Northern Edge of Its Distribution.” Biological Conservation 141, no. 4: 1043–1054. https://doi.org/10.1016/j.biocon.2008.01.016.

[67] Scharine, P. D., C. K. Nielsen, E. M. Schauber, L. Rubert, and J. C. Crawford. 2011. “Occupancy, Detection, and Habitat Associations of Sympatric Lagomorphs in Early-Successional Bottomland Forests.” Journal of Mammalogy 92, no. 4: 880–890. https://doi.org/10.1644/10-MAMM-A-078.1.

[68] Scheibe, J. S., and R. Henson. 2003. “The Distribution of Swamp Rabbits in Southeast Missouri.” Southeastern Naturalist 2, no. 3: 327–334. https://doi.org/10.1656/1528-7092(2003)002[0327:TDOSRI]2.0.CO;2.

[69] Scheibe, J. S., Swamp Rabbit Working Group. 2016. “The Effects of the 2011 Birds Point-New Madrid Levee Breach on Swamp Rabbits (Sylvilagus aquaticus) Inhabiting the Birds Point-New Madrid Floodway.” Final Report to the Missouri Department of Conservation.

[70] Sole, J. D. 1994. “Assessing Swamp Rabbit Distribution in Kentucky.” Proceedings of the Annual Conference of the Southeast Association of Fish and Wildlife Agencies 48: 145–151.

[71] Stanturf, J. A., E. S. Gardiner, P. B. Hamel, M. S. Devall, T. D. Leininger, and M. E. Warren. 2000. “Restoring Bottomland Hardwood Ecosystems in the Lower Mississippi Alluvial Valley.” Journal of Forestry 98, no. 8: 10–16. https://doi.org/10.1093/jof/98.8.10.

[72] Swanston, C., L. A. Brandt, M. K. Janowiak, et al. 2018. “Vulnerability of Forests of the Midwest and Northeast United States to Climate Change.” Climatic Change 146, no. 1–2: 103–116. https://doi.org/10.1007/s10584-017-2065-2.

[73] Swihart, R. K., T. M. Gehring, M. B. Kolozsvary, and T. E. Nupp. 2003. “Responses of ‘Resistant’ Vertebrates to Habitat Loss and Fragmentation: The Importance of Niche Breadth and Range Boundaries.” Diversity and Distributions 9, no. 1: 1–18. https://doi.org/10.1046/j.1472-4642.2003.00158.x.

[74] Terrel, T. L. 1972. “The Swamp Rabbit (Sylvilagus aquaticus) in Indiana.” American Midland Naturalist 87, no. 2: 283. https://doi.org/10.2307/2423562.

[75] Travis, J. M. J. 2003. “Climate Change and Habitat Destruction: A Deadly Anthropogenic Cocktail.” Proceedings of the Royal Society of London. Series B: Biological Sciences 270, no. 1514: 467–473. https://doi.org/10.1098/rspb.2002.2246.

[76] Turner, R. E., S. W. Forsythe, and N. J. Craig. 1981. “ Bottomland Hardwood Forest Land Resources of the Southeastern United States.” In Developments in Agricultural and Managed Forest Ecology, edited by J. R. Clark and J. Benforado, 13–28. Elsevier.

[77] United States Geological Survey [USGS]. 2011. “National Land Cover Database 2011 [web application].” United States Geological Survey. https://www.mrlc.gov/viewer/.

[78] U.S. Environmental Protection Agency [EPA]. 2013. “Level III Ecoregions of the Conterminous United States.” EPA Office of Research and Development, National Health and Environmental Effects Research Laboratory. https://www.epa.gov/eco-research/level-iii-and-iv-ecoregions-continental-united-states.

[79] USGS. 2021. “National lAnd Cover Database 2021 [web application].” United States Geological Survey. https://www.mrlc.gov/viewer/.

[80] USGS. 2023. “The National Map Data Download and Visualization Services [web application].” United States Geological Survey. https://apps.nationalmap.gov/downloader/.

[81] Whitaker, J. O., and B. Abrell. 1986. “The Swamp Rabbit (Sylvilagus aquaticus) in Indiana, 1984-1985.” Proceedings of the Indiana Academy of Science 95: 563–570.

[82] Zollner, P. A., W. P. Smith, and L. A. Brennan. 1996. “Characteristics and Adaptive Significance of Latrines of Swamp Rabbits (Sylvilagus aquaticus).” Journal of Mammalogy 77, no. 4: 1049–1058. https://doi.org/10.2307/1382785.

[83] Zollner, P. A., W. P. Smith, and L. A. Brennan. 2000a. “Microhabitat Characteristics of Sites Used by Swamp Rabbits.” Wildlife Society Bulletin 28, no. 4: 1003–1011.

[84] Zollner, P. A., W. P. Smith, and L. A. Brennan. 2000b. “Home Range Use by Swamp Rabbits (Sylvilagus aquaticus) in a Frequently Inundated Bottomland Forest.” American Midland Naturalist 143, no. 1: 64–69. https://doi.org/10.1674/00030031(2000)143[0064:HRUBSR]2.0.CO;2.

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