The North American Beaver (Castor canadensis) is Recolonizing the

Garret D. Langlois,,1, Robert D. Cox,1, Philip S. Gipson,1, and Richard D. Stevens,1,2

1Department of Natural Resources Management and 2Natural Science Research Laboratory of the Museum of Tech University, Lubbock, TX 79409 U. S. A.

Abstract Five millennia ago, the North American Beaver (Castor canadensis) was extirpated from the Southern High Plains by droughts. Beaver were found to be largely absent from the Llano Estacado, despite exhaustive search efforts. Here we report the first definitive evidence of an extant C. canadensis population recolonizing the Llano Estacado.

Resumen Hace cinco milenios, el castor norteamericano (Castor canadensis) fue extirpado de las Altas Llanuras del Sur por las sequías. Se encontró que los castores estaban en gran parte ausentes del Llano Estacado, a pesar de los exhaustivos esfuerzos de búsqueda. Aquí reportamos la primera evidencia definitiva de una población existente de C. canadensis recolonizando el Llano Estacado.

Keywords: , ecosystem engineer, keystone species, Lubbock, Panhandle Plains, pioneering population, range expansion, urban ecology, , wetland restoration

 Correspondence: [email protected]  G.D.L.: orcid.org/0000-0001-8498-0891 R.D.C.: orcid.org/0000-0002-4005-1019 P.S.G.: orcid.org/0000-0003-2026-5180 R.D.S.: orcid.org/0000-0002-9821-0633

1 of 10 The North American Beaver (Order: Rodentia, Family: Castoridae, Castor canadensis Kuhl, 1820) is the largest extant rodent native to North America (Hazard 1982). Beaver are semiaquatic, and their habitation along streams is generally conspicuous: family groups will construct burrows, canals, dams, and lodges (Berry 1923; Jackson 1961). Beaver dams are iconic for creating vital wetland habitat by impounding water. For that reason, beaver are a keystone species that engineer ecosystems, affecting natural communities disproportionately greater than would be expected, relative to their local abundance (Rosell et al. 2005; Brazier et al. 2021; Wohl 2021). The fossil record revealed that C. canadensis (hereafter beaver) occurred in north- less than 125,000 BP (Dalquest 1962). Further evidence of range expansion by southwestern beaver include fossil remains at the New Mexico – Mexico border (Harris 1993), and northwest Arizona (Jass 2002). Beaver colonization of semiarid and arid landscapes (e.g., the American southwest) was almost certainly achieved through a vast network of beaver-dammed streams (Wohl 2021). Following two extensive droughts 6,500 ‒ 4,500 BP (Holliday 1985), beaver were extirpated from the Southern High Plains (Bolen and Flores 1986; Bolen et al. 1989). No evidence of recolonization from neighboring escarpments, nor of an extant beaver population, was reported in 1831‒1832 (Pike 1969), 1986 (Bolen and Flores 1986), 1989 (Bolen et al. 1989), 1994 (Haukos and Smith 1994), or 2003 (Baker and Hill 2003). Further into the 21st century, beaver were still considered to be absent from the Llano Estacado, save Randall County in northwestern Texas (Schmidly and Bradley 2016; Ueda 2020). On the 4th of November 2015, the carcass of an adult beaver (accession number of skull: TTU-M 128469) was found on the bank of Canyon Lake 5 in Mackenzie Park (33°35'24.3"N 101°49'49.9"W), Lubbock, Texas (Garcia et al. 2016). The Canyon Lakes are a series of six narrowly constructed lakes, considered relatively drought proof (HDR Engineering, Inc. 2018), because a substantial portion of their inflow is reclaimed municipal effluent (Winn 1973). This lake system follows the North Fork of the Double Mountain Fork of the Brazos River, an intermittent stream which runs through Yellow House Canyon (Winn 1973). The occurrence of that specimen in Canyon Lake 5 was considerably disjunct from the known range of beaver in the Panhandle Plains (Garcia et al. 2016; Schmidly and Bradley 2016). Garcia et al. (2016) speculated that the specimen had not been anthropogenically translocated, but arrived alive and

2 of 10 under its own power, likely during the high waters of summer 2015 via eastern ingress. No further evidence of beaver was presented beyond that single carcass. Southeast from Canyon Lake 5 is Canyon Lake 6, and the parks of Mae Simmons and Dunbar Historical Lake, in that order. Mae Simmons is a 98.3 acre semi-natural recreational park, and one of the more wooded sites along the Canyon Lakes system. We classified the semi- natural portions of the park into four ecological map units of the High Plains ecoregion (Elliott et al. 2014). The southwestern lakeshore was riparian hardwood forest, which contained eastern cottonwood (Populus deltoides) and black willow (Salix nigra) tree species. Southwest of the riparian hardwood forest was a depressional marsh, a natural community distinct from the closed wetland system of a playa. Floodplain hardwood forest grew surrounding the depressional marsh and adjacent to the riparian hardwood forest. Further upland was shortgrass prairie. Considering these habitat types and the natural history of beavers, we hypothesized that if beaver could occur in the Canyon Lakes, they would do so in Mae Simmons Park. In January 2018, we discovered chewed stumps from one to three seasons past, along the shoreline of Canyon Lake 6 in Mae Simmons Park (33°34'39.7"N 101°49'34.1"W). A pattern of fresh evidence appeared the following weeks, and into spring (Figure 1). Encouraged by signs of potential beaver habitation, we conducted water quality analyses, to confirm the suitability of the lakewater for beaver (Table 1). On the 30th of March 2018, we deployed three motion-activated trail cameras (Bushnell Trophy Camera Brown Model 119537; Bushnell Corp., Overland Park, Kansas, U. S. A.). We captured images and video until the 30th of July 2018. With permission from the Lubbock Parks & Recreation Department, trail cameras were placed in discreet, off-trail locations, and programmed to only activate at night. Using these cameras, we documented a pair of beavers on the 8th of July 2018 (Figure 2, Supplementary Material: Video S1). The return of beaver to the Llano Estacado after a multi-millennia absence is significant. This colonization also ushers in the type of human–wildlife challenges that can arise when the public are unaccustomed to a novel animal on the landscape. The public and these beaver have already begun to interact, and some of the beaver have unfortunately become victims of road mortality (Ueda 2019). Monitoring this new population would be advisable to best mitigate potential human–beaver conflicts. This effort could be achieved taxpayer free, as we anticipate broad and enduring community-based enthusiasm for such a project. Long-term monitoring of

3 of 10 these beaver could be conducted by volunteers, and engage municipal educators, and local naturalists both young and old alike. Ultimately, we assert there are more benefits than drawbacks in the recolonization of the Llano Estacado by beaver. These beaver will enhance habitat for semiaquatic furbearers and other mammals, waterfowl and other birds, amphibians, reptiles, fish, and pollinating insects. Especially considering that Lubbock will expand the Canyon Lakes system with the addition of Canyon Lake 7: a 774-acre lake, slated to cost $251 million, and to be completed by the year 2040 (HDR Engineering, Inc. 2018; Texas Water Development Board 2020). Expansions of the Canyon Lakes will very likely be colonized by this pioneering population of beaver. This is a conservation opportunity of mutual benefit for both beaver and the residents of of the Southern High Plains. On rangeland where they have been restored, beaver dams can lengthen seasonal streamflows, raise groundwater levels, reduce streambank incision and erosion, control flooding, improve surface water flows, enhance resilience to drought and wildfire, increase biodiversity, improve aquatic and riparian habitat, and hasten groundwater and well-water recharge rates (Charnley 2018, 2019; Kantor and Charnley 2020; Wohl 2021). If granted the opportunity, beavers could fulfill their role as low-cost ecosystem restoration engineers of the Llano Estacado, which we suggest is worth consideration.

Acknowledgments We are grateful for the interdisciplinary collaboration with artists, David Chapman Lindsay and Stephanie Rae Berrie. We appreciate the field support and expertise of Matthew R. Jackson and Robert C. Lee. We are thankful for the laboratory supplies and technical support, provided by Drs. Mark C. Wallace and Matthew A. Barnes. We thank Dr. Lionel Plummer, and the Lubbock Parks & Recreation Department for facilitating site use for this project. The iNaturalist entries of Barry Keith were helpful in spotlighting beaver interactions with the West Texas public. Lastly, we enjoyed interacting with the many friendly and helpful citizens of Lubbock, who approached us while in the field with good-natured curiosity.

4 of 10 References Baker, B. W., and E. P. Hill. 2003. Beaver (Castor canadensis). Pages 288–310 in G. A. Feldhamer, B. C. Thompson, and J. A. Chapman, eds. Wild Mammals of North America: Biology, Management, and Conservation (2nd ed.). The Johns Hopkins University Press, Baltimore, Maryland, U.S.A. Berry, S. S. 1923. Observations on a Montana Beaver Canal. Journal of Mammalogy 4:92–103. Bolen, E. G., and D. L. Flores. 1986. Prairie Wetlands of West Texas: the History and Ecology of Playa Lakes. Page 23.02 in A. Davis and G. Stanford, eds. Proceedings of the Tenth North American Prairie Conference (Vol. 10). Presented at the The Prairie: Roots of Our Culture, Foundation of Our Economy, Native Prairie Association of Texas, Texas Women’s University, Denton, Texas, U.S.A. Bolen, E. G., L. M. Smith, and H. L. Schramm,. 1989. Playa Lakes: Prairie Wetlands of the Southern High Plains. BioScience 39:615–623. Brazier, R. E., A. Puttock, H. A. Graham, R. E. Auster, K. H. Davies, and C. M. L. Brown. 2021. Beaver: Nature’s ecosystem engineers. WIREs Water 8:29. Charnley, S. 2018. Beavers, landowners, and watershed restoration: experimenting with beaver dam analogues in the Scott River basin, California (Research Paper No. PNW-RP-613). U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station, Portland, Oregon, U.S.A. ———. 2019. If you build it, they will come: ranching, riparian revegetation, and beaver colonization in Elko County, Nevada (Research Paper No. PNW-RP-614). U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station, Portland, OR. Dalquest, W. W. 1962. The Good Creek Formation, Pleistocene of Texas, and Its Fauna. Journal of Paleontology 36:568–582. Elliott, L. F., A. Treuer-Kuehn, C. F. Blodgett, C. D. True, D. German, and D. D. Diamond. 2014. Ecological Systems of Texas: 391 Mapped Types. Phase 1–6. 2009-2014 Geodatabase, Interpretive Guides, and Technical Type Descriptions, Texas Parks & Wildlife Department and Texas Water Development Board, Austin, Texas, U.S.A. Garcia, C. J., J. Q. Francis, C. Rios-Blanco, J. D. Stuhler, G. D. Langlois, E. E. Bohlender, M. A. Madden, et al. 2016. New Distributional Records of Mammals in Texas. Occasional Papers, Museum of Texas Tech University 327:1–6. Harris, A. 1993. Quaternary vertebrates of New Mexico. Pages 179–197 in S. G. Lucas and J. Zidek, eds. Vertebrate Paleontology in New Mexico, Bulletin. New Mexico Museum of Natural History and Science, Albuquerque, New Mexico, U.S.A. Haukos, D. A., and L. M. Smith. 1994. The importance of playa wetlands to biodiversity of the Southern High Plains. Landscape and Urban Planning, Wildlife Habitat Conservation 28:83–98. Hazard, E. B. 1982. Order Rodentia: Rodents. Pages 51–112 in The Mammals of Minnesota (2nd ed.). University of Minnesota Press, Minneapolis, Minnesota, U.S.A. HDR Engineering, Inc. 2018. Strategic Water Supply Plan for the City of Lubbock Texas (Municipal Plan). Strategic Water Supply. City Council and Water Advisory Commission, Lubbock, Texas, U.S.A. Holliday, V. T. 1985. New Data on the Stratigraphy and Pedology of the Clovis and Plainview Sites, Southern High Plains. Quaternary Research 23:388–402.

5 of 10 Jackson, H. H. T. 1961. Mammals of Wisconsin. University of Wisconsin Press, Madison, Wisconsin, U.S.A. Jass, C. N. 2002. Preliminary taphonomic analyses of the mammalian microfauna. Pages 179–190 in P. R. Geib, D. R. Keller, and M. Butterwick, eds. Bighorn Cave: test excavations of a stratified dry shelter, Mohave County, Arizona. Northern Arizona University: Ralph M. Bilby Research Center, Flagstaff, Arizona, U.S.A. Kantor, S., and S. Charnley. 2020. Ranchers, Beavers, and Stream Restoration on Western Rangelands. Science Findings 229:1–5. King, J. W. 1983. The Physicochemical Aspects Of The Lubbock Canyon Lakes (M.S. Thesis). Texas Tech University, Lubbock, Texas, U.S.A. Pike, A. 1969. Albert Pike’s journey in the prairie: 1831-1832. Panhandle-Plains Historical Review. Panhandle-Plains Historical Society, Canyon, Texas, U.S.A. Rosell, F., O. Bozsér, P. Collen, and H. Parker. 2005. Ecological impact of beavers Castor fiber and Castor canadensis and their ability to modify ecosystems. Mammal Review 35:248–276. Schmidly, D. J., and R. D. Bradley. 2016. The Mammals of Texas (7th ed.). The University of Texas Press, Austin, Texas, U.S.A. Texas Water Development Board. 2020. Lubbock County - Lubbock Jim Bertram Lake 7. Texas State Water Plan 2022. Ueda, K. 2019. iNaturalist Research-grade Observations (Occurrence Dataset No. 25752147). https://doi.org/10.15468/ab3s5x. iNaturalist.org, Lubbock, Texas, U.S.A. ———. 2020. iNaturalist Research-grade Observations (Occurrence Dataset No. 43835140). https://doi.org/10.15468/ab3s5x. iNaturalist.org, Amarillo, Texas, U.S.A. Wade, D. A., and C. W. Ramsey. 1986. Identifying and Managing Aquatic Rodents in Texas: Beaver, Nutria and Muskrats (Bulletin No. B-1556). Texas A&M University System: Texas Agricultural Extension Service, College Station, Texas, U.S.A. Winn, W. T. 1973. A Pilot Study of the Canyon Lakes Project (M.S. Thesis). Texas Tech University, Lubbock, Texas, U.S.A. Wohl, E. 2021. Legacy effects of loss of beavers in the continental United States. Environmental Research Letters 16:025010.

6 of 10 Table 1. Physicochemical characteristics of water samples collected on the 20th of March and the 24th of April 2018 from Canyon Lake 6, at Mae Simmons Park, Lubbock, Texas. Collection sites were shoreline locations of both active beaver use (33°34'34.1"N 101°49'28.1"W), and past beaver use (33°34'30.7"N 101°49'16.1"W). Each test was conducted four times; we are reporting the average. Water quality metrics were either within the range of what King (1983) reported for this lake system, or sufficiently close that the difference was explainable by variation in sampling site and season.

Water Sample Collection Sites

Water Quality Metric Active Beaver Use Past Beaver Use Unit of Measurement

Turbidity 20 20 JTU

Acidity 7.5 8.0 pH

Alkalinity 304 278 mg/L CaCO3

Ammonia 0.39 0.15 mg/L NH4‒N

Nitrates 0.0 0.0 mg/L NH3‒N

3− Phosphorus 0.14 0.11 mg/L PO4

Dissolved Oxygen 1.4 7.0 mg/L SaO2

7 of 10 Figure 1. A tetraptych of beaver signs observed along the western shoreline of Canyon Lake 6, at Mae Simmons Park, Lubbock, Texas. Images are ordered chronologically, by date of discovery. The freshly chewed limbs of a felled black willow (Salix nigra) and extensive beaver trails were observed on the 14th of February 2018 at 33°34'34.1"N 101°49'28.1"W. We observed chewed, then charred, stumps from one or two seasons past on the 21st of March 2018 at 33°34'30.2"N 101°49'23.5"W. Finally, we observed freshly chewed stumps (U.S. penny for scale) on the 19th of April 2018, again at 33°34'34.1"N 101°49'28.1"W. These conspicuous signs were clear indicators of beaver activity (Wade and Ramsey 1986). Additionally, on the 1st of February 2018, we conversed with a local angler who provided a descriptive account of beaver activity. He claimed to have occasionally observed beavers in June, July, and August of 2017, between 00:00 ‒ 01:00. He stated the beaver were traveling downstream from Canyon Lake 5, out of the culvert under U.S. Highway 62 (33°34'40.5"N 101°49'33.6"W) and into Canyon Lake 6.

8 of 10 Figure 2a.

Figure 2. On the 8th of July 2018, our trail camera captured images and video of beaver activity. A pair of beavers were swimming at the mouth of a rheocrene spring-fed brook (33°34'34.5"N 101°49'29.3"W), which empties into Canyon Lake 6, at Mae Simmons Park, Lubbock, Texas. Previously, on the 24th of June 2018 at 21:30, we had observed a beaver swimming at this same site. Additionally, on the 19th of June 2018 between 21:30 ‒‒ 22:30, we observed a beaver swimming at the southeast corner of Canyon Lake 6, 8 20 m northwest of the Dunbar Lake dam (33°33'57.7"N 101°48'06.8"W).

9 of 10 Figure 2b.

10 of 10