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Spatial distribution of muskrat Ondatra zibethicus live‐trapping areas and translocation wetlands (black circles; n = 5) for muskrats in Voyageurs National Park near International Falls, MN, USA during summers of 2018 and 2019.
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Muskrats Ondatra zibethicus are semiaquatic herbivores experiencing long-term and widespread population declines across North America. Translocation may be a viable tool to bolster or reestablish local populations; however, subsequent effects of translocation on muskrats are unknown. We live-trapped and translocated radiomarked muskrats (n = 65) du...
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... Muskrats occurring in drought-affected wetlands are reluctant to move into upland areas and search for other good-quality habitats (Errington 1939). Space use by Muskrats is largely restricted to within-water areas (Ahlers et al. 2010a, Ganoe et al. 2021, Matykiewicz et al. 2021, and individuals using terrestrial areas can incur greater 55:43-49 44 mortality risks (Ahlers et al. 2015). Muskrat population abundances are dynamic , Erb et al. 2000, though little is known about survival rates or population growth. ...
... We did not trap when daily low temperatures were forecasted ≤ 0°C or during rain events. We fastened live-traps to floating rafts (modified track boards; Larreur et al. 2020, Matykiewicz et al. 2021, Reynolds et al. 2004, Schooley et al. 2012) kept buoyant by Styrofoam sandwiched between two plywood sheets (122 × 61 × 4 cm). We floated trap boards along wetland edges near active Muskrat burrows or in areas with Muskrat signs (e.g., Muskrats, tracks, scat, clippings) and tethered them to sturdy vegetation or structure (e.g., rocks, Eastern Redcedar trees or stumps, Cattails). ...
... We floated trap boards along wetland edges near active Muskrat burrows or in areas with Muskrat signs (e.g., Muskrats, tracks, scat, clippings) and tethered them to sturdy vegetation or structure (e.g., rocks, Eastern Redcedar trees or stumps, Cattails). We covered traps with local vegetation to conceal them and provide cover from adverse weather and direct sunlight (Matykiewicz et al. 2021). We baited traps with apple (e.g., Ahlers et al. 2010a) and checked twice daily, once in the morning and again in the evening. ...
Apparent declines in Ondatra zibethicus Linnaeus (Muskrat) populations across North America necessitate information regarding key demographic parameters. In the Flint Hills ecoregion in Kansas, USA, Muskrat habitat is generally characterized by man-made wetlands used for ranching operations. The relative quality of these habitats for Muskrat populations is poorly understood. We marked and recaptured Muskrats (2020-2022) in the Flint Hills to quantify daily rates in apparent survival. Trap success was low, resulting in a small sample size for inference (n = 22). Our most-supported Cormack-Jolly-Seber model suggested daily recapture probabilities were greater in 2021 (p = 0.67) than in 2022 (p = 0.36). Daily apparent survival rates (Φ = 0.92, 95% CI = 0.75-0.98) were lower than reported in other studies, suggesting poorer habitat conditions for Muskrats in the Flint Hills. We did not capture or detect kits during our study, possibly revealing drought-induced Allee effects in a low-density Muskrat population.
... We considered old and new dams built within a resident adult beaver's 100% minimum convex polygon home range to be built by that individual. We designated new dams built by translocated beavers when the construction date was known and within 100 m of at least four concurrent locations of a translocated beaver (Woodford, Macfarland, & Worland, 2013;Touihri et al., 2018;Matykiewicz et al., 2021). We assigned all other new dams encountered as unknown. ...
Wildlife translocation facilitates conservation efforts, including recovering imperiled species, reducing human–wildlife conflict, and restoring degraded ecosystems. Beaver (American, Castor canadensis; Eurasian, C. fiber) translocation may mitigate human–wildlife conflict and facilitate ecosystem restoration. However, few projects measure outcomes of translocations by monitoring beaver postrelease, and translocation to desert streams is relatively rare. We captured, tagged, and monitored 47 American beavers (hereafter, beavers) which we then translocated to two desert rivers in Utah, USA, to assist in passive river restoration. We compared translocated beaver site fidelity, survival, and dam‐building behavior to 24 resident beavers. We observed high apparent survival (i.e., survived and stayed in the study site) for eight weeks postrelease of resident adult beavers (0.88 ± 0.08; standard error) and lower but similar apparent survival rates between resident subadult (0.15 ± 0.15), translocated adult (0.26 ± 0.12), and translocated subadult beavers (0.09 ± 0.08). Neither the pre‐ nor the post‐translocation count of river reaches with beaver dams were predicted well by the Beaver Restoration Assessment Tool, which estimates maximum beaver dam capacity by river reach, suggesting beaver‐related restoration is not maximized in these rivers. Translocated beavers exhibited similar characteristics as resident subadult beavers during dispersal; they were more vulnerable to predation and many emigrated from the study sites. High mortality and low site fidelity should be anticipated when translocating beavers, but even so, translocation may have contributed to additional beaver dams in the restoration sites, which is the common goal of beaver‐assisted river restoration. Multiple releases at targeted restoration sites may eventually result in establishment and meet conservation objectives for desert rivers.
... maximum river distance detected for our resident beavers), used for ≥7 days for transient sites, and ≥91 days (3 months) for permanent sites (similar to methods in Woodford et al., 2013;Matykiewicz et al., 2021). Time to permanent settlement was recorded as the time an individual was released subtracted from the first time an individual was encountered at its permanent settlement site. ...
Wildlife translocations alter animal movement behavior, so identifying common movement patterns post-translocation will help set expectations about animal behavior in subsequent efforts. American and Eurasian beavers (Castor canadensis; Castor fiber) are frequently translocated for reintroductions, to mitigate human-wildlife conflict, and as an ecosystem restoration tool. However, little is known about movement behavior of translocated beavers post-release, especially in desert rivers with patchy and dynamic resources. We identified space-use patterns of beaver movement behavior after translocation. We translocated and monitored nuisance American beavers in desert river restoration sites on the Price and San Rafael Rivers, Utah, USA, and compared their space use to resident beavers after tracking both across 2 years. Resident adult (RA) beavers were detected at a mean maximum distance of 0.86 ± 0.21 river kilometers (km; ±1 SE), while resident subadult (RS) (11.00 ± 4.24 km), translocated adult (TA) (19.69 ± 3.76 km), and translocated subadult (TS) (21.09 ± 5.54 km) beavers were detected at substantially greater maximum distances. Based on coarse-scale movement models, translocated and RS beavers moved substantially farther from release sites and faster than RA beavers up to 6 months post-release. In contrast, fine-scale movement models using 5-min location intervals showed similar median distance traveled between RA and translocated beavers. Our findings suggest day-to-day activities, such as foraging and resting, were largely unaltered by translocation, but translocated beavers exhibited coarse-scale movement behavior most similar to dispersal by RSs. Coarse-scale movement rates decreased with time since release, suggesting that translocated beavers adjusted to the novel environment over time and eventually settled into a home range similar to RA beavers. Understanding translocated beaver movement behavior in response to a novel desert system can help future beaver-assisted restoration efforts to identify appropriate release sites and strategies.
... 26%]) using live traps, as described previously.15 After capture, we transferred muskrats to aFrom the Veterinary Population Medicine Department, College of Veterinary Medicine, University of Minnesota, 1365 Gortner Avenue, St. Paul, MN 55108, USA (Aarrestad and Wolf); Department of Horticulture and Natural Resources, Kansas State University, 1712 Claflin Road, Manhattan, KS 66506, USA (Matykiewicz and Ahlers); National Park Service, Voyageurs National Park, 360 Highway 11 East, International Falls, MN 56649, USA (Windels and Olson); and Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, 1971 Commonwealth Avenue, St. Paul, MN 55108, USA (Rendahl and Burton). ...
Muskrat (Ondatra zibethicus) populations show long-term and widespread declines across North America, necessitating research into potential mechanistic explanations, including population health. Previous research established reference hematology values, a proxy of individual health, of muskrats occurring in highly modified ecosystems. However, our knowledge of hematology metrics in muskrat populations occurring in more natural ecosystems is limited. We measured several hematological parameters of wild-caught muskrats (n = 73) in the Greater Voyageurs Ecosystem in northern Minnesota in 2018-2019 to establish baseline muskrat health in a relatively intact, near-pristine ecosystem. Additionally, we measured rectal temperature and heart and respiratory rates and collected whole blood for complete blood cell count assessment. We established baseline physiologic and hematologic reference ranges for the population and describe variations between total white blood cells, nucleated cell differentials, and basic erythron and platelet estimates and demonstrate methods of estimation to be poor proxies for more standardized counting methods. Our results establish a baseline to compare muskrat health assessments for populations affected by landscape change or in decline.
The positive relationship between biodiversity and beaver‐modified habitats such as ponds, dams, and canals has been demonstrated; however, the association between biodiversity and beaver lodges is rarely investigated. Due to increasing habitat fragmentation, there is a growing need to identify local biodiversity hotspots.
This systematic review assessed current scientific knowledge concerning the association between beaver lodges and biodiversity. Specifically, the study aimed to 1) investigate the evidence for beaver lodges being local biodiversity hotspots; 2) identify areas of future research centred around the relationship between biodiversity and beaver lodges; and 3) provide recommendations on how to monitor the relationship between biodiversity and beaver lodges within the UK.
Through a stepwise process of database searching and literature sorting, a final dataset of 35 articles emerged, with each article including at least one species, besides beavers, interacting with beaver lodges.
Analysis of the final dataset of articles showed beaver lodges offer multiple uses and fitness benefits for several species in highly seasonal environments, with daily and seasonal visitor variation influenced by intraspecific and interspecific interactions. Beaver lodges were shown to have higher species richness and diversity compared to microhabitats in the surrounding areas, supporting the concept of beaver lodges being local biodiversity hotspots.
We recommend that future studies use videographic methodology to monitor beaver lodges and other treatment groups in the surrounding area. Using the described methodology, beaver management plans should monitor beaver lodges across the northern hemisphere, helping to further understand these important local biodiversity hotspots.
In this paper, I review questions about the 5 Ws ̶ Who, What, When, Where, and Why ̶ of mammal trapping that I judge significant to better understand the pros and cons of mammal trapping: who traps mammals and who objects to such activities; who is responsible for professional and ethical mammal trapping; what is mammal trapping, the performance thresholds of standards, capture efficiency, and selectivity; what alternatives can be used to mammal trapping; why mammal trapping is necessary; why mammal trapping is controversial; when mammal trapping should be allowed; when concerns about mammal trapping will stop; where trapping should occur; and where we should focus our attention in mammal trapping. This review points out that there is recurrent questioning about the necessity of mammal trapping and the welfare of trapped animals. On the basis of this review, I recommend the use of a decision process to justify mammal trapping in 5 categories: sustenance, research, human-wildlife conflict, fur trapping, and wildlife management. I suggest that the common denominator for all these mammal trapping categories is the necessity to use state-of-the-art trapping technology and species-selective trapping systems.