Habitat engineering by beaver benefits aquatic biodiversity and ecosystem processes in agricultural streams

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Ecosystem engineering by invasive exotic beavers reduces in-stream diversity and enhances ecosystem function in Cape Horn,Chile

Species invasions are of global significance, but predicting their impacts can be difficult. Introduced ecosystem engineers, however, provide an opportunity to test the underlying mechanisms that may be common to all invasive engineers and link relationships between changes in diversity and ecosystem function, thereby providing explanatory power for observed ecological patterns. Here we test specific predictions for an invasive ecosystem engineer by quantifying the impacts of habitat and resource modifications caused by North American beavers (Castor canadensis) on aquatic macroinvertebrate community structure and stream ecosystem function in the Cape Horn Biosphere Reserve, Chile. We compared responses to beavers in three habitat types: (1) forested (unimpacted) stream reaches, (2) beaver ponds, and (3) sites immediately downstream of beaver dams in four streams. We found that beaver engineering in ponds created taxonomically simplified, but more productive, benthic macroinvertebrate assemblages. Specifically, macroinvertebrate richness, diversity and number of functional feeding groups were reduced by half, while abundance, biomass and secondary production increased three- to fivefold in beaver ponds compared to forested sites. Reaches downstream of beaver ponds were very similar to natural forested sections. Beaver invasion effects on both community and ecosystem parameters occurred predominantly via increased retention of fine particulate organic matter, which was associated with reduced macroinvertebrate richness and diversity (via homogenization of benthic microhabitat) and increased macroinvertebrate biomass and production (via greater food availability). Beaver modifications to macroinvertebrate community structure were largely confined to ponds, but increased benthic production in beaver-modified habitats adds to energy retention and flow for the entire stream ecosystem. Furthermore, the effects of beavers on taxa richness (negative) and measures of macroinvertebrate biomass (positive) were inversely related. Thus, while a generally positive relationship between diversity and ecosystem function has been found in a variety of systems, this work shows how they can be decoupled by responding to alterative mechanisms. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Habitat conditions at beaver settlement sites: implications for beaver restoration projects

Recognition that beavers are integral components of stream ecosystems has resulted in an increase in beaver‐mediated habitat restoration projects. Beaver restoration projects are frequently implemented in degraded stream systems with little or no beaver activity. However, selection of restoration sites is often based on habitat suitability research comparing well‐established beaver colonies to unoccupied stream sections or abandoned colonies. Because beavers dramatically alter areas they occupy, assessing habitat conditions at active colonies may over‐emphasize habitat characteristics that are modified by beaver activity. During 2015–2017, we conducted beaver activity surveys on streams in the upper Missouri River watershed in southwest Montana, United States, to investigate habitat selection by beavers starting new colonies in novel areas. We compared new colony locations in unmodified stream segments to unsettled segments to evaluate conditions that promoted colonization. Newly settled stream segments had relatively low gradients (β ± SE = ?0.72 ± 0.27), narrow channels (β = ?1.31 ± 0.46), high channel complexity (β = 0.76 ± 0.42), high canopy cover of woody riparian vegetation (β = 0.56 ± 0.21), and low‐lying areas directly adjacent to the stream (β = 0.36 ± 0.24), where β denotes covariate effect sizes. Habitat selection patterns differed between our new settlement site analysis and an analysis of occupied versus unoccupied stream segments, suggesting that assessing habitat suitability based on active colonies may result in misidentification of suitable site conditions for beaver restoration. Our research provides recommendations for beaver restoration practitioners to select restoration sites that will have the highest probability of successful colony establishment.     

Ecosystem engineering by beavers affects mayfly life histories

1. The North American beaver has been studied as a model ecosystem engineer for many decades. Previous studies have documented physical, chemical and biological impacts attributed to beaver engineering in both aquatic and terrestrial environments. This study focused on the effects of ecosystem engineering by beavers on life histories of a common mayfly and on the potential consequences for mayfly populations. 2. We studied 18 montane beaver ponds of varying size and shape in western Colorado near the Rocky Mountain Biological Laboratory. Our goal was to test whether variation in beaver pond morphology (pond size and shape) explains downstream changes in stream temperature, mayfly size and timing of emergence. 3. Downstream water temperatures varied predictably with pond morphology, being colder downstream of high‐head dams and warmer downstream of low‐head dams. Pond morphology was also a significant predictor of variation in the size of mature female Baetis bicaudatus (the most abundant mayfly), with larger females emerging downstream of high‐head dams and smaller females downstream of low‐head dams. The size of male B. bicaudatus was not significantly related to pond morphology or stream temperature. There was no relationship between pond morphology and variation in the timing of emergence of Baetis (males or females) between upstream and downstream reaches. 4. Our results have implications for the effects of beaver ponds on Baetis individual fitness because large Baetis females are more fecund. Therefore, predictable female size variation associated with beaver pond morphology makes it possible to model the effects of beaver activity on local contributions of Baetis to the regional pool of reproductive adults at the catchment scale. Additionally, predictable changes in the size of emerging mayflies may have important consequences for the magnitude of aquatic to terrestrial resource subsidies in beaver‐modified systems.     

Beavers (Castor canadensis) influence habitat for juvenile salmon in a large Alaskan river floodplain

Our aim was to determine how beavers affect habitats and food resources for juvenile salmon in the Kwethluk River in western Alaska.

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Beaver dams maintain fish biodiversity by increasing habitat heterogeneity throughout a low‐gradient stream network

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Lentic Meadows and Riparian Functions Impaired After Horse and Cattle Grazing

Perennially and intermittently available water in lentic, spring-fed herbaceous meadows supports wetland plants that build and maintain absorbent soil organic matter, capture sediment, prevent erosion, and thereby sustain riparian ecosystems. Enhanced forage and available water attract a diversity of wildlife and grazing animals that can degrade riparian vegetation through prolonged overuse. We tested novel monitoring methods and adapted existing methods to obtain quantified vegetation data that have been consistently linked to riparian functionality and compared these data to ungulate species use. We quantified ungulate use with time-lapse cameras at 10 Nevada spring-fed herbaceous meadows where core greater sage-grouse (Centrocercus urophasianus) habitat, public land grazing allotments, and free-roaming horse (Equus caballus) herd management areas (Bureau of Land Management) or territories (U.S. Department of Agriculture Forest Service) overlapped. Free-roaming horses used most study sites over longer periods and grazed more intensely than cattle or domestic sheep. Native ungulate grazing intensity was comparatively negligible. Free-roaming horses selected spring-fed meadow sites on average 51 (±33 [SE]) times more than the surrounding rangelands, and cattle selected them 30 ± 23 times more. Within the wettest area of a site, study sites with longer duration of use and higher intensity of use had more soil alteration and bare ground. Riparian ecosystem degradation occurred where meadows had limited rest or recovery time from grazing during the growing season. At all sites we noted loss of riparian function, especially within the hydric areas with the highest potential to grow abundant cover of stabilizing wetland plant species. Transects for monitoring soil alteration and vegetation cover in this hydric location can provide a leading indicator of riparian recovery or degradation and help in adjusting free-roaming horse population levels or livestock management strategies. © 2021 The Wildlife Society.     

新疆乌伦古河流域蒙新河狸巢穴特征和巢址生境选择

2014年11—12月和2015年4月,采用样方法对新疆乌伦古河流域冷季和暖季早期蒙新河狸(Castor fiber birulai)巢穴特征和巢址生境选择进行了调查研究。确定冷季160个蒙新河狸巢穴和暖季早期158个蒙新河狸巢穴,其中61个地面巢平均长(2.54±1.69)m,宽(1.68±0.91)m,高(0.54±0.32)m。与冷季相比,暖季早期蒙新河狸利用的巢穴生境具有河宽、水域面积、水深和植物郁闭度较大,河岸坡度较小的特征,是由季节更替导致的温度等气候变化引起的,而在其他生态因子选择上无差异(P0.05)。以冷季为例,蒙新河狸巢址生境选择特征表现为:(1)地理分布因子:海拔1000m,临近水域河岸1.0m、坡度75°、水深1.0m、河面宽度和面积适中;(2)隐蔽因子:巢穴隐蔽级较高,附近的植物特征(郁闭度高,乔木密度大、灌木密度低以及高度低)也辅助实现了较好的隐蔽性;(3)干扰因子:巢穴位置选择最近公路或居民点的河流异侧;(4)食物因子:巢穴多选择在密度较高的柳树林中,且距离冬季食物堆较近。建议:寻找适合蒙新河狸生存的其他潜在生境;减少在蒙新河狸生活流域修建水坝,或者在其附近修建蒙新河狸迁徙通道;加强蒙新河狸分布区的保护管理。     

Population dynamics of the threatened Oregon spotted frog before and after drought mitigation

Amphibians are among the most sensitive taxa to climate change, and species inhabiting arid and semiarid landscapes at the extremes of their range are especially vulnerable to drought. The Jack Creek, Oregon, USA, population of Oregon spotted frogs (Rana pretiosa) faces unique challenges because it occupies the highest elevation site in the species' extant range and one that has been transformed by loss of American beavers (Castor canadensis), which historically maintained open water. We evaluated the effects of drought mitigation (addition of excavated ponds) on relationships between local and regional water availability, inactive legacy beaver dams, and Oregon spotted frog population dynamics in the Jack Creek system. We conducted egg mass surveys and capture-mark-recapture sampling at a treatment reach with excavated ponds and 3 reference reaches over 13 years; surveys spanned a period before and after pond excavation at the treatment and 1 primary comparison reference reach. We analyzed data using a combination of robust design capture-mark-recapture estimators and generalized linear mixed models to characterize population dynamics. Adult Oregon spotted frog survival was approximately 19.5% higher at the treatment reach than the primary reference reach during the study period. Annual survival was most strongly associated with late summer vegetation greenness, a proxy for water availability, and males had higher survival than females. Among the 4 study reaches, the treatment reach consistently had higher late summer vegetation greenness, and the hydrology functioned more independently of regional precipitation patterns relative to the reference reaches; however, these dynamics were not linked to pond excavation. Breeding was concentrated in 2 legacy beaver ponds that were deepened by excavation during the study compared to an unexcavated beaver pond, 2 excavated ponds without legacy beaver dams, and 9 reference ponds. These results point to the benefit of enhancing existing beaver structures and indicate that management actions aimed at maintaining surface water for breeding in spring and saturated soils and ponded water for adults in late summer would benefit this unique population of Oregon spotted frogs in the face of drought.     

Effects of livestock exclusion on in‐stream habitat and benthic invertebrate assemblages in montane streams

1. Stream and riparian ecosystems in arid montane areas, like the interior western United States, are often just narrow mesic strands, but support diverse and productive habitats. Meadows along many such streams have long been used for rangeland grazing, and, while impacts to riparian areas are relatively well known, the effect of livestock grazing on aquatic life in streams has received less attention. 2. Attempts to link grazing impacts to disturbance have been hindered by the lack of spatial and temporal replication. In this study, we compared channel features and benthic macroinvertebrate communities (i) between 16 stream reaches on two grazed allotments and between 22 reaches on two allotments where livestock had been completely removed for 4 years, (ii) before and after the 4‐year grazing respite at a subset of eight sites and (iii) inside and outside of small‐scale fenced grazing exclosures (eight pairings; 10+ year exclosures) in the meadows of the Golden Trout Wilderness, California (U.S.A.). 3. We evaluated grazing disturbance at the reach scale in terms of the effects of livestock trampling on per cent bank erosion and found that macroinvertebrate richness metrics were negatively correlated with bank erosion, while the percentage of tolerant taxa increased. 4. All macroinvertebrate richness metrics were significantly lower in grazed areas. Bank angle, temperature, fine sediment cover and erosion were higher in grazed areas, while riparian cover was lower. Regression models identified riparian cover, in‐stream substratum, bank conditions and bankfull width‐to‐depth ratios as the most important for explaining variability in macroinvertebrate richness metrics. 5. Small‐scale grazing exclosures showed no improvements for in‐stream communities and only moderate positive effects on riparian vegetation. In contrast, metrics of macroinvertebrate richness increased significantly after a 4‐year period of no grazing. 6. The success of grazing removal reported here suggests that short‐term removal of livestock at the larger, allotment meadow spatial scale is more effective than long‐term, but small‐scale, local riparian area fencing, and yields promising results in achieving stream channel, riparian and aquatic biological recovery.     

Persistence at distributional edges: Columbia spotted frog habitat in the arid Great Basin,USA

A common challenge in the conservation of broadly distributed, yet imperiled species is understanding which factors facilitate persistence at distributional edges, locations where populations are often vulnerable to extirpation due to changes in climate, land use, or distributions of other species. For Columbia spotted frogs (Rana luteiventris) in the Great Basin (USA), a genetically distinct population segment of conservation concern, we approached this problem by examining (1) landscape‐scale habitat availability and distribution, (2) water body‐scale habitat associations, and (3) resource management‐identified threats to persistence. We found that areas with perennial aquatic habitat and suitable climate are extremely limited in the southern portion of the species’ range. Within these suitable areas, native and non‐native predators (trout and American bullfrogs [Lithobates catesbeianus]) are widespread and may further limit habitat availability in upper‐ and lower‐elevation areas, respectively. At the water body scale, spotted frog occupancy was associated with deeper sites containing abundant emergent vegetation and nontrout fish species. Streams with American beaver (Castor canadensis) frequently had these structural characteristics and were significantly more likely to be occupied than ponds, lakes, streams without beaver, or streams with inactive beaver ponds, highlighting the importance of active manipulation of stream environments by beaver. Native and non‐native trout reduced the likelihood of spotted frog occupancy, especially where emergent vegetation cover was sparse. Intensive livestock grazing, low aquatic connectivity, and ephemeral hydroperiods were also negatively associated with spotted frog occupancy. We conclude that persistence of this species at the arid end of its range has been largely facilitated by habitat stability (i.e., permanent hydroperiod), connectivity, predator‐free refugia, and a commensalistic interaction with an ecosystem engineer. Beaver‐induced changes to habitat quality, stability, and connectivity may increase spotted frog population resistance and resilience to seasonal drought, grazing, non‐native predators, and climate change, factors which threaten local or regional persistence.     

Effects of a small dam on freshwater mussel growth in an Alabama (U.S.A.) stream

1. Dams, ubiquitous features in many lotic ecosystems, are believed to have many broad‐ranging and predominantly negative effects on stream biota. Whereas the impacts of larger dams are well studied, few studies have quantified effects of small dams on streams. 2. Recent surveys found numerous locations where mussels were abundant and larger in reaches immediately downstream from small dams. We examined mussel shell growth and resource conditions in Sandy Creek, a small (third‐order) tributary of the Tallapoosa River in east‐central Alabama (U.S.A.), to determine whether larger populations and individuals result from more rapid growth or longer lifespans of mussels downstream from the dam. 3. Growth rates for populations occurring immediately downstream from the dam (mill reach), c. 5 km downstream from the dam (downstream reach) and upstream from the impoundment (upstream reach) were compared with environmental conditions (seasonal measures of nutrient concentrations and water chemistry) and food availability [total suspended solids (TSS)]. Water temperature was continuously monitored using data loggers. 4. Analysis of length‐at‐age data using multiple growth models found that mill reach mussels grew faster than both up‐ and downstream populations. This dam appears to substantially increase water temperatures and may extend the shell growth period in the mill reach. TSS quantity varied seasonally between sites but was generally highest in the impoundment and mill reach during spring and autumn. TSS quality was highest in the upstream reach from spring through autumn but was highest in the impoundment and mill reach during winter. 5. Our data suggest that some small impoundments enhance conditions for freshwater mussel growth in downstream reaches. However, we do not know how far downstream this subsidy extends or how different species respond to mill dam augmentation. Regardless, mounting evidence suggests that this phenomenon is geographically and taxonomically widespread in eastern North America. Heretofore, undocumented positive effects of small dams suggest that some older dams may warrant protection or restoration if downstream reaches support imperilled mussel populations. Further, some small dams may prove useful conservation tools for natural resource managers attempting to identify sites for mussel culture facilities or translocation refugia.     

Beavers alter stream macroinvertebrate communities in north-eastern Utah

1. Understanding changes in macroinvertebrate communities is important because they play a large role in stream ecosystem functioning, and they are an important food resource for fish. Beaver-induced changes to stream morphology could alter macroinvertebrate communities, which in turn could affect food webs and ecosystem function. However, studies investigating the effects of North American beaver activities on macroinvertebrates are rare in the inter-mountain west, an area with high potential for beaver-assisted restoration.
2. The aim of this study was to quantify differences in the macroinvertebrate community between unaltered segments of streams and within beaver ponds in north-eastern Utah, U.S.A. We assessed macroinvertebrate species richness, biomass, density, functional feeding group composition, mobility group composition, and macroinvertebrate habitat characteristics to test the hypothesis that macroinvertebrate communities will differ among habitat types (undammed stream segments and beaver ponds) in beaver-occupied streams.
3. Beaver pond communities significantly differed from lotic reach communities in many ways. Beaver ponds were less diverse with 25% fewer species. Although there was variability among streams, in general, beaver ponds had 75% fewer individuals and 90% lower total macroinvertebrate biomass compared to lotic reaches.
4. Regarding functional feeding groups, beaver ponds contained more engulfers, while lotic reaches contained more scrapers, filterers, and gatherers. For mobility groups, beaver ponds had more sprawlers, while lotic reaches had more clingers. Swimmers were also more prevalent in lotic reaches, although this is probably due to the abundance of Baetis within lotic reaches. More beaver pond taxa were classified as lentic-dwelling insects, while more lotic reach taxa were categorised as preferring lotic habitats.
5. The creation of ponds by beavers fundamentally altered the macroinvertebrate community in north-eastern Utah streams. Such changes to stream macroinvertebrate communities suggest that recolonisation of beavers across North America may be altering stream functioning and food webs. Our study highlights the need to further investigate the effects of beaver recolonisation on stream communities.

     

Beaver activity increases aquatic subsidies to terrestrial consumers

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Reintroduction of beavers <Emphasis Type="Italic">Castor fiber</Emphasis> may improve habitat quality for vespertilionid bats foraging in small river valleys

Beavers strongly modify their environment by not only building dams and creating ponds, which slow the water flow, but also by selective cutting and removing of trees, which change the spatial structure of the forest. We aimed to test the hypothesis that beaver activity promotes new foraging sites for insectivorous bats. The beaver’s influence can be especially significant on aerial hawkers that prefer moderate structural clutter, like the Pipistrellus species (by creating new canopy gaps), and on water-surface foragers, like Myotis daubentonii (by creating ponds with smooth water surface). The study was conducted on small streams in forest areas of northern Poland, which were colonized by the European beaver (Castor fiber). Bat activity was recorded with a Pettersson D-980 ultrasound detector on line transects. The number of bat passes was significantly higher in the stream sections modified by beavers (flooded and subjected to intensive tree cutting) than in the unmodified sections (for Pipistrellus nathusii, Pipistrellus pipistrellus, Pipistrellus pygmaeus, Nyctalus noctula, and all species lumped together). Contrary to our expectations, the activity of the Myotis species was significantly lower on the transect with the largest beaver ponds, possibly due to the blanket of duckweed (Lemnaceae), which is known to produce clutter echoes, thereby reducing prey detection by echolocating M. daubentonii.     

Pond-Breeding Amphibian Species Richness and Habitat Selection in a Beaver-Modified Landscape

ABSTRACT Beaver (Castor canadensis) activity creates wetland habitats with varying hydroperiods important in maintaining habitat diversity for pond-breeding amphibians with significantly different breeding habitat requirements. We documented pond-breeding amphibian assemblages in 71 freshwater wetlands in Acadia National Park, Maine, USA. Using 15 variables describing local pond conditions and wetland landscape characteristics, we developed a priori models to predict sites with high amphibian species richness and used model selection with Akaike's Information Criterion to judge the strength of evidence supporting each model. We developed single-species models to predict wood frog (Rana sylvatica), bullfrog (R. catesbeiana), and pickerel frog (R. palustris) breeding site selection. Sites with high species richness were best predicted by 1) connectivity of wetlands in the landscape through stream corridors and 2) wetland modification by beaver. Wood frog breeding habitat was best predicted by temporary hydroperiod, lack of fish, and absence of current beaver activity. Wood frog breeding was present in abandoned beaver wetlands nearly as often as in nonbeaver wetlands. Bullfrog breeding was limited to active beaver wetlands with fish and permanent water. Pickerel frog breeding sites were best predicted by connectivity through stream corridors within the landscape. As beavers have recolonized areas of their former range in North America, they have increased the number and diversity of available breeding sites in the landscape for pond-breeding amphibians. The resulting mosaic of active and abandoned beaver wetlands both supports rich amphibian assemblages and provides suitable breeding habitat for species with differing habitat requirements. Land managers should consider the potential benefits of minimal management of beavers in promoting and conserving amphibian and wetland diversity at a landscape scale.     

The forgotten prey of an iconic predator: a review of interactions between grey wolves Canis lupus and beavers Castor spp.

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Succession of Beaver Ponds in Colorado 50 Years After Beaver Removal

ABSTRACT In 1954 and 1955, I conducted studies on 4 beaver (Castor canadensis) colonies in Routt County, Colorado, USA, to develop a reliable and practical census method. In fall of 1955, these colonies were trapped to extirpation to obtain accurate counts and colony compositions. I established photo stations and took a series of photographs approximately every 5 years, in late September, from 1955 to 2005 to document beaver-population dynamics and beaver-pond successional changes after complete beaver removal. The number and configuration of dams, ponds, and canals remained remarkably similar, with maintenance conducted by succeeding generations of beaver. Quaking aspen (Populus tremuloides) and autumn willow (Salix serissima) boundaries also remained stable, but conifers slowly encroached. At 3 of 4 colony sites, beaver did not attempt to construct food caches for overwintering. By fall of 2005, the fourth site was also without a cache. Carrying capacity of these areas was likely limited by severe winter weather at 2,620-m to 2,900-m elevations, aspen depletion, pond-depth reduction, and sustained grazing by cattle. Although beaver carefully maintained dams, pond depths were reduced in most cases. This slow transition from an aquatic to a terrestrial system is a natural progression in this region.     

The influence of Eurasian beaver Castor fiber activity on fish assemblages in small steppe rivers in Russia

In recent decades, the Eurasian beaver (Castor fiber) has once again become the keystone species in small river ecosystems in Russia. In many places, beaver activity has resulted in a significant change in lotic habitats, affecting the diversity, density, and biomass of aquatic organisms, including fish. While many studies have considered the ecosystem impacts of beavers, relatively few have focused on understanding the influence of beaver activity on steppe rivers. We conducted the first quantitative study of beaver impacts on fish assemblages in beaver-influenced and beaver-free sites on two small steppe rivers in the Don River basin in Russia. The presence of beavers altered the habitats in small steppe rivers and affected the diversity, density, and biomass of fish. A comparison of the number of species, density, and biomass of fish in six types of river habitats showed that these parameters were lower in beaver ponds than at riverine sites without beaver activity. Three fish species primarily preferred a single habitat type. Barbatula barbatula was found in riffles, Misgurnus fossilis in old beaver ponds, and Eudontomyzon mariae in abandoned beaver ponds. Beavers impacted fish distribution and density by changing dissolved oxygen, pH, and water current velocity. Overall, our results showed that the presence of beavers led to a temporary homogenization of fish habitats at a local scale in the valleys of small steppe rivers because beavers occupied these rivers only for a short period. However, habitat heterogeneity may increase if the beaver population stays stable or expands in the future.

     

Proximate weather patterns and spring green‐up phenology effect Eurasian beaver (Castor fiber) body mass and reproductive success: the implications of climate change and topography

Low spring temperatures have been found to benefit mobile herbivores by reducing the rate of spring‐flush, whereas high rainfall increases forage availability. Cold winters prove detrimental, by increasing herbivore thermoregulatory burdens. Here we examine the effects of temperature and rainfall variability on a temperate sedentary herbivore, the Eurasian beaver, Castor fiber, in terms of inter‐annual variation in mean body weight and per territory offspring production. Data pertain to 198 individuals, over 11 years, using capture‐mark‐recapture. We use plant growth (tree cores) and fAPAR (a satellite‐derived plant productivity index) to examine potential mechanisms through which weather conditions affect the availability and the seasonal phenology of beaver forage. Juvenile body weights were lighter after colder winters, whereas warmer spring temperatures were associated with lighter adult body weights, mediated by enhanced green‐up phenology rates. Counter‐intuitively, we observed a negative association between rainfall and body weight in juveniles and adults, and also with reproductive success. Alder, Alnus incana, (n = 68) growth rings (principal beaver food in the study area) exhibited a positive relationship with rainfall for trees growing at elevations >2 m above water level, but a negative relationship for trees growing <0.5 m. We deduce that temperature influences beavers at the landscape scale via effects on spring green‐up phenology and winter thermoregulation. Rainfall influences beavers at finer spatial scales through topographical interactions with plant growth, where trees near water level, prone to water logging, producing poorer forage in wetter years. Unlike most other herbivores, beavers are an obligate aquatic species that utilize a restricted ‘central‐place’ foraging range, limiting their ability to take advantage of better forage growth further from water during wetter years. With respect to anthropogenic climate change, interactions between weather variables, plant phenology and topography on forage growth are instructive, and consequently warrant examination when developing conservation management strategies for populations of medium to large herbivores.