While the evolutionary history of the European Bison continues to be developed and debated, two subspecies are widely recognized as the Lowland Bison (Bison bonasus bonasus) and the Caucasian Bison (Bison bonasus caucasicus) (Kowalczyk and Plumb 2020).

The species is placed in genus Bos L., 1758 by some references (e.g., the Mammal Diversity Database; ASM 2024).

European regional assessment: Near Threatened (NT)
EU 27 regional assessment: Near Threatened (NT)

This Red List Assessment (RLA) was requested by the IUCN Red List Unit as a contribution to the European Red List (ERL) Pulse reassessment of 11 taxonomic groups of species within the IUCN European Region (IUCN 2007). This RLA maintains the basic framework of the most recent Global Red List assessment for the European Bison (Plumb et al. 2020) and does not include analyses of subspecies or genetic lines. This assessment focuses primarily on free-living (wild) subpopulations that are larger than Minimum Viable Population (MVP) size (150 mature animals), and does not include two subpopulations that occur outside the IUCN European region in the Caucasus Mountain Range of the Russian Federation that otherwise were included in Plumb et al. (2020). This assessment finds a stable to slightly increasing abundance and distribution within the IUCN European assessment region since Plumb et al. (2020), such that the species continues to no longer qualify for threatened status (Critically Endangered, Endangered, or Vulnerable) under Red List Criteria A-E per below (IUCN 2019). A comprehensive species survey for 2021 (published in the 2022 European Bison Pedigree Book) identified only seven subpopulations greater than MVP that included 2,664 mature animals within the IUCN European assessment region, with only one subpopulation including greater than 500 mature animals; thus making this species nearly qualify for Vulnerable C2a(i). Additional consideration of free-living subpopulations that are less than MVP, indicates that this species warrants Near Threatened status in light of its dependence on ongoing conservation programmes to persist beyond the next five years, a very limited number of viable free-living subpopulations (seven), and a large number of small isolated free-living subpopulations less than MVP (37). While the number of conservation herds and individuals in subpopulations managed for species conservation and ecological restoration is increasing, all free-living mature individuals occur within active management programmes which, if ceased, would result in the species qualifying for a threatened status. The species is not currently in decline, but the overall free-living population size of wild mature individuals could decline or suffer extreme fluctuation if current protections are reduced or removed. This is a conservation-dependent species and several exacerbating factors described below are anticipated to continue across the current and next generation unless there are substantial multi-national adjustments in the management of free-living European Bison.

1. Population viability
There are very few viable subpopulations (only seven out of 44 free-living subpopulations are greater than MVP). There were 8 free-living subpopulations greater than MVP identified in the 2020 European Bison assessment (Plumb et al. 2020), and since then, one such subpopulation in Lithuania has dropped below MVP (EBPB 2022). Most free-living bison subpopulations are very small (e.g. ~30% < 25 mature animals, ~50% <50 mature individuals, and ~80% include less than MVP of 150 mature animals), indicating that natural selection dynamics are very likely not operating adequately. Quantitative population viability analyses of the seven free-living populations greater than MVP have not been completed.

2. Genetics
Mean expected heterozygosity, calculated on the basis of microsatellite data, has been estimated as 0.29 (29%) for the Lowland line and 0.35 (35%) for the Lowland-Caucasian line (Tokarska unpublished). This low genetic variability negatively influences effective population size (Ne). For example, for the large subpopulation is the Polish part of the Białowieża Forest (~470 mature animals), yet the effective population size is calculated was less than 30 (Tokarska et al. 2009). Based on the extremely limited number of founder animals, this tremendous disparity between subpopulation number of mature animals and Ne can be reliably inferred for other free-ranging subpopulations.

3. Fragmentation
Approximately 70% of free-living subpopulations for which information is available are functionally isolated by distance or an impermeable barrier (man-made or natural). For subpopulations not isolated by a natural or man-made barrier, 60% are at least 60 km from the nearest neighbour subpopulation (range 60–530 km). It can be expected that subpopulations at a greater distance from a nearest neighbour are much less likely to see successful natural dispersal or exchange of mature animals between subpopulations across multiple generations, thus we can infer further genetic drift of inherently low genetic diversity to be amplified through long-term isolation.

4. Supplemental feeding and selective culling
The majority of free-living European Bison subpopulations were restored into forest habitats, which often do not provide sufficient food resources year round for this large herbivore. Supplemental feeding occurs at all seven subpopulations greater than MVP, and is reported for ~30 out 45 free-living subpopulations for which information is available. Selective culling is reported for six out of seven subpopulations greater than MVP. While supplemental feeding and selective culling are well-intentioned to manage subpopulation distribution and abundance to protect bison from poaching and to reduce conflicts with surrounding land uses, there is concern that long-term reliance on these management techniques could lead to unintended consequences, including unsustainable expense, reduced subpopulation viability, and disruption of the species evolved natural life history.

5. Conservation dependence
Free-living European Bison is a conservation-dependent species. Though the total mature population size for the seven subpopulations within the IUCN European Region greater than MVP has been increasing for the past generation, there have also been recent incidents of local extinction of other subpopulations (see WWF 2019). While the species is not currently in decline, the abundance of wild mature individuals could be reduced if there are significant perturbations such as a major disease outbreak, or current management regimes are negatively changed or removed. Such major perturbations have occurred previously leading to the species changing from Vulnerable to Endangered status in Red List Assessments conducted in 1996 and 2000. Progress in the recovery of the European Bison through large-scale ecological restoration projects will depend on significant changes in its legal status and management as wildlife by governments, harmonisation of policies and activities among agencies at multiple levels, cooperation with environmental organisations, and public tolerance and support of free-living bison managed as wildlife on large landscapes. Cooperation and coordination are particularly important where different nations and organisations have separate management jurisdiction for adjacent land areas within an ecosystem unit in which ecological restoration of bison is possible.

Red List Criterion A – Population Size Reduction.
Not applicable. Over three generations (36 years, 1985–2021), the number of free-living mature animals in subpopulations greater than MVP has increased from several hundred to over 2,600.

Red List Criterion B – Geographic Range.
Not applicable. The minimum-maximum area of occupancy (AOO) of the seven subpopulations above MVP within the IUCN European assessment region is 13,236-22,100 km², and exceeds the Criteria B threshold of 2,000 km². The extent of occurrence (EOO) for these seven subpopulations exceeds the criterion B threshold of 20,000 km². Although the species is fragmented, the species is not undergoing continuing decline or extreme fluctuations.

Red List Criterion C – Small Population Size and Decline.
In 2021, only 2,664 mature individuals occurred in seven isolated wild free-living subpopulations with total mature animals greater than MVP, and only one subpopulation was greater than 500 mature animals, thus making this species nearly qualify for Vulnerable under criterion C2a(i).

Red List Criterion D – Very Small or Restricted Population.
Not applicable. Subpopulations are widely distributed across portions of the historic range and exceed criteria D1 threshold of 1,000 total mature individuals.

Red List Criterion E – Quantitative Analysis.
Not applicable. Quantitative population viability analyses of the seven free-living subpopulations greater than MVP have not been completed.

Palaeontological and archaeological findings indicate that the species distribution during the Holocene extended east from France to the Urals and the Northern Caucasus, and north from Bulgaria to southern Sweden, not including the Iberian Peninsula (Soubrier et al. 2016, Hofman-Kamińska et al. 2019). European Bison were historically distributed across Western and Eastern Europe (Węcek et al. 2017, Pucek et al. 2004). While the species was deemed to also occur in the northern Caucasus Mountains and foothills (Heptner et al. 1966), this area is not included in the IUCN European assessment range for this analysis.

As a generalist quadruped, the European Bison evolved to utilise open or mixed habitats; and with relatively high mobility in response to environmental drivers, there was likely substantial variation in local abundance and density, including extended absences at local to regional scales while the species was still distributed across the historic range. In short, the European Bison was likely patchily distributed and did not occur everywhere all the time within suitable habitat within its historic range. Extensive forest expansion occurred 12,000–8,000 Before Present (BP) concomitant with reduced open habitats available for large herbivores such as Bison and Aurochs. Humans expanded with the development of Neolithic agriculture (7,000-5,000 years BP) resulting in pressures on bison including hunting and land use conversion to agriculture.

The species became absent from most of Europe between 9,500 and 7,000 years BP, and after this period, recovered or recolonised, probably from the east (see Hofman-Kamińska et al. 2019). Since the 16^th century, European Bison persisted in the wild only through royal protection. By the 19^th century, free-living European Bison were limited to only the Białowieża Forest of northeast Poland and western Belarus, and the Caucasus Mountains (Pucek et al. 2004). By the early 20^th century, the species was increasingly imperilled in the wild, with the Lowland Bison subspecies becoming Extinct in the Wild in 1919, and the Caucasian Bison subspecies Extinct in the Wild by 1927 (Pucek et al. 2004). All extant populations are present as a result of reintroduction efforts.

This assessment adheres to the IUCN Red List Guidelines and utilises IUCN terminology intended for consistency across taxa (IUCN 2019). For this assessment, ‘subpopulation’ does not infer a meta-population. The Red List term ‘wild’ equates to the ‘free-living’ animals as reported in the EBPB, and does not include the EBPB “captivity” or “semi-free living (e.g. large enclosures)” categories. This assessment also refers to the term ‘minimum viable population (MVP)' as an ecological threshold that specifies the smallest number of individuals in a subpopulation capable of persisting at a specific statistical probability level for a predetermined amount of time. This Red List assessment (RLA) uses the occupied grid cell approach to estimate ‘area of occupancy (AOO)’; by counting the number of occupied cells in a uniform grid that covers the entire range of distribution, and then tallying the total area (km²) of all occupied cells; so that AOO = number of occupied cells × area of an individual cell (IUCN 2019). Though the Red List Guidelines recommend using a uniform 2 x 2 km grid for consistency across taxon, we also used a comparative 10 x 10 km grid that better aligns to the spatial scale of the landscape ecology of the European Bison (see Kowalczyk et al. 2013, Kuemmerle et al. 2018, J.A. Hernandez-Blanco pers. comm. 2020, G. Wilson pers. comm. 2020), in order to generate comparative minimum and maximum AOO estimates. The term ‘extent of occurrence (EOO)’ is the calculated minimum convex polygon area size (km²) for a set of subpopulations (IUCN 2019).

In addition to information from the European Bison Pedigree Book (EBPB), this assessment also considers subpopulation-specific information to assess whether a subpopulation is deemed to contribute to the number of mature individuals considered in a Red List Assessment. A key consideration is whether a free-living subpopulation includes sufficient mature animals to maintain the potential for ecological adaption through the effects of natural selection operating on viable populations. While there is variation in age-class demography between subpopulations, this information is not uniformly monitored or reported to EBPB. As reported in the detailed species monograph by Krasińska and Krasiński (2013), the mature age class generally accounts for approximately 60% of a subpopulation. Thus, for this assessment, the 60% mature age class was applied uniformly to each subpopulation. Taking into account the levels of inbreeding of the European Bison population (described below), Brook et al. (2002) calculated the MVP of a subpopulation as 250 individuals for a 95% probability of subpopulation survival for 100 years; thus yielding a generalised MVP of 150 mature animals (250 * 0.60). Subpopulation size trend (increasing, decreasing, stable) was assessed between 2015–2019 (as reported in the 2016 and 2020 EBPB). The Red List Guidelines prescribe analyses to be conducted for the recent 10 years, or three generations, whichever is longer (IUCN 2019). For this assessment, generation length is calculated as 1/adult mortality + age of first reproduction (IUCN 2019), wherein the age of first reproduction is set at four years and adult mortality set at 13% (Krasińska and Krasiński 2013), so that generation length = 4+ 1/.13 = 11.7 rounded up to 12 years. Thus, for the analyses herein, three generations equal 36 years. Fragmentation is considered through measurements of distance (km) to nearest neighbour subpopulation and whether there are natural or man-made barriers to dispersal movement between subpopulations. Additional consideration is given to whether subpopulation resources are naturally limited or if the subpopulation otherwise receives supplemental feeding; and whether a subpopulation is subject to selective culling. In 2021, only seven free-living subpopulations exceeded MVP (range 166–462 mature animals) with a total of 2,664 mature animals (see Table 1 in Supplementary Information). During the past three generations (36 years, 1985–2021), there was a genuine, observed increase in the abundance of mature free-living European Bison living in subpopulations greater than MVP, from a few hundred to over 2,600.

The majority of European Bison subpopulations were (re)introduced to forest habitats (Kerley et al. 2012). However, patterns of habitat use strongly vary between different populations and are strongly shaped by habitat structure (forest cover) and management actions (Hofman-Kamińska et al. 2018). Preference towards open habitats such as meadows, river valleys, abandoned farmland, forest gaps and clearing is observed (Kuemmerle et al. 2011, Kowalczyk et al. 2019, Zielke et al. 2019). European Bison are mixed feeders or browsers (Gębczyńska et al. 1991, Kowalczyk et al. 2011, 2019; Bocherens et al. 2015, Merceron et al. 2015), which continuously adjust their diet with seasonal availability of easily digestible non-grass vegetation (Kowalczyk et al. 2019). In winter, bison foraging ecology can be strongly influenced by supplementary feeding (Kowalczyk et al. 2011). Non-fed populations usually utilise open habitats and agriculture areas. Farm crops depredation is compensated in some countries.

European Bison are not territorial, and their spatial organisation and population density are influenced by habitat quality and food abundance (Kerley et al. 2020). Home ranges of European Bison cover from several dozen to two hundred km², in relation to habitat structure and seasonal migrations (Kowalczyk and Plumb 2020). Home range sizes of mixed groups are influenced by the distribution and availability of forage resources, while home range of mature males is more related to reproductive behaviour and activity than food-related factors. In many populations seasonal migrations are observed, driven by supplementary feeding or access to food resources out of forest habitats, or having altitudinal character to avoid harsh winter conditions (Kowalczyk et al. 2013, Perzanowski et al. 2012). Dispersal by male bison has occurred up to several hundred km (Krasińska and Krasiński 2013). Dispersal by mixed groups is beginning to be observed in expanding populations, as the result of density-dependent intra-specific competition (Kowalczyk et al. 2013, Krasińska et al. 2014). The European Bison exhibits a well-developed and dynamic social organisation (Krasińska et al. 2014). Mixed groups of up to 20 individuals generally, including adult cows, two to three year-old sub-adults and calves are the basic social units. Males remain solitary or form bachelor groups of two to eight animals. The size and composition of mixed groups are dynamic and change seasonally, being the largest during rut and winter aggregations (Krasińska and Krasiński 2013). Daily activity is typical of large ruminants and includes foraging bouts (up to five hours) alternating with resting bouts (up to four hours) devoted primarily to rumination (Caboń-Raczyńska et al. 1987).

Genetics
Contemporary genetic variability of European Bison is relatively low, being an effect of population bottleneck due to species extirpation in the wild in the early 20^th century and subsequent restoration from limited number of captive survivors. The entire contemporary species population derives from only 12 individual genotypes (Pucek et al. 2004, Wójcik et al. 2009, Tokarska et al. 2011). Mean expected heterozygosity, calculated on the basis of microsatellite data, has been estimated as 0.29 (29%) for the Lowland line and 0.35 (35%) for the Lowland-Caucasian line (Tokarska, unpublished). This low genetic variability negatively influences effective population size (N_e). For example, the largest subpopulation is the Polish part of the Białowieża Forest (462 mature animals), yet the effective population size is likely less than 30 (Tokarska et al. 2009). Based on the extremely limited number of founder animals, this tremendous disparity between subpopulation number of mature animals and N_e can be reliably inferred for other free-ranging subpopulations.

Fragmentation and small population size
Approximately 70% of free-living subpopulations for which information is available are functionally isolated and fragmented from nearest neighbour populations by distance or barriers (man-made or natural). There are only seven subpopulations that exceed MVP within the IUCN European Region (e.g. ~30% < 25 mature animals, ~50% <50 mature individuals, and ~80% include less than MVP of 150 mature animals). Given the small size of most free-living subpopulations, those at a greater distance from a nearest neighbour are much less likely to see successful natural dispersal or exchange of cows (and their genetics) between subpopulations across multiple generations, and thus we can infer further genetic drift of inherently low genetic diversity to be amplified through long-term isolation.

Refugee species
When restoration into the wild began in 1952, the European Bison was characterised as a forest specialist and thus the species was restored to forest habitats. Increasing scientific evidence demonstrates that the European Bison is also adapted to effective use of open and mixed habitats (Mendoza and Palmqvist 2008, Kerley et al. 2012, Bocherens et al. 2015, Hofman-Kamińska et al. 2019). Recently, the species has been recharacterized as a refugee species, that can no longer access optimal habitat, but is confined to sub-optimal habitats, with consequences of decreased fitness and density, and attendant conservation risks (Kerley et al. 2012). The process of becoming a refugee species likely started after the last glaciation due to increasing human pressure related to human spread and development of Neolithic agriculture, and was reinforced during species restoration (Kerley et al. 2012, Hofman-Kamińska 2019). Confinement of an open-habitat adapted species to forest habitats may act against natural selection pressures, entails supplementary feeding, intensifies management complexity, increases management expense, increases vulnerability to disease and parasites, and may increase risks of human-wildlife conflicts when bison attempt to move out of forests (Hofman-Kamińska and Kowalczyk 2012, Kerley et al. 2012, Kowalczyk et al. 2013, Kołodziej-Sobocińska et al. 2016a,b,c; Samojlik et al. 2019). Contemporary habitat selection indicates the species’ preference for open and wet/open habitats and abandoned fields over the forests, especially coniferous ones (Kuemmerle et al. 2010, 2018; Kowalczyk et al. 2019; Zielke et al. 2019). As a large and potentially conflicting species, European Bison require large spaces of mosaic habitats supporting the populations year-round, with lower human densities and agricultural activities, to reduce potential conflicts. Such areas are limited in Europe. Increasing land abandonment in Eastern Europe (Russia and Ukraine) creates potentially suitable conditions for species restoration (Alcantara et al. 2013), however, instability of nature conservation in those countries makes these areas risky. Forest introductions are still continuing (e.g. Bad Berleburg, Germany and Augustów Forest, NE Poland), though recent reintroduction in Romania and Bulgaria in suitable remote mountainous areas may lead to subpopulation growth with less conflict.

Disease
Knowledge on health status of European Bison comes from limited number of populations, mainly in Poland. While several diseases are known to occur in European Bison, including Bluetongue Virus (BTV), Foot-and-mouth Disease Virus (FMDV), respiratory viruses, and Bovine Tuberculosis (Larska and Krzysiak 2019), they are not as broadly distributed within or across free-ranging populations as the infectious parasites. Nearly 90 species of parasites in European Bison were identified (Karbowiak et al. 2014a, b), with species richness, prevalence and intensity of infections increasing in multiple populations (Drożdż 1998). It was documented that supplementary feeding and unnatural aggregation of bison in winter at fixed locations lead to increased parasitic load (Radwan et al. 2010, Kerley et al. 2012, Karbowiak et al. 2014b, Kołodziej-Sobocińska et al. 2016b). Adaptive management has proven effective in reducing parasite transmission and risk of diseases (Kołodziej-Sobocińska et al. 2016b).

Culling, hunting, and poaching
Paradoxically for a species with low numbers, some free-living subpopulations (including small ones) are subjected to culling to reduce the number, regulate sex-age structure or even for commercial hunting purposes. This policy contrasts strongly with the management of other large mammals which have undergone similar population declines as the European Bison and for which populations are now increasing in response to conservation management, such as the rhinoceros or the Cape Mountain Zebra (Emslie 2008, IUCN SSC African Rhino Specialist Group 2008, Hrabar and Kerley 2013). Poaching plays a locally important role, especially in small populations exposed to high stochasticity. In the 1990s, uncontrolled hunting and poaching in Ukraine during democratic transformation resulted in a strong decline or extirpation of bison herds (WWF 2019).

Social conflict and war
In February 2022, Russia invaded Ukraine, and several European Bison protected areas became either directly occupied or are threatened by long-range artillery, rocket fire, mines, environmental degradation and active warfare. At present it is impossible to closely monitor the situation of protected areas and species, nevertheless over 50% of European bison in Ukraine are directly threatened by acts of warfare, and restoration to pre-war status will undoubtedly require the involvement of international organizations like the Bison Specialist Group of the IUCN Species Survival Commission, the European Bison Conservation Center, or the World Wildlife Fund (Perzanowski and Smagol 2022).

Policy inconsistency
Though this issue was identified in the 2004 European Bison Status Survey and Conservation Action Plan (Pucek et al. 2004), it still remains an important concern. The European Bison is generally a protected species in the countries where it occurs. It is covered by EU legislation in the frame of Council Directive 92/43/EEC on the conservation of natural habitats and of wild fauna and flora, and included in Annex 2 (animal and plant species of community interest whose conservation requires the designation of special areas of conservation) as priority species, and Annex 4 (animal and plant species of community interest in need of strict protection). However, across the historic range, there are inconsistent national policies regarding management and conservation procedures, that can concede to habitat degradation, population restriction, and selective culling. Following political transformations in Eastern Europe, uncontrolled hunting and poaching in Russia and Ukraine lead to population decline (Pucek et al. 2004, WWF 2019). Such inconsistency not only impacts existing populations but also limits the possibility of restoration and population expansion. Large areas of abandoned fields in eastern Europe in recent decades (especially in Russia and Ukraine) (Alcantara et al. 2013) may now be suitable for the introduction of the bison but cannot currently be considered due to insufficient protection.

In general, free-living European bison are not subject to extensive trade and use. All free-living subpopulations exist at locations where management emphasis is primarily on protection of the species; with some locations utilising supplemental feeding and selective culling to manage local distribution and abundance in order to mitigate potential poaching and conflicts with surrounding land uses.

Population viability
While the European Bison is no longer threatened by extinction, most free-living subpopulations are small and isolated. Small, isolated subpopulations are at risk from random catastrophic events and also lose genetic diversity more quickly than large subpopulations through the process of genetic drift, which in turn can decrease the viability of populations through an accumulation of inbreeding and loss of adaptive capacity. To mitigate the loss of genetic diversity in these isolated subpopulations, bison population viability analyses have suggested increasing subpopulation size where possible, and otherwise restoring effective gene flow among subpopulations and managing under a meta-population framework, where gene flow can be restored either through the restoration of natural movements between populations or through the translocation of animals (or gametes) among populations (Daleszczyk and Bunevich 2009, Hartway et al. 2019).

Conservation planning
In 2004, the IUCN-SSC-BSG published a report entitled “European Bison Status Survey and Conservation Action Plan” (Pucek et al. 2004). With the free-living population growing from 1,848 in 2003 to 6,244 in 2019, it is clearly time to undertake a new collaborative multi-stakeholder conservation planning process to produce an update to the 2004 CAP that includes a long-term conservation action plan with a very strong scientific basis and actionable consensus. Key issues needing to be examined include climate and environmental change, science advances and needs, increased interest in restoration programs involving large mammals, meta-population dynamics, conservation genetics (including the prevailing emphasis on separation of the Lowland (B. b. bonasus) and Caucasian (Bison bonasus bonasus x B. b. caucasicus) genetic lines amongst free-living subpopulations), disease ecology, habitat availability and shifting land use practices, restoration and translocation priorities, human dimensions, integrated in situ and ex situ management, and European Union and variable national and legal and policy status. The IUCN SSC BSG is formally partnering with the IUCN SSC Conservation Planning Specialist Group and multiple European wildlife conservation organisations to undertake collaborative conservation planning to produce an updated IUCN CAP that will serve as an innovative, efficient and effective milestone for its potential to empower new initiatives and result in better alignment of multi-national conservation strategies and actions.

Science needs
There is a critical need to enhance levels of collaborative and comparative science. Enhancing the effectiveness and sustainability of restoration activities should include testing of alternative hypotheses about landscape ecology, analysing habitat availability and suitability for optimal restoration designs, and comparative analyses of population viability and potential meta-population management strategies (see Daleszczyk and Bunevich 2009; Hartway et al. 2020; Kerley et al. 2012, 2020). Comparative analyses of the effects of selective culling and supplemental feeding will be important for improving the efficiency and effectiveness of local conservation management. Also needed are comparative analyses of bison ecology across the historic range (e.g. population ecology, metapopulation macrophysiology, foraging ecology, competition with sympatric wild ungulates, ecological cascades, ethology, etc.), comprehensive disease and parasitology monitoring, and innovative social science that addresses the human dimensions of bison recovery.

Adaptive management
Achieving the full ecological recovery of the European Bison conservation will require the collaboration of researchers, managers, and policymakers to develop and implement science-based adaptive management (Kerley and Knight 2010). There is a need to institutionalise evidence-based capacity to learn and adjust management as needed to restore bison to optimal habitats that secure the needs of the species throughout the year and spacious enough to maintain viable populations (Samojlik et al. 2019). It is very important to adaptively manage for an effective and efficient balance of supplementary feeding and culling with conservation of the full extent of the species naturally evolved ecology. Adaptive management can also serve as a framework to restore large heterogeneous landscapes that include forests, meadows and open habitats for both existing and future bison herds, thereby potentially lowering the expense of supplementary feeding when introducing to suitable habitats; to gain and employ an improved understanding of the human dimensions of bison recovery and thereby enhance active social support that includes financial and habitat commitments; and to strive for effective long-term genetic conservation and population viability by establishing sufficiently large meta-populations that link smaller isolated populations across regional geographic ranges.