REVIEW: The management of wild large herbivores to meet economic, conservation and environmental objectives

Abstract

Summary 1.Wild large herbivores provide goods and income to rural communities, have major impacts on land use and habitats of conservation importance and, in some cases, face local or global extinction. As a result, substantial effort is applied to their management across the globe. To be effective, however, management has to be science-based. We reviewed recent fundamental and applied studies of large herbivores with particular emphasis on the relationship between the spatial and temporal scales of ecosystem response, management decision and implementation. 2. Long-term population dynamics research has revealed fundamental differences in how sex/age classes are affected by changes in density and weather. Consequently, management must be tailored to the age and sex structure of the population, rather than to simple population counts. 3. Herbivory by large ungulates shapes the structure, diversity and functioning of most terrestrial ecosystems. Recent research has shown that fundamental herbivore/vegetation interactions driving landscape change are localized, often at scales of a few metres. For example, sheep and deer will selectively browse heather Calluna vulgaris at the edge of preferred grass patches in heather moorland. As heather is vulnerable to heavy defoliation, in the long term this can lead to loss of heather cover despite the average utilization rate of heather in a management area being low. Therefore, while herbivore population management requires a large-scale approach, management of herbivore impacts on vegetation may require a much more flexible and site-specific approach. 4. Localized impacts on vegetation have cascading effects on biodiversity, because changes in vegetation structure and composition, induced by large herbivores affect habitat suitability for many other species. As such, grazing should be considered as a tool for broader biodiversity management requiring a more sophisticated approach than just, for example, eliminating grazing from conservation areas through the use of exclosures. 5. Synthesis and applications . The management of wild large herbivores must consider different spatial scales, from small patches of vegetation to boundaries of an animal population. It also requires long-term planning based on a deep understanding of how population processes, such a birth rate, death rate and age structure, are affected by changes in land use and climate and how these affect localized herbivore impacts. Because wild herbivores do not observe administrative or political boundaries, adjusting their management to socio-political realities can present a challenge. Many developing countries have established co-operative management groups that allow all interested parties to be involved in the development of management plans; developed countries have a lot to learn from the developing world's example.

The impact of red deer on liverwort-rich oceanic heath vegetation

“…This was particularly noticeable in those sample plots of oceanic heath that were in transition to grassland associated with the edges of existing patches of grassland. This edge effect is consistent with the literature since red deer are known to exert a greater impact on heather where it borders patches of grassland than elsewhere in a heathland (Clarke et al 1995ab;Hester and Baillie 1998;Milne and Hartley 2001;Gordon et al 2004). Grassland is a poor habitat for the Northern Atlantic hepatic mat community (Ratcliffe 1968) with reduced humidity and no protection from extremes of temperature and insolation.…”

“…The interaction between herbivores and vegetation is localised within a landscape but remains an important driver of change (Gordon et al 2004). Therefore, it is expected that within an area of heather moorland there will be places that are more intensively used than others.…”

“…The sensitivity of the landscape is influenced by the patchiness of vegetation because change is fastest at the boundaries between plant communities (Milne and Hartley 2001). For example, red deer prefer to browse Calluna at the edge of grass patches in upland heath leading to loss of heather cover (Hester and Baillie 1998;Gordon et al 2004). Patches of Northern Atlantic hepatic mat were expected to be at lower risk from the effects of trampling or loss of the dwarf-shrub layer in places where it was awkward for deer to access or less attractive for grazing.…”

How constraints affect the hunter’s decision to shoot a deer

“…ungulate populations in industrialized countries, management centers around population control and recreational aspects (2,4) or around conservation and balancing the exploitation for meat and trophies (12,18). For both settings, there is a pressing need to understand how different selection patterns are formed and how they influence the development of wildlife populations.…”

Estimating densities of large herbivores in tropical forests: Rigorous evaluation of a dung‐based method

“…Large herbivores are integral to terrestrial habitats across the Earth and as primary consumers are key to food webs and the functioning of ecosystems they inhabit (Gordon, Hester, & Festa‐Bianchet, 2004; Malhi et al., 2016). Populations of large herbivores across the earth have, however, collapsed, and many large herbivore species are threatened with large‐scale extirpations (Ripple et al., 2015).…”