Background Refaunation/rewilding by large ungulates represents a cost-efficient approach to managing natural biotopes and may be particularly useful for areas whose biodiversity depends on disturbance dynamics and is imperilled by successional changes. To study impacts of refaunation on invertebrates, we focused on butterflies inhabiting the former military training range Milovice, Czech Republic, refaunated since 2015 by a combination of Exmoor pony (“wild” horse), Tauros cattle (“aurochs”), and European wisent. Methods We analysed butterfly presence-absence patterns immediately after the military use termination (early 1990s), prior to the refaunation (2009), and after it (2016–19); and current abundance data gained by monitoring butterflies at refaunated and neglected plots. We used correspondence analysis for the presence-absence comparison and canonical correspondence analysis for the current monitoring, and related results of both ordination methods to the life history and climatic traits, and conservation-related attributes, of recorded butterflies. Results Following the termination of military use, several poorly mobile species inclining towards oceanic climates were lost. Newly gained are mobile species preferring warmer continental conditions. The refaunated plots hosted higher butterfly species richness and abundances. Larger-bodied butterflies developing on coarse grasses and shrubs inclined towards neglected plots, whereas refaunated plots supported smaller species developing on small forbs. Conclusion The changes in species composition following the cessation of military use were attributable to successional change, coupled with changes in species pool operating at larger scales. By blocking succession, large ungulates support butterflies depending on competitively poor plants. Restoring large ungulates populations represents a great hope for conserving specialised insects, provided that settings of the projects, and locally adapted ungulate densities, do not deplete resources for species with often contrasting requirements.

Background: Refaunation by large ungulates represents a cost-efficient approach to managing natural biotopes. We studied butterflies inhabiting grasslands of the former Milovice military training range in the Czech Republic, grazed since 2015 by a combination of Exmoor pony (“wild” horse), Tauros cattle (“aurochs”) and European wisent. Methods: We compared presence-absence patterns from two surveys preceding the refaunation, one immediately after military use termination (early 1990s), the other prior to the refaunation (2009), with the current (2016–19) results of monitoring 8 grazed and 8 ungrazed plots. We analysed the life history, climatic and conservation-related traits of recorded butterflies to gain insights into the ungulates’ impacts. Results: Following the termination of military use, several poorly mobile species displaying broad oceanity niches were lost. Newly gained species are more mobile and prefer warmer continental conditions. Currently, numbers of butterfly species do not differ between refaunated and neglected plots, but the former hosted higher abundances. Butterflies developing on coarse grasses and shrubs inclined towards neglected plots, whereas refaunated plots supported species developing on small forbs. Conclusion: The changes in species composition following the cessation of military use are attributable to successional change, coupled with climate-driven expansion of thermophilous and mobile species. By blocking succession, large ungulates support butterflies depending on competitively poor plants. Preserving butterflies of late-successional stages is ensured by the diverse setting of the reserves and by the relatively low ungulate densities.

Background: Refaunation/rewilding by large ungulates represents a cost-efficient approach to managing natural biotopes and may be particularly useful for areas, whose biodiversity depends on disturbance dynamics and is imperilled by successional changes. To study impacts of refaunation on invertebrates, we focused on butterflies inhabiting the former military training range Milovice, Czech Republic, refaunated since 2015 by a combination of Exmoor pony (“wild” horse), Tauros cattle (“aurochs”) and European wisent.Methods: We compared butterfly presence-absence patterns immediately after the military use termination (early 1990s), prior to the refaunation (2009) and after it (2016–19); and quantitative data gained by monitoring butterflies at refaunated and neglected plots. We used the correspondence analysis for the presence-absence comparison and the canonical correspondence analysis for the quantitative data, and related results of both ordination methods to the life history, climatic and conservation-related traits of recorded butterflies. Results: Following the termination of military use, several poorly mobile species inclining towards oceanic climates were lost. Newly gained species are more mobile and prefer warmer continental conditions. The numbers of butterfly species did not differ between refaunated and neglected plots, but the former hosted higher abundances. Butterflies developing on coarse grasses and shrubs inclined towards neglected plots, whereas refaunated plots supported species developing on small forbs. Conclusion: The changes in species composition following the cessation of military use were attributable to successional change, coupled with climate-driven changes in species pool. By blocking succession, large ungulates support butterflies depending on competitively poor plants. Restoring large ungulates populations represents a great hope for conserving specialised insects, provided that settings of the projects, and locally adapted ungulate densities, do not deplete resources for species with often contrasting requirements.

Background: Refaunation/rewilding by large ungulates represents a cost-efficient approach to managing natural biotopes and may be particularly useful for areas whose biodiversity depends on disturbance dynamics and is imperilled by successional changes. To study impacts of refaunation on invertebrates, we focused on butterflies inhabiting the former military training range Milovice, Czech Republic, refaunated since 2015 by a combination of Exmoor pony (“wild” horse), Tauros cattle (“aurochs”), and European wisent.Methods: We compared butterfly presence-absence patterns immediately after the military use termination (early 1990s), prior to the refaunation (2009), and after it (2016–19); and abundance data gained by monitoring butterflies at refaunated and neglected plots. We used correspondence analysis for presence-absence comparison and canonical correspondence analysis for quantitative data, and related results of both ordination methods to the life history, climatic, and conservation-related traits of recorded butterflies. Results: Following the termination of military use, several poorly mobile species inclining towards oceanic climates were lost. Newly gained species are more mobile and prefer warmer continental conditions. The numbers of butterfly species did not differ between refaunated and neglected plots, but the former hosted higher abundances. Butterflies developing on coarse grasses and shrubs inclined towards neglected plots, whereas refaunated plots supported species developing on small forbs. Conclusion: The changes in species composition following the cessation of military use were attributable to successional change, coupled with climate-driven changes in species pool. By blocking succession, large ungulates support butterflies depending on competitively poor plants. Restoring large ungulates populations represents a great hope for conserving specialised insects, provided that settings of the projects, and locally adapted ungulate densities, do not deplete resources for species with often contrasting requirements.