Reintroduce mammals as ecosystem engineers

Overall effectiveness category Awaiting assessment
Number of studies: 1
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Background information and definitions

Large mammals can act as ecosystem engineers, altering the habitat around them. This often takes the form of disturbance: by grazing, browsing, uprooting or felling dominant plant species (Hess et al. 2014). This creates new habitats (such as bare ground, deadwood, or open water), which may benefit butterfly and moth species directly, or allow the establishment of less competitive plant species on which butterflies and moths depend (de Schaetzen et al. 2018). Common examples of mammals considered to be ecosystem engineers include elephants, wild boar (de Schaetzen et al. 2018), bison (Hess et al. 2014) and beavers.

_{de Schaetzen F., van Langevelde F. & WallisDeVries M.F. (2018) The influence of wild boar (Sus scrofa) on microhabitat quality for the endangered butterfly Pyrgus malvae in the Netherlands. Journal of Insect Conservation, 22, 51–59.}

_{Hess A.N., Hess R.J., Hess J.L.M., Paulan B. & Hess J.A.M. (2014) American Bison influences on lepidopteran and wild blue lupine distribution in an oak savanna landscape. Journal of Insect Conservation, 18, 327–338.}

Study locations

Key messages

One study evaluated the effects on butterflies and moths of reintroducing mammals as ecosystem engineers. This study was in Italy.

COMMUNITY RESPONSE (1 STUDY)

Richness/diversity (1 study): One replicated, site comparison study in Italy found that olive groves with wild boar present had a lower species richness of butterflies than groves without wild boar.

POPULATION RESPONSE (1 STUDY)

Abundance (1 study): One replicated, site comparison study in Italy found that olive groves with wild boar present had a lower total abundance of butterflies, and a lower abundance of six individual species, but a higher abundance of two species, than groves without wild boar.

BEHAVIOUR (0 STUDIES)

About key messages

Key messages provide a descriptive index to studies we have found that test this intervention.

Studies are not directly comparable or of equal value. When making decisions based on this evidence, you should consider factors such as study size, study design, reported metrics and relevance of the study to your situation, rather than simply counting the number of studies that support a particular interpretation.

Supporting evidence from individual studies

A replicated, site comparison study in 2011–2012 in 10 olive groves in Campania, Italy (Scandurra et al. 2016) found that groves with wild boar Sus scrofa present had a lower abundance, species richness and diversity of butterflies than groves where boar were absent. The abundance, species richness and diversity of butterflies in olive groves with wild boar were lower than in groves without boar (data not presented). Habitat specialist species were 83% less abundant in groves with wild boar than groves without boar, whereas habitat generalist species were 27% less abundant where boar were present. Although two species (clouded yellow Colias croceus and common blue Polyommatus icarus) were more abundant in groves with boar than groves without boar, six species (brown argus Aricia agestis, tree grayling Hipparchia statilinus, wall Lasiommata megera, Italian marbled white Melanargia arge, southern gatekeeper Pyronia cecilia and Lulworth skipper Thymelicus acteon) were less abundant in groves with boar (see paper for full species results). Five olive groves with signs of heavy wild boar disturbance, and five groves with no signs of wild boar, were selected. From April–September 2011–2012, butterflies were surveyed 2–3 times/month on one 200-m transect in each grove. Butterflies were classified as “habitat specialists” or “habitat generalists” according to their habitat preferences.
Study and other actions tested
Referenced paper
Scandurra A., Magliozzi L., Fulgione D., Aria M. & D'Aniello B. (2016) Lepidoptera Papilionoidea communities as a sentinel of biodiversity threat: The case of wild boar rooting in a Mediterranean habitat. Journal of Insect Conservation, 20, 353-362.

Please cite as:

Bladon A.J., Bladon, E. K., Smith R.K. & Sutherland W.J. (2023) Butterfly and Moth Conservation: Global Evidence for the Effects of Interventions for butterflies and moths. Conservation Evidence Series Synopsis. University of Cambridge, Cambridge, UK.