Sika could come to dominate Scottish woodlands, study warns

Non-native sika deer may come to dominate Scottish woodlands unless management practices change, according to a new study published in 2025.

The research, titled The ungulate pretender: Why the non-native sika deer may dominate Scottish woodlands, warns that non-selective deer culling strategies are inadvertently helping sika outcompete native red and roe deer.

.

General culls favour sika

Sika’s greater resilience and higher breeding rates mean that general deer culls disproportionately reduce native species, shifting the competitive balance further in sika’s favour. The deer are thriving in conifer plantations and mixed woodlands, with the ability to reach higher numbers than native species under current management.

The British Deer Society, highlighting the findings, stresses the importance of species-specific culls. Modern deer management pilots, including NatureScot schemes, are placing greater emphasis on controlling non-native deer in forestry and woodland restoration areas.

.

Hybridisation complicates conservation efforts

Complicating matters, a 2019 genetic study found that 26% of deer thought to be pure were actually red-sika crossbreeds. These hybrids look like pure animals, making them difficult to identify without genetic testing.

Charles Smith-Jones, BDS technical adviser, told Shooting Times: “Sika can be highly adaptable and secretive, so they can quickly gain the upper hand if deer management strategies are not carefully targeted. By focusing on species-specific control and coordinated monitoring, we can protect Scotland’s native deer populations and the woodlands they rely on.”