A recent report by ReWild Wicklow as part of a Europe-wide wildlife monitoring project has shown the “continued dominance” of non-native sika deer in Co. Wicklow.
As part of its camera trap initiative across east Wicklow in 2023, ReWild Wicklow monitored 47 sites, collected 183,297 photographs and captured 11 wild mammal species and 16 bird species.
The project is part of Snapshot Europe, which seeks to establish a snapshot of mammal distribution and frequency across Europe during September and October each year.
Sika were by far the most common species detected, making up 72% (4,526) of all 6,313 independent observations of wild mammals, with the next most common species being red squirrel at 11% (689).
One of the locations, however, accounted for 41% (281) of red squirrel observations. The next most common mammal was red fox with 10% (601) of observations as part of the volunteer-run initiative.
Sika were recorded at all 47 operational camera trap sites, followed by red fox which was captured at 36 sites, and red squirrels at 26 project sites, report findings show.
There were 2,114 observations of adult female sika,1,433 observations of adult males, and 177 unknown adults. A total of 576 observations included a juvenile sika, and 293 sika observations were of unknown age and sex classes.
Sika deer
Nearly every site previously monitored in 2021 and 2022 were again monitored in 2023, except for those sites that were clear felled or where land access was impossible.
In 2021 and 2022, sika deer were the most dominant species by a large margin. The report states there is an indication of a “significant increase” in sika abundance between 2021 and 2023.
Compared to the Snapshot Europe survey in 2022, sika males were more common relative to females, similar to 2021 findings. Sika juveniles were seen at approximately the same rate compared to females in all years.
Sika are now widely distributed in Ireland with an understanding that their population has been increasing in recent years, according to the recently published ReWild Wicklow report.
Central Co. Wicklow is a “deer hotspot” and requires coordinated and planned management, especially of sika, to mitigate potential deer damage that is both economic and ecological, the report states.
Sites where red deer were recorded are more common this year than in previous years, but these events were very rare relative to sika, and most observations showed clear evidence of hybridisation despite more red deer phenotypes (traits).
New wild mammals recorded last year, compared to 2022, were fallow deer and the eastern grey squirrel. In total, there were 6,679 independent observations, of which 6,313 were wild mammals.
While some mammals remain undetected, they are believed to be in the area, such as the European rabbit, stoat, Eurasian otter, and American mink, according to the report.