Statistical News Release: Marine and Terrestrial Species Indicators - Experimental Official Statistic

NatureScot has today released the latest figures tracking the abundance and occupancy of 2,803 Scotland’s marine and terrestrial species.

The average abundance for 14 breeding seabirds fell by 41% over the long term (1994-2019).  In the short term (2016-2019) this indicator declined by 8%.

The average abundance for 337 terrestrial species (birds, mammals, butterflies and moths) was stable over the long term (1994-2019).  In the short term (2016-2019) this indicator increased by 14%.

This indicator is mainly driven by the moths and birds as they contribute the most species (170 and 133, respectively).  Birds have remained relatively stable since 2004 – between 13% and 20% above their 1994 value.  Moths have shown recovery in recent years (since 2015), probably due to warmer summers, although they remain 27% lower than their 1994 value.  Although much fewer species (25), butterflies have seen a rapid increase since 2016 and so is also likely to be a driver for the increase seen in the overall terrestrial abundance indicator over that period.  As for moths, the increase seen in butterfly abundance is likely to be caused by warmer summers.

The average occupancy of 2,466 terrestrial species (invertebrates, lichens and bryophytes) has not been updated since the last release and so the latest available data remains an increase of 24% over the long term (1994-2016).  In the short term (2015-2016) the indicator was stable.

The baseline of 1994 was chosen as it is the earliest for which we have comprehensive records.  It does not represent a target level. Other evidence (e.g. Natural Capital Asset Index) suggests that biodiversity in Scotland had already declined markedly prior to 1994.