Butterflies in Scotland

Butterflies are as important as they are beautiful, supporting the delictate network of  biodiversity that underpins our natural spaces and agricultural industry. They also act as valuable indicator of wider habitat and ecosystem health as they are quick to respond to enviornmental changes (JNCC, 2023). 

Background and Importance:
Atleast 35 species of butterfly are known to consistently breed in Scotland (Butterfy Conservation Scotland, 2020). A full list of these species can be found here: Butterflies of Scotland.   Butterfly species are split into two categories depending on their preferred habitats. 
Generalist species are able to live in a wide variety of habitats (NatureScot, 2023 b), and include species such as Peacock butterflies and Orange-tip butterflies (fig. 1) (NatureScot, 2016). Specialist species require specific habitat types, and so are more vulnerable to habitat loss (JNCC, 2023). Two examples of this subset include the Marsh Fritillary (fig. 2) and the Pearl Bordered Fritillary (NatureScot, 2023 c).                                                                                                                                                                                                            While not technically classed as vital pollinators (the category of bees for example), the precense of butterflies is necessary to support vital pollinator species (NatureScot, 2023 b). They play a multitude of crucial roles in Scotland’s ecosystems, from acting as prey for native birds and bats, to controllering numbers of smalller insects.  They are also highly valuable in scienfitic research, and can be beneficial to communities and mental healthy outcomes by getting people engaged with the outdoors (Butterfly Conservation, 2021). 

Recent Trends and distribution:
Overall, Scottish pollinator numbers have been on a decreasing trend since the 1980s, dropping by atleast a half as of 2017 (Scottish Government, 2017). Butterfly numbers on the other hand have seen more success, rising overall by 35% in the same four decades (NatureScot, 2023 a). 
It is important to note how these patterns vary between species. As is displayed in fig. 3, generalist species have been much more successful than specialist species. Generalist species have recorded a 47% increase between 1979 and 2022  (NatureScot, 2023 b), while specialist species decreased by 67% between 1979 and 2014 (NatureScot, 2016). 
The picture of the wider UK is not overly positive, with JNCC (2023) reporting either deteriorating or consistent status in UK butterfly species numbers, with no overall populations recovery observed. 

Factors Affecting Butterly Numbers:
Positive Change-
For generalist species, increasing temperatures caused by climate change are believed to have had positive effects thus far. It is known that multiple species, both year round and migratory residents, have directly and significantly benefitted from climate change warming, expanding their ranges further North (NatureScot, 2016). 
Additionally, the many organisations, charites and community groups involved in butterfly protection and research are positively contributing to Scotland’s butterflies. 
Negative Change- 
The breaking apart and reduction of habitat, often due to agriculture, has a significantly negaitve effect on butterfly numbers. Habitat loss and fragmentation both reduce butterfly numbers, and their ability recover from other adverse efffects, as small groups become isolated from one another (NatureScot, 2023 b). 
Change change also has the potential to bring negative impacts. Shifting plant seasonality and increasinly extreme, unpredictable weather could reduce butterfly numbers, and the permanent nature of such climate alterations would make recovery difficult (NatureScot, 2023 b). 

Conservation Efforts:
Currently, Scotland is a stronghold for various species that are threatened in other parts of the country (Butterfly Conservation, 2018). With climate change and human caused landscape degredation, the risks all butterfly species face will continue to rise without concerted efforts towards conservation. 
Thankfully, many butterfly conservation projects and groups are in action across the country. Some examples include:
- The Pollinator Strategy for Scotland 2017-2027
oA collaborative project by Scottish Natural Hertiage the Scottish Government, and many other groups, aiming to protect and promote pollinators in Scotland (NatureScot, 2020 a). 
- Butterfly Monitoring Scheme (UKMBS)
o A long-running project, using community involvement to monitor butterfly numbers since 1976 (UKBMS, n.d.)
- Species on the Edge 
o A project by NatureScot to protect highly threatened species and habitats in Scotland. Butterflies protected by the project include the Marsh Fritillary, the Northern Brown Argus, and the Small Blue Butterfly, as well as various moth species (NatureScot, 2020 b).