Moth Conservation
Moths in Decline - Part 1
29/01/2024
Moths are a barometer for the health of the environment around us, and they are in trouble. 
The population of the stunning Garden Tiger collapsed by over 90% since the late 1960s. Mild, wet winters and warm springs are believed to have impacted larval survival
Moths are special and important and it is therefore are it is deeply concerning that a number of long term studies have produced strong evidence that many of our moths are in trouble.
A decrease of 33% in overall numbers have been found in across Britain between 1968 and 2017. A Scottish study found that moth abundance declined by 46% between 1990 and 2018, with the situation worsening in recent years. During the 20th century 62 species were lost from Britain. In Ireland 14 species are considered to have gone regionally extinct, with a further 43 macro moths assessed as threatened
Large declines have been recorded elsewhere in Europe, and even within nature reserves. Rarely do we see the windscreens of our cars covered in dead insects after driving on warm summer nights, which was a common experience in the past decades. It appears that moths are a good barometer for the health of other insect groups, which is very worrying nature and humans.
Many of the species we can find in North Antrim are those which are experiencing the greatest population declines. Even our “common” species are much less frequent than in the past.
It would be wrong though, to assume that these declines are only a recent phenomenon, simply because that is when reliable datasets began. What the previous generation considered normal, may itself been a shadow of the diversity and numbers of moths present in previous centuries. In North Antrim the Belted Beauty was formally a resident species, around Ballycastle, but was lost in the late 19th or early 20th Century and the beautiful Portland moth was last recorded from Portrush and Portballintrae in 1903.
Moths are being lost across a range of habitats. Scientists led by Rothamsted Research have discovered that populations of moths in the UK have more than halved in broadleaf woodland, compared to average losses of 34% across the other habitats. It may be that the woodlands have been later in reaching these dramatic declines.
It is not just changes in numbers of moths that is of concern, but also changes in their distribution. Some species are moving north, some to high altitudes and others are retreating in their range to core areas.
While the reasons for the rapidly changing populations and distribution in our moths is not fully understood. a number of likely causes have been identified for these declines, though the action of humans appear to be the common link. Loss and degradation of habitat, climate change and various forms of pollution all are likely playing their part. These actions have been catastrophic not only for the moths, but also the web of life which they support.
A decrease of 33% in overall numbers have been found in across Britain between 1968 and 2017. A Scottish study found that moth abundance declined by 46% between 1990 and 2018, with the situation worsening in recent years. During the 20th century 62 species were lost from Britain. In Ireland 14 species are considered to have gone regionally extinct, with a further 43 macro moths assessed as threatened
Large declines have been recorded elsewhere in Europe, and even within nature reserves. Rarely do we see the windscreens of our cars covered in dead insects after driving on warm summer nights, which was a common experience in the past decades. It appears that moths are a good barometer for the health of other insect groups, which is very worrying nature and humans.
Many of the species we can find in North Antrim are those which are experiencing the greatest population declines. Even our “common” species are much less frequent than in the past.
It would be wrong though, to assume that these declines are only a recent phenomenon, simply because that is when reliable datasets began. What the previous generation considered normal, may itself been a shadow of the diversity and numbers of moths present in previous centuries. In North Antrim the Belted Beauty was formally a resident species, around Ballycastle, but was lost in the late 19th or early 20th Century and the beautiful Portland moth was last recorded from Portrush and Portballintrae in 1903.
Two charismatic moths lost from North Antrim by the early 20th Century - Belted Beauty and Portland Moth
Moths are being lost across a range of habitats. Scientists led by Rothamsted Research have discovered that populations of moths in the UK have more than halved in broadleaf woodland, compared to average losses of 34% across the other habitats. It may be that the woodlands have been later in reaching these dramatic declines.
It is not just changes in numbers of moths that is of concern, but also changes in their distribution. Some species are moving north, some to high altitudes and others are retreating in their range to core areas.
While the reasons for the rapidly changing populations and distribution in our moths is not fully understood. a number of likely causes have been identified for these declines, though the action of humans appear to be the common link. Loss and degradation of habitat, climate change and various forms of pollution all are likely playing their part. These actions have been catastrophic not only for the moths, but also the web of life which they support.