Climate Change? Let’s worry about Habitat Loss

The phrase “climate change” is inescapable right now. I heard the phrase used in the budget speech in the Dáil. I heard the term in a House of Commons debate on Tuesday 8th October.  It is used everywhere, on TV, radio, online. It is used in school textbooks so everyone, young and old, is familiar with it. It has fired campaigning zeal especially from the young. Concern about climate change is not new. In The Great Gatsby, the American novel by F. Scott Fitzgerald published in 1926, Tom Buchanan expresses his confused view of climate change:

“I read somewhere that the sun’s getting hotter every year,” said Tom genially. “It seems pretty soon the earth’s going to fall into the sun-or wait a minute-it’s just the opposite-the sun’s getting colder every year”.

Tom does not comment on anthropomorphic climate change, the subject of most of today’s climate discourse but his remarks show an awareness of climate change.

Climate change is ‘normal’. It has occurred throughout history and pre-history. The nineteenth-century saw some very curious weather patterns in these islands. We had damp, warm weather in the second half of the 1840s, good weather for the most part from 1850-1877 and mainly colder conditions for most of the rest of the nineteenth century with the occasional warm, sunny summer (1893).

We have had some bitterly cold winters and even cold years. This most notably happened in the years 1739-1741 when bitterly cold weather killed an estimated 310,000-480,000 people out of an Irish population estimated at 2.4 million. This killed up to 20% of the Irish population, a far higher percentage than those killed by The Great Famine 1845-1850. The seas froze, cattle and sheep died of the cold, crops failed. The frozen Shannon was crossed on horseback.

No cause has been identified for this remarkable climate event. Climate change expert Professor John Sweeney of the Irish Climate Analysis Research Unit (ICARUS) at Maynooth University said the cause of the catastrophic winter of 1740-41, often referred to as the mini Ice Age, remains a mystery.

Where does this leave us today? While I am not a climatologist, I feel that the current focus on climate change is probably somewhat misplaced. Butterfly and moth populations are often seen as indicators of climate change. Many species have very particular requirements that are easily upset by change. The immature stages are the most sensitive. The larval stage is the growth stage and without the correct conditions, larvae do not develop. Pupae formerly believed not to be particularly sensitive to damp have recently been demonstrated to suffer from prolonged exposure to rain in a number of British and Irish species.

However, in the most recent assessments of our butterfly and moth populations published by the National Parks and Wildlife Service, Department of Arts, Heritage and the Gaeltacht, Dublin in 2010 (butterflies) and 2016 (macro-moths) which assessed the conservation status of 30 butterflies and 501 macro-moths (the larger moth species) pointed mainly to habitat change as the cause of declines. Climate change is not mentioned in relation to the conservation status of any of the butterflies assessed.

Only three of the 501 moths were stated to be negatively affected now or predicted to be negatively affected in the future by climate change; these are Red Carpet (“Habitat loss is considered one of the main causes for this decline but it may also be impacted by climate change.”), Sandhill Rustic (“The moth occurs on undercliffs and upper beach so is threatened by habitat loss through factors such as erosion and in the long term by climate change”) and Northern Dart (“The upland habitat used is threatened by changing land use, overgrazing and climate change.”) However, in the case of these three species, habitat loss is also strongly implicated. While the conservation status of Lepidoptera species Ireland does not appear to be affected by climate change (except for three species), of course, this may not be the case elsewhere.

What is known for certain is that habitat has been lost and continues to be lost. Habitats can be lost arising from climate change (coastal erosion, for example)  but most of our habitat loss in this part of the world has been the result of straight forward destruction by humans. This is by far the greatest threat to our butterfly and moth populations.

Habitat loss is a global crisis. This is the crisis that should be to the forefront of campaign activism. We have clear, undeniable evidence for habitat loss and its effects. The same cannot be said for certain aspects of climate change. Evidence for habitat loss in prehistory can be obtained from the fossil records, showing massive declines in tree pollen as humans cleared the land of woodland. We have little or no fully natural ancient woodland on this island. In the last 80 years, we have all but destroyed our precious, precious peatlands.

The source of high carbon emissions: the destruction of a raised bog releases carbon into the atmosphere. The burning of peat for fuel releases more carbon. The specialist plants and animals that rely on the habitat are wiped out. © J.Harding.

The impulse towards ravaging the few sad, degraded remnants remains virulent. Here is a recent example. Ballynafagh Bog, about 1 km west of Prosperous village in county Kildare was designated as a Special Area of Conservation under the EU Habitats’ Directive. This gives it legal protection. Looking at the bog, I find it hard to understand why this small, badly damaged site was designated as a protected site. Quite a lot of restoration work is needed given how badly damaged it is by burning, cutting (out of 160 hectares of the bog, 90 hectares has been cut) and afforestation. However, in the budget £5m was ringfenced to restore damaged peatlands. Good news for the climate, because bogs are carbon stores, good news for flood prevention because bogs hold massive quantities of water, good news for nature.

However, the government department that designated the bog, The Department of Arts, Heritage and the Gaeltacht, applied to Kildare County Council to open a new turf cutting site on Coolree Bog which is part of Ballynafagh Bog but outside the boundary line of the protected/designated zone. Kildare County Council refused permission. Determined to proceed, The Department of Arts, Heritage and the Gaeltacht appealed the decision to An Board Pleanála. The Board also refused permission mainly on the grounds of carbon emissions. The Department wanted to relocate turf cutters from Ballynafagh Bog which the state must protect, to a ‘new’ bog.

Think of the logic. The state, supposedly worried about carbon emissions and climate change, have a strategy of reducing carbon emissions by allowing turf cutting which vastly increases carbon emissions. The state, under a legal obligation to protect and restore damaged peatlands, is using peat cutting as a conservation tool. The state, whose politicians just offered a budget to address carbon emissions, will continue to push turf cutting, which destroys bogs. The state published the Red List for Irish Butterflies which describes the threats faced by the Large Heath butterfly:

The Large Heath is confined to extensive blanket bogs and raised bogs and has lost much of its habitat due to drainage, afforestation, and peat extraction. The assessment of the overall status and future prospects of its habitats is poor… A population reduction is suspected to be met in the future (>30%) based on a decline in habitat quality…

The Large Heath is rated Vulnerable on the Red List. The next step up is Endangered, a rating likely if ongoing peatland destruction continues.

 

The Large Heath maintains a small population on an area of the cutover bog at Drehid North, County Kildare. A proposal to drain some of the bog may remove it altogether. © J. Harding.

In short, the state aims to reduce emissions by increasing emissions, to damage habitats and then repair them and to conserve habitats by destroying them. As for the state’s attitude to biodiversity on bogs, represented in this article by the demise of the Large Heath…

Perhaps we should be really worried about habitat destruction? Habitat removal brings climate change.  This applies to the destruction of bogs, forests,  natural and semi-natural grasslands and other habitat types. Such is the damage that has been and continues to be done to the habitats in our environment locally and globally that there is no catastrophising about habitat loss.

Sources:
Allen, D., O’Donnell, M., Nelson, B., Tyner, A., Bond, K.G.M., Bryant, T., Crory, A., Mellon, C., O’Boyle, J., O’Donnell, E., Rolston, T., Sheppard, R., Strickland, P., Fitzpatrick, U., & Regan, E. (2016) Ireland Red List No. 9: Macro-moths (Lepidoptera). National Parks and Wildlife Service, Department of Arts, Heritage and the Gaeltacht, Dublin, Ireland.

O’Connell, C, Madigan, M and Farrell, P (2019) Peatland News Issue 68 Autumn 2019. Irish Peatland Conservation Council.
Regan, E.C., Nelson, B., Aldwell, B., Bertrand, C., Bond, K., Harding, J., Nash, D., Nixon, D., & Wilson, C.J. (2010) Ireland Red List No. 4 – Butterflies. National Parks and Wildlife Service, Department of the Environment, Heritage and Local Government, Ireland.

https://www.independent.ie/irish-news/our-cold-snap-was-nothing-compared-to-the-great-irish-frost-of-1740-26609822.html
Accessed: October 13th 2019
Author: Alison Bray
Date: December 30th 2010

 

 

October Fare

The fairly dramatic deluges and winds of the past two weeks have altered the landscape and butterfly scene, underlining the onset of autumn. Yesterday, Sunday, October 6th, provided a welcome break, with sunshine and light breezes.

A late Small Tortoiseshell basking in a sheltered, south-facing nook. © J.Harding.

In October one must look more assiduously for butterflies, peering at shadows cast by a high-flying insect or shading eyes against sharp autumn light to check clusters of blackberries and ivy blossom for feeding moths and butterflies.

Indeed, Ivy is a very useful plant for moths, butterflies and many other creatures. At this stage many ivy plants are in full bloom, their yellowish-green inflorescence packed with nectar. At night it is a favourite with moths; in daylight, these same moths often roost in its dense, evergreen foliage. For anyone with patience, it is often well worth checking ivy draped over a wall that had Holly Blue butterflies flying around it in August and September. Check the stalk of the flowers for slug-shaped Holly Blue caterpillars. These are feeding on the developing berry, their heads deep within the oval cup, scooping out its goodness.

Common Ivy is an excellent plant for wildlife if allowed to flower. Clip it back, if you need to, in February but try to leave some areas uncut. © J.Harding.

While the clouds of Painted Ladies are gone, the scarlet and black Red Admiral is still about, feeding on wounded blackberries and ivy and, if it can find it, a tree leaking sap. I saw a few of these handsome butterflies yesterday but these are easily disturbed at this time of year, often flying into tree-tops when you approach one that is lower down on bramble.

Comma butterflies, still rare or absent in most areas, are nomadic in autumn and can turn up anywhere that nectar exists near woods, dense hedgerows or groves of trees. I was lucky to see one yesterday, perching briefly on a now bedraggled buddleia before gliding casually off to hide in tall willow. The Comma will sit still at other times, especially on fallen fruit or Ice Plant flowers, giving wonderful views of its deep orange-red upper surfaces and deeply scalloped wing margins.

Comma,  high up on Buddleia at Louisa Bridge, County Kildare. © J. Harding.

Finally, even though most butterflies have finished flying, their caterpillars can be searched for quite profitably in areas that were heavily frequented by the adults. With this in mind, I checked Common Sorrel leaves where I had seen Small Coppers loitering in early September. After finding hatched eggs on the upper sides of some leaves, I checked the undersides and soon found some young, first instar larvae. These will feed for a time before over-wintering deep in the grassy vegetation before resuming feeding in spring.

Small Copper larva, first instar, on the underside of a Common Sorrel leaf, County Meath. © J. Harding.

There are some lovely moths too, especially for moth trappers who leave their light traps out in good habitat on mild nights. Beaded Chestnut, with its rich wood-coloured wings, is really abundant in early October and if you are fortunate, a Merveille du Jour may turn up to brighten any October morning when you go out to inspect your catch.

Beaded Chestnut on an oak leaf. © J.Harding.

Keep on looking-autumn, the “season of mist and mellow fruitfulness” has much to offer and if one has to look harder to find it, the discoveries are all the sweeter.

Merveille du Jour moth, an autumn flyer and a favourite for moth lovers. You may have this in your garden if you have native oak trees. © J.Harding.