By Paul Homewood
This is another perennial scare:
Rare breeding birds are becoming increasingly vulnerable to extinction in the UK due to climate change, a new report reveals.
Species such as dotterel, whimbrel, common scoter and Slavonian grebe are all said to be in danger, based on projections around the impact of global warming.
The findings come from a new report compiled by the RSPB, the British Trust for Ornithology (BTO) and the Wildfowl and Wetlands Trust (WWT), along with various statutory nature conservation bodies.
Experts fear that the Scottish crossbill, which is found only in Scotland, is at risk of becoming extinct altogether.
The Scottish crossbill, which is found only in Scotland, could become extinct (PA Archive/PA Images)
By contrast, however, some other birds were found to have thrived in the warmer, wetter climate, which has enabled them to expand their range further north.
The study found climate change is already affecting bird life in the four countries of the UK, which is responding to a 1C (1.8F) increase in average summer temperatures since the 1980s.
“Birds in the UK are showing changes in abundance and distribution, predominantly moving northwards, in a way that is consistent with a changing climate,” the report said.
“Migratory birds are arriving earlier and egg-laying dates have advanced such that swallows, for example, are arriving in the UK 15 days earlier, and breeding 11 days earlier, than they did in the 1960s.”
For species such as the dotterel, whimbrel, common scoter and snow bunting – whose UK breeding populations are found almost entirely in Scotland – population declines are said to have been considerable already.
Breeding success of the Slavonian grebe has also been impacted, with Scotland on average 11% wetter between 2007-2016 than it was in 1961-1990
The UK’s kittiwake population has declined by 70% since 1986 (PA Archive/PA Images)
The report went on: “The UK’s kittiwake population has declined by 70% since 1986 because of falling breeding success and adult survival.
“Climate change has reduced the availability of the sandeels they rely upon in the breeding season.
“Other species that feed largely on sandeels, such as Arctic skua, Arctic tern and puffin, are at high risk of climate-related decline.”
On a more positive note, the report also found that warmer temperatures during the breeding season have had a positive effect on breeding success for a range of species.
Birds that feed insects to their young, such as great tits and chaffinches, have improved their productivity in warm, dry springs, while nuthatch, goldfinch and chiffchaff have been expanding their range into Scotland over the last 30 years with large increases in numbers north of the border.
Dr David Douglas, principal conservation scientist at RSPB Scotland, said: “The recent research compiled in this year’s The State of the UK’s Birds report shows that many birds in Scotland are being affected by a changing climate.
“For some birds this means they are becoming increasingly vulnerable to UK extinction, including many species where most, if not all, of the breeding population is found in Scotland.
“Other birds appear to have thrived in this warmer, wetter climate, which has allowed them to expand their range further north.”
Colette Hall, of WWT, said: “Each winter, tens of thousands of waterbirds migrate to the UK and our long-running network of volunteer waterbird counters has tracked their changes over decades.
“Warmer winters on the continent have meant more birds of certain species wintering further east, such as the European white-fronted goose.
“However, that trend can mask real declines in some species, such as the Bewick’s swan and the common pochard.
“For this reason, amongst many others, it is vital we continue to monitor our bird populations so we can pinpoint where, and subsequently try to work out why, these changes are happening.”
I’ll look at some of this in another post, but let’s first consider the Scottish Crossbill.
This bird was only officially recognised as separate species in 2006, as it is so similar to other native crossbills. Apparently it is only recognised by its song.
Very little is known about it even now, as Wild Scotland state:
The next steps in the Scottish crossbill study are to find out its population size and habitat requirements. With the current estimate of 1,500 birds for its global population, being little better than a guess, a detailed survey is crucially important to put together the right conservation and management measures to protect and conserve it.
In other words, we have absolutely no idea what population trends have been in recent decades, never mind the impact of climate change.
But here is the key statement, which comes from Trees for Life:
The Scottish crossbill is confined to the Highlands of Scotland, where it occurs in the pinewood remnants of the Caledonian Forest, and in conifer plantations which are 100 years or older in age. The population has been estimated at 1,500 adult birds, but because of the difficulties in distinguishing it from the common and parrot crossbill, the actual numbers of Scottish crossbills are unknown. Work is currently underway on differentiating between the 3 species by analysing recordings of their calls, and if this is successful it should lead to a more accurate population estimate.
Before the native pinewoods were reduced to their present figure of just 1% of their original extent, the Scottish crossbill must have been much more numerous and widespread, with a population between 10 and 100 times that of today.
If the population really is at such low levels, the obvious major reason is deforestation, even where it may have been replaced with new conifer plantations.
Let’s also take a quick look at the Dotterel:
This bird spends its summers on the high plateaus of the Scottish Highlands:
It nests in tundra and in mountains across Eurasia to western Alaska and as far south as Britain and the Balkans. While it is possible that it may eventually vanish from Scotland, it certainly won’t die out, as there are many other suitable sites in Europe and elsewhere where it is abundant. In other words, the headline claim about extinction is simply a lie.
The UK population is in any event insignificant in overall terms, with about 510 to 750 breeding couples.
via NOT A LOT OF PEOPLE KNOW THAT
December 5, 2017 at 01:33PM