The earth’s climate is drastically changing and nature is having to adapt as a consequence. The industrial revolution made carbon levels in our atmosphere rapidly increase along with our reliance on fossil fuels. In May of last year, carbon levels reached 424 parts per million – a new record high.
Globally, there are approximately 50 billion birds remaining today, that’s 6 for every human being. Without a doubt, anthropogenic-induced climatic change affects birds and pressurises their survival. Of the 632 approximate bird species in Great Britain, 48% are recorded to have decreased since 2015. This has placed both challenges and opportunities on various groups.
How Does Climate Change Affect Birds?
The pressures bird populations face are multi-faceted and cannot be solely attributed to the climate change impact on birds, although it is a significant factor. Alterations in temperatures, moisture content and precipitation levels are all having major effects on bird communities around the world. These are coupled with issues such as avian flu, land use change, factory farming, intensive pesticide use and hedgerow reduction.
Consequently, dedicated researchers are collaborating to conclude which species are winning and which are sadly losing. Species are particularly struggling to shift to new ranges due to advanced fragmentation, human land-use change and intensive farming operations. Populations are also experiencing indirect pressures such as different prey and predator species and exposure to parasites in new environments. These issues are dramatically altering the reproductive success and survival of natural communities.
Migration
Climate change is also upsetting the distribution of species across regions by shrinking their migratory ranges and seasonal bird behaviours. Many species are arriving in spring breeding grounds unusually early as well as laying eggs earlier due to warming.
The British Trust for Ornithology has calculated that Britain has lost 73 million birds since 1970, most of which are farmland species. This is particularly evident for migratory birds where climate change is affecting both their breeding and over wintering regions. This includes physical effects on their habitat, and reductions in available food sources.
Climate change affects bird migrations by altering the start date of their migration and the location they decide to reside. Due to warmer winters, species are wintering further North and East of Europe, increasing competition over winter food stores.
Long-distance migratory birds such as the Common Sandpiper, already in decline in Europe, struggle due to limited food sources along their migratory path. Species also struggle to alter their arrival date in spring breeding grounds and track the availability of their prey, i.e. insects.
UK Bird Species at Risk Due to Climate Change
With warmer seasons in Southern Britain, food sources are reducing. Consequently, fewer migratory birds are traveling the usual great distances across the Sahara desert. Cuckoo’s arrive in early April to the UK where they are either loved or hated for their distinctive, repetitive, call. They then start their migration in June, or used to. Scientists state that cuckoos are struggling to adjust their internal clocks. Therefore, they face crossing the Sahara in awful conditions or too late when there are no food sources or mates remaining.
However, the climate change impact on birds is not always detrimental. Some species are taking advantage of the extended warming periods. The Reed Warbler is successfully producing more young every year. UK bird ringers are also welcoming the increasing sightings of Bee-Eaters and Black-Winged stilts, both non-native species. These species were not previously seen in such quantities but have been spotted in Eastern England in flourishing breeding pairs.
Physical effects
The summer of 2023 saw the waters surrounding the UK rise by 4-5 degrees celsius above average. Warming seas are consequently negatively affecting a variety of marine life such as Sand Eels, a species reliant on cooler waters for survival. They are also key sources of food for Kittiwakes and Puffins which are both critically endangered around the British coastline. The RSPB has petitioned and halted industrial Sand Eel fishing in North Sea waters, backed by 95% of governmental groups.
Little Terns are also increasingly at risk as more storm surges wipe away their beach dwelling nests. Similarly, Lapwings face losing their nests increasingly due to summertime flooding events which is even more concerning. This is also true for Manx Shearwaters whereby 80% of the world’s population return to the UK in spring to breed.
Rising sea temperatures are also having a dramatic effect on the marine food chain. Zooplankton numbers are diminishing, as are the sprats, other small fish and crustaceans which feed on them. This is all affecting our seabirds, which are dependent on healthy seas to feed themselves.
What Can be Done to Reduce the Climate Change Impact on Birds?
The climate change impact on birds is hugely diverse and constantly changing. As birds adapt their diet or migratory timings we are seeing very different sightings of species in the UK and vast changes in population numbers.
The main takeaway is the resilience of nature when faced with a rapidly warming world. However, we cannot rely on resilience in order to conserve birds. Instead society must incorporate nature-based and friendly solutions across industries. Such solutions put nature at the heart of business ethic and recognise the role bird ringers, volunteers, scientists and enthusiasts have in preserving species diversity.
