Bird stories have been soaring into the nature headlines over the past week, however unfortunately the reasons behind their appearance are not so good. Attention has been drawn to the issue that many British seabird populations are coming under increasing threat due to problems such as climate change and anthropogenic waste. Alongside this, extreme global weather conditions are causing unusual migrations to take place, resulting in great opportunities for birdwatchers, but potentially causing issues for our native species.
Sea bird populations are struggling particularly in Scotland where decreases in already threatened populations are causing increased concerns. One reserve on Orkney Island has recorded a 53% decline in numbers since the last full UK seabird population census in 2000. On another Orkney reserve, populations of Guillemots have not managed to raise a single chick this year. A similar case has shown that only one pair of Kittiwakes remain in an area that was once home to 150 breeding pairs.
Reasons for these vast declines are related mainly to gale force winds that occurred in May, which particularly affected arctic turns and disrupted the nesting of many other species. The overall situation has been described as “bleak” and the RSPB is proposing another census is carried out so that trends can be properly identified and conservation methods be put in place.
Another issue facing seabirds is the increasing build-up of plastics in oceans. Off the welsh coast, 40,000 breeding pairs of gannets arrive on Grassholm Island to breed and nest. However researchers from the University of Plymouth have found that an increasing amount of birds are using synthetic materials to make their nests, which they find floating off shore. The new resources include pieces of plastic, synthetic rope, fishing line and unwanted nets.
These materials don’t biodegrade meaning that the breeding pairs that return to the same sites every year are continually accumulating the rubbish, with an estimated 18.46 tonnes of plastic now on the Island. This leads to further problems with many birds becoming caught in the nests, resulting in an annual effort trying to release trapped birds. Each year the majority of birds are successfully released, however around 65 birds die from their entanglement. It is hoped that in the future, marine reserves can be extended further out to sea to ensure that the areas the birds use for feeding and nesting materials are not affected by anthropogenic disturbances and waste.
In other, more optimistic, bird related news we have seen a close to record high number of species arriving in Britain from all over the world this year. The 442 species are set to rival the 2008 total of 445 and bird watchers are optimistic that this will happen. The influx of species is said to be because of the extreme weather conditions and hurricanes that have occurred in North America and Asia, which are being linked primarily to climate change. The strong winds have redirected migration paths towards Britain and we are now playing host to a number of exhausted species who have travelled very long journeys to get here. Other reasons for the high numbers are thought to be the melting of Arctic sea ice, also related to climate change, which are opening up new routes for migrating birds from the pacific to Britain.
The changing of bird populations and species in Britain are certainly keeping ornithologists busy and it can be hoped that conservation techniques can be developed to help stabilise our sea bird populations while being able to enjoy the exotic variety of species arriving to our shores.
By Lizy Tinsley