With the nesting season coming to an end, many climbing areas have been opened early either due to birds fledging early or no birds at all. For those wishing for a few more weeks on their climbing projects this may come as welcome news but the stark reality of this is the impact of a changing climate on the ocean and our sea bird populations is having a drastic affect.
This article will not be able to cover every aspect and the tides that move our planet are too complicated to be detailed in a short article, its also not this author's speciality, but we will look into the shallows of what is affecting our sea bird populations.
Different species of birds are being affected in different ways, this can be due to the ranges of the species (how far an individual can cover), their foraging behaviours; do they hunt near the surface or dive like Guillemots, and also the range of diet. Species that rely solely on one species of fish will be affected greater by the change in the size of that population.
In the UK around 20 species have been identified that the marine habitat is their primary foraging resource. Evidence suggest that 11 of these are negatively affected by climate change and 14 of them are regarded at being at high or medium risk to the effects of climate change.
Food and Foraging
Changes in food sources are having a big impact during the breeding season, many birds rely on sand eel populations to feed their young before they fledge and there is a limited distance many birds can travel to forage for their food. Sand eels are important as they bridge the food chain gap between plankton and predatory fish and seabirds. The changes in oceanic temperatures are influencing the spawning times of sand eel eggs, which can delay hatch times meaning that they don’t coincide with sea bird nesting times.
Other species such as herring and capelin are migrating to cooler waters making it harder for birds to forage particularly during the critical breeding and nesting seasons. This is leading to lower reproductive rates, and ultimately a decline in population.
To complicate matters further, excess dissolved carbon dioxide is leading to ocean acidification, this is also having a negative affect on oceans food chains, phytoplankton and zooplankton have shells that cannot form or dissolve in an acidic ocean, and when plankton declines this has an affect on everything above them in the food chain, including our sea bird colonies.
Weather
Changing weather patterns are also having an abrupt effect on sea bird populations, as I’m sure many of us have noticed the increased number of storms affecting the British Isles, what we may forget is many of our sea birds are at the brunt of them, and although our populations of sea birds are well adapted to the British weather, there are always limits.
Powerful storms can have a severe and instant impact on many sea bird colonies by washing away nests. The increase in storm surges is also having an effect on coastal erosion and as a consequence can cause habitat losses. For species such as Kittiwakes that nest low on the cliffs, the smallest increase of sea levels can cause dramatic effect on these low nests.
The changing seasons, weather, and food availability is having an impact on some species of migratory patterns. Many British sea birds undertake long-distance migrations and the impacts on these populations are more complex and harder to measure, impacts could affect the migratory journey, the breeding grounds, stopover locations, wintering destinations and the dependencies between them.
Birds do have an ability to adapt to some of the migratory problems, they might neccessitate flyer longer distances or towards alternaive destinations. However, it is essential to consider the repercussions on the regions they are journeying to. Resting sites during migration play a pivotal role in the suffescul completion of species' migratory jounrneys, ways in which the climate impacts may have an affect on these are: rising sea levels, more extreme weather events, and human impacts such as construction work.
Disease
If it's not enough that the affects of climate change are having a negative impact on bird numbers, avian flu outbreaks are taking an unprecedented affect on many species of birds. Kittiwakes, black headed gulls, herring gulls, terns and guillemots are being washed up on many beaches, showing symptoms of avian flu.
The graph above shows the sad decline of Kittiwake numbers on the Little Orme.
What can you do to help
The Royal Society for the Protection of Birds (RSPB) and British Ornothogical Society both undertake huge amounts of research to investigate the affects of climate change, reporting any nests or sighting can be helpful to this process.
In England, Wales and Scotland you can go to the following page Report dead wild birds - GOV.UK (www.gov.uk). If you know the species you can also go to BirdTrack | BTO - British Trust for Ornithology.
As climber and hill walkers we can keep checking the RAD and minimising our own affects on bird populations by keeping dogs under close control and keeping clear of any wild birds nests.
DOWNLOAD: the BMC RAD app
Get all the info on crags with the RAD (Regional Access Database) app from the BMC! Available now for Android and iOS, it's free and comes with a host of new features like navigation and parking, weather and tidal updates, and of course information on restrictions or notes on access advice. Get it here now!
RAD is community led and your comments help keep it up to date so don’t be afraid to add any relevant information after a crag visit which might be useful for other visitors – anything from conditions on the crag, favourite routes or reports of rockfall/other recent changes to the crag are all useful for other climbers visiting.
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