Why Climate Change Could Kill off Coastal Birds
New research published recently in Philosophical Transactions of the Royal Society B and conducted by The Australian National University, suggests that coastal nesting birds do not adapt to tidal floods.
The study looked at Eurasian oystercatchers over a period of 20 years. This species breed on coastal salt marshes, sand and shingle, beaches and cliff tops. These are areas where flooding is becoming more common and more severe due to climate change. The situation is predicted to get worse in the coming years.
New Research into Coastal Nesting Birds
Researchers found that the birds did not move their nests to higher locations in response to the changing conditions. This could be because there is a greater threat from predators in higher locations. The vegetation may also be less suitable for the birds’ needs.
The Eurasian Oystercatcher
According to the IUCN red list, many birds adapt to the new conditions by laying their eggs earlier in the year when floods are less common. This could become a strategy for the Eurasian oystercatcher but there is no evidence that they have altered their nesting habits yet. The birds have a wide range including Iceland, Scandinavia, Russia, Europe, the Mediterranean, West Africa, India, China, South Korean and New Zealand.
Their nests are shallow scrapes on the ground. They will often choose raised surfaces in open areas or short vegetation. They will also nest on rocky outcrops or clearings in woods and moorland. But woodlands and moors have been impacted by human activity.
Coastal Birds in the US
Another recent study collated thousands of bird surveys conducted on the east coast of America from Maine to Virginia. This also revealed a decline in the populations of coastal marsh birds. It is feared that some species will be driven to extinction and possibly within the next 20 years. The birds simply do not appear to be adapting quickly enough or at all to the new conditions, or at least they haven’t yet. There has also been a decline in coastal birds in Northern Europe.
It looks as if there is an urgent need for conservation projects to help coastal birds around the world. These species have already been seriously impacted by various forms of human activity including boats, low flying aircraft, walkers, urbanisation, pollution and fishing. Fishing removes potential food sources from the coastal waters and seabirds can be caught up in tackle during long line deployments.
To make matters worse the increasing acidification of the oceans, caused by rising temperatures, affects shell species such as plankton. This then impacts the rest of the marine food chain and the coastal birds are near the top of this chain.