Barn owl cpt Richard Bowler
Flooding is a natural phenomenon but extreme floods are devastating for people, and for wildlife too.
This is especially true at certain times of the year and when there is not enough space across the landscape for wildlife to take refuge from these extreme events. There are some species in particular that may suffer in prolonged wet weather:
Barn owls: Night after night of wet weather means barn owls can’t get out to hunt without their delicate (and silent) plumage becoming waterlogged.
Water voles and otters: water voles spend much of the winter in their burrows where they store food. But water levels can rise so fast that voles are flooded out of burrows and washed away. Despite their name, they are not strong swimmers so may try and take refuge on higher ground, where unfortunately they are easy prey for predators such as American mink and birds of prey. Otter holts may also be flooded in such conditions.
Fish-eating birds: the deep fast flowing rivers and streams that are also cloudy due to the sediment loads make hunting difficult for birds such as herons and kingfishers.
Fish: the eggs of migratory fish such as Atlantic salmon and Brown trout that have been laid in gravels on the river bed are at risk of being washed away
Hedgehogs: In floodplains animals like hedgehogs that are hibernating under vegetation will be drowned if they can’t escape. Some species, such as the adder, adapt to such possibilities by hibernating at higher sites.
The way land and rivers are now managed causes problems for wildlife. The fact that many of our species and habitats are fragmented is a major problem during these extreme events. In a large area of wetland, there is usually somewhere for species like water voles to take refuge that is still fairly safe. If the wetland is just a linear strip of habitat alongside the river, there is nowhere for voles to go.
Where big embankments line rivers (to allow farmland to be drained as part of historic flood defences), floodwater that overtops the banks gets trapped for long periods of time. This lying water can drown all the worms and insects that live in the soil which are vital food for birds like waders (and the farmers can lose their grass). The land drainage embankments which allow land to be farmed more intensively also push water downstream increasing the risk of flooding to communities downstream.
Deeper, wider ditches that are excavated in an attempt to reduce flooding will result in lower ground water levels throughout the rest of the year, which may affect a wide range of plant communities and the species that depend on them.
Heavy rainfall causes storm sewers to open releasing pollution - untreated waste and toxic substances that people pour down drains. When this ends up in our rivers it has disastrous consequences for wildlife. Intensive agriculture causes high levels of silt build up causing poor water quality.
In general, however, flooding is a natural process and when it is not excessive, can benefit many species.
Floodwaters help plants and animals to disperse across the landscape. Seeds are moved around in floodwaters, settling in new places and allowing plants to colonise new areas. Unfortunately this also means that problem (invasive) plants like Giant Hogweed or Himalayan Balsam spread downstream in such flood events.
Some of the rare water snails need flooding to move from one location to another. Anisus vorticulus - the little ramshorn whirlpool snail is a rare species that often occurs in ditches in wet fields that flood in winter, flooding is thought to be important in enabling young snails to colonise new ditches.
The smaller temporary ponds that are created during flooding provide breeding sites for the common frog.
Flooded areas enable ducks such as pochard, tufted duck and teal to feed in new areas of open water. Wading birds like snipe and lapwing will be seen probing the soft ground or patrolling around the edges of floodwater picking up small insects and worms.
Aquatic wildlife and vegetation is fairly resilient to extreme weather, and habitats can quickly recover from any superficial impacts.
Though water voles can be badly affected by flooding it can also aid their dispersal effect which can result in re-colonisation of areas off main channels and in a wider distribution of the species in the following breeding season. This was noticed in surveys of a translocated population on the River Colne after the 2012 floods. In 2013 the distribution of water voles was much wider than it had been. Most wildlife can cope with predictable flood patterns – it is out of season flooding or extraordinary events like the storm surge, that cause issues.
High rainfall in winter can ensure that ponds and other wetland habitats are topped up at the end of the winter, which will mitigate any unusually dry periods. If the high rainfall periods are followed by more settled and seasonal weather in spring and summer, wetland invertebrates will probably breed well in the spring, which will also benefit.
Across the UK staff from individual Wildlife Trusts have reported a series of dramatic impacts on local wildlife witnessed during the floods and tidal surges of 2013-2014
The Wildlife Trust for Bedfordshire, Cambridgeshire and Northamptonshire reports large numbers of wading birds - see images of flooding here.
Cornwall Wildlife Trust says seals and seabirds are taking a relentless beating in the storms - see release here.
In Cumbria, the South Walney Nature Reserve on the tip of Walney Island off Barrow was seriously affected when the road to the reserve completely flooded. The floods have created lots of temporary new ponds around the reserve, some very large ones in areas that would otherwise remain dry.
Wading birds, in particular redshanks, are taking advantage of all these new wet areas. A lot of debris was been washed into the reserve, with driftwood, small and large, which will no doubt be used by birds as nesting materials- in particular the nature reserve’s gull colony will benefit from some of the larger pieces for sheltering their nests against. Unfortunately a lot of rubbish has washed onto the reserve and this will require many litter picks with lots of volunteers to remove it. Along the west coast of the reserve Cumbria Wildlife Trust has lost up to 15 metres of land in some places, completely washed away. There has been damage to some of the reserve bird hides, with roofing materials being pulled loose by the wind.
Devon Wildlife Trust have an update on Dawlish Warren here.
In Dorset the Dorset Wildlife Trust is concerned about how wildlife in will be affected by the severe winds, rain and high tides that have battered the coastline in recent weeks.
After braving strong winds and enormous waves, exhausted and distressed seabirds such as the Razorbill, Fulmar (pictured) and Shag have been found stranded on Chesil Beach and at Kimmeridge in Dorset. See release here.
DWT’s Marine Awareness Officer, Julie Hatcher said, "The weather conditions will make it hard for birds that live and feed around the coast, and there’s a risk they could become weak from not being able to feed properly. The biggest concern is that seabirds will become dehydrated, as their intake of water comes from the food they eat.
"We are encouraging members of the public who come across an injured bird to phone the RSPCA for assistance.”
There is also concern that the repeated storms are washing up considerable amounts of litter onto Dorset’s beaches. Dorset Wildlife Trust will be running beach clean events to try and combat the litter. For info on beach clean events visit its website.
In Durham an increase in the number of otters killed on the roads has been reported. This could be a result of high water levels forcing otters out of the river channel. Also water voles are likely to have suffered - lower populations than usual are expected in the Spring on some of the more flashy rivers. For more, please see Durham Wildlife Trust.
Kent Wildlife Trust's Oare Marshes experienced a higher than anticipated tidal surge. The cattle bridge on the east side buckled and a number of dead rudd along the roadside were found, indicating a sudden increase in saline levels.
It seems very likely that there has been considerable ecological damage to the fresh water habitat on the reserve.
In Lincolnshire, the impact of the early December storm surge on wildlife is still quite difficult to assess. But the biggest impact seen so far has been on site infrastructure and visitor centres. Those at Gibraltar Point and Far Ings are still closed and will be for some time.
The damage is particularly bad at Gibraltar Point. Staff are currently looking at re-locating events and school bookings, and possibilities for temporary facilities to provide refreshments and toilets at Gibraltar Point.
We will never know exactly how many seal pups at Donna Nook were lost during the tidal surge, as many were already quite old and about ready to go to sea. It may be that they just returned to sea a bit earlier than expected.
At least 12 pups were rescued and taken to Mablethorpe Seal Sanctuary. Natureland in Skegness has also reported an increase in the number of abandoned pups they have taken in.
Freshwater pits and reedbeds at Far Ings National Nature Reserve were inundated with seawater. Wardens are monitoring the salinity of the pits which is dropping quickly. There isn’t any evidence of fish deaths so Lincolnshire Wildlife Trust is hopeful for other wildlife too.
Freshwater habitats (marsh, ponds and lagoons) at Gibraltar Point NNR were also inundated with seawater. Lincolnshire Wildlife Trust is expecting the ecology of these areas to change and will be monitoring the impact. The sea bank was breached in five places at Gibraltar Point; high tides could cause re-flooding of freshwater habitats but so far haven’t.
Please see the Lincolnshire Wildlife Trust’s website for updates and access details as well as info about their fund-raising appeal to help pay for storm damage.
In London, the storm water will have affected river quality and ecosystems – especially the tidal Thames and River Lea - storm sewers will have been overflowing directly into Thames – and the River Lea suffers from polluted run off. The Thames Barrier has also been closed on more than 28 times since 6 December 2013. This represents one fifth of all the closures - about 150 - since it was inaugurated in the 1980s. London Wildlife Trust.
Norfolk Wildlife Trust sites suffered two confirmed breaches along the coast between Cley and Salthouse. The shingle bank along this section has retreated inland by between 100m – 200m in some places and lowered significantly along some stretches most notably impacting on the saline lagoons. Both Cley Beach Road and Salthouse Beach Road were entirely covered in metres of shingles.
Northumberland Wildlife Trust has noticed a number of dead and exhausted seals along the shoreline that they care for in the region of Druridge Bay.
In Shropshire, birds such as lapwings and geese are taking full advantage of the wet fields surrounded by floods, where they are safe from predators like foxes. Water engulfed large areas along the banks of the Severn where hedgehogs may have been hibernating for the winter. Small mammals will have retreated into higher vegetation wherever possible and people have spotted bank and field voles in trees when they would usually only be seen on the ground. Badger setts have also been flooded too.
Shropshire Wildlife Trust. set up a hedgehog rescue project when flooding in neighbouring Staffordshire washed away hedgehog foraging grounds. Shropshire Wildlife Trust is rescuing the hedgehogs, feeding them up, then releasing them in places where wild habitat has been improved.
Sussex Wildlife Trust reports that lots of weird and wonderful sea creatures have been washed up during the recent storms, including this sea mouse.
The tidal level in Harbour of Rye in Sussex was measured by the harbourmaster at 5.1m (predicted 4.1m) on 5 December 2013. This overtopped the flood defence within the Rye Harbour Nature Reserve and then eroded the shingle bank it sat on. This created a 30m breach allowing sea water into an area that is managed as saltmarsh by means of a culvert (with managed high water level usually at 3.4m). There have been much higher than normal levels in three saline lagoons but this hasn’t caused a problem. For updates see Sussex Wildlife Trust website.
Wildlife Trusts Wales is calling on the Welsh Government to invest in natural solutions to flood control following the recent extreme weather conditions. Wales is unique in its ability to nature to reduce flooding thanks to its blanket bogs which, if restored, would hold up to 20 times their own weight in water or the equivalent of two Elan Valleys reservoirs. Montgomeryshire Wildlife Trust manages the Pumlumon Living Landscape scheme with the aim of storing 41.9 billion litres of water by appropriately managing 3,730 hectares of land. See Nature offers a cost-effective solution to flooding.
Yorkshire Wildlife Trust’s Spurn Point bore the brunt of the North Sea tidal surge floods. More information can be found about the clean-up operation and the future of the beauty spot here.
Natural England report that: The storm event and prolonged rainfall of early January also exacerbated flooding on inland SSSIs located on river floodplains, predominantly on the Somerset Levels and Moors. Across the Somerset suite of SSSIs, mostly comprising floodplain grazing marsh, approximately 7000 ha are currently flooded or subject to high water levels, as is much of the rest of the 29,000 ha floodplain. The wetland wildlife of the area is naturally resilient to winter flooding and full natural recovery is expected. The key challenge will be to work with Internal Drainage Boards and landowners to manage the transition to lower water levels in the Spring that are suitable for breeding wader assemblages. In the past there has been a tendency for over-pumping to leave the sites too dry.
In many areas, hides and boardwalks on Wildlife Trust nature reserves were damaged, such as this one in Gloucestershire.
What we can do to help
- Contact those Wildlife Trusts mentioned above which need volunteers to help with the clean-up or have launched appeals to repair affected nature reserves
- Be mindful of what we put down our sinks, drains and use on our gardens - environmentally damaging products kill wildlife when they are washed into our rivers and streams
- Create green roofs - whether on our homes or on top of the garden shed - it all helps to slow the flow of water run-off in bad weather and helps stop flooding
- Dig up paving slabs and plant up our gardens! The trend for paving over front gardens in recent decades has done much to make urban areas less absorbent
- Consider creating wetland habitats in our gardens - whether it's a pond or beautiful bog garden, these habitats all help absorb water and are wonderful for wildlife. Find out more in our wildlife gardening pages.
- If you are a farmer contact your local Wildlife Trust to find out how to improve natural habitats on your farm
- Get involved - many of Wildlife Trusts have community schemes and need volunteers to help restore our wetlands, rivers and wildlife-rich meadows. Find your nearest Wildlife Trust here.