Lakenheath Fen - Crane powerhouse

The fact that Lakenheath Fen RSPB reserve was a carrot field some 20 or so years ago is often repeated.  The detail that has gone into the design of the site and the management for key species is less often appreciated.  This is no airy-fairy, lets see how it develops type of reserve, beloved of some sections of the conservation community.  This is a targeted and planned development that now delivers for Bitterns, Cranes, Bearded Tits, Marsh Harriers, Water Voles, Otters and a range of specialised wetland and Breck plants and invertebrates.

This week, I attended the ecological review for the year and undertook the annual audit.  There were a minimum of 5 booming Bitterns, with at least 3 successful nests. We reviewed the results of the fish survey throughout the reserve and discussed the habitat management. The detailed management undertaken for Bitterns that has led to a remarkable recovery in the UK is well known, but perhaps the work for Cranes less so.  Cranes have also had a good year at Lakenheath Fen with three chicks fledged from the 2 nesting pairs.  But this is no chance event, rather the result of considerable effort by site staff.

The case of Cranes is an interesting one.  Recently released figures show a total of 48 pairs in the UK this year:  a combination of 27 pairs of (mainly) wild birds in 4 population centres and 21 pairs of the ongoing re-introduction scheme in Somerset. At least 16 young were reared this year. The population in the Fens is doing well, contributing 7 of these fledged youngsters, whilst the Broads contributed 4 and Somerset just one.

There have been several re-introduction schemes of various species of cranes around the world.  None have been totally successful.  They have suffered from various problems such as imprinting on humans, lack of migratory instinct, poor productivity and the cranes generally failing to think and act like wild cranes, particularly when it comes to predators! The well publicised nesting attempts of some of the released birds where they clearly fail to recognize good nesting habitat or exhibit typical crane behaviour is a good example.  Lets hope these issues can be resolved.

So how has Lakenheath become the UK crane powerhouse? The birds first appeared in 2007.  DNA analysis of feathers suggested a Finnish/Russian origin.  Over 10 years, 23 clutches of eggs have been laid, with 11 chicks fledging: an average of 0.55 young per pair.  The fledging rate was poor at first but is increasing in recent years; the last 5 years average 0.8 and a remarkable 1.5 for the last 2 years.  Detailed study of the Cranes by site staff since they first appeared at Lakenheath, notably by Norman Sills, has led to a good understanding of their requirements.   Habitat management seeks to create ideal conditions for both nesting and chick rearing.  However, it is predation, mainly by Foxes that poses the major threat to the youngsters.  Habitat manipulation can help with this but ultimately some control of Foxes is required.  To ensure success, the latest technology of trail cameras and thermal imagers is used in conjunction with a skilled marksman.

The reedbed management aims to create structural diversity for the benefit of the key species.  Cutting and grazing are the key management tools and also aim to enhance viewing opportunities for visitors.  No airy-fairy stuff this – rather it is determined and targeted conservation effort that brings results.

Photo below - Dartmoor ponies eating reed and typha rhizomes

 

The Albufera of Valencia

A work trip to a conference in Valencia in Spain provided the opportunity to learn about and see the Albufera of Valencia; a shallow lake in excess of 2,000 ha located to the south of the city.   Little more than a metre deep, it is of huge importance for its wildlife, supporting around 90 breeding bird species and up to 50,000 wintering waterfowl.  Around 8,000 years ago, the Albufera was open to the Mediterranean Sea but gradually became cut off by sandbanks.  Originally some 30,000 ha in extent, it slowly reduced in extent through both sedimentation and its margins being progressively claimed for agriculture, principally rice production.

There have been major issues with water quality, notably nutrient enrichment, since the 1980s, mainly as a result of spreading urban development from the city and the surrounding agriculture. The formerly clear waters, full of aquatic waterweeds, have given way to algal dominated turbidity. The population of 1,000 or so pairs of Coot declined to just a few tens of pairs as the vegetation disappeared. As the floating vegetation nesting platforms of Whiskered Terns disappeared, so did the terns.  To try to resolve this problem a partnership of organisations came together to form the LIFE+ Albufera Project, funded by the EU.  Between 2007-2012, three areas of rice fields close to the lake were converted to wetlands designed to enhance water quality.  These 'tancats' were carefully land-formed and then planted with a range of emergent plants such as Phragmites and Typha that will extract the nutrients from the water as it flows through.  Water flows down a series of terraces before being pumped back up into the lake. One of these areas, the Tancat de la Pipa was created in 2008 on the northern side of the lake. Its construction was supported by the Ministry of Agriculture, Food and Environment and is managed by SEO Birdlife and Accio Ecologista Agro.  Early results show that significant improvements have been made.

I was shown around the site by the excellent guys from SEO Birdlife (the Spanish Ornithological Society, notably Pablo Vera, who has undertaken many of the bird studies in recent years.  Despite some declines, the Albufera is still a fantastic place for wildlife.  The bird list is impressive, with many species doing well. For example, latest estimates suggest 60 pairs of Purple Heron, 400 of Squacco Heron, 200 pairs of Glossy Ibis, 50 pairs of Little Bittern, 600 pairs of Gull-billed Tern and 1,000+ pairs of both Common and Sandwich Tern.  Around 40 pairs of Red-crested Pochard, a local priority species, breed annually. There have been re-introductions of both Marbled Teal and Red-knobbed Coot, a nest-building pair of the latter causing great excitement on my visit.

A short video here:  The Albufera of Valencia

A quick trip to China

Winter birding at Chongming Dongtan in China is like a good UK winter and a mega autumn rolled into one.  You get huge numbers of ducks and geese along with stripey warblers and pipits. This was my fourth visit to Chongming, with one trip in each season.  We were back for a weeks stay at the ‘eco-village’ with a mixed programme of site checking, report writing and presentations. The aim was to prepare a management and monitoring plan for the nature reserve and its new habitats that are now appearing as a result of the Bird Habitat Optimisation Project.  Just to remind you, the project is to eliminate 16 km² of invasive Cord-grass Spartina alternifolia and then create 25 km² of wetland habitat, mainly lagoons and reedbeds.  After the design and build phase, with contractors being on site for the last 2 years, the lagoons are now taking shape and the Spartina is being cut and flooded.

Pallas's and Yellow-browed Warblers, Red-flanked Bluetails and Daurian Redstarts flit around the village gardens while we work.  The early morning walks around the fields beyond the village gate reveal hundreds of Red-throated, Water and Buff-bellied Pipits with Rustic, Black-faced and Pallas's Reed Bunting.

Back to the plan.  The target species are Reed Parrotbill, Hooded Crane, Tundra Swan, Great Knot, Far Eastern Curlew, Spoon-billed Sandpipers, Nordmann's Greenshank, Black-faced Spoonbills and Saunders’s Gull. Weeks of reading everything published on these species ends up getting distilled into the plan.  How do we create and maintain suitable feeding, breeding, roosting habitat for the key species?

Out to section A of the reserve to check the newly created reedbed pools and ditches.  Snipe ping away, Reed Parrotbills noisily crunch through reed stems to find their scale bug dinners and Chinese Penduline Tits swirl around in flocks.  Dusky Warblers and Bluethroats hop around the reed bottoms.  The lagoons support hundreds of wildfowl: Spot-billed Duck, Pochard, Pintail, Falcated Duck, Goosander and Goldeneye.  Two separate sections of the reserve will be managed by WWF and The Nature Conservancy (TNC).  Both are currently developing visitor and educational facilities. A high five moment as the roosting islands we had created in front of the proposed WWF viewpoint had ....roosting waders.  Eighty Black-faced Spoonbills loafed in front of the TNC visitor centre as we arrived but they rapidly took flight to find a quieter area.  A bit more screening required perhaps.  

Final presentations done and report crunched, we headed back out to the saltmarsh to find the wintering Tundra Bean Geese, Hooded and Common Cranes. In the duller moments, the flocks of gulls kept us going and seemed to contain Mongolian, Heuglin's, Slaty-backed and Saunders’s. Being an ecologist is not such a bad job at times.

Photos: top - from design (lower) to habitat on the ground (top)
Below - Black-faced Spoonbills, Chinese Penduline Tit, Red-throated Pipit, Pallas's Warbler.

Wallasea - a wetland designed for the future

The RSPB’s wetland creation project at Wallasea Island in Essex has been much in the news over the last year.  In July, the first phase of the intertidal habitat was completed and the sea wall breached.  On completion of all five phases of this innovative and forward-looking project, around 700 hectares of saline to fresh water habitats will have been created.

The project aims to combat the threats from climate change and coastal flooding by recreating a wetland landscape of mudflats and saltmarsh, lagoons and pasture.  It will also help to compensate for the loss of tidal habitats elsewhere. Habitat design will look to accommodate colonizing species from the south.  Much of this design is difficult to see at ground level but the aerial photograph above shows many of the habitat features incorporated into the design.  This is what can be seen:

A – This will be the visitor hub in the future.  Immediately adjacent are three shallow saline lagoons that will be managed for passage and breeding waders (top photo below).  They will be rotationally dried and flooded to maximize their food supply.  They will provide ideal conditions for Black-winged Stilts.

B – The entrance to the reserve will be through an area of saltmarsh saline creaks with shallow pools, suitable for a range of specialist invertebrates.

C – Shallow saline lagoon with islands and seasonal brackish pools suitable for breeding birds and a range of characteristic flora and fauna.  The conditions will be suitable for species currently more frequent to the south and that are likely to move northwards.

D – Seasonally drying salt pan, for Kentish Plovers with a bit of luck.

E – Freshwater marsh and grassland with pools and ditches for breeding waders.  These areas will be protected from mammalian predators by a barrier fence built into the surrounding ditches (see photo below).

F – Rough grass and wild-bird cover around the margins of the wetland will provide habitat for small mammals, reptiles and invertebrates.  The photo shows the mosaic cutting pattern to increase the structural diversity of the rough grassland. This will also benefit birds of prey such as harriers and owls.

G – An area of regulated tidal exchange with numerous islands, where water levels can be controlled (see sluice photo below) for the benefit of breeding, passage and wintering waterbirds.

H – The inter-tidal area has numerous features designed into it, including shallow lagoons that will provide the ideal feeding conditions and food resource for Spoonbills.  Once fed-up and in the mood, higher islands with scrub have been provided for the Spoonbills for nesting.

I – The range of islands provided includes some with shingle, sand and cockle-shells for nesting terns (hopefully Little Tern) and Ringed Plovers.  Will it all work?  We shall see.