Pondscapes for Great Crested Newts

Over the past year I have been observing with interest within my locality the development of a project run by the Lancashire Wildlife Trust and funded by Natural England that aims to create new ponds and improve existing ponds for Great Crested Newts. In Hurst Grange Park, Walton Park, near Dog Kennel Wood, and at Brockholes Nature Reserve I have seen old ponds dug out and new ones created and this is only a small portion of the work that is taking place across Lancashire.

The great crested newt is ‘the UK’s most pond-dependent amphibian’. Since the last half of the twentieth century it has been in decline due to the destruction and loss of the pondscapes it inhabits. Many ponds on agricultural land have been filled in or destroyed because ‘they reduce the extent and crop yield of fields and are no longer needed for livestock due to piped water systems’. More have been got rid of to make way for housing, roads, industry, commerce, and recreation.

Some ponds have been lost to natural succession – if a pond is not regularly cleared of vegetation the dead plant matter builds up and the pond is filled in and dries out. Chemical pollution, nutrification, and the introduction of fish also make ponds unsuitable for great crested newts.

Another factor is the loss of terrestrial habitat – great crested newts favour ‘rough grassland, scrub and woodland’ and need dead wood and underground crevices beneath roots to shelter. Habitat fragmentation caused by human-made obstacles to their movement is another cause of decline.

North West England has ‘the highest pond density’ in England and Wales. Whilst many of these ponds are ‘flooded, abandoned marl pits’ dated to 150 to 200 years ago ‘they are interspersed with ponds of diverse origin’. Some are also man-made such as ‘brick pits, tile pits, pottery clay pits, gravel pits, sand pits, rock quarries, peat diggings, spoil hollows, water mill ponds, bomb craters, saw pits, mine entrances, textile mill lodges, public reservoirs, farm reservoirs, angling ponds, man-made subsidence hollows (flashes)… moats, duck decoys,’ and ‘ornamental ponds’.

Other ponds are much older and of natural origin such as ‘proglacial lakes, meltwater channels, kettleholes, inter-dune slacks, cut-off meanders and ox-bow lakes’ and ‘ancient subsidence hollows’. These could date back to after the Ice Age and have existed for over 10,000 years during which lowland Lancashire was a water country* of marshland, peat bog, reed bed, alder carr, willow scrub, and damp oak woodland interspersed with countless lakes, ponds, and pools – perfect newt habitat.

Great crested newts are one of Europe’s oldest amphibians. They belong to the family Salamandridae. The remains of their ancestors, salamanders, have been dated to the Jurassic (160 million years ago). The great crested newt (Tritutus cristatus) developed as a species 40 million years ago and spent the Ice Age in the Carpathians then expanded its range across the rest of Europe after the glaciers melted.

It is possible to imagine a march of great crested newts moving slowly northwards, much like our ancestors, from pond to pond, crossing the land-bridge of Doggerland, making their homes here in Britain.

The great crested newt is so dependent on ponds because they are central to its life cycle. After hibernating through the winter under dead wood or underground it emerges between February and April and moves to ponds to mate. The male chooses a display area known as a ‘lek’ in an open part of the pond. Displaying his remarkable crest he rocks, leans, and whips and fans his white-striped tail to waft pheromones at the female. Once he has gained her interest, touching his tail with her nose, he deposits his spermatophore, which she collects in her vent before fertilisation takes place internally.

The female lays around 250 eggs in a jelly capsule with a light yellowish centre 4.5 – 6mm long on the submerged leaves of plants, carefully wrapping them with her back legs. Species favoured include grasses such as sweet or flote grasses (Glyceria spp.), small wide-leaved plants such as water mint (Mentha aquatica), and narrow-leaved plants such as water forget-me-not (Myosotis scorpioides).


The larvae hatch and develop in the pond and reach a length of 50 – 90mm before metamorphosing into juveniles known as ‘efts’ who grow up to 120mm in length and leave the pond for the first time. They have all the features of adults – black or dark brown skin with a warty appearance and orange ‘nail varnish’ on their claws, but it isn’t until the second season that the distinctive black patterning on their fiery bellies which marks each as an individual becomes fixed and, upon reaching sexual maturity that the male develops his eponymous crest and white tail-stripe. Males reach a maximum length of 170mm and females 130mm and on average they live for around 14 years.

Ponds are the only food source for newt larvae and and are an important part of the diet of adults, who feed on the tadpoles of frogs and sometimes other newts and invertebrates such as ‘water lice (Asellus spp.), water shrimps, small snails, lesser water boatmen (Corixa spp).,’ ‘fly larvae including the phantom midge (Chaoborus spp)’ and also ‘zooplankton such as water fleas (Daphnia spp)’. They also forage above ground, eating invertebrates ‘such as earthworms, insects, spiders and slugs.’

Most of the foraging activities of great crested newts take place within 250m of their breeding pond. When the juvenile newts disperse they may travel up to 1000m to colonise new ponds and attract a mate. Great crested newts fare best in a metapopulation – ‘a group of associated populations’ who ‘breed in, and live around a cluster of ponds.’ This means there is less threat if one or more ponds are lost.

Thus current conservation efforts are focusing on areas that are already well endowed with ponds in the North West. A whole new terminology, coined by Robin F. Grayson in 1994, has developed around this topic. A pondscape is a ‘landscape with six or more ponds shown on Pathfinder maps in each adjacent 1 km square of the National Grid.’ A ‘core pondscape is ‘where the mapped pond density is 15 or more ponds per 1 km square’. A pondway is ‘a linear tract of pondscape, typically 10 or more km in length’. A pond supercluster is ‘a large tract of pondscape, typically covering 100 square km.’

Pondways have been identified across Lancashire. I was delighted to find out there is a South Ribble Pondway, which is located not only in the borough of South Ribble, but covers a strip 25km long and 5km wide from the estuary of the river Douglas to Brockhall Hospital in Blackburn. Grayson links the end of the pondway with the failure of Northern Drift – sands, clays and erratics deposited by glaciers. There is also a North Ribble Pondway 9km long and 2.5km wide, a Wigan Pondway that links to the South Ribble Pondway in Croston that stretches 50km, and a Fylde Supercluster.

The creation of pondscapes for great crested newts fits well with other projects aiming to restore the water country such as the re-wetting of the drained wetlands around Martin Mere (WWT) and Leighton Moss (RSPB) and peat bogs such as Chat Moss and Winmarleigh Moss (LWT).

As winters become cooler and wetter and summers hotter and drier as a result of the climate crisis, the restoration of wetlands will be essential not only for human needs such as flood mitigation and carbon capture, but as homes for the wetland plants and creatures who are at increasing risk due to human and climatic pressures.

*The area around Martin Mere was known as ‘the Region Linuis’ ‘the Lake Region’ and John Porter refers to the Iron Age Setantii tribe of the Lancashire lowlands as ‘the Dwellers in the Water Country’.

SOURCES

Robin F. Grayson, ‘The Distribution and Conservation of the Ponds of North West England’, Lancashire Wildlife Journal, Numbers 2 & 3, (1992/3)

Robin F. Grayson, ‘Surveying and Monitoring Great Crested Newts’, English Nature, vol. 20, (1994)

Tom Langton, Catherine Beckett, and Jim Foster, Great Crested Newt Conservation Handbook, (Froglife, 2001)

‘New life to Europe’s oldest reptile and amphibians’, LIFE-Nature Project, (2006)

One thought on “Pondscapes for Great Crested Newts

  1. Ogden Fahey says:

    Wonderful stuff – there used to be hundreds of newts at a gravel pit we used to swim in as children – I just went and googled + its now a nature reserve, and still has the newts there! 🙂

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