In the 1950s I clearly remember taking a slow worm into St Michael’s School, Dalston. After it had been examined by everyone, it was re-released into the churchyard . These silky- textured creatures are burrowing legless lizards which are capable of dropping their tail if threatened. In June 2012 Tullie House Records Centre held only six recorded sightings of slow worms from Dalston Parish, exclusively in the churchyard, and the next nearest recorded population was around 20 miles away. Nationally slow worms are a threatened species and so our small, extremely isolated population is very important on a local scale.
Four adults were recorded at the churchyard in June 1989, and around 2008 there were two adults each around 18” long. That is around the maximum size that they may reach and could indicate individuals 30 or more years old. In addition one was also seen rearing up in a shaft of sunlight inside the church in 2009.
In 1990 a national scheme called The Living Churchyard was supported by HRH Prince of Wales, and in 2012 he agreed to be the first president of a charity called Caring for God’s Acre. It recognizes the vital ecological role played by ancient churchyards in preserving wild flowers, insects, birds, mammals, amphibians and reptiles (like our slow worms). Churchyards like Dalston’s are unique and precious remnants of uncultivated meadowland. Following the 1990 scheme, a conservation management plan for Dalston churchyard was agreed and it has been carried out for the past 20 or more years. Among other things it took into consideration the requirements of slow worms. A metre- wide strip was left uncut alongside Church Lane in an unobtrusive place and the area between the Church and the Square was cut only once or twice a year. This year (2012) the cutting regime was disastrously changed from once or twice a year to once per week. The metre-wide strip was also strimmed hard back. A large amount of good slow worm habitat was destroyed and probably many slow worms were killed at the same time.
It was with some sadness that my second ever slow worm discovered in Dalston churchyard, in June 2012, was dead. With no long grass cover they are very prone to predation by cats, crows, magpies, etc. A few days later I found another dead adult slow worm. This had been mutilated, presumably by a strimmer, in the location where the metre-wide uncut strip had previously been located. Two more dead slow worms had also been seen near Dalston Square.
There are of course legislative issues as it is illegal to kill or injure a slow worm. The Natural Environment and Rural Communities Act 2006 makes it a duty of all local authorities, including Parish Councils, to ‘have regard to conserving biodiversity when carrying out their functions.‘ Also in law it states ‘Conserving biodiversity includes restoring and enhancing species and habitats.’
At this stage the police wildlife crime officer became involved and sent quite a hard hitting advisory letter to the Parish Council who manage the churchyard.
Situation in July 2012
Slow worms are very elusive creatures and not often seen in the open. However they like to lie under sheets of black plastic, corroded metal or roofing felt and this allows them to be located, so by placing artificial refugia for them to shelter under, their numbers and distribution can be assessed. In July 2012 it was discovered that a small population did still exist in Dalston churchyard, but confined to a very tiny area of around 20 metres x 25 metres in the south east corner near the church. Many of the individuals were juveniles of around 8 ins. in length. These are probably yearlings and have a rich golden colour with a black vertebral stripe and black sides.
Juveniles of this size may need to survive for three more years before they are mature enough to breed.
Another young slow worm around 8 inches
These young ones can move extremely fast through grassland
Adults can grow up to 20ins. long , but most of the adults in Dalston churchyard were around 12 ins with a few 15 ins in length. In July 2012 there are probably a minimum of ten adults including several breeding females. With the constant threat of being killed by a mower, the lifespan of the Dalston slow worm population is probably not very long. The mower needs to be set at a depth of 4 to 6 inches and ideally the grass should be cut after the slow worms have gone into hibernation in mid October.
A relatively large slow worm of around 15 ins. in Dalston churchyard July 2012
Habitat Slow worms are cold blooded creatures and all their body heat comes from external sources including the sun and decaying vegetation. They require sunny areas where they can bask or a compost heap into which they can burrow or simply lie on the surface and absorb the heat. Of course a compost heap in a sunny place provides the ideal habitat component. On cool days they need to warm their bodies before they can begin active foraging. Fallen leaves and debris from trees also provides a foraging site with a degree of protection from predators
Slow worms gathered on a compost heap ( photo by Sam Griffin)
Slow worms need long vegetation for shelter from predators and favour rank grassland as their preferred habitat. Such vegetation also holds populations of white netted slugs and small worms which are the slow worms favourite food items
Long grassland area Dalston Churchyard, a suitable slow worm habitat
Another habitat requirement is a hibernaculum or place where they can hibernate. This may comprise the interior space in an old wall or under large slabs or fallen tombstones . The area around the church holds many of these slabs, often with old mammal holes providing access underneath. Bobby Nichol remembers seeing large slow worms frequently basking in the sun on these slabs in the 1950s.
It may be advisable to leave some longer areas of grassland around these slabs as shelter for emerging slow worms
Mammal holes under some large sandstone slabs near church A possible refuge and hibernating area for slow worms.
Slow worms mate in April and May and at this time adult males actively seek out females. The female incubates eggs within her body , but live young are produced. From three to twenty young, each two inches long are born in August. Prior to this the females spend much time basking in the sun because they need the extra heat to allow the incubation and development of the young.
Juvenile yearling and adult slow worm
Toads and thrushes may feed on the newly born young. Dense surrounding vegetation will help to provide shelter and minimise predation. The churchyard holds a good population of toads.
Cats are probably a major predator of the churchyard slow worm population and I have had one report of a cat seen carrying a dead and headless slow worm in it’s mouth. The slow worms do have a defense mechanism when they are attacked or captured and may drop their tail which continues to twitch and distracts the predator. The tail can grow back but always to a much smaller size.
Slow worm with missing tail and showing wounds from a predator encounter
Miscellany of slow worms
- Snakes have coarse overlapping scales whereas slow worms have smooth scales which do not overlap
Slow worms have a tongue with a notch at the tip ( snakes have a forked tongue)
Three adult slow worms in Dalston churchard, a good sign for the future
And even better, six adult slow worms some of which appear to be pregnant females.(Dalston churchyard)
There was a seventh juvenile with the above group but it sped away before the photo was taken.
An adult female of 12 inches which has retained it’s juvenile colouration
Below a short video of slow worms which were warming up until rudely disturbed. There is eventually some movement on the video
UPDATE 17th JULY 2012
A count today consisted of 15 adult slow worms and two juveniles . There was a single group of nine individuals. Eight of these are shown in the following photo. If the habitat can be maintained in the future with the implementation of a strong management plan and sensible and sympathetic grass cutting techniques then this population could go on for many more decades.
Eight or maybe nine adult slow worms ?
Dave Hickson July 2012