Although thought to be fairly widespread and common in places, the Viviparous (or Common) Lizard is rarely recorded in Avon.
Again, although thought to be widely distributed it is considered to be declining nationally. They can be very elusive as well as being small, browny creatures!
With relatively so few records how can we determine its status in our region? One way is to compare recent recording with anecdotal and actual records of times past. For example, I can recall seeing lizards reasonably regularly when I was much younger, but rarely see them today.
Other evidence can be the lack of records. This may not always determine that a species is declining but can suggest that it does not currently occur in high numbers in the region.
In addition, we can look at those places which lizards are known to prefer, such as undisturbed grassland, upland moors and heaths. We know that upland moors do not occur in Avon, that heathland is a rare commodity, that has become much fragmented, and that unimproved grassland has undergone dramatic reduction over recent years.
The loss of habitat is usually accompanied by the loss of invertebrates that lizards prey on for food. Lizards can survive on derelict land, railway embankments, churchyards and archaeological sites, but even these relatively undisturbed areas have, in many cases, undergone increased management with the use of insecticides, herbicides and site clearances.
Lizards need to hibernate and may do so within old hedgebanks and old drystone walls, which provide the kind of refuge they require. Over the last few decades many old hedges and old walls have either been removed or are now managed fairly intensively, effectively removing these as suitable hibernation sites.
In summary therefore, a lack of records, anecdotal records of times past, a known reduction of suitable habitats and reduction of available food sources indicate strongly that the Viviparous Lizard is indeed likely to be declining in our region, and probably occurs less widely than before.
However, if we all look out for this wild animal and contribute records of it then we can be more accurate as to their status and rate of decline/increase. At the same time more records adds more information for research into the ecology and requirements of this elusive reptile. What we don’t want to do is merely record the decline and possible eventual extinction of lizards in Avon.
Spring is a good time to look out for them; the vegetation is much lower and less dense compared to high summer, making it easier to spot the lizards. They will emerge to bask on rocks, stone paths, lower tree trunks, walls and sidings in order to build up heat and energy reserves, before going off to hunt for food. Until they have built up these reserves they are not capable of moving quickly enough to catch prey, which means that if you do find lizards basking you should not disturb them, as they might not get another opportunity. With the early morning and late afternoon temperatures being colder than later in the year the lizards will often need to bask for longer periods. It is best to keep an eye out in the morning sunshine or when the sun is shining again following a shower or cloudy part of the day. Once they have built up enough energy to move quickly they will be off hunting in the vegetation. If you do happen to come across a basking lizard then note the place, as they will often use the same places quite regularly.
Although lizards prefer the habitats mentioned above they do occur occasionally in a wide variety of places including gardens and wetlands.