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The Grass Snake Research Project
This project is run by the Conservation Ecology Research Team at Swansea University, in conjunction with WGARG
Why study this species?
Natrix natrix is an extremely under studied species, particularly the helvatica subspecies that is found in the UK. Even with this lack of research, individuals that come into contact with grass snakes on a regular basis have noted a marked decline over the past few decades (Corbett 1989, Beebee & Griffiths 2000, Vaughan 2007).
There are many proposed factors that may contribute to this decline, they include:-
- Habitat destruction & fragmentation
- Increased disturbance
- And decline in prey
The Wildlife and Countryside Act 1981 states that it is illegal to intentionally kill or injure this species in the UK, but there is no protection for grass snake habitats. N. natrix helvatica is Britain’s most mobile species; this is due to their varying habitat requirements depending on the time of year. In broad terms, grass snakes need scrub land with access to amphibian and fish prey, but it must be understood that this species also has other prime ecological needs. The various requirements of grass snakes are seldom found in a single specific area. Traditional feeding grounds are wet/damp areas due to the nature of the chief prey items. Furthermore, hibernating, basking and egg laying sites are only found in drier areas. Such varied habitat requirements force the animals to migrate distances that may exceed several kilometres depending on the time of the year. Expansion of road networks and land developments invariably result in habitat loss and fragmentation (Societas Europaea Herpetologica 2005). The destruction of traditional hibernation & egg laying sites is always a devastating blow to a colony and can rapidly contribute towards the extinction of grass snakes in the area.
Grass snakes are notoriously elusive and secretive animals, even a slight breeze and the resulting swaying vegetation has been known to cause a basking animal to seek refuge. In addition to the more obvious factors of habitat destruction and fragmentation, increased human activity and encroachment due to increased access schemes and outdoor leisure pursuits for example, has proven to have significant effect upon the individuals in a particular area. Often leading to the animals migrating away from pristine habitat in order to avoid repeated disturbance (Vaughan 2007).
In recent decades a decline in prey, particularly amphibians, has also been noted, which obviously has an impact on grass snake numbers. The reasons behind the decline of prey species are also directly associated with habitat destruction and fragmentation, as well as water pollution.
All these factors clearly show that the habitats of grass snakes and their prey need to be conserved in order to maintain this species. British grass snakes need their status revised, they are currently classed as ‘least concern’ by the IUCN, a more fitting title is needed that shows this species could well be on the road to extinction. This can not happen until research takes place that shows conclusive evidence that populations are declining. Not only do populations and their variables need to be measured, but their little known behaviours need to be investigated to better understand the exact needs of Britain’s largest snake.
Objectives
Population – the numbers and make up of the population over a number of years will be studied to determine if there is any decline.
Behaviour – the more we know about the behaviours of this under studied species, the more we can access their needs. By using radio-tracking and loggers we hope to discover more information about their movements, activity pattern and diving behaviour.
Faecal collection – samples that are collected are sent off to Cardiff University to be analysed. A method of molecular identification is used to determine the prey in predator diets, which is revolutionary in this field (Symondson 2002).
Study Area
We have many study sites all over West Glamorgan, varying in habitat type and quality
Applications
Reseach on this species will assist how and when we study N.natrix, by discovering more about their behaviour. Hopefully all this research combined with other studies across the UK will assist in raising awareness and protection of this enthralling species.
References
Beebee, T. J. C. & Griffiths, R. A., 2000. Amphibians and reptiles—A natural history of the British herpetofauna. London: HarperCollins.
-Corbett, K., 1989. Conservation of European Reptiles and Amphibians. London: Christopher Helm.
-Vaughan, R., 2007. The British Grass Snake: A study of Natrix natrix helvatica. LULU.COM.
-Societas Europaea Herpetologica., 2005. Natrix natrix. Post-workshop draft Species Account for review Vol.2. Global Reptile Assessment Regional Workshop – non-Mediterranean Reptiles of the western Palaearctic.
Symondson, W. O. C., 2002. Molecular identification of prey in predator diets. Molecular Biology, 11, 627-641.
