Newly published data from the UK, France, Italy and Nigeria provides evidence that a number of snake species populations declined synchronously over a four-year period. The research, published in the journal Biology Letters, was led by Dr Chris Reading from the Centre for Ecology & Hydrology in collaboration with colleagues from Italy, France, Nigeria and Australia.
Long-term studies have previously revealed population declines in fish, amphibians, reptiles, birds and mammals. Many of these declines are a global phenomenon whose causes may vary but are often unclear. Among reptiles, snakes are top predators and therefore a decline in their numbers may have serious consequences for the functioning of many ecosystems.
The new research examined long term datasets from 17 snake populations from the UK, France, Italy, Nigeria and Australia. The data was collected between 1987 and 2009. Record lengths for individual species ranged from 13 to 22 years. All data sets covered the period 1997 to 2008.
The smooth snake, which is found in the UK, is among those showing decline.
"Although we do not know the cause of these observed declines we wish to alert snake ecologists to what appears to be happening and to stimulate further research."
Dr Chris Reading, Centre for Ecology & Hydrology
Dr Reading said, “This is the first documented evidence from anywhere in the world that snake populations may be declining. Of 17 snake populations (11 species), 11 (8 species) from tropical (Nigeria), Mediterranean (Italy) and temperate (France and the UK) climates declined synchronously and over a period of about four years between 1998 and 2002."
He added, "Although we do not know the cause of these observed declines we wish to alert snake ecologists to what appears to be happening and to stimulate further research.”
Dr Reading appeared on BBC television’s Springwatch series on 1 June 2010 talking about smooth snakes, one of the species discussed in the new paper in Biology Letters. The smooth snake, Coronella austriaca, is Britain’s rarest snake, and one of only three snake species present in the UK. It is restricted to the lowland heaths of southern England.
Springwatch on iPlayer– from 37:00 minutes (available till Thursday 24th June 2010)
Snakes declining at alarming rate, say scientists - The Guardian - 9 June 2010
Snakes in mysterious global decline - BBC Online - 9 June 2010
Snake populations plummet - New Scientist - 9 June 2010