Habitat use by grass snakes and three sympatric lizard species on lowland heath managed using 'conservation grazing'

• Published in: The Herpetological journal Vol. 26; no. 2; pp. 131 - 138
• Main Authors: Reading, Christopher J, Jofre, Gabriela M
• Format: Journal Article
• Language: English
• Published: 01.04.2016
• Subjects: Anguis fragilis; Lacerta agilis; Lacertilia; Molinia caerulea; Natrix natrix; Zootoca vivipara
• ISSN: 0268-0130

Cattle grazing is being used increasingly by landowners and statutory conservation bodies to manage heathlands in parts of mainland Europe and in the UK, where it is called 'conservation grazing'. Between 2010 and 2013, cattle were excluded from six hectares of lowland heath, in southern England, that had been subject to annual summer cattle grazing between May 1997 and autumn 2009. Changes in grass snake Natrix natrix, common lizard Zootoca vivipara, slow worm Anguis fragilis and sand lizard Lacerta agilis numbers were recorded annually in the ungrazed area and in a four hectare area of heathland adjacent to it that continued to be grazed. The number of grass snake, common lizard and slow worm sightings were significantly higher in the ungrazed heath than the grazed heath and were associated with increased habitat structure, resulting principally from increased height and cover of grasses, particularly Molinia caerulea. Conversely, there was no significant difference in the number of adult sand lizard sightings between the grazed and ungrazed heath though sighting frequency was inversely correlated with both grass and grass litter cover. Our results suggest that the use of cattle grazing as a management tool on lowland heath is detrimental to grass snake, slow worm and common lizard populations but may be less so to adult sand lizards. Although newborn slow worms and common lizards were observed throughout the study area, significantly fewer were found in the grazed areas than the ungrazed areas. The absence of newborn grass snakes and sand lizards in the grazed areas suggests that successful breeding had not occurred in these areas.