Table 2. Number of surveys required to determine species presence at occupied sites.

80% confidence level
Species	2009, 29 sites	2010, 29 sites	2010, 45 sites
Slow-worm	1 (0.4–0.9)	1 (0.6–1.3)	1 (0.6–1.3)
Common lizard	1 (1.2–1.8)	2 (1.4–2.3)	2 (1.3–2.0)
Sand lizard	3 (1.6–6.9)	6 (2.8–27.0)	3 (1.7–5.9)
Adder	2 (1.6–2.6)	2 (1.5–2.6)	2 (1.5–2.5)
Grass snake	2 (1.6–3.0)	2 (1.4–2.4)	3 (2.2–3.8)
Smooth snake	1 (0.5–1.6)	2 (1.1–2.3)	1 (1.1–2.3)
90% confidence level
Species	2009, 29 sites	2010, 29 sites	2010, 45 sites
Slow-worm	1 (0.6–1.3)	1 (0.8–1.9)	1 (0.9–1.8)
Common lizard	2 (1.6–2.6)	3 (2.0–3.3)	2 (1.9–2.8)
Sand lizard	4 (2.3–9.9)	8 (3.9–38.6)	5 (2.5–8.5)
Adder	3 (2.3–3.7)	3 (2.2–3.7)	3 (2.1–3.6)
Grass snake	3 (2.2–4.3)	3 (2.0–3.4)	5 (3.2–5.4)
Smooth snake	1 (0.7–2.3)	2 (1.5–3.3)	2 (1.7–2.9)
95% confidence level
Species	2009, 29 sites	2010, 29 sites	2010, 45 sites
Slow-worm	1 (0.7–1.6)	2 (1.1–2.5)	2 (1.2–2.4)
Common lizard	3 (2.1–3.4)	3 (2.5–3.7)	3 (2.5–3.7)
Sand lizard	6 (3.0–12.8)	10 (5.1–50.2)	6 (3.3–11.0)
Adder	4 (2.9–4.8)	4 (2.8–4.8)	4 (2.7–4.6)
Grass snake	4 (2.9–5.6)	3 (2.6–4.4)	5 (4.2–7.0)
Smooth snake	2 (1.–3.1)	3 (2.0–4.3)	3 (2.0–4.2)

Data provided at three levels of certainty, with 95% confidence intervals in parentheses.