Reptile Survey Guide - surrey-arg.org.uk
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Reptile Survey Guide This guide is intended to serve as a reference aid for NARRS surveyors participating in the National Reptile Survey. Reptiles need to warm up by basking in sunshine or bright weather, near to the safety of dense vegetation, or by lying beneath objects that conduct heat. They may need to spend several hours warming up every day, and this is the best time to survey them. Reptile survey should combine two techniques: • visual search, • artificial refugia. All species of reptile can be found using visual search, but artificial refugia can increase your chances of detection, particularly for certain species. Slow-worms (and smooth snakes) are rarely seen basking in the open, and artificial refugia greatly increase your chances of finding them. Adders and grass snakes are also attracted to artificial refugia, although with a little skill they can often be found without the need for refugia. Common lizards (and sand lizards) will use artificial refugia, but you should not rely solely on refugia to detect them; otherwise you are likely to miss many basking lizards. Avoid the tendency to walk quickly from one refuge to another without searching visually along the way. Survey should take place in suitable weather conditions, at the right times of day, and the right time of year. Knowing what this means comes with practice, but some good pointers should get you started and produce results. The optimum time of day varies with the time of year and the weather. Time of day - The middle hours of the day (c.11am-3pm) are best during the early spring, but as the spring progresses, reptiles come out to bask earlier in the day (and often re-appear later in the day). By the summer, the best times to survey are reduced to windows of an hour or two in the morning (c.8-10am) and evening (c.5-7pm). Hot weather during the day can produce completely negative results. However, if the weather is overcast, or the sun has come out after cloud or rain, reptiles may come out at any time of day, even in the summer. Time of year - Overall, the best time to survey reptiles is the spring (centred on April), as reptiles are very active and visible at this time of year. Males need to bask to get into breeding condition, and given the cool weather, all reptiles need to bask for longer at this time of year. As the spring progresses into the summer, survey is still possible but only during short periods of the day. Then as the weather becomes cooler in the autumn, survey conditions become better again. Weather - Apart from the cold winter period when reptiles are hibernating, there is no clear-cut way of defining the right or wrong weather for reptile survey. Strong wind and heavy rain are not good, but any other conditions can be productive, depending on the time of year. In the early spring or late autumn, the weather must be sunny or only partially cloudy. Air temperature need only be between 10-20°C, and in fact these are the best temperatures to survey. Later in the spring, cloudy and bright overcast weather can often be good, as this forces reptiles to stay out basking longer than they would in sunny weather. A particularly good time to survey is sunshine after rain, or the first sunshine after several dull overcast days. Photos by Lee Brady and Chris Gleed-Owen. Compiled by The Herpetological Conservation Trust, with financial support from Natural England. © The HCT 2007
Transcript of Reptile Survey Guide - surrey-arg.org.uk
Reptile Survey Guide This guide is intended to serve as a reference aid for NARRS surveyors participating in the National Reptile Survey.
Reptiles need to warm up by basking in sunshine or bright weather, near to the safety of dense vegetation, or by lying beneath objects that conduct heat. They may need to spend several hours warming up every day, and this is the best time to survey them.
Reptile survey should combine two techniques: • visual search, • artificial refugia.
All species of reptile can be found using visual search, but artificial refugia can increase your chances of detection, particularly for certain species. Slow-worms (and smooth snakes) are rarely seen basking in the open, and artificial refugia greatly increase your chances of finding them. Adders and grass snakes are also attracted to artificial refugia, although with a little skill they can often be found without the need for refugia. Common lizards (and sand lizards) will use artificial refugia, but you should not rely solely on refugia to detect them; otherwise you are likely to miss many basking lizards. Avoid the tendency to walk quickly from one refuge to another without searching visually along the way.
Survey should take place in suitable weather conditions, at the right times of day, and the right time of year. Knowing what this means comes with practice, but some good pointers should get you started and produce results. The optimum time of day varies with the time of year and the weather.
Time of day - The middle hours of the day (c.11am-3pm) are best during the early spring, but as the spring progresses, reptiles come out to bask earlier in the day (and often re-appear later in the day). By the summer, the best times to survey are reduced to windows of an hour or two in the morning (c.8-10am) and evening (c.5-7pm). Hot weather during the day can produce completely negative results. However, if the weather is overcast, or the sun has come out after cloud or rain, reptiles may come out at any time of day, even in the summer.
Time of year - Overall, the best time to survey reptiles is the spring (centred on April), as reptiles are very active and visible at this time of year. Males need to bask to get into breeding condition, and given the cool weather, all reptiles need to bask for longer at this time of year. As the spring progresses into the summer, survey is still possible but only during short periods of the day. Then as the weather becomes cooler in the autumn, survey conditions become better again. Weather - Apart from the cold winter period when reptiles are hibernating, there is no clear-cut way of defining the right or wrong weather for reptile survey. Strong wind and heavy rain are not good, but any other conditions can be productive, depending on the time of year. In the early spring or late autumn, the weather must be sunny or only partially cloudy. Air temperature need only be between 10-20°C, and in fact these are the best temperatures to survey. Later in the spring, cloudy and bright overcast weather can often be good, as this forces reptiles to stay out basking longer than they would in sunny weather. A particularly good time to survey is sunshine after rain, or the first sunshine after several dull overcast days.
Photos by Lee Brady and Chris Gleed-Owen. Compiled by The Herpetological Conservation Trust, with financial support from Natural England. © The HCT 2007
Visual search - some tips on where to look and how to spot reptiles Walk slowly along with your eyes on the sunny side of vegetation, keeping the sun behind you or to your side. Tune your eye in to look at edges between vegetation types, and changes in vegetation height. These are often the places where reptiles bask. Remember: reptiles only expose themselves as much as they have to; they are seldom more than a body-length away from dense cover.
Walk slowly, scanning the ground Look for sheltered spots that act as suntraps
Junction between bramble/scrub and grass Varied height structure - look in shorter patches
Gorse edge meets rough grass Mossy patches in between heather stands
Artificial refugia Press down close to the ground, in good vegetation cover or at the edge of dense vegetation. Choose sunny locations away from public view.
Sheets of corrugated metal or ‘tins’ Old rusty tins often better
Corrugated bitumen-based roofing material Roofing felt
Shed felt (weighted with stone/brick) Roofing slate Also: rubber car mats, plastic sheeting, carpet – particularly for slow-worms. Only lay refugia when you have permission to do so, there are no livestock present, and you are sure no one will find them. Lift and replace refugia carefully, taking care not to squash retreating animals, and using a stick or adder-proof glove if necessary to ensure safety.
Pre-existing objects acting as refugia It is worth checking under any old discarded objects that may already be on site and that could be used by reptiles. Look out for reptiles basking on top of objects too.
Rusty old bits of ‘tin’ Old wooden boards
Scraps of wood Old tyres, wheels, scrap etc
Discarded clothing, plastic, rubber etc Fallen road signs (if in deep grass)
