As we enter the month of June - the beginning of summer in climatic terms - we can look back on a spring that has been the warmest and driest for many years. Reptiles in the UK have undoubtedly benefited from this warm weather, which has set them a few steps ahead in the annual cycles, in terms of breeding, lifestage, and phenology.
Most people are surprised to learn that reptiles are active from February/March onwards in the UK, and are most readily found basking in cool or cold weather. As the weather gets warmer and sunnier later in the spring and summer, reptiles do not need to bask out in the open so much. So the springtime really is the key window for carrying out surveys most effectively. It is not the only time surveys can be carried out, but it is the best time.
The spring of 2011 has been one of the best in living memory for reptiles. March had many sunny days, and April was an almost-solid month of sunshine, with days as warm as summer, and temperatures reaching the mid-twenties centigrade. This meant that sand lizards and other reptiles got into breeding condition earlier than normal, and females became pregnant earlier than usual.
With warm, sunny weather continuing into May, many sand lizards laid their eggs some two weeks earlier than normal (mid to late May rather than late May, early June). Some female slow-worms are already looking rather bulky, and many common lizard females are looking heavily pregnant too. Presumably adders have had a good early-starting breeding season too.
The good weather will have benefited the young of all species, allowing them a growth spurt. The effect will be to make them slightly larger than their cohort would normally be at this time.
Thankfully it hasn't been wall-to-wall sunshine. A few days of rain here and there are essential. Reptile ecologists always notice a flurry of reptile activity in the first sunny weather after rain or a period of bad weather. Reptiles come out en-masse to bask, but also to feed on the flurry of basking insects and other invertebrates.
