Back in April while carrying out a survey, temporarily place a couple of male smooth newts in an aquarium and fired of a few shots
In spring male smooth newt grow a large crest along their back and the colour become more vivid, also they can attract a female to breed.
The webbing on their feet also becomes more noticeable.
As well as smooth newts I also pulled out this fine male Great Crested Newt and got a couple of shots (under schedule 5 license), before returning it to the pond along with the smooth newts.