Blue attractiveness

As temperatures have been rising last week, I started visiting the moor frog area daily. The first three visits I did not see or hear any frog or other amphibian. On Tuesday, when I was at work, I received a sign that the first blue frogs were seen. 

Pond with 55 blue moor frogs - Canon 7DMKII, tripod, remote release, 175 mm, 1/320 sec, F 8, ISO100

Near the lake are two ponds with warmer water in which the majority of the moor frogs can be found and in which the spawn will be laid. Last Wednesday afternoon, I visited the area to 'catch' the moor frogs but to my surprise it seemed that they became more shy than last year. I used my new 150-600 mm lens but with every small step I made, a lot of the blue frogs dived under and their bubbling noise disappeared. Although I visited the ponds with warm and sunny weather when the frogs were active, their timidity became frustrating. 
On Friday, I checked the ponds twice and in the early afternoon when the sun was shining a lot of moor frogs were in the both ponds and two moor frogs were a little bit cooperative.

Moor frog - Canon 7DMKII, tripod, remote release, 600 mm, 1/250 sec, F 7.1, ISO160

It costed me some time and wet clothes to approach the moor frogs slowly. 
Because of the backlight, I twice choose consciously an overexposure and used the flash to obtain their blue colour which they only have a few days to attract female frogs and ...... a lot of photographers.

Moor frog - Canon 7DMKII, tripod, remote release, 600 mm, 1/85 sec, F 7.1, ISO100