Posted: 14/03/2012 at 16:09
Hi JenBee, do the frogs normally spawn in your pond? If so, it could be that the one frog is just waiting for the others to arrive. Spawning occurs much later in the east of the UK than in the west, and it has been quite cold lately. We are supposed to have some rain this weekend, so it could be just what your frogs need to finally come to your pond to spawn.
As regards the slowly diminishing number, there could be a number of reasons. It could be that the frogs are choosing other ponds in preference to yours, or that it isn't as easy to accss your garden as it once was. Disease is also a possibility, or even predation by local cats. Adults normally only spend the mating season near ponds, so are often found a fair distance away from water. Also the last couple of years have been very dry in Suffolk, so that could have affected frog numbers.
Take a look at Nature's Calendar for frogspawn sightings in your area: http://www.naturescalendar.org.uk/wildlife/factfiles/amphibians/frogspawn.htm
And do let us know if more frogs join in for spawning this year. I'm still waiting for mine to spawn!