Solitary osprey at nest, Threave, Castle Douglas 12 April

Visited the Threave, Castle Douglas osprey nest 12 April 2012. Four local RSPB members were there and some discussion about female osprey took place. I said my son had seen a pair of ospreys on the nest on 5 April. Today, again, only one (male?) osprey was at the nest.

Here is one of the photos he took of the pair on the nest. I assume they were a male and female.

Pair of ospreys Threave, Castle Douglas 5 April 2012