Friday the thirteenth proved lucky for a seemingly elderly osprey who laid her 46th last week, to the delight of Scottish Wildlife Trust rangers.
An SWT webcam will record the progress of the new egg
Staff at the Loch of Lowes reserve, in Perthshire, said they hope the egg is only the first of two or three to be laid over the next few days.
Despite initial thoughts that the egg belonged to a new female, the mum-to-be has been at the site since 1991.
Bird lovers will be able to watch the progress of the egg via an SWT webcam.
The arrival of the osprey egg on Friday, 13 April was all the more surprising for volunteers at the reserve because staff had thought the 19-year-old female osprey had come to the end of her natural lifespan.
Ranger Andrea Williams said: "A new red-ringed female did come in with our male and he mated with her but several days later an unringed female arrived and took over the nest.
"After a few days of close observation, it became clear, particularly from her confident behaviour and markings on her shoulder, that she was our original female bird."
To date the female osprey at the reserve has produced an impressive 46 eggs - making a significant contribution to osprey conservation.
Ospreys are afforded the highest degree of legal protection under the Wildlife and Countryside Act 1981.
It is an offence to intentionally take, injure or kill an osprey or to take, damage or destroy its nest, eggs or young.
It is also an offence to intentionally or recklessly disturb the birds close to their nest during the breeding season.
Breaking the law can lead to fines up to £5,000 per offence and/or a prison sentence of up to six months.