The oldest breeding female osprey ever recorded in the UK laid a record-breaking 68th egg on Saturday.
The egg is the fourth to be laid by the veteran bird this season which saw Lady return to Loch of the Lowes, near Dunkeld, for the 23rd year.
Staff at the centre said it was “unusual” but not unprecedented for an osprey to lay four eggs, a feat even more impressive given Lady’s age.
Val Gall, wildlife interpretation officer at the Loch of the Lowes visitor centre, said they were delighted by the arrival of a fourth egg, which has sparked interest from around the globe.
She said: “She’s laid a fourth egg, which is absolutely amazing news.
“Obviously with her age it’s even more tremendous news.
“What we’ve been doing is when we get a change over from the male to the female incubating the eggs we’ve been checking to see if they are OK, because the male has a habit of plonking a stick on top of them.
“So we’ve been checking the eggs to make sure that they are intact and OK. We though there could be (a new egg) due to watching her behaviour overnight.
“This morning at 11 there was a changeover and sure enough there were four eggs. There are great celebrations here, as you can imagine.
“Staff are elated and so many visitors have heard the news via Twitter, people are sending messages by Facebook and staff have been inundated with phone calls.”
Staff at the centre will continue to keep an eye on the nest until the chicks hatch.
Val said: “Our male is clearly providing an abundance of fish for the female so we are looking forward to the last week in May when the first egg will be due to hatch.
“Staff and volunteers will continue to monitor the nest 24/7 to ensure security and record observations.”
She added that a fourth egg was a “rare” event as most ospreys usually lay three eggs.
She said: “Females will have two eggs in their first breeding year and three in subsequent years. It’s not unheard of to have four but it is quite rare.”