Just when we were enjoying a routine and peaceful incubation, drama on our Osprey nest at Loch of the Lowes.
As we all know, all birds eggs need warmth and a regular humidity to incubate successfully, not to mention protection from opportunistic predators. All birds are dedicated parents, and the bird on duty rarely leaves their eggs for long, except in emergencies or dire need themselves. Our female osprey never leaves the eggs for more than a couple of minutes, on her short ‘toilet’ flights or at a changeover with the male, and vigilantly turns them and protects them.
However today our male osprey left the eggs unattended for over half an hour from just before 2pm till about 2:30pm. There was no sign of an intruder to chase so what he was doing is anyone’s guess – rather out of character for him though. Luckily the female returned just in time to protect the eggs from a rather vicious hale storm which was sweeping in. Needless to say we were all beside ourselves with worry until she returned, knowing there was nothing we could do without putting the birds or the eggs at further risk.
This is not the first time this has happened- previous males at this nest have also been ‘distracted’ during incubation and left eggs unattended. In 2010 the then male Green 7Y left them for 35 minutes , but no harm was done and they hatched normally. However, in 2011, the fact that all three eggs didn’t hatch despite being fertilised, was put down to the fact that Green 7Y went AWOL for about 40+ minutes on the cold evening of the 26th April.
How long can the eggs stay uncovered safely for depends on two things: firstly the weather- if it is cold and wet even a short time might be risky, if it is warm and dry like today, longer is ok. Secondly predators: if a parent bird is close by and able to defend the eggs they will be ok. At one nest I monitored in a previous ranger post in the Scottish Borders, one pair of Ospreys left eggs for 50 astonishing and nerve-wracking minutes, on a warm spring day, and they went on to hatch normally.
We will all simply have to wait to see if these eggs have been compromised by today’s events, but I have a feeling they will be ok- fingers crossed.
Staying on the theme of eggs, today the staff were treated to the sight of a Weasel trying to get our mother Mallard’s eggs for its own food. She is nesting beneath one the visitor centre windows in full view of the new children’s hide, and sensibly stayed stubbornly on her nest defending her eggs, so the weasel eventually gave up.
Lastly, our male osprey tried to make up for his transgression today by fishing in full view of the hides on the loch- a truly spectacular sight!